Antimicrobial Resistance of Salmonella typhi Isolated from Patients with Typhoid Fever

Abstract

The objective of this study was to determine the antimicrobial resistance patterns of Salmonella typhi (S. typhi) isolated from patients with typhoid fever. The study was carried out in Khartoum State during the period from March 2012 to October 2012. Stool specimens were collected from patients suffering from typhoid fever who attended Khartoum, Omdurman and Ibrahim malik Teaching hospitals. The specimens were cultured on selenite F broth then Xylose lysine Deoxycholate (XLD) to isolate the causative agent. The identification of the isolates was done by colonial morphology, Gram stain and biochemical tests. Antimicrobial resistance of each isolate was determined by modified Kirby-Bauer disc diffusion method. The antibiotics used were tetracycline, ceftazidime, co-trimoxazole, ciprofloxacin, ceftriaxone and chloramphenicol. Out of 100 stool specimens investigated, only 7 isolates of S. typhi were recovered. Antimicrobial susceptibility test showed that the resistance rate of S. typhi was as follows: 100% to tetracycline and ceftazidime, 50% to co- trimoxazole and no resistance was noticed against ciprofloxacin , ceftariaxone and chloramphnicol. The study concluded that the resistance of S. typhi to tetracycline is very high, but still sensitive to members of quinolone such as ciprofloxacin and ceftriaxone. Further studies with large number of specimens are highly recommended to validate the present study.