Relationship between pH, Chloride Levels and Multiple Antibiotic Resistance Index of Bacteria Isolated from Sachet Drinking Water in Ota, Nigeria

Abstract

The presence of waterborne pathogens in drinking water and physiochemical parameters, such as pH and chloride levels, that are outside of the usual range, are serious issues with water quality that can jeopardize safety.  Thus, the purpose of this study was to isolate the pathogens present in commercially available sachet water and to determine the effect of pH and chloride content on the antibiotic resistance pattern of the bacteria recovered from the sachet drinking water. Seven different brands of sachet samples of commercial drinking water were purchased from different retail shops in Ota, Ogun State, Nigeria.  Biochemical tests and the analytical profile index (API) method were used to identify the bacteria. In addition, antibiotic susceptibility testing was carried out using the Kirby-Bauer method. The Multiple Antibiotic Resistance (MAR) index was calculated for all the isolates, and Spearman’s rank correlation coefficient was used to assess the association between pH, chloride, and MAR index of the isolates recovered from the sachet water. The Analytical Profile Index revealed seven dominant bacteria in all the samples, namely, Enterobacter aerogenes, Citrobacter freundii, Chryseobacterium meningosepticum, Escherichia fergusonii, Edwardsiella hoshinae, Escherichia coli, and Chromobacterium violaceum. In addition, the Multiple Antibiotic Resistance index of 0.2 was observed in 71.4% of the isolates. The pH values and chloride content recorded were 6.28 to 6.80 and 11.36 to 21.30 mg/L, respectively. A non-significant correlation was observed between pH and MAR index (ρ = 0.49, P-value = .269) and chloride and MAR index (ρ = - 0.67, P-value = .098). Thus, the multidrug resistance characteristics of the isolates recovered in this study are most likely inherent in the source water or a result of human contamination during water processing. Hence, stricter procedures and hygiene standards should be followed when processing drinking water in sachets.