Genotypes and phenotypes of Shiga toxin-producing Escherichia coli (STEC) in Abeokuta, Southwestern Nigeria

Abstract

PurposeTo characterize the prevalence of hemolytic Shiga toxin-producing Escherichia coli (STEC) with a multidrug-resistant pattern in different age groups in Abeokuta, Nigeria.MethodsNonrepetitive E. coli isolates were collected from 202 subjects with or without evidence of diarrhea. Each isolate was biochemically identified and antimicrobial susceptibility testing was performed using the disk diffusion method. A sorbitol fermentation test of all the E. coli isolates was done and the minimum inhibitory concentration of suspected STEC was measured by the standard broth microdilution method to determine antibiotic resistance. The genotypes of stx1, stx2, and hlyA were determined by polymerase chain reaction assay.ResultsThe majority of subjects were aged ≥40 years (41.6%) and were female (61.9%). Of the 202 subjects, 86.1% had STEC isolates (P<0.05). A high rate of STEC isolates resistant to amoxicillin (90.6%), cefotaxime (77.7%), and cefuroxime (75.7%) was observed. Resistance to amoxicillin, gentamicin, and cefotaxime was demonstrated with a minimum inhibitory concentration >16 μg/mL in 13.9%, 11.4%, and 10.4% of the isolates, respectively. The prevalence of stx1, stx2, and hlyA was 13.9%, 6.9%, and 2.0%, respectively; 5.5% of stx1 were in the 0–10-year-old age group, 3.5% of stx2 were aged ≥40 and above, and 1.0% of the hlyA isolates were in the 0–10-year-old age group.ConclusionThe prevalence of virulent STEC is a public health concern. The use of polymerase chain reaction assay should aid quick detection of this virulent serotype and help curb the severe epidemic of human diseases associated with STEC infections.

Prevalence, characterization and antibiotic resistance of Shiga toxigenic Escherichia coli serogroups isolated from fresh beef and locally processed ready-to-eat meat products in Lagos, Nigeria

“…In the overall, 79.2% of the STEC isolated were non-O157 STEC serotypes while 20.8% were E. coli O157:H7 ( Table 3 ). This finding is a confirmation that consumers are more exposed to non-O157 STEC from food sources than E. coli O157:H7 STEC in Nigeria, as it is the trend in other part of the world (Grant et al, 2011;Johnson et al, 2006); yet the reports on the incidence of non-O157 STEC infection in Nigeria is far lower than that of E. coli O157:H7 (Olowe et al, 2014). The high prevalence of non-O157 STEC in the current study supported previous reports on high level of these pathogens in the animals from which the meat and meat products are sourced in the southwestern Nigeria (Adenipekun et al, 2015;Ajayi et al, 2011;Nsofor et al, 2013;Ojo et al, 2010).…”

Prevalence and Antibiotic Resistance Profile of Pseudomonas aeruginosa from Hospital Sinks in South Western Nigeria

“…In our study there was also high level resistance observed against augumentin (amoxicillin/clavunalate) with 65% resistance. This high level resistance is indicative of the presence of extended spectrum beta lactamase (ESBL) among our isolates, even though ESBL testing was not conducted on the isolates; a resistance to both cephalosporin and augumentin shows the presence of ESBL enzyme [18][19][20]. Pseudomonas aeruginosa, resistance to blactam antibiotics and aminoglyco-sides has been reported to be associated with the production of enzymes, such as, carbenicillin hydrolyzing b-lactamases, extended-spectrum blactamases (ESBL), oxacillinases, metallo-blactamases(MBLs) ae well as aminoglycosidemodifying enzymes [10,11].…”