دراسة دور حامض السالسيليك في تحييد بلازميدات المقاومة لنوعين من بكتريا الزحار

Abstract

ABSTRACTTwo strains of Shigella (Sh.sonnei, Sh.dysenteriae) were isolated frompatients suffering from diarrhea. The strains were screened for their resistanceto some antibiotics, and the screening results indicated that they were resistantto Ampicillin, Cefotaxime, Kanamycin, Streptomycin and Nalidixic acid.Resistance to: Tetracyclin and Chloramphenicol varied between the strains.One of the strains (Sh.sonnei) was found to have the ability to producebacteriocin.The two strains (Sh.sonnei and Sh.dysenteriae) contained large plasmidband and various small bands.Results of conjugation experiments between the Shigella as a donor andthe standard E.coli strain (MM294) as a recipient indicated the transfer ofresistance of Tetracyclin , Streptomycin , Nalidixic acid and Ampicillin inaddition to bacteriocin production , this may refer to their location on aconjugative plasmid. Resistance to Cefotaxime was not transferable byconjugation, but by transformation. Transformation also expressed resistanceto Ampicillin , Nalidixic acid and Tetracyclin which may indicate the presenceof another copy of resistance genes on a non-conjugative plasmid in Shigella.The study utilized the salicylic acid (150mg/ml) effects on the growth andas a curing agent , the results showed there was no effect of this acid on thegrowth of Shigella spp , while the results found a curing effect on theresistance genes of both species of Shigella.Keywords: Salicylic acid, curing, shigella.PDF created