Occurrence of virulence gene signatures associated with diarrhoeagenic and non-diarrhoeagenic pathovars of Escherichia coli isolates from some selected rivers in South-Western Nigeria

Abstract

BackgroundDiarrhoeal diseases are attributable to unsafe water stemming from improper sanitation and hygiene and are reportedly responsible for extensive morbidity and mortality particularly among children in developed and developing countries.MethodsWater samples from selected rivers in Osun State, South-Western Nigeria were collected and analyzed using standard procedures. Escherichia coli isolates (n=300) were screened for 10 virulence genes using polymerase chain reaction for pathotyping.ResultsWhile the virulence gene (VG) lt for enterotoxigenic E. coli had the highest prevalence of 45 %, the enteropathogenic E. coli genes eae and bfp were detected in 6 and 4 % of the isolates respectively. The VGs stx1 and stx2 specific for the enterohemorrhagic E. coli pathotypes were detected in 7 and 1 % of the isolates respectively. Also, the VG eagg harboured by enteroaggregative pathotype and diffusely-adherent E. coli VG daaE were detected in 2 and 4 % of the isolates respectively and enteroinvasive E. coli VG ipaH was not detected. In addition, the VGs papC for uropathogenic and ibeA for neonatal meningitis were frequently detected in 19 and 3 % of isolates respectively.ConclusionsThese findings reveal the presence of diarrhoeagenic and non-diarrhoeagenic E. coli in the selected rivers and a potential public health risk as the rivers are important resources for domestic, recreational and livelihood usage by their host communities.

Prevalence of <i>Escherichia coli</i> virulence genes in patients with diarrhoea in Ouagadougou, Burkina Faso

“…Similar results were found in subSaharan Africa and others countries [2,26,27,28]. ETEC causes a significant number of cases of childhooddiarrhoea and gastroenteritis among the most common agent of traveller'sdiarrhoea with food and water implicated as the modes of transmission [3]. In our study, we did not found ETEC but co-infections was found with EAEC.…”

“…EPEC infection is primarily a disease of infants younger than 2 years of age. Numerous case-control studies in many countries have found that EPEC is more frequently isolated from children with diarrhoea than from healthy controls [2,3].However, in our study, the detection rate of EPEC strains from adults with diarrhoea was low (only one typical EPEC) and it co-infection with EAEC. In this study no EPEC was detected from children under five years.…”

“…However Bonkoungou in Burkina Faso showed the presence of ETEC in the children with diarrhoea. ETEC were detected on important proportion in others study conducted in sub-Saharan Africa countries [3,5,9,19]. EAEC is an emerging pathogen associated with diarrhoea.…”

“…The aetiological agents include a wide range of viruses, bacteria and parasites [2]. Among bacterial pathogens, diarrhoeagenicEscherichia coli (DEC) is an important agent of endemic and epidemic diarrhoea worldwide [3]. Escherichia coli (E. coli) is a heterogeneous group of typically nonpathogenic gram-negative bacteria, which are a natural partof the intestinal flora of animals and humans [4,5].…”

“…DiarrhoeagenicE. coli (DEC) strains are important causesof diarrhoea in the developing world and, to a lesser extent, inthe developed world [3].Diarrheal illness causes much mortality worldwide, particularly in children under the age of 5 [7]and particularly in countries in sub-Saharan Africa and South Asia, where children suffer many diarrhoea-related deaths. While there are many etiological agents responsible for diarrhoea, pathogenic E. coli is major contributor [8,9].Diarrheal disease morbidity in children living in underserved countries is a leading cause of mortality andmorbidity in children living in underserved countries [9].…”