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.
