Frequency and Antimicrobials Resistance of Citrobacter freundii Isolated from Urine Specimens

Abstract

This study was carried out in Khartoum state during the period from November 2008 to March 2009, to investigate antimicrobial resistance of C. freundii isolated from patients suffering from urinary tract infections. Three hundred and eleven urine specimens were collected from patients who attended Khartoum Teaching Hospital, Fedail Center and Gaffer Iben Auff specialized Hospital for Children. The specimens were cultured on blood agar and MaCconkey's agar for primary isolation of pathogen. Identification of the isolates was done by colonial morphology, gram stain and biochemical tests using API 20 E and oxidase test. The modified Kirby-Bauer disc diffusion method was adopted to investigate the resistance rate of C. freundii, to some antibiotic. Minimum Inhibitory Concentrations (MICs) were determine by E. test. Of the three hundred and eleven urine specimens examined, 11 (3.5 %) C. freundii were recovered. The result revealed that the antimicrobial resistance of C. freundii was as follows: amoxicillin and ceftazidime (100% each), nitrofuratoin, chloramphenicol and gentamicin (0 % each), nalidixic acid and amoxyclav (54.5% each), and co-trimoxazole (63.6%). The result indicated that the MIC, MIC50 and MIC90 of ceftazidime (>240μg/ml each), gentamicin (0.1-5.0 μg/ml, 5.0 μg/ml and 5.0 μg/ml), amoxyclav (1.0->240 μg/ml, >240 μg/ml and >240 μg/ml ), amoxicillin (30->240 μg/ml, 30 μg/ml and >240 μg/ml), chloramphenicol (1.0 μg/ml each). The study concluded that the prevalence of C. freundii in patients with urinary tract infection is increasing. The Resistance rate of C. freundii to commonly used antimicrobial agents is slightly high.