ABSTRACT
This study was carried out to determine the antibiotic susceptibility, plasmid profile and conjugative abilities of Shigella species isolated from different towns in Sudan during 2005-2007. Stool specimens were collected in Carry Blair transport medium from patients presenting with diarrhea from different sites in Sudan between the years 2005-2007. All specimens were inoculated on Mac Conkey' s agar and Xylose Lysine Dioxycholate [XLD] [Mast group Ltd. Merseyside UK]. Bacteria was isolated and subjected to different antibiotics to detect sensitivity and transference of resistance. One hundred and fourteen Shigella isolates were included in the study. Eighty [70.1%] were Shigella flexeneri representing the dominant isolate, followed by 20 [17.5%] isolates of Shigella dysenteriae, 9 [7.9%] Shigella sonnei and 5 [4.5%] Shigella boydii. Most of the isolates showed resistance to streptomycin [70%], tetracycline [52%] and co-trimoxazole [43%]. They were highly sensitive to norfioxacin [97%], nalidixic acid [95%], gentamicin [89%] and chloramphenicol [77%]. Multi-drug resistance to two or more antibiotics was apparent in most of the isolates [64, 56.1%]. Fifty nine of the resistant Shigella isolates were studied for their ability to transfer resistance to the donor E. coli K[12] by conjugation. Of these, six were able to transfer resistance to streptomycin, tetracycline and co-trimoxazole. Extraction of the plasmid DNA from both donors and trans-conjugants showed a single type of plasmid with a molecular weight of 4.6 Kb. The transfer of multi-drug resistant plasmids and the emergence of antibiotic Shigella and other bacterial species should raise the awareness and the seriousness of the uncontrolled [unsupervised] use of antibiotics in the medical practice