Diarrheagenic Escherichia coli Markers and Phenotypes among Fecal E. coli Isolates Collected from Nicaraguan Infants

Abstract

We analyzed the prevalence of diarrheagenic Escherichia coli (DEC) markers and common phenotypes in 2,164 E. coli isolates from 282 DEC-positive samples. Enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) were very diverse and were not correlated with diarrhea. Enterotoxigenic E. coli (ETEC) estA and enterohemorrhagic E. coli (EHEC) belonged to a few phenotypes and were significantly correlated with diarrhea.In Nicaragua, diarrheagenic Escherichia coli (DEC) strains are considered to be common causes of diarrhea among infants, with enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) the most common DEC types found (4, 6, 12). We previously performed a large screening study on stool samples from 526 infants with and without diarrhea to detect the prevalence of five different categories of DEC and to determine the phenotypic diversity of E. coli isolates from diarrheal and control infants. A one-step multiplex PCR using a mixture of eight primer pairs was applied to the primary streak of E. coli cultures, and eight isolates per sample were analyzed by biochemical fingerprinting (7, 12). As many as 54% of the diarrheal samples and 53% of the control samples were positive for one or more DEC markers, and no clear connection between biochemical phenotypes found in DECpositive samples and diarrhea could be established.For the present report, we analyzed eight E. coli isolates from each of the 282 DEC-positive stool samples by PCR for the occurrence of the respective DEC markers found in the primary streak.PCR and PhP typing of E. coli isolates. E. coli isolates analyzed in the study were recovered from a study conducted from

Diarrheagenic Escherichia coli pathotypes investigation revealed atypical enteropathogenic E. coli as putative emerging diarrheal agents in children living in Botucatu, São Paulo State, Brazil

“…So, the data demonstrated in this study is in disagreement with previous findings from such countries. On the other hand, results from Nicaragua, Peru, and Brazilian cities have found almost the same scenario herein described, that is, lower frequencies for STEC when compared with other DEC pathotypes .…”

“…So, the data demonstrated in this study is in disagreement with previous findings from such countries. On the other hand, results from Nicaragua, Peru, and Brazilian cities have found almost the same scenario herein described, that is, lower frequencies for STEC when compared with other DEC pathotypes (31,(38)(39)(40)(41). Curiously, EAEC and aEPEC were detected in similar frequencies between both the diarrheic and control children studied (Table 3), thus making it difficult to associate these DEC pathotypes with diarrheal disease, even when statistical analyses were performed considering the different age groups of this study (data not shown).…”

Frequency of Diarrheagenic <i>Escherichia coli</i> among Children in Surabaya, Indonesia

“…EPEC was detected significantly more frequently in non-diarrheal children (25.0z) than in diarrheal children (0.8z) (P º 0.0001). Previous studies reported that the rate of atypical EPEC isolation from children with diarrhea was not significantly different from the rate of isolation from children without diarrhea (4)(5)(6)(7). One of the explanations may be that most of the diarrheal children were already prescribed antibiotics before hospitalization.…”

“…DEC can be classified into five major categories on the basis of their specific virulence properties: Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), and enteroinvasive E. coli (EIEC) (2). The importance of DEC has been reported in developing countries (3)(4)(5)(6)(7). In Indonesia, while a high incidence of diarrhea in children has been reported (8,9), no study has compared diarrheal children with non-diarrrheal or healthy children to elucidate the role of DEC in pediatric diarrheal diseases.…”