Frequency and Antibiotic Resistance of Salmonella enteritidis in Sudanese Patients

Abstract

This study was carried out in Khartoum state during the period from October 2008 to April 2009 to determine the antibiotic resistance patterns of the clinical isolates of Salmonella enteritidis. A total number of three hundred and fifty patients suffering from symptoms and signs of Salmonellosis were included in this study. Stool specimen was collected from each patient and cultured on Salanit F broth, then subcultured on Xylose lysine deoxyclolate , Deoxycholate citrate agar, Salmonella Shigella Agar and MacConkey agar for primary isolation of the pathogen. Identification of the isolates was done by colonial morphology, Gram stain and biochemical tests using Analytical Profile index (API 20E ) and oxidase test and also serological diagnosis. The modified Kirby – Bauer disc diffusion method was used to determine the resistance rate of S. enteritidis to different types of antibiotics. The minimum inhibitory concentration (MIC) of S. enteritidis was determined by HiComb (MIC test). On this study, 216 (61.7%) of patients were males while 134 (38.3%) were females. The ages of patients ranging from 9 month to 74 years old. 305 (87.1%) of patients revealed no pathogenic organism isolated while 45 (12.8%) were infected by different types of microorganisms. The prevalence rate of S. enteritidis among all patients was 3(0.9%). All the three isolates of S. enteritidis were sensitive to a number of the antibiotic tested like Ciprofloxacin and Gentamicin. But all the three isolates of S. enteritidis were resistant to Chloramphenicol, PenicillinG, Ceftazidime, Amoxycillin and Cephalexin. Also,one isolate (33.3%) of S. enteritidis isolates were resistant to Tetracycline, Tobromycin and Amikacin. The range of minimum inhibitory concentration, the MIC50 and MIC90 for S. enteritidis is (3μg/ml for each) to Ceftazidime, (0.5-1μg/ml, 0.5μg/ml and 1μg/ml) to Tetracyclin, (0.10-0.25μg/ml, 0.10μg/ml and 0.25μg/ml) to Gentamicin, (0.001-0.05μg/ml, 0.001μg/ml and 0.05μg/ml) to Nalidixic acid, (1-2μg/ml, 1μg/ml and 2μg/ml) to Amoxycillin, (0.1-1μg/ml, 0.1μg/ml and 1μg/ml) to Tobromycin, (4-8μg/ml, 4μg/ml and 8μg/ml) to Ticarcillin, (0.032-0.064μg/ml, 0.064μg/ml and 0.032μg/ml) to Cephotaxime, (0.05μg/ml for each) to Co-triooxazol and (7.5μg/ml for each) to Nitrofurantoin and Cephalexin. This study recommended that, patients treatment should be based upon both and up-to-date knowledge of the effective agent and antibiotic sensitivity testing to each specific isolate.