ABSTRACT
Campylobacter spp. are an important cause of bacterial gastroenteritis frequently isolated from animal, poultry and environmental samples. In this study, we investigated the zoonotic potential of Campylobacter spp. by comparing prevalence rates and species in 394 children with diarrhoea and 652 animals in Vellore using PCR-based tools. Eighteen children (4.5%) had campylobacteriosis, a majority of whom had co-pathogens (15/18) and most were infected with Campylobacter jejuni (16/18). A few C. coli and mixed infections with both species were also seen. Among the animal samples, 16/25 chicken samples (64%) were positive and all were found to be C. jejuni.
Subject(s)
Animals , Bacteriological Techniques/methods , Campylobacter coli/classification , Campylobacter coli/isolation & purification , Campylobacter jejuni/classification , Campylobacter jejuni/isolation & purification , Child, Preschool , Coinfection/microbiology , Diarrhea/epidemiology , Diarrhea/microbiology , Feces/microbiology , Gastroenteritis/epidemiology , Gastroenteritis/microbiology , Humans , India , Infant , Polymerase Chain Reaction/methods , PrevalenceABSTRACT
Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Helicobacter Infections/diagnosis , Helicobacter pylori/immunology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Infant , Male , Middle Aged , Serologic Tests , Urease/diagnosisABSTRACT
The effect of oxidative stress in the form of exogenous H2O2 on the survival of four species of Shigella and two nonpathogenic Gram negative gut bacteria and the role of catalase as an antioxidant enzyme, neutralizing the effect of H2O2 were examined. A significant decrease in the number of colony forming units (CFUs) after exposure to exogenous H2O2 (122 +/- 37), compared to control bacteria (218 +/- 63, P < 0.001) was observed. There was an induction of catalase activity after exposure to exogenous H2O2 and the specific activity of catalase in H2O2 exposed bacteria was significantly increased (2.88 +/- 1.25), compared to control bacteria (1.5 +/- 0.44; P < 0.05). A direct correlation was observed between the decrease in bacterial counts and increase in catalase activity after exposure of H2O2 (regression coefficient (0.56). Gut bacteria appear to be susceptible to oxidative stress and inducible catalase activity may form an important part of the antioxidant defence mechanism against oxidative stress.