Changing pattern of prevalence and susceptibility of various urinary isolates in Rawalpindi / Islamabad

ABSTRACT

A number of 7585 microorganisms isolated from urine specimens between Jan 1989 and Dec 1993, at Armed Forces Institute of Pathology, Rawalpindi, were tested for their susceptibility to various antimicrobials. The disk diffusion technique [Kirby Bauer Method] using sensitest agar [Oxoid] [alone and/or with 5% horse blood] was adopted for various isolates against different antimicrobials. Escherichia coli remains the most common [46.96%] isolate, followed by pseudomonas aeruginosa [13.05%] and Klebsiella pneumoniae [12.99%]. There was no significant change in the rate of isolation of most of the organisms. However, there is decrease in isolation of Klebsiella pneumoniae from 1989 [20.07%] to 1993 [12.99%] and increase in isolation of Staphylococcus aureus [3.81% 9.80%] and streptococcus [Enterococcus] faecalis [0.55 to 4.81%]. Resistance of Escherichia coli against co-trimoxazole [COT] and ampicillin [AMP] has increased respectively from 40.32% and 39.65% [1989] to 76.18% and 77.98% [1993]. Resistance of Pseudomonas aeruginosa against ofloxacin [OFL] has increased from 46.3% [1989] to 60.83 h [1993]. Resistance of Klebsiella pneumoniae against nitrofurantoin [NIT] and norfloxacin [NOR] has increased respectively from 60% and 4.5% [1989] to 79.17% and 19.91% [1993]. Resistance of Staphylococcus aureus against AMP has increased from 86.85% [1989] to 95.09% [1993]. In 1993, all the isolates [excluding Pseudomonas aeruginosa and S. faecalis] revealed resistnace against NIT, 32.17% NOR, 20.31%; pipernedic acid, 37.19% COT, 78.68%; AMP, 86.83%; cephradine, 35.15%; gentamicin, 32.24%; OFL, 14.19% and ceftriaxone, 20.16%. It appears that AMP and COT should not be used empirically in urinary tract infection [UTI] and instead NIT or NOR may be preferred as empirical treatment of UTI