J. RAJENDFIRAN AND R. S ELVARAJ PANDIAN
Abstract
Density and diversity of pathogenic bacteria were assessed by isolating them from the mouthparts and external surface of Musca domestica and these flies were collected from three ecologically different sites at Madurai Corporation. The isolated organisms were identified based on Gram staining, motility, their growth on selective and differential media and their response to various biochemical tests. Susceptibility of these organisms to a set of selected antibotics was also assessed by Kirby-Bauer disc diffusion method. Fifteen species of bacteria have been identified from the pure cultures and among them Staphylococcus aureus, Streptococcus sp., Shigella sp., Salmonella sp. and Escherichia coli were isolated from the three population of the flies, but other species showed spatial variation in their occurrence by their presence in one or two population. Among the isolated organisms, strains of E. coil, Salmonella sp., Klebsiclla pneumoniae, Pseudomonas sp., Streptococcus sp. and Proteus nzirabilis exhibited multi-drug resistance. Among the tested antibiotics, ciprofloxacin exhibited highest sensitivity and penicillin G exhibited lowest sensitivity.