Plasmids profile of E. COLI extracted from different sources (human, animal, water) .

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Research type: Research Paper

Authors: Abu El Gasim, Raga Mohamed .

Abstract: This study aimed to show the antibiotics susceptibility, conjugation studies and plasmids extraction of E. COLI isolated from human, animals and water. On hundred and fifty six isolates of E. COLI were collected from different sources including human, animals and water, fifty from each of the juman and water and fifty six from animals. The antibiotics susceptibility of the isolates showed high resistance to the commonly used antibiotics. Of the human isolates (84 percent) of them were resistant to streptomycin, (74 percent) to ampicillin, (74 percent) to tetracycline, (68 percent) to cotrimoxazole, (36 percent) to gentamicine, (30 percent) to chloramphenicol and (6 percent) to nalidixic acid. Similarly the animal E. COLI isolates showed high resistance to the same antibiotics. (62 percent) of them were found to be resistant to streptomycin, (59 percent) to ampicllin, (57 percent) to tetracycline, (39 percent) to cotrimoxazole, (25 percent) to nalidixic acid, (18 percent) to chloramphenicol and (14 percent) to gentamicin. The water isolates showed high resistance to ampicillin (84 percent), (48 percent) to streptomycin, (32 percent) to cotrimoxazole, (12 percent) to gentamicin and low resistance to tetracycline (8 percent) as well as chloramphenicol (8 percent), where as no resistance was noticed to nalidixic acid. High incidence of multiple resistance was noticed among the different isolates of human, animal and water. Twenty two isolates of the human E. COLI were studied for their ability to transfer resistance. Nine of them (41 percent) were transferred resistance to the recipient E. COLI. Whereas, out of twenty animal isolates only four (20 percent) were able to transfer resistance. Different patterns of resistance transfer were noticed. No resistant transfer detected during the conjugational study of the water isolates. The commonest pattern of resistance transfer in the human isolates was to the combination of ampicillin, tetracycline, cotrimoxazole and streptomycin. Whereas in animals the commonest pattern transferred was to the combination of ampicillin, tetracycline and cotrimozazole. Plasmids extraction was done from the human and animal donors and their transconjugants. Also from animal isolates which were unable to transfer resistance and som selected water isolates. Different numbers and sizes of plasmids were identified. In the human donors the numbers of plasmids varied from 1 to 3 plamids per isolate. The sizes of plasmids ranged from 2,9 to 108 md. The commonest size was the plasmid 76 md. Plasmid extraction from transconjugants also showed different numbers and sizes plasmid. In the animal donor isolated the number of plasmids varied from 1 to 3 plasmids per isolate. The sizes of plasmids ranged from 2,8 to 60 md. The commonest plasmid size seen in the donors was the plasmid with the molecular weight range 3 - 4 md. The commonest plasmid size identified in the transcomjugants was the plasmid with the molecular weight 60 md. The plasmid extraction from animal isolates which were unable to transfer their resistance noticed to harbour small plasmid sizes. Plasmid extraction from water isolates showed 1 to 8 plasmids per isolate with sizes ranged from 2,2- 10 md. The commonest plasmid sizes ranged from 3 - 3,7 md.