PATHOGENS FROM DRINKING WATER

Isolation and antibiogram of pathogenic organisms from drinking water in Quetta city

Abstract

… Objectives: Main objective was to check drinking water for pathogenic bacterial
load, their resistance to antimicrobials and to create awareness among the people of Quetta city
about safe drinking water. Place and Duration of Study: The study was conducted in
Department of Microbiology Bolan Medical Complex Hospital Quetta during the hot season in
Quetta City (June- September 2013). Methodology: One hundred and twenty five (125) tape
water samples were collected aseptically in 200 ml sterile caped glass bottles from different
localities of Quetta city. Samples were passed through mille pore assembly containing 0.45 μmpore-size
cellulose nitrate sterile membrane filter (MF).Viable count technique was used for
enumeration of water samples having high bacterial burden. Serological tests and analytical
profile index API-20E (Biomerieux France) were used to identify pathogens according to the
manufacturer’s directions. Standardized antibiotic sensitivity test was performed on Mueller
Hinton agar using disc diffusion Kirby Bauer technique and McFarland Turbidity Standard
method 0.5 following CLSI protocols. Results: Out of hundred and twenty five (125) tape water
samples 110 (88 %) showed highly pathogenic bacterial load, in which the most prominent
organism was E.coli 36 (28.8 %), followed by Enterobacter 35 (28 %), Klebsiella 24 (19.2 %),
Pseudomonas, 10 (08 %), and Salmonella 05 (04 %). All pathogens in this study expressed a high
level of resistance to antimicrobials that are commonly used in clinical medicine i.e. Tetracycline,
Gentamycin, Sulphamethaxazole, Piperacillin, Ampicillin, Augmentin and Imipenam etc. Only 15
(12 %) samples were pathogens free. Conclusion: Among drinking water samples the presence
of pathogenic bacteria (88%) is alarming for public health authorities. The emergence of
resistance and decreasing level of susceptibility of pathogens to a wide spectrum of
antimicrobials is a matter of great concern, because it may limit the availability of antimicrobials
for clinical management of water born outbreaks in future.