Diversity and distribution of antibiotics resistant bacteria in well water within Iwo, Osun State, Nigeria

Abstract

Safe water is a crucial need in public health in this twenty first Century. This study assessed the diversity and distribution of antibiotic resistant bacteria in underground water within Iwo. Well water samples were collected from thirty wells in duplicates. Physicochemical and bacteriological analyses of the well water were carried out. Bacteria species were isolated using standard microbiological procedures and were identified through biochemical characterization. The isolated bacteria were screened for antibiotic susceptibility using disc diffusion method by placing antibiotic multidisc containing eight different antibiotics. The multidrug resistant bacteria (resistance to ≥ 3classes) were subjected to pathogenicity test using blood agar. The mean conductivity value ranged between 20.40 µs/cm – 293.00 µs/cm and there were significant differences in the samples. pH value of the water sampled ranged from 4.40 – 10.00 and the depths of the well sampled ranged from 0.61 to 12.4m. In addition all the samples had very high coliform counts. Coliforms population ranged from 23 to 1100+ MPN/100ml. No well recorded zero while the highest value of 1100+ was recorded 50 times out of 60 samples. A total of 219 bacteria were isolated from all the well water sampled. The organisms isolated belonged to sixteen genera and were identified as Citrobacter, Enterobacter, Escherichia, Klebsiella, Morganella, Neisseria, Proteus, Providencia, Pseudomonas, Salmonella, Serratia, Arthrobacter, Bacillus, Micrococcus, Staphylococcus and Streptococcus. All the isolates were susceptible to ciprofloxacin and gentamicin while resistance was highest in cefixime (88.7%). Genus Klebsiella recorded the highest level of resistance. The results showed that thirteen (13) bacteria species out of 32 multi drug resistant isolates were positive for the blood pathogenity test. The multiple drug resistance and haemolysis exhibited by the isolated bacteria in well water within Iwo town, Nigeria is a major health concern. Their presence signifies a public health hazard and could possibly lead to waterborne diseases. There is therefore need for proper treatment of well water to make it safe for domestic use. To reduce the rate and spread of multi-antibiotics resistant, it is recommended that awareness and policy be made on the usage, control and sales of antibiotics.