Enterotoxigenic Escherichia coli in children with acute diarrhoea and controls in Teresina/PI, Brazil: distribution of enterotoxin and colonization factor genes

Abstract

Aims: To investigate the distribution of the genes that encode enterotoxins and the colonization factors (CF) types as well as the antibiotic susceptibility profile of enterotoxigenic Escherichia coli (ETEC) isolated from children from the Brazilian Northeast. Methods and Results: We conducted a 3·5‐year prospective study that involved 250 children with and 150 without diarrhoea, aged 1–60 months, from low‐income families in Teresina/Brazilian Northeast. All samples were assayed for E. coli, enterotoxin and CF genes and antimicrobial susceptibility by microbiological methods and PCR. ETEC strains were isolated from 9·2% children with and 4·0% without diarrhoea. Infection was more common in children aged 6–24 months in rainy months. elt+/CFA/IV+ and elt+/CS14+ were the most frequent genotypes. Susceptibility to nalidixic acid, ciprofloxacin and gentamicin and resistance to ampicillin, cephalothin and sulfamethoxazole–trimethoprim were common. Conclusions: elt + isolates and ETEC strains harbouring genes encoding CFA/IV and CS/14 were the most common ETEC found in Brazilian Northeast. Significance and Impact of the Study: Our data, the first generated for north‐eastern Brazilian children, may be important for the development of an effective vaccine and for facilitation of an empirical choice of antibiotic treatment or prophylaxis for traveller’s diarrhoea in the area studied.

Molecular Characterization of Enterotoxigenic Escherichia coli Isolates Recovered from Children with Diarrhea during a 4-Year Period (2007 to 2010) in Bolivia

“…The proportion of the ETEC strains isolated from children with diarrhea that were CF positive was significantly higher than the proportion of ETEC isolates from control children as previously described for ETEC strains in Bangladesh (25), suggesting that the presence of CFs is related to virulence. In our study, CFA/I SThonly or LT/STh strains were the most common combinations of ETEC strains isolated from diarrhea cases, similar to recent reports from Brazil and Bangladesh (20,26). During 2007, comparably high prevalences of CS14-positive ETEC infections were reported, but the prevalence of CS14 ETEC infections was dramatically reduced during the following years, suggesting a possible outbreak of such strains in 2007.…”

“…However, variations in toxin profiles were observed from year to year. Different studies in Latin America have shown differences in the predominant toxin type; for instance, LT/ST ETEC strains were found to be most prevalent in Peru (19), ST-only ETEC strains in Brazil (20) and LT ETEC strains in Argentina (23), in Nicaragua (21), and in a previous report from Bolivia (16). A similar trend has been observed in Bangladesh, where different toxin profiles have predominated over the years (24)(25)(26).…”

“…In Bolivia, a previous report showed that ETEC strains expressing LT CS17 constituted the most common pathotype isolated between 2002 to 2005, but those strains were from different clonal origins (31). In recent studies in Peru, CS6-and CS12-positive strains (19), and, in Brazil, CFA/I-and CS14-expressing ETEC strains (20) were the predominant pathotypes. Several review articles have indicated that a limited number of CFs, including CFA/I, CS1 to -6, and, more recently, CS7, CS14, and CS17, are repeatedly identified as the most common CFs for ETEC, suggesting a continuous circulation of similar strains among populations (2,6,32).…”

Identification of common virulence factors present in enterotoxigenicEscherichia coliisolated from diarrhoeal patients in Kolkata, India

“…ETEC in children with acute diarrhoea and controls in Teresina/PI, Brazil overall, CF genes were identified in 53·3% (32/60) of the ETEC strains isolated from 19 (67·6%) children, 15 (78·9%) with diarrhoea and four (21·1%) controls (Nunes et al . ). In Peruvian children effected with ETEC, CFs were identified in 64% of diarrhoeal samples and 37% of control samples (Rivera et al .…”

“…The CS14 and CFA/IV were the most common CFs in Teresina, Brazil (Nunes et al . ). In Bangladesh, the predominant CFs were CS6, CS5, CFA/I, CS7, CS17, CS1, CS3 and CS14 (Begum et al .…”