Distribution of multiple antibiotic-resistant Gram-negative bacteria in potable water from hand-dug wells in Iwo, Nigeria

Abstract

The provision of potable water is a global challenge. Infections caused by drinking contaminated water are a regular occurrence in developing countries. This study was carried out to determine Gram-negative bacterial distribution and antibiotic resistance in potable water from hand-dug wells within Iwo, Nigeria. Thirty hand-dug wells were randomly selected within Iwo for sampling carried out between October and December 2018. Bacteria identification was carried out using standard methods. The most probable number (MPN) and antibiotic resistance profile as well as Multiple Antibiotic Resistance Index (MARI) for these isolates were determined in addition to studying their haemolysis patterns on blood agar. Results showed that all the water samples from these hand-dug wells were highly contaminated. The highest value >1,100+ was recorded for 21 samples. In addition, 11 genera of bacteria were isolated: Citrobacter, Enterobacter, Escherichia, Klebsiella, Morganella, Neisseria, Proteus, Providencia, Salmonella, Serratia and Pseudomonas. Antibiotic resistance to cefixime and cefuroxime were 92.6 and 90.9%, respectively. One hundred and sixty-nine (96.6%) isolates had a MARI greater than 0.2 and all showed haemolysis. Ingestion of this contaminated water has major public health implications. Hence, it is advisable that every individual should embark on in-house water treatment to avoid water-borne diseases.