Background: Family members of Enterobacteriaceae are found in small numbers associated with acute diarrhea. These species are sometimes mistaken for ETEC.
Methods: Forty-four non-E. coli species from travelers' diarrhea are compared to 30 strains of Escherichia coli (ETEC) and 30 strains of normal flora E. coli. Tissue culture supernatants were assayed by enzyme-linked immunosorbent assay for amounts of IL-8, IL-1, and IL-1ra. Amounts of heat-stable (ST) and heat-labile (LT) enterotoxins were assayed from cell culture supernatants by enzyme-linked immunoassay. PCR was use to determine which species was positive colonization factor antigens, CFA/I, CS3, and CS6.
Results: Normal flora E. coli significantly induced the production of more IL-8 than non- E. coli and ETEC. Normal E. coli also induced the production of more IL-1and IL-1ra than ETEC. Non-E. coli produced more ST than ETEC. A small percentage of enterotoxigenic non- E. coli gram negatives and ETEC were positive for CFA/I and CS6. None of the strains were positive for CS3.
Conclusions: Non-E. coli enterotoxigenic gram negatives were similar to ETEC in their virulence factors. Identification and further study of these non-E.coli strains is important for understanding their pathogenic role in acute diarrhea.
|Advisor:||DuPont, Herbert L.|
|Commitee:||Brown, Eric, Jiang, Zhi-Dong, Rodin, Andrei|
|School:||The University of Texas School of Public Health|
|Department:||Epidemiology & Disease Control|
|School Location:||United States -- Texas|
|Source:||DAI-B 74/01(E), Dissertation Abstracts International|
|Keywords:||Colonization factor antigens, Cytokines, Diarrhea, Enterobacteriaceae, Enterotoxins|
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