Gastrointestinal carriage of toxigenic bacteria: relation to diarrhea and to serum immune response.
We followed up a cohort of babies from birth to two years by examination of fecal samples for heat-labile enterotoxigenic (LT+) bacteria and administration of a questionnaire about any episodes of diarrhea each week. We sampled serum at birth, every six months, at the beginning of an episode of diarrhea, and two weeks later. We tested sera for antibody to cholera toxin. We identified LT+ bacteria in 16% of fecal samples, LT+ Escherichia coli in 11%. Thirty-four episodes of diarrhea occurred within a week of isolation of LT+ bacteria. Bacterial species and weeks of exposure to LT+ bacteria correlated with diarrhea. Fourfold rises in antibody titer followed 53% of diarrhea episodes caused by LT+ bacteria. Whether a baby had an immune response was not related to his age, duration of diarrhea, cord serum antibody, previous asymptomatic carriage of LT+ bacteria, or breast-feeding. Second episodes did not boost antibody levels. Rises in antibody titers followed diarrhea without the presence of toxin but did not follow asymptomatic carriage of LT+ bacteria.
D000367:Age Factors; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000032:analysis; D001427:Bacterial Toxins / Q000032:analysis; D001942:Breast Feeding; D002772:Cholera Toxin / Q000032:analysis; D003968:Diarrhea, Infantile / Q000276:immunology / Q000382:microbiology*; D004064:Digestive System / Q000382:microbiology*; D004768:Enterotoxins / Q000032:analysis; D004926:Escherichia coli / Q000472:pathogenicity; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D006801:Humans; D007231:Infant, Newborn; D012959:Socioeconomic Factors
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C022924:colonization factor antigens; C034151:heat stable toxin (E coli); D036781:Fimbriae Proteins; D002772:Cholera Toxin; C027538:heat-labile enterotoxin, E coli