GASTROENTERITIS

GASTROENTERITIS

Diagnosis, Diagnostics, Immunodiagnosis & Immunodiagnostics:

ABSTRACTS

January 2003

6049. Ahmed A. Use of angiotensin-converting enzyme inhibitors in patients with heart failure and renal insufficiency: how concerned should we be by the rise in serum creatinine? J Am Geriatr Soc 2002 Jul;50(7):1297-300

PURPOSE: To determine the association between the early rise in serum creatinine levels associated with the use of angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) and the long-term renoprotective properties of these drugs in patients with chronic renal insufficiency. BACKGROUND: Large-scale clinical trials have demonstrated survival benefits of ACE inhibitors in patients with heart failure. In patients with renal insufficiency, whether associated with diabetes mellitus or not, use of ACE inhibitors is associated with slowing in the progression of renal disease. In fact, patients who have the most advanced renal insufficiency at baseline are the ones who show the maximum slowing of the disease progression, but these patients are also more likely to show an early rise in serum creatinine levels after ACE inhibitor therapy. There is evidence that patients with renal insufficiency often do not receive ACE inhibitors. There is also evidence that patients with heart failure are not receiving this life-saving drug or are receiving it at dosages lower than that used in the clinical trials. One of the main reasons for this underutilization of ACE inhibitors in patients with heart failure is the underlying renal insufficiency or the rise in serum creatinine level after initiation of therapy with an ACE inhibitor. METHODS: The authors reviewed 12 randomized clinical trials of ACE inhibitor or ARB therapy in patients with preexisting chronic renal insufficiency, with or without diabetes mellitus or heart failure. Studies were included for review if they met the following criteria: subjects were randomized to receive ACE inhibitor; subjects were followed up for a minimum of 2 years; and most of the subjects had baseline chronic renal insufficiency (>or=25% loss of renal function), irrespective of cause. Of the 12 studies that met these criteria, six were multicenter double-blind placebo-controlled studies. The other six were smaller randomized studies. The studies had a mean +/- standard deviation follow-up of 3.2 +/- 0.3 years. One thousand one hundred two patients were randomized to receive ACE inhibitors or ARBs. Of these, 705 (64%) had data on renal function at baseline (within 6 months of the start) and at the end of the study. The authors examined the changes in serum creatinine levels or glomerular filtration rates (GFR) in patients who were randomized to receive ACE inhibitors. The authors also assessed the blood pressures achieved in the trials. RESULTS: Patients with preexisting chronic renal insufficiency who achieved their blood pressure control goals were likely to demonstrate an early rise in serum creatinine levels, approximately 25% above the baseline (approximately 1.7 mg/dL) after initiation of ACE inhibitor or ARB therapy. This rise in serum creatinine was more acute (by approximately 15% from the baseline) during the first 2 weeks of therapy and was more gradual (additional approximately 10%) during the third and fourth weeks of therapy (Figure 1). The serum creatinine level was likely to stabilize after about 4 weeks, provided patients had a normal salt and fluid intake. In addition, patients who did not show a rise in serum creatinine level during the first 2 to 4 weeks of therapy, were less likely to experience one after that period, unless they were dehydrated from use of diuretics or gastroenteritis or had used a nonsteroidal antiinflammatory drug (NSAID). In spite of this early rise in serum creatinine in patients with chronic renal insufficiency (a serum creatinine level of >or=124 micromol/L or >or=1.4 mg/dL) who were randomized to receive an ACE inhibitor, these patients receiving the drug showed a 55% to 75% lower risk of worsening renal function than those with normal renal function receiving the drug. The rate of risk reduction was inversely related to the severity of renal impairment at baseline, but data were limited on the benefit of ACE inhibitors in patients with more advanced renal insufficiency (GFR <30 mL/min). The authors noted that those aged 65 and older were likely to have much lower GFRs for given levels of serum creatinine than younger patients and were therefore likely to have advanced renal insufficiency at serum creatinine levels as low as 2 mg/dL (vs 4 mg/dL for younger patients). Patients with normal renal function were likely to show a much smaller rise in serum creatinine level (approximately 10% above the baseline of 0.9 mg/dL), mostly occurring during the first week after initiation of therapy, with subsequent stabilization, whereas patients with normal renal function suffering from heart failure, volume depletion, or bilateral renal artery stenosis experienced a significant rise (approximately 225% above baseline) in serum creatinine level, much higher in magnitude and rate than that experienced by those with renal insufficiency (Figure 1). Serum creatinine levels in these patients sharply increased (by approximately 75% above baseline) in the 2 weeks after the initiation of therapy with an ACE inhibitor, followed by an even sharper increase (another approximately 150%) during the subsequent 2 weeks. Patients with chronic renal insufficiency (serum creatinine>1.5 mg/dL) who received therapy with ACE inhibitors had about a five times higher risk of developing hyperkalemia than those with normal renal function, whereas presence of heart failure increased the risk of hyperkalemia by about three times over those without heart failure. Concomitant use of diuretics was associated with an approximately 60% reduction in risk of hyperkalemia. CONCLUSION: The authors conclude that, in patients with renal insufficiency (serum creatinine>1.4 mg/dL) treated with ACE inhibitors, there is a strong association between early (within the first 2 months) and moderate (not exceeding 30% over baseline) rise in serum creatinine and slowing of the renal disease progression in the long run. The authors recommend that ACE inhibitor therapy should not be discontinued unless serum creatinine level rise above 30% over baseline during the first 2 months after initiation of therapy or hyperkalemia (serum potassium level >or=5.6 mmol/L) develops.

6050. Crum NF. Update on Listeria monocytogenes infection. Curr Gastroenterol Rep 2002 Aug;4(4):287-96

Listeria monocytogenes is a gram-positive bacillus that causes meningitis, encephalitis, bacteremia, and febrile gastroenteritis. Most disease occurs in immunosuppressed individuals. Recent seroepidemiologic studies show that the infection is foodborne. Due to the increasing number of immunosuppressed individuals at risk for listeriosis, as well as the persistence of substantial foodborne outbreaks, L. monocytogenes has gained worldwide attention as an important pathogen. Heightened surveillance and quality control by the food industry have been instituted, leading to a reduction in the number of cases and deaths from this infection in the past decade. However, due to the ubiquity of the organism in the environment, outbreaks and sporadic disease continue to occur. The standard therapy for listeriosis is a combination of ampicillin and gentamicin or, for patients who are intolerant of b-lactam agents, trimethoprim-sulfamethazole. Despite the availability of therapy, the mortality rate remains high in those with T-cell immunodeficiencies.

6051. Girish R, Broor S, Dar L, Ghosh D. Foodborne outbreak caused by a Norwalk-like virus in India. J Med Virol 2002 Aug;67(4):603-7

An outbreak of acute gastroenteritis occurred in the nurses' hostel of a civil hospital in Delhi, after a farewell party involving 130 nurses and some of the housekeeping staff. All affected persons had eaten salad sandwiches at the party. Stool samples were collected from six of these patients on the second day of infection. All six samples, when tested for the presence of common bacteria, parasites, and rotavirus, were found to be negative. The clinical features of this outbreak matched the criteria set for outbreaks caused by Norwalk-like viruses (NLVs). Reverse transcription-polymerase chain reaction (RT-PCR) was carried out on these six samples, using primers from the RNA-dependent RNA polymerase (RdRp) gene of NLVs. Immunoelectron microscopy was carried out on two of the samples, using convalescent phase serum. All six samples were positive for genogroup (GG) II NLVs by RT-nested PCR. Aggregates of 32-nm viral particles were visualized by immunoelectron microscopy in one of the two samples. Sequencing of the RdRp gene was done on amplicons from three samples; phylogenetic analysis placed the isolates NDV/1999 in a Toronto virus cluster of GG II NLVs. This is the first report of a food-borne outbreak attributable to NLVs from India. Copyright 2002 Wiley-Liss, Inc.

6052. Mori I, Matsumoto K, Sugimoto K, Kimura M, Daimon N, Yokochi T, Kimura Y. Prolonged shedding of rotavirus in a geriatric inpatient. J Med Virol 2002 Aug;67(4):613-5

This study concerns a nosocomial rotaviral infection of a geriatric patient with clinical symptoms of acute gastroenteritis. The virological diagnosis was based on the detection of rotaviral antigens using a Rota kit, viral genome RNA by reverse transcription-polymerase chain reaction method, and viral particles by electron microscopy in the stool samples. Prolonged rotaviral shedding was suggested to be due to impaired natural killer cell activity, possibly together with deficiency of specific local immune response of the patient. Copyright 2002 Wiley-Liss, Inc.

6053. Mori M, Kuwabara S, Yoshiyama M, Kanesaka T, Ogata T, Hattori T. Successful immune treatment for non-paraneoplastic limbic encephalitis. J Neurol Sci 2002 Sep 15;201(1-2):85-88

A 21-year-old woman subacutely developed memory loss subsequent to gastroenteritis. Brain MRI with gadolinium enhancement showed symmetric involvement of the amygdala. The CSF was acellular with increased protein level. There was no evidence suggestive of neoplasm or viral infection. Combined treatment with plasmapheresis and immunoglobulin improved her clinical symptoms and lessened abnormalities manifested in the MRI. This case suggests the presence of immune-mediated limbic encephalitis without association with neoplasms or infections.

6054. Steele AD, Nimzing L, Peenze I, De Beer MC, Geyer A, Angyo I, Gomwalk NE. Circulation of the novel G9 and G8 rotavirus strains in Nigeria in 1998/1999. J Med Virol 2002 Aug;67(4):608-12

An epidemiological survey investigating the prevalence of rotavirus infection in infants and young children with acute diarrhoea was undertaken in Jos State, Nigeria, between January 1998 and April 1999. In total, 672 faecal specimens were collected from children aged between 1 and 60 months with acute infantile gastroenteritis. The 10-20% stool suspensions were examined by an ELISA for the presence of group A rotavirus antigen (Rotavirus IDEIA, Dako, UK). Only 116 specimens (17.3%) were positive for the group A rotavirus antigen detected by this ELISA. The rotavirus-positive specimens were analysed with monoclonal antibodies specific for rotavirus VP6 subgroup I and II, and for VP7 serotypes G1-G4, G8, and G9. Of the rotavirus strains that could be subgrouped, VP6 subgroup I and II strains circulated at similar levels. Amongst the strains that could be serotyped, VP7 G9 strains predominated occurring in 17 cases, with G3 (n = 10) and G1 (n = 9) strains occurring in lower numbers. Four G8 strains were detected and only one G2 and no G4 strains were identified. This report extends the description of the global distribution of G9 rotavirus strains. Copyright 2002 Wiley-Liss, Inc.

Pathogenesis:

6055. Bresee JS, Widdowson MA, Monroe SS, Glass RI. Foodborne viral gastroenteritis: challenges and opportunities. Clin Infect Dis. 2002 Sep 15;35(6):748-53.

Norwalk-like viruses (NLVs) are estimated to be the most common causes of foodborne disease in the United States, accounting for two-thirds of all food-related illnesses. The epidemiologic features and disease burden associated with NLVs have, until recently, been poorly understood because of the lack of sensitive detection assays and the underuse of available diagnostic tools. However, the application of molecular techniques to diagnose and investigate outbreaks of infection during recent years has led to a growing appreciation of the importance of these agents. NLVs are a principal cause of outbreaks of acute-onset vomiting and diarrhea in all age groups-most commonly, via contamination of uncooked foods by infected foodhandlers, but also via foods contaminated at their sources, such as oysters and raspberries. NLVs may also account for >10% of sporadic cases of gastroenteritis in children and adults. Future research will focus on the development of easy-to-use diagnostic assays based on antigen and antibody detection as well as vaccine development. Implementation of simple prevention measures, including correct food-handling practices, will continue to be a priority.

6056. Gorkiewicz G, Feierl G, Zechner R, Zechner EL. Transmission of Campylobacter hyointestinalis from a pig to a human. J Clin Microbiol. 2002 Jul;40(7):2601-5.

We report on a case of human gastroenteritis caused by the pathogen Campylobacter hyointestinalis. Recurrent watery diarrhea and intermittent vomiting were the most significant symptoms of the previously healthy patient. Whole-cell protein electrophoresis and 16S rRNA gene sequencing were used to identify this Campylobacter species. Investigation of the patient's surroundings led to the recovery of a second C. hyointestinalis strain originating from porcine feces. Subsequent typing of the human and the porcine isolates by pulsed-field gel electrophoresis revealed similar macrorestriction profiles, indicating transmission of this pathogen.

6057. Katayama K, Shirato-Horikoshi H, Kojima S, Kageyama T, Oka T, Hoshino F, Fukushi S, Shinohara M, Uchida K, Suzuki Y, Gojobori T, Takeda N. Phylogenetic analysis of the complete genome of 18 Norwalk-like viruses. Virology. 2002 Aug 1;299(2):225-239.

"Norwalk-like viruses" (NLV), a member of the family Caliciviridae, are the major causative agents of acute gastroenteritis and are genetically divided into two groups, genogroup I (GI) and genogroup II (GII). We have determined the complete nucleotide sequences of 10 new NLV strains. Using this information together with eight known NLV sequences, the criteria to further classify genotypes of NLV were investigated. Validation of the topological error based on the bootstrap value and the branch length (distance) allowed us to identify two potential subgenomic regions suitable for the genotyping. They were the putative 3D-like RNA-dependent RNA polymerase (polymerase) and the capsid N-terminal/Shell domains (capsid N/S domain). When the distance distribution analysis was performed, the polymerase-based classification did not separate the strains into internal clusters within the genogroup. Furthermore, a diversity plot analysis of the complete nucleotide sequences of WUG1, a NLV GI strain, and Saitama U1, a NLV GII strain, indicated that the genotype was different between the polymerase and capsid N/S domain, suggesting that these strains are the genetic recombinants. Therefore, polymerase is not suitable for genotyping. On the other hand, the clustering based on the capsid N/S domain successfully distinguished the NLV as well as the grouping based on the antigenicity, as determined by both antigen and antibody ELISAs with recombinant virus-like particles. As the nucleotide sequences of the primers for the capsid N/S domain are highly conserved among the NLV, the amplification of the unknown genotype can be easily performed. This method will facilitate global surveying as well as epidemiologic study on NLV.

6058. Kukuruzovic R, Robins-Browne RM, Anstey NM, Brewster DR. Enteric pathogens, intestinal permeability and nitric oxide production in acute gastroenteritis. Pediatr Infect Dis J. 2002 Aug;21(8):730-9.

BACKGROUND: Aboriginal children hospitalized with diarrheal disease in northern Australia have high rates of acidosis, hypokalemia and osmotic diarrhea, as well as abnormal small bowel permeability and elevated nitric oxide (NO) production. METHODS: In a study of 291 diarrheal admissions and 84 controls, we examined the relationship of diarrheal severity outcomes with specific enteric pathogens. NO production was measured by urine nitrate plus nitrite excretion on a low nitrate diet, small bowel permeability by the lactulose:rhamnose ratio on a timed blood specimen and stool pathogens by standard microbiologic investigations and PCR. RESULTS: The addition of diagnostic tests for diarrheagenic to standard stool microbiologic testing increased the rate of specific diagnoses from 53% to 75%, but with multiple pathogens isolated from 34%. The most frequently isolated pathogens from diarrheal patients were enteroaggregative (28.9%), rotavirus (26.5%), enteropathogenic (17.2%), spp. (10.7%), (7.2%) and (7.2%). High geometric mean permeability ratios (95% confidence intervals) occurred with rotavirus (19.6; 15.3 to 25.1), enteroaggregative (21.2; 15.3 to 29.3) and (23.0; 15.1 to 35.1) compared with 9.4 (6.8 to 13.1) for no pathogens. NO production was highest for (3.7; 2.3 to 6.1) compared with 0.6 (0.4 to 1.1) for no pathogens. Multiple regression analysis revealed significant associations ( <0.001) for rotavirus with acidosis and osmotic diarrhea, for with wasting and hypokalemia and for with severe and prolonged diarrhea.CONCLUSIONS: Cryptosporidium, Strongyloides, rotavirus and enteroaggregative are important contributors to the severe manifestations of acute gastroenteritis in Australian Aboriginal children.

6059. Nachamkin I, Liu J, Li M, Ung H, Moran AP, Prendergast MM, Sheikh K. Campylobacter jejuni from patients with Guillain-Barre syndrome preferentially expresses a GD(1a)-like epitope. Infect Immun. 2002 Sep;70(9):5299-303.

GM(1)- and GD(1a)-like ganglioside mimicry in Campylobacter jejuni lipooligosaccharide (LOS) is considered to be involved in the pathogenesis of Campylobacter-induced Guillain-Barre syndrome (GBS). Compared with gastroenteritis-related isolates, GBS-related C. jejuni isolates were strongly associated with the expression of GD(1a)-like mimicry. The presence of a few genes involved in LOS ganglioside mimicry, cst-II, cgtA, and cgtB, was also associated with GBS-related strains. GD(1a)-like epitope expression may be an important virulence phenotype associated with the risk of developing GBS following campylobacter infection.

6060. Nygard K, Guerin P, Andersson Y, Giesecke J. Detection of a previously uncommon salmonella phage in tourists returning from Europe. Lancet. 2002 Jul 13;360(9327):175. No abstract.

6061. Osawa R, Iguchi A, Arakawa E, Watanabe H. Genotyping of pandemic Vibrio parahaemolyticus O3:K6 still open to question. J Clin Microbiol. 2002 Jul;40(7):2708-9. No abstract.

6062. Thong KL, Goh YL, Radu S, Noorzaleha S, Yasin R, Koh YT, Lim VK, Rusul G, Puthucheary SD. Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia. J Clin Microbiol. 2002 Jul;40(7):2498-503.

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.

Therapy:

6063. Villa L, Mammina C, Miriagou V, Tzouvelekis LS, Tassios PT, Nastasi A, Carattoli A. Multidrug and broad-spectrum cephalosporin resistance among Salmonella enterica serotype enteritidis clinical isolates in southern Italy. J Clin Microbiol. 2002 Jul;40(7):2662-5.

From 1992 to 1997, only six sporadic isolates of Salmonella enterica serotype Enteritidis from patients with cases of gastroenteritis in southern Italy exhibited resistance to broad-spectrum cephalosporins. Five isolates produced SHV-12, and one isolate encoded a class C beta-lactamase. The bla(SHV-12) gene was located in at least two different self-transferable plasmids, one of which also carried a novel class 1 integron.

April 2003

6690. Bernstein DI, Sack DA, Reisinger K, Rothstein E, Ward RL.Second-year follow-up evaluation of live, attenuated human rotavirus vaccine 89-12 in healthy infants. J Infect Dis 2002 Nov 15;186(10):1487-9

Rotavirus vaccine development is a high priority. The association between the tetravalent rhesus-human reassortant rotavirus vaccine and intussusception has increased the need to develop new vaccines. In a small efficacy trial, the human rotavirus vaccine 89-12 recently has been shown to be safe and effective; 184 of the 215 healthy infants initially enrolled in this trial were followed for a second year. Vaccine efficacy during the second year was 59% (P=.047). For the 2 years of observation, vaccine efficacy was 76% against rotavirus gastroenteritis, 83% against severe rotavirus gastroenteritis, and 100% against rotavirus illnesses requiring medical intervention (P<.001 for each). These encouraging results have led to continued evaluation, in several countries, of a vaccine candidate derived from strain 89-12.

6691. Tatsumi M, Nakata S, Sakai Y, Honma S, Numata-Kinoshita K, Chiba S.Detection and differentiation of Norwalk virus by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. J Med Virol 2002 Oct;68(2):285-90

We have developed a reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay (RT-PCR-ELISA), using genetic cluster-specific probes in a microtiter plate format, for the detection and differentiation of Norwalk virus (NV) in stool samples. The specificity of the RT-PCR-ELISA was confirmed by testing 76 stool specimens and 15 tissue culture fluids derived from growths of unrelated viruses. The sensitivity of the RT-PCR-ELISA was compared with conventional PCR and Southern hybridization by testing the four cDNA clones derived from the RNA-dependent RNA polymerase region of the NV68 (NV/GI) virus and viruses in the NV/GII/P1B, the NV/GII/P2A, and the NV/GII/P2B cluster. This assay was as sensitive as the conventional RT-PCR with Southern hybridization regardless of primer pairs and probes used in the experiments. However, the actual sensitivity of this method was higher when clinical stool samples were examined because this assay examines all the samples irrespective of the RT-PCR results. The RT-PCR-ELISA format is simple, time saving, and suitable for testing many samples. It should be reliable for large-scale epidemiological studies of NV. Copyright 2002 Wiley-Liss, Inc.

Vaccines:

6692. Peter G, Myers MG; National Vaccine Advisory Committee.; National Vaccine Program Office. Intussusception, rotavirus, and oral vaccines: summary of a workshop. Pediatrics 2002 Dec;110(6):

Rotavirus gastroenteritis continues to cause substantial morbidity and mortality worldwide, despite widespread breastfeeding and use of oral rehydration therapy. This burden of disease indicates that an effective, safe rotavirus vaccine is needed, and in 1998 the first rhesus-human reassortant rotavirus tetravalent vaccine, Rotashield, was licensed in the United States. However, the recommendations for its use were withdrawn in 1999 because of the recognition of an uncommon but serious adverse event, intussusception. A workshop in September 2001 was held to review the subsequent developments and research regarding this association, the proceedings of which are summarized here. Although the pathogenesis of this association remains unknown, epidemiologic evidence supports a causal relationship, with a population attributable risk of approximately 1 per 10 000 (range of 1 in 5000 to 1 in 12 000) vaccine recipients. Whether this association will exist with other candidate rotavirus vaccine strains and whether the attributable risk for intussusception would be similar in other populations administered this vaccine are unclear. Because perceptions of vaccine safety derive from the relative disease burdens of the illness prevented and adverse events induced, the acceptance of rare adverse events may vary substantially in different settings. Nevertheless, a continuing consensus on the need for a safe and effective vaccine to prevent rotavirus gastroenteritis, especially for use in developing countries, exists.

July 2003

7220. Daikh BE, Ryan CK, Schwartz RH. Montelukast reduces peripheral blood eosinophilia but not tissue eosinophilia or symptoms in a patient with eosinophilic gastroenteritis and esophageal stricture. Ann Allergy Asthma Immunol. 2003 Jan;90(1):23-7.

BACKGROUND: Eosinophilic gastroenteritis (EG) is an uncommon entity of which the pathogenesis is unclear. As no controlled treatment trials exist, treatment of EG remains largely empiric. Limited results have been achieved with oral cromolyn, ketotifen, and other antihistamines. Oral corticosteroids are effective, but long-term use is complicated by side effects including growth retardation, diabetes, and osteoporosis. OBJECTIVES: We sought to determine whether treatment with montelukast would improve symptoms and decrease both peripheral blood and tissue eosinophilia (TE) in a patients with steroid-dependent EG for 20 years complicated by esophageal stricture. METHODS: In an unblinded, n = 1 trial, we treated the patient for 5 months with montelukast (20 to 30 mg daily) while his baseline dose of prednisone (10 mg daily) was continued. Complete blood counts and symptoms were monitored weekly. Esophageal biopsies were obtained before and after 5 months of therapy with montelukast. After the posttreatment biopsy was obtained, montelukast was discontinued. Outcome measures included patient symptoms and peripheral and tissue eosinophil counts. RESULTS: During treatment with montelukast, the mean peripheral blood eosinophil count fell from 5,064 cells/microL (average 28 determinations over 20 years; range 1,408 to 12,500 cells/microL) to 1,195 cells/microL (average 14 determinations over 16 weeks; range 556 to 2,193 cells/microL), a 76% reduction. The corresponding TE as calculated from esophageal biopsies was 31 eosinophils/high power field before and 70 eosinophils/high power field after treatment. The patient noted no appreciable improvement in esophageal symptoms. CONCLUSIONS: Montelukast dramatically reduced peripheral blood eosinophilia, but did not affect TE or symptoms in this patient with severe, long-standing EG complicated by esophageal stricture.

7221. Farkas T, Thornton SA, Wilton N, Zhong W, Altaye M, Jiang X. Homologous versus heterologous immune responses to Norwalk-like viruses among crew members after acute gastroenteritis outbreaks on 2 US Navy vessels. J Infect Dis 2003 Jan 15;187(2):187-93

Host immune responses to human caliciviruses are difficult to study because of the lack of a clear definition of antigenic or serological types. This report describes antibody responses to several Norwalk-like viruses in large outbreaks of acute gastroenteritis on 2 US Navy ships. Enzyme immunoassays (EIAs) were used to measure antibody responses. To understand the antibody response to a homologous strain causing the outbreaks, the viral capsid gene of one isolate (C59) was expressed in baculovirus and included in the EIAs. Significantly greater seroresponses were detected in patients against the homologous strain than against the heterologous strains. Strains within genogroups reacted more strongly than did strains between genogroups. Significantly higher antibody titers against the outbreak strain were detected in acute serum samples from control subjects than in those from case patients. These results indicate that recombinant EIAs are useful for outbreak investigation and that the homologous antibody might be protective against reinfection.

7222. Ferrari M, Scalvini A, Losio MN, Corradi A, Soncini M, Bignotti E, Milanesi E, Ajmone-Marsan P, Barlati S, Bellotti D, Tonelli M. Establishment and characterization of two new pig cell lines for use in virological diagnostic laboratories. J Virol Methods. 2003 Feb;107(2):205-12.

Two pig cell lines derived from kidney and trachea tissues and referred to as newborn swine kidney (NSK) and newborn pig trachea (NPTr) were established following serial culture of primary cells. They were characterized by an epithelial-like morphology, high capacity to replicate and stability of the cell monolayer for several days after seeding. Their modal chromosome number was modified in comparison to that of primary swine cells and they both displayed a transforming potential in vitro and displayed oncogenicity in nude mice. Infection with pig endogenous retroviruses was detected. Almost all the swine viruses tested, i.e., pseudorabies virus, pig parvovirus, hog cholera virus, transmissible gastroenteritis virus of swine, encephalomyocarditis virus, swine vesicular disease virus and the enteroviruses, except pig reproductive respiratory syndrome virus, were capable of replicating in the new cell lines with titres similar to the ones detected in the reference culture systems. Furthermore, all the selected influenza virus sub-types isolated from human, swine and avian species replicated with cytopathic effect in NSK and NPTr cells, whereas, of all the equine influenza viruses tested only the Miami and Suffolk sub-types replicated.

7223. Wang CL, Wu YT, Liu CA, Lin MW, Lee CJ, Huang LT, Yang KD. Expression of CD40 ligand on CD4+ T-cells and platelets correlated to the coronary artery lesion and disease progress in Kawasaki disease. Pediatrics. 2003 Feb;111(2):E140-7.

OBJECTIVE: Kawasaki disease (KD) is an acute febrile vasculitic syndrome in children. CD40 ligand (CD40L) has been implicated in certain types of vasculitis. We proposed that CD40L expression might be correlated with coronary artery lesions in KD. METHODS: Blood samples were collected from 43 patients with KD before intravenous immunoglobulin (IVIG) treatment and 3 days afterward. Forty-three age-matched febrile children with various diseases were studied in parallel as controls. CD40L expression on T-cells and platelets were detected by flow cytometry, and soluble CD40L (sCD40L) levels were measured by enzyme-linked immunosorbent assay. RESULTS: We found that CD40L expression on CD4(+) T-cells was significantly higher in patients with KD than in the febrile control (FC) group (28.69 +/- 1.17% vs 4.37 +/- 0.36%). CD40L expression decreased significantly 3 days after IVIG administration (28.69 +/- 1.17% vs 13.53 +/- 0.55%). CD40L expression on platelets from patients with KD was also significantly higher than in the FC group (8.20 +/- 0.41% vs 1.26 +/- 0.12%) and decreased after IVIG therapy. sCD40L levels were also significantly higher in KD patients with those of FC (9.69 +/- 0.45 ng/mL vs 2.25 +/- 0.19 ng/mL) but were not affected by IVIG treatment 3 days afterward (9.69 +/- 0.45 ng/mL vs 9.03 +/- 0.32 ng/mL). More interesting, we found that in KD patients, CD40L expression on CD4(+) T-cells and platelets but not on CD8(+) T-cells or sCD40L was correlated with the occurrence of coronary artery lesions. CONCLUSIONS: CD40L might play a role in the immunopathogenesis of KD. IVIG therapy might downregulate CD40L expression, resulting in decrease of CD40L-mediated vascular damage in KD. This implicates that modulation of CD40L expression may benefit to treat KD vasculitis.

Pathogenesis:

7224. Bidawid S, Malik N, Adegbunrin O, Sattar SA, Farber JM. A feline kidney cell line-based plaque assay for feline calicivirus, a surrogate for Norwalk virus. J Virol Methods. 2003 Feb;107(2):163-7.

Feline calicivirus (FCV) has been used by researchers as a surrogate for Norwalk virus (NV), since they share a similar genomic organization, physicochemical characteristics, and are grouped in the same family, Caliciviridae. Unlike NV, however, FCV can grow in established cell lines and produce a syncytial form of cytopathic effect. In this report, we describe the development and standardization of a plaque assay for FCV using monolayers of an established line of feline kidney (CrFK) cells in 12-well cell culture plates. The assay method has demonstrated reproducibility, ease of performance and resulted in clear plaque zones, readable in 24 h after virus inoculation. The infectivity titre of the virus by this plaque assay agreed well with tissue culture infectious dose(50) (TCID(50)) determinations. The described plaque assay would be a valuable tool in conducting various quantitative investigations using FCV as a model for NV and Norwalk-like viruses (NLV).

7225. Boddicker JD, Knosp BM, Jones BD. Transcription of the Salmonella invasion gene activator, hilA, requires HilD activation in the absence of negative regulators. J Bacteriol. 2003 Jan;185(2):525-33.

Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. Infection is initiated by entry of the bacteria into intestinal epithelial cells and is mediated by a type III secretion system that is encoded by genes in Salmonella pathogenicity island 1. The expression of invasion genes is tightly regulated by environmental conditions such as oxygen and osmolarity, as well as by many bacterial factors. The hilA gene encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. HilD is an AraC/XylS regulator that has been postulated to act as a derepressor of hilA expression that promotes transcription by interfering with repressor binding at the hilA promoter. Our research group has identified four genes (hilE, hha, pag, and ams) that negatively affect hilA transcription. Since the postulated function of HilD at the hilA promoter is to counteract the effects of repressors, we examined this model by measuring hilA::Tn5lacZY expression in strains containing negative regulator mutations in the presence or absence of functional HilD. Single negative regulator mutations caused significant derepression of hilA expression, and two or more negative regulator mutations led to very high level expression of hilA. However, in all strains tested, the absence of hilD resulted in low-level expression of hilA, suggesting that HilD is required for activation of hilA expression, whether or not negative regulators are present. We also observed that deletion of the HilD binding sites in the chromosomal hilA

promoter severely decreased hilA expression. In addition, we found that a single point mutation at leucine 289 in the C-terminal domain of the alpha subunit of RNA polymerase leads to very low levels of hilA::Tn5lacZY expression, suggesting that HilD activates transcription of hilA by contacting and recruiting RNA polymerase to the hilA promoter.

7226. Gorski L, Palumbo JD, Mandrell RE. Attachment of Listeria monocytogenes to radish tissue is dependent upon temperature and flagellar motility. Appl Environ Microbiol. 2003 Jan;69(1):258-66.

Outbreaks of listeriosis and febrile gastroenteritis have been linked to produce contamination by Listeria monocytogenes. In order to begin to understand the physiology of the organism in a produce habitat, the ability of L. monocytogenes to attach to freshly cut radish tissue was examined. All strains tested had the capacity to attach sufficiently well such that they could not be removed during washing of the radish slices. A screen was developed to identify Tn917-LTV3 mutants that were defective in attachment to radish tissue, and three were characterized. Two of the three mutations were in genes with unknown functions. Both of the unknown genes mapped to a region predicted to contain genes necessary for flagellar export; however, only one of the two insertions caused a motility defect. The third insertion was found to be in an operon encoding a phosphoenolpyruvate-sugar phosphotransferase system. All three mutants were defective in attachment when tested at 30 degrees C; the motility mutant had the most severe phenotype. However, not all of the mutants were defective when tested at other temperatures. These results indicate that L. monocytogenes may use different attachment factors at different temperatures and that temperature should be considered an important variable in studies of the molecular mechanisms of Listeria fitness in complex environments.

7227. Hutson AM, Atmar RL, Marcus DM, Estes MK. Norwalk virus-like particle hemagglutination by binding to h histo-blood group antigens. J Virol. 2003 Jan;77(1):405-15.

Noroviruses are a major cause of epidemic acute nonbacterial gastroenteritis worldwide. Here we report our discovery that recombinant Norwalk virus virus-like particles (rNV VLPs) agglutinate red blood cells (RBCs). Since histo-blood group antigens are expressed on gut mucosa as well as RBCs, we used rNV VLP hemagglutination (HA) as a model system for studying NV attachment to cells in order to help identify a potential NV receptor(s). rNV VLP HA is dependent on low temperature (4 degrees C) and acidic pH. Of the 13 species of RBCs tested, rNV VLPs hemagglutinated only chimpanzee and human RBCs. The rNV VLPs hemagglutinated all human type O (11 of 11), A (9 of 9), and AB (4 of 4) RBCs; however, few human type B RBC samples (4 of 14) were hemagglutinated. HA with periodate- and neuraminidase-treated RBCs indicated that rNV VLP binding was carbohydrate dependent and did not require sialic acid. The rNV VLPs did not hemagglutinate Bombay RBCs (zero of seven) that lack H type 2 antigen, and an anti-H type 2 antibody inhibited rNV VLP HA of human type O RBCs. These data indicated that the H type 2 antigen functions as the rNV VLP HA receptor on human type O RBCs. The rNV VLP HA was also inhibited by rNV VLP-specific monoclonal antibody 8812, an antibody that inhibits VLP binding to Caco-2 cells. Convalescent-phase sera from NV-infected individuals showed increased rNV VLP HA inhibition titers compared to prechallenge sera. In carbohydrate binding assays, the rNV VLPs bound to synthetic Lewis d (Le(d)), Le(b), H type 2, and Le(y) antigens, and these antigens also inhibited rNV VLP HA of human type O RBCs. Overall, our results indicate that carbohydrate antigens in the gut are a previously unrecognized factor in NV pathogenesis.

7228. Makino K, Oshima K, Kurokawa K, Yokoyama K, Uda T, Tagomori K, Iijima Y,Najima M, Nakano M, Yamashita A, Kubota Y, Kimura S, Yasunaga T, Honda T, Shinagawa H, Hattori M, Iida T. Genome sequence of Vibrio parahaemolyticus: a pathogenic mechanism distinct from that of V cholerae. Lancet. 2003 Mar 1;361(9359):743-9.

BACKGROUND: Vibrio parahaemolyticus, a gram-negative marine bacterium, is a worldwide cause of food-borne gastroenteritis. V parahaemolyticus strains of a few specific serotypes, probably derived from a common clonal ancestor, have lately caused a pandemic of gastroenteritis. The organism is phylogenetically close to V cholerae, the causative agent of cholera. METHODS: The whole genome sequence of a clinical V parahaemolyticus strain RIMD2210633 was established by shotgun sequencing. The coding sequences were identified by use of Gambler and Glimmer programs. Comparative analysis with the V cholerae genome was undertaken with MUMmer. FINDINGS: The genome consisted of two circular chromosomes of 3288558 bp and 1877212 bp; it contained 4832 genes. Comparison of the V parahaemolyticus genome with that of V cholerae showed many rearrangements within and between the two chromosomes. Genes for the type III secretion system (TTSS) were identified in the genome of V parahaemolyticus; V cholerae does not have these genes. INTERPRETATION: The TTSS is a central virulence factor of diarrhoea-causing bacteria such as shigella, salmonella, and enteropathogenic Escherichia coli, which cause gastroenteritis by invading or intimately interacting with intestinal epithelial cells. Our results suggest that V parahaemolyticus and V cholerae use distinct mechanisms to establish infection. This finding explains clinical features of V parahaemolyticus infections, which commonly include inflammatory diarrhoea and in some cases systemic manifestations such as septicaemia, distinct from those of V cholerae infections, which are generally associated with non-inflammatory diarrhoea.

7229. Nadan S, Walter JE, Grabow WO, Mitchell DK, Taylor MB. Molecular characterization of astroviruses by reverse transcriptase PCR and sequence analysis: comparison of clinical and environmental isolates from South Africa. Appl Environ Microbiol. 2003 Feb;69(2):747-53.

A comparative analysis was performed with 25 isolates of astroviruses (AstVs) detected in sewage sources and 22 concurrently identified clinical AstV isolates from the Tshwane (Pretoria) Metropolitan Area in South Africa. The samples and specimens were screened for AstVs by using an enzyme immunoassay and/or a reverse transcriptase PCR (RT-PCR) for the highly conserved untranslated region (3' end) of the genome. The RT-PCR results were confirmed by oligonucleotide probe dot blot hybridization. Viable viruses were propagated in cell cultures for amplification when a minimal specimen was available or indeterminate sequences were obtained. AstV strains were characterized by RT-PCR and partial sequence analysis of the capsid region. The presence of multiple human AstV (HAstV) types in a single sewage sample complicated identification of individual strains, and additional type-specific RT-PCR and sequence analyses of the capsid region were required for characterization. Amplification and characterization of one genotype from a sample, therefore, did not preclude the possibility that a sample harbored additional different genotypes. Genotype and sequence information obtained from AstVs in wastewater samples were compared to information obtained from AstV strains from human stools. HAstV type 1 (HAstV-1), as well as HAstV-3, -5, -6, and -8, were identified among the clinical isolates, and HAstV-1, -2, -3, -4, -5, -7, and -8 were identified among the environmental samples. Phylogenetic analysis demonstrated that HAstV-1, -3, -5, and -8, which were present in human stool and sewage samples, clustered together, indicating that these viruses are closely related. The concurrent presence of identical HAstV strains in wastewater samples and in hospitalized patients suggests that AstVs present in the environment pose a potential risk to communities in which fecally contaminated water is used for recreational and domestic purposes.

7230. Oliver SL, Dastjerdi AM, Wong S, El-Attar L, Gallimore C, Brown DW, Green J, Bridger JC. Molecular characterization of bovine enteric caliciviruses: a distinct third genogroup of noroviruses (Norwalk-like viruses) unlikely to be of risk to humans. J Virol. 2003 Feb;77(4):2789-98.

Bovine enteric caliciviruses (BoCVs) have been classified in the Norovirus (Norwalk-like virus) genus of the Caliciviridae, raising questions about zoonotic transmission and an animal reservoir for the human Norwalk-like viruses (NLVs), an important cause of nonbacterial gastroenteritis in humans. We examined the genetic relationship of human NLVs to BoCVs that were identified by using reverse transcription-PCR with primer pairs originally designed to detect human NLVs. Polymerase, capsid, and open reading frame 3 (ORF3) gene sequence analyses of BoCVs that were identified from 1976 to 2000 from throughout the United Kingdom showed that BoCVs formed a distinct third genogroup of closely related viruses distinct from the human genogroup I and II NLVs. Evidence was not obtained to support the concept that BoCVs are circulating in humans and pose a threat to human health.

7231. Pedalino B, Feely E, McKeown P, Foley B, Smyth B, Moren A. An outbreak of Norwalk-like viral gastroenteritis in holidaymakers travelling to Andorra, January-February 2002. Euro Surveill. 2003 Jan;8(1):1-8.

A retrospective cohort study was conducted to investigate an outbreak of Norwalk-like viral gastroenteritidis that occurred in Irish holidaymakers visiting Andorra, in January-February 2002. Preliminary results showed the risk exposure was higher for tourists who stayed in Soldeu and consumed ice cubes in their drinks (OR = 2.5, 95% CI [1.3-4.6)], after logistic regression and adjusting for sex and water consumption).

7232. Spiller RC. Estimating the importance of infection in IBS. Am J Gastroenterol. 2003 Feb;98(2):238-41. No abstract available.

Therapy:

7233. Britton LA. Microbiological threats to health in the home. Clin Lab Sci 2003 Winter;16(1):10-5.

OBJECTIVE: To explore a range of pathogenic microorganisms and their toxins that can cause disease in the home environment through a review of the literature.

7234. Pedalino B, Feely E, McKeown P, Foley B, Smyth B, Moren A. An outbreak of Norwalk-like viral gastroenteritis in holidaymakers travelling to Andorra, January-February 2002. Euro Surveill 2003 Jan;8(1):1-8.

October 2003

7952. Doganay M. Listeriosis: clinical presentation. FEMS Immunol Med Microbiol. 2003 Apr 1;35(3):173-5.

Listeria monocytogenes is an uncommon cause of illness in the general population. However, this bacterium is an important cause of severe infections in neonates, pregnant women, the elderly, transplant recipients and other patients with impaired cell-mediated immunity. Various clinical syndromes due to L. monocytogenes have been described such as sepsis, central nervous system infections, endocarditis, gastroenteritis and localized infections. A review of the clinical presentation of listeriosis is given in this paper.

7953. Gunson R, Miller J, Carman WF. Comparison of primers for NLV diagnosis. J Clin Virol. 2003 Apr;26(3):379-80. No abstract.

7954. Kageyama T, Kojima S, Shinohara M, Uchida K, Fukushi S, Hoshino FB, Takeda N, Katayama K. Broadly reactive and highly sensitive assay for Norwalk-like viruses based on real-time quantitative reverse transcription-PCR. J Clin Microbiol. 2003 Apr;41(4):1548-57.

We have developed an assay for the detection of Norwalk-like viruses (NLVs) based on reverse transcription-PCR (RT-PCR) that is highly sensitive to a broad range of NLVs. We isolated virus from 71 NLV-positive stool specimens from 37 outbreaks of nonbacterial acute gastroenteritis and sequenced the open reading frame 1 (ORF1)-ORF2 junction region, the most conserved region of the NLV genome. The data were subjected to multiple-sequence alignment analysis and similarity plot analysis. We used the most conserved sequences that react with diverse NLVs to design primers and TaqMan probes for the respective genogroups of NLV, GI and GII, for use in a real-time quantitative RT-PCR assay. Our method detected NLV in 99% (80 of 81) of the stool specimens that were positive by electron microscopy, a better detection rate than with the two available RT-PCR methods. Furthermore, our new method also detected NLV in 20 of 28 stool specimens from the same NLV-related outbreaks that were negative for virus by electron microscopy. Our new assay is free from carryover DNA contamination and detects low copy numbers of NLV RNA. It can be used as a routine assay for diagnosis as well as for elucidation of the epidemiology of NLV infections.

7955. Vinje J, Vennema H, Maunula L, von Bonsdorff CH, Hoehne M, Schreier E, Richards A, Green J, Brown D, Beard SS, Monroe SS, de Bruin E, Svensson L, Koopmans MP. International collaborative study to compare reverse transcriptase PCR assays for detection and genotyping of noroviruses. J Clin Microbiol. 2003 Apr;41(4):1423-33.

To allow more rapid and internationally standardized assessment of the spread of noroviruses (previously called Norwalk-like viruses [NLVs]) as important food-borne pathogens, harmonization of methods for their detection is needed. Diagnosis of NLVs in clinical diagnostic laboratories is usually performed by reverse transciptase PCR (RT-PCR) assays. In the present study, the performance of five different RT-PCR assays for the detection of NLVs was evaluated in an international collaborative study by five laboratories in five countries with a coded panel of 91 fecal specimens. The assays were tested for their sensitivity, detection limit, and ease of standardization. In total, NLVs could be detected by at least one RT-PCR assay in 69 (84%) of the samples that originally tested positive. Sensitivity ranged from 52 to 73% overall and from 54 to 100% and 58 to 85% for genogroup I and II viruses, respectively. In all, 64% of the false-negative results were obtained with a set of diluted stools (n = 20) that may have lost quality upon storage. Sensitivity was improved when these samples were excluded from analysis. No one single assay stood out as the best, although the p1 assay demonstrated the most satisfactory overall performance. To promote comparability of data, this assay will be recommended for newly starting groups in future collaborative studies.

Pathogenesis:

7956. Abernathy CO, Thomas DJ, Calderon RL. Health effects and risk assessment of arsenic. J Nutr. 2003 May;133(5 Suppl 1):1536S-8S.

Humans can be exposed to arsenic (As) through the intake of air, food and water. Although food is usually the major source of As exposure for people, most adverse effects are seen after As exposure from drinking water. The two main reasons for this situation are that most food arsenicals are organic and have little or no toxicity, and in many cases, As exposures from drinking water sources are to the more toxic inorganic form and occur at relatively high doses, e.g., hundreds of micrograms per day. In various parts of the world, As in drinking water is associated with such effects as gastroenteritis, neurological manifestations, vascular changes, diabetes and cancers (bladder, lung, liver, kidney and prostate). After reviewing the As database, the U.S. Environmental Protection Agency promulgated a maximum contaminant level for As in drinking water of 10 micro g/L.

7957. Bohnker BK, Thornton S. Explosive outbreaks of gastroenteritis in the shipboard environment attributed to Norovirus. Mil Med. 2003 May;168(5) No abstract

7958. Gwee KA, Collins SM, Read NW, Rajnakova A, Deng Y, Graham JC, McKendrick MW, Moochhala SM. Increased rectal mucosal expression of interleukin 1beta in recently acquired post-infectious irritable bowel syndrome. Gut. 2003 Apr;52(4):523-6.

Background and aims: Chronic bowel disturbances resembling irritable bowel syndrome (IBS) develop in approximately 25% of patients after an episode of infectious diarrhoea. Although we have previously shown that psychosocial factors operating at the time of, or prior to, the acute illness appear to predict the development of post-infectious IBS (PI-IBS), our finding of an increased inflammatory cell number in the rectum persisting for at least three months after the acute infection suggested that there is also an organic component involved in the development of PI-IBS. To evaluate this further, we measured expressions of interleukin 1beta (IL-1beta) and its receptor antagonist (IL-1ra) in these patients to provide additional evidence that the pathogenesis of PI-IBS is underpinned by an inflammatory process. METHODS: Sequential rectal biopsy samples were prospectively obtained during and three months after acute gastroenteritis, from eight patients who developed post-infectious IBS (INF-IBS) and seven patients who returned to normal bowel habits after acute gastroenteritis (infection controls, INF-CON). Eighteen healthy volunteers who had not suffered from gastroenteritis in the preceding two years served as normal controls (NOR-CON). IL-1beta and IL-1ra gene expressions were assayed by reverse transcriptase-polymerase chain reaction, and their levels of expression were quantitated by optical densitometry after electrophoresis on agarose gel. RESULTS: INF-IBS patients exhibited significantly greater expression of IL-1beta mRNA in rectal biopsies than INF-CON patients both during and three months after acute gastroenteritis. Moreover, IL-1beta mRNA expression had increased in biopsies taken from INF-IBS patients at three months after the acute infection but no consistent change was observed in INF-CON patients. IL-1beta mRNA expression of INF-IBS patients at three months post gastroenteritis was significantly greater than NOR-CON whereas that of INF-CON patients was not significantly different from NOR-CON. Despite these differential changes in IL-1beta mRNA expression, no significant changes were observed in IL-1ra mRNA expression among the three groups. CONCLUSIONS: These findings indicate that those patients who develop IBS post infection exhibit greater IL-1beta mRNA expression, both during and after the infection, compared with individuals who do not develop PI-IBS. We conclude that such patients may be susceptible to inflammatory stimuli, and that inflammation may play a role in the pathogenesis of PI-IBS.

7959. Sabra A, Bellanti JA, Rais JM, Castro HJ, de Inocencio JM, Sabra S. IgE and non-IgE food allergy. Ann Allergy Asthma Immunol. 2003 Jun;90(6 Suppl 3):71-6.

BACKGROUND: Food allergy (FA) is characterized by an abnormal immunologic reactivity to food proteins. The gastro-intestinal tract serves not only a nutritive function but also is a major immunologic organ. Although previously thought to be triggered primarily by an IgE-mediated mechanism of injury, considerable evidence now suggests that non-IgE mechanisms may also be involved in the pathogenesis of FA. OBJECTIVE: To review the immunologic disturbances that occur in FA and to correlate these with the clinical manifestations expressed in affected target organs based upon a classification of IgE and non-IgE mechanisms. METHODS: Data collected from a computerized MEDLINE search were used for the analysis of the following topics: immediate GI hypersensitivity, oral allergy syndrome, acute urticaria and angioedema, acute bronchospasm, celiac disease, cow's milk enteropathy, dietary protein enterocolitis, breast milk colitis, proctolitis, proctitis, dermatitis herpetiformis, Heiner syndrome, eosinophilic gastroenteritis, atopic dermatitis, asthma, attention-deficit-hyperactivity disorder and behavioral disorders, as well as systems affected by mucosal associated lymphoid tissue-mediated injury of associated lymphoid tissues and the immunologic deviation to Th1 or Th2 mechanisms of FA. CONCLUSIONS: The results of this review allow the construction of a central, unifying hypothesis for a new classification of FA as follows: the clinical manifestations of FA, expressed in affected target organs, may be the result of immunologic injury mediated by interaction of food antigens with contiguous elements of mucosal associated lymphoid tissue. These appear to be modulated by relative imbalances of the Th1/Th2 paradigm, which may be the ultimate determinant governing the expression of FA as IgE-mediated, non--IgE-mediated, or mixed forms of IgE/non-IgE mechanisms of FA.

7960. Weitkamp JH, Kallewaard N, Kusuhara K, Feigelstock D, Feng N, Greenberg HB, Crowe JE Jr. Generation of recombinant human monoclonal antibodies to rotavirus from single antigen-specific B cells selected with fluorescent virus-like particles. J Immunol Methods. 2003 Apr 1;275(1-2):223-37.

Technical difficulties have severely limited the yield of methods for the generation of human antiviral monoclonal antibodies (Mabs) in the past. We describe here a novel method for the efficient development of human Mabs against viruses. Rotavirus (RV) is a major cause of gastroenteritis in infants and adults worldwide. We generated fluorescent virus-like particles (VLPs) to identify and physically sort single RV-specific B cells from healthy adult blood donors, or RV-infected infants or adults. We expanded the sorted single B cells in culture, tested for RV-specific antibody secretion, and cloned and sequenced the antibody heavy and light chain variable region (VH and VL) genes. The percentage of wells that produced antibodies after sorting and expanding RV-specific adult B cell clones was high at 23%. The overall efficiency of RV-specific antibody gene recovery after the isolation, confirmation, and cloning of RV-specific VH segments was 1.3% of sorted cells in adults. RV-specific variable gene segments also were obtained from acutely infected infants, although infant B cells did not proliferate and differentiate in culture as well as adult B cells. We expressed recombinant Fabs incorporating the VH and VL genes from RV-specific B cell clones using a new modified bacterial Fab expression vector that we describe. Finally, we demonstrated binding of purified Fabs to RV proteins by immunofluorescence and ELISA. This method for the generation of recombinant human Mabs to RV from single antigen-specific B cell clones selected with fluorescent VLPs could be used to generate human Mabs to many other viruses whose proteins can self-assemble into VLPs.

Therapy:

7961. Byington CL, Rittichier KK, Bassett KE, Castillo H, Glasgow TS, Daly J, Pavia AT. Serious bacterial infections in febrile infants younger than 90 days of age: the importance of ampicillin-resistant pathogens. Pediatrics. 2003 May;111(5 Pt 1):964-8.

BACKGROUND: Intrapartum antibiotic prophylaxis against group B Streptococcus (GBS) has reduced the occurrence of serious bacterial infections (SBI) in young infants caused by GBS. Recommendations for initial antibiotic therapy for the febrile infant 1 to 90 days old were developed when infections with GBS were common and antibiotic resistance was rare. OBJECTIVE: To document the pathogens responsible for SBI in recent years in febrile infants 1 to 90 days old and the antibiotic susceptibility of these organisms. METHODS: The results of bacterial cultures from infants 1 to 90 days old evaluated for fever at Primary Children's Medical Center in Salt Lake City, Utah, between July 1999 and April 2002 were analyzed. Antibiotic susceptibility profiles were collected and patient records were reviewed to determine if initial antibiotic therapy was changed following the identification of the organism. RESULTS: Of 1298 febrile infants enrolled from the Primary Children's Medical Center emergency department, 105 (8%) had SBI. The mean age of the infants with SBI was 39 days (range 2-82 days) and 2 (2%) were <7 days. SBI included urinary tract infection (UTI; 67%), bacteremia (16%), bacteremia and UTI (6%), bacteremia and meningitis (5%), meningitis (2%), abscess (2%), meningitis and UTI (1%), and meningitis and gastroenteritis (1%). Eighty-three (79%) of 105 episodes of SBI were caused by Gram-negative bacteria, including 92% of UTI, 54% of bacteremia, and 44% of meningitis cases. The most common pathogen was Escherichia coli (61%). Other Gram-negative pathogens were responsible for 19% of SBI. Staphylococcus aureus was the most common Gram-positive pathogen, causing 8% of SBI. GBS accounted for 6% of SBI. Of the 105 pathogens, 56 (53%) were resistant to ampicillin. Of the pathogens causing meningitis, UTI, and bacteremia, 78%, 53%, and 50%, respectively, were resistant to ampicillin. Antibiotic therapy was changed in 54% of cases of SBI following identification of the organism. CONCLUSIONS: In Utah, ampicillin-resistant Gram-negative bacteria are the most common cause of SBI in febrile infants <90 days old. This finding impacts antibiotic selection, especially in cases of meningitis. Local surveillance of pathogens and antibiotic susceptibility patterns is critical to determine appropriate antibiotic therapy.

7962. Leruez-Ville M, Ouachee M, Delarue R, Sauget AS, Blanche S, Buzyn A, Rouzioux C. Monitoring cytomegalovirus infection in adult and pediatric bone marrow transplant recipients by a real-time PCR assay performed with blood plasma. J Clin Microbiol. 2003 May;41(5):2040-6.

The objective of this study was to evaluate the advantages of cytomegalovirus (CMV) real-time PCR in blood plasma to monitor CMV infection in a population of adult and pediatric bone marrow recipients in comparison with the pp65 antigenemia method. Fifty allogeneic bone marrow transplant recipients from our center, including 23 adults and 27 children, were enrolled. A CMV real-time PCR designed to amplify a well-conserved region of the UL123 gene was evaluated for its results with whole blood and blood plasma. The CMV real-time PCR assay and the CMV antigenemia method were performed in parallel with 558 blood samples. The results obtained by the two techniques were significantly correlated (r = 0.732; P < 0.0001). Twenty patients developed at least one episode of CMV replication, with a total of 24 episodes detected by CMV PCR; antigenemia assays were positive in 17 of these 24 episodes. The first positive PCR test preceded the first positive antigenemia by a median of 8 days. The median time interval necessary to obtain a negative CMV PCR test after implementation of preemptive treatment was 28 days. CMV PCR of plasma was positive in two children with CMV disease (one with early CMV pneumonia and one with CMV gastroenteritis), while CMV antigenemia remained negative. The use of CMV PCR with plasma to guide both implementation and discontinuation of CMV preemptive therapy might reduce the risk of occurrence of CMV disease since patients would be treated earlier, and it might also help to reduce the duration of treatment, which could attenuate the side effects of antiviral drugs.

7963. Naumova EN, Egorov AI, Morris RD, Griffiths JK. The elderly and waterborne Cryptosporidium infection: gastroenteritis hospitalizations before and during the 1993 Milwaukee outbreak. Emerg Infect Dis. 2003 Apr;9(4):418-25.

We used the Temporal Exposure Response Surfaces modeling technique to examine the association between gastroenteritis-related emergency room visits and hospitalizations in the elderly and drinking water turbidity before and during the 1993 Milwaukee waterborne Cryptosporidium outbreak. Before the outbreak, the rate of such events increased with age in the elderly (p</=0.001), suggesting that the elderly are at an increased risk. During the outbreak, strong associations between turbidity and gastroenteritis-related emergency room visits and hospitalizations occurred at temporal lags of 5-6 days (consistent with the Cryptosporidium incubation period). A pronounced second wave of these illnesses in the elderly peaked at 13 days. This wave represented approximately 40% of all excess cases in the elderly. Our findings suggest that the elderly had an increased risk of severe disease due to Cryptosporidium infection, with a shorter incubation period than has been previously reported in all adults and with a high risk for secondary person-to-person transmission.

7964. Spiller RC. Postinfectious irritable bowel syndrome. Gastroenterology. 2003 May;124(6):1662-71.

A small but significant subgroup of patients with irritable bowel syndrome (IBS) report a sudden onset of their IBS symptoms after a bout of gastroenteritis. Population-based surveys show that although a history of neurotic and psychologic disorders, pain-related diseases, and gastroenteritis are all risk factors for developing IBS, gastroenteritis is the most potent. More toxigenic organisms increase the risk 11-fold, as does an initial illness lasting more than 3 weeks. Hypochondriasis and adverse life events double the risk for postinfective (PI)-IBS and may account for the increased proportion of women who develop this syndrome. PI-IBS is associated with modest increases in mucosal T lymphocytes and serotonin-containing enteroendocrine cells. Animal models and some preliminary human data suggest this leads to excessive serotonin release from the mucosa. Both the histologic changes and symptoms in humans may last for many years with only 40% recovering over a 6-year follow-up. Celiac disease, microscopic colitis, lactose intolerance, early stage Crohn's disease, and bile salt malabsorption should be excluded, as should colon cancer in those over the age of 45 years or in those with a positive family history. Treatment with Loperamide, low-fiber diets, and bile salt- binding therapy may help some patients. Serotonin antagonists are logical treatments but have yet to be evaluated.

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