OCCURRENCE AND ANTIBIOTIC RESISTANCE PATTERNS OF COLIFORMS ISOLATED FROM WELL WATER SOURCES IN ILARAMOKIN, ONDO STATE, NIGERIA

Abstract

The objectives of this research was to isolate and identify the coliforms and other enteric bacteria species from selected well water sources, determine the physicochemical properties of the well water, screen for the presence of heavy metals and determine the antibiotic sensitivity and resistance patterns of the isolates from each well water source. Twelve selected wells were used for this study, the water samples were collected in triplicate from each well. During the dry season, January and February, 2020 and during the rainy season in May, 2020. The Most Probable Number method was used. High value of bacterial counts were recorded in this study and it ranged from 7 to 250 cfu/100ml. The bacterial isolates were, Esherichia coli, Salmonella typhi, Shigella dysentariae and Klebsiella pnuemoniae. Esherichia coli was isolated from all samples collected, while Salmonella typhi was isolated from 70% of the samples. The isolates were tested on ten different antibiotics which were Sparfloxacin (10ug), Ciprofloxacin (30ug), Amoxicillin (30ug), Augmentin (10ug), Gentamicin (30ug), Pefloxacin (30ug), Ofloxacin (10ug), Streptomycin (30ug), Septrin (30ug) and Chloramphenicol (30ug). Resistant isolates were selected according to Clinical laboratory standard institute (CLSI) standard. The isolates from ward one during the dry season were 100% sensitive to ciprofloxacin, sparfloxacin, pefloxacin, and ofloxacin. High rate of resistance occurred in E. coli and K. pnuemoniae (66.7%) when tested with augmentin, Salmonella typhi (50%) when tested with amoxicillin, Shigella dysentariae (45%) when tested with streptomycin in dry season. Higher rate of resistance was recorded during the rainy season than the dry season. The value obtained for hardness, conductance and total dissolved solids were 122.9mg/L, 48.0mS, 5.8mg/L in the dry season, and 123.6mg/L, 48.1mS and 7.2mg/L in the rainy season respectively. In the dry season the mean value obtained for lead, Cadmium, Zinc, Iron and Manganese were 0.294mg/L, 0.039mg/L, 0.166mg/L, 1.78mg/L, 0.202mg/L and 0.241mg/L, 0.028mg/L, 0.227mg/L, 1.922mg/L, 0.053mg/L in the rainy season respectively