Frequency and Antimicrobial Resistance of Serratia marcescens in Sudanese Patients with Community-acquired UrinaryTract Infections

Abstract

This study was conducted in Khartoum state hospitals during the period from November 2008 to March 2009. The aim of this work was to determine the frequency and antimicrobial resistance of Serratia marcescens isolated from Sudanese patients with community acquired UTIs. A total of three hundred and eleven urine specimens were collected from Khartoum Teaching Hospital, Gaffar Ibn Auff Specialized Hospital and Yastabshiroon Medical Centre. The specimens were cultured on blood agar and MacConkeys’ agar for primary isolation. Identification of the isolates was done by colonial morphology, Gram stain’s and biochemical tests using API 20E. The modified Kirby-Bauer disc diffusion method was adopted to evaluate the resistance rate of S. marcescens to nitrofurantoin, amoxycillin, nalidixic acid, co- trimoxazole and amoxyclav. Minimum inhibitory concentration (MIC) of nitrofuration, nalidixic acid, co- trimoxzole, amoxycillin and amoxyclav were evaluated by using E-test. Of the three hundred and elevn urine specimens examined, 10 (3.2%) Serratia marcescens were recovered. The result revealed that the antimicrobial resistance profile of Serratia marcescens was as follows nitrofurantoin, amoxycillin and amoxyclav (100% each), nalidixic acid and co-trimoxzole (0% each). The result showed that the MIC, MIC 50, MIC90 of nitrofurantoin (>240 μg/ml each). nalidixic acid (0.001-0.05μg/ml, 0.05 μg/ml and 0.05 μg/ml) amoxycillin (10-60 μg/ml, 30 μg/ml and 60 μg/ml), co-trimoxzole (0.1 -0.5 μg/ml, 0.1 μg/ml and 0.5 μg/ml) and, amoxyclav (120 μg/ml each). This study concluded that the responsibility of Serratia marcescens to CAUTIs was not high and the antimicrobial resistance pattern of Serratia marcescens to the traditional antimicrobial agents was high .