Abstract:
The study aimed to compare the bacteriological quality of an urban and rural irrigation water
source. Bacterial counts, characterization, identification and diversity of aerobic bacteria
were determined. Escherichia coli isolated from both sites was subjected to antibiotic
susceptibility testing, virulence gene (Stx1/Stx2 and eae) determination and (GTG)5 Rep-PCR
fingerprinting. Low mean monthly counts for aerobic spore formers, anaerobic spore
formers and Staphylococcus aureus were noted although occasional spikes were observed. The
most prevalent bacterial species at both sites were Bacillus spp., E. coli and Enterobacter
spp. In addition, E. coli and Bacillus spp. were most prevalent in winter and summer
respectively. Resistance to at least one antibiotic was 84% (rural) and 83% (urban). Highest
resistance at both sites was to cephalothin and ampicillin. Prevalence of E. coli possessing
at least one virulence gene (Stx1/Stx2 and eae) was 15% (rural) and 42% (urban). All (rural)
and 80% (urban) of E. coli possessing virulence genes showed antibiotic resistance.
Complete genetic relatedness (100%) was shown by 47% of rural and 67% of urban E. coli
isolates. Results from this study show that surface irrigation water sources regardless of
geographical location and surrounding land-use practices can be reservoirs of similar bacterial
pathogens.
