Abstract

This work was designed to undertake a comparative analysis of the drug resistance pattern of enteric bacteria isolated from humans and those isolated from the multifarious microbial environments of the sewage. Human and sewage isolates of enteric Gram-negative bacilli were examined for resistance to ten antibacterial agents. A total of 2400 bacterial isolates (from human n = 1404, and sewage n = 996) isolated over a consecutive three – year (2007 to 2009) period were studied. They include species of Enterobacter, Escherichia coli, Klebsiella, Proteus, Pseudomonas and Salmonella. Source distribution of resistant isolates showed that sewage isolates were significantly (p < 0.05) more resistant than human isolates to most of the drugs tested. High correlations of up to 0.938 between resistance to drugs of sewage and human isolates showed that variation in resistance between the two groups was systematic. Resistance selection and sustenance occur more in the sewage than in human gut but the mechanisms for resistance development are similar, differing only in rate. 

Key words:  Gram-negative bacilli, human isolates, sewage isolates, drug resistance, resistance correlation