Spectrum of Uropathogens and their Antibiotic Susceptibility Pattern – Four Years Data from a Reference Laboratory of Karachi, Sindh

Abstract

Background: Urinary tract infections are amongst the most common bacterial infections. It is therefore important to investigate spectrum of uropathogens as well as their antibiotic susceptibility in order to implement appropriate use of antibiotics. The aim of the present study is to investigate common pathogens isolated from urine samples and to reveal antibiotic susceptibility patterns of these pathogens against routinely used antibiotics.

Method: This retrospective study was conducted at the Dow Diagnostic Research and Reference Laboratory during 2009 – 2012. All urine samples collected during the study period were investigated for culture growth and sensitivity patterns. Isolated uropathogens were then tested against antibiotics by Kirbu bur disc diffusion method.

Results: Out of 14,787 urine samples investigated, 4,479 (30%) showed significant bacterial growth. Among those which showed bacterial growth, 2647 (59%) were from females patients while 1832(40.9%) were from male patients. Overall, frequency of gram negative bacteria was higher 3919(87%) compared to gram positive bacteria 560 (12%). Of the gram negative organisms, 2268 (58%) samples were positive for Escherichia coli while in the gram positive; Enterococci species was most frequent 283 (50.5%). The antibiotic sensitivity profile of the isolated microorganisms showed that Imipenem, Piperacillin/Tazobactam, Amikacin and Fosfomycin were most effective antibiotics for gram negative bacteria and Vancomycin and Chloramphenicol were most effective against gram positive bacteria.

Conclusion: Our data demonstrated that prevalence of urinary tract infection is 30 %. E.coli is the most common gram negative bacteria and Enterocccus is the most common gram positive bacteria isolated from the investigated urine samples. Antibiotic susceptibility pattern showed that gram negative bacateria are highly sensitive to Imipenem, Piperacillin/ Tazobactam, Amikacin and Fosfomycin and gram positive bacteria are highly susceptible to Vancomycin and Chloramphenical. These antibiotics can be used for empirial treatment of urinary tract infection. It is necessary to have proper and effective use of antibiotics for treatment of UTI to avoid recurrence and emergence of resistant strains.

Key words: Urinary tract infection, Gram positive bacteria, Gram negative bacteria, Multidrug resistant.