ABSTRACT
This study investigated the prevalence of 19 virulence factors and biofilm production in 86 EAEC isolates causing diarrhea in children less than 5 years of age from Ifakara, Tanzania. Virulence factors were detected by PCR, whereas biofilm production was determined using a microtiter plate assay. No virulence factor, with the exception of the aat gene used to identify EAEC, was detected in 11/86 isolates (12.8%). The most frequently detected virulence factor was the aggR gene in 53 (61.6%) EAEC, followed by antigen 43 in 33.7%, dispersin in 26.7%, yersiniabactin in 22.1%; autrotransporter Sat in 20.9%; Shigella enterotoxin-1 in 16.3%, and heat-stable toxin-1 in 15.1%. Biofilm was produced in 66/86 (76%) isolates. AggR was the most prevalent virulence factor in the biofilm-forming group (65% versus 38%, P = 0.032). These results again show the high heterogeneity of virulence factors among EAEC isolates causing diarrhea in children, and that biofilm may be an important virulence factor, strongly associated with the presence of AggR.
Subject(s)
Diarrhea/epidemiology , Escherichia coli/pathogenicity , Virulence , Base Sequence , Child, Preschool , DNA Primers , Diarrhea/microbiology , Escherichia coli/isolation & purification , Escherichia coli/metabolism , Humans , Infant , Infant, Newborn , Polymerase Chain Reaction , Tanzania/epidemiologyABSTRACT
A total of 451 stool specimens were collected from children less than five years of age with acute diarrhea from Ifakara, Tanzania and processed to detect bacterial enteropathogens, parasites, and rotaviruses. These specimens were divided into 348 from the dry season and 103 from the rainy season. Overall, diarrheogenic Escherichia coli (35.7%) were the predominant enteropathogens, with enterotoxigenic E. coli, enteroaggregative E. coli, and enteropathogenic E. coli being the most prevalent. Moreover, enteroaggregative E. coli (63% versus 35.5%; P < 0.05), Shigella spp. (24% versus 12%; P < 0.05), and rotavirus (23% versus 4%; P < 0.05) were more prevalent in the dry season than in the rainy season and enterotoxigenic E. coli (51.6% versus 20%; P < 0.05) and Giardia lamblia (14% versus 1%; P < 0.05) were more prevalent in the rainy season.
