Prevalence of Different Virulence Factors and Biofilm Production in EnteroaggregativernEscherichia coli Isolates Causing Diarrhea in Children in Ifakara (Tanzania)

摘要

Abstract. This study investigated the prevalence of 19 virulence factors and biofilm production in 86 EAEC isolatesncausing diarrhea in children less than 5 years of age from Ifakara, Tanzania. Virulence factors were detected by PCR,nwhereas biofilm production was determined using a microtiter plate assay. No virulence factor, with the exception of thenaat gene used to identify EAEC, was detected in 11/86 isolates (12.8%). The most frequently detected virulence factornwas the aggR gene in 53 (61.6%) EAEC, followed by antigen 43 in 33.7%, dispersin in 26.7%, yersiniabactin in 22.1%;nautrotransporter Sat in 20.9%; Shigella enterotoxin-1 in 16.3%, and heat-stable toxin-1 in 15.1%. Biofilm was producednin 66/86 (76%) isolates. AggR was the most prevalent virulence factor in the biofilm-forming group (65% versus 38%,nP u0001 0.032). These results again show the high heterogeneity of virulence factors among EAEC isolates causing diarrheanin children, and that biofilm may be an important virulence factor, strongly associated with the presence of AggR.