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

الملخص EN

Two strains of Shigella (Sh.sonnei, Sh.dysenteriae) were isolated from patients suffering from diarrhea.

The strains were screened for their resistance to some antibiotics, and the screening results indicated that they were resistant to 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 produce bacteriocin.

The two strains (Sh.sonnei and Sh.dysenteriae) contained large plasmid band and various small bands.

Results of conjugation experiments between the Shigella as a donor and the standard E.coli strain (MM294) as a recipient indicated the transfer of resistance of Tetracyclin , Streptomycin , Nalidixic acid and Ampicillin in addition to bacteriocin production , this may refer to their location on a conjugative plasmid.

Resistance to Cefotaxime was not transferable by conjugation, but by transformation.

Transformation also expressed resistance to Ampicillin , Nalidixic acid and Tetracyclin which may indicate the presence of another copy of resistance genes on a non-conjugative plasmid in Shigella.

The study utilized the salicylic acid (150mg/ml) effects on the growth and as a curing agent , the results showed there was no effect of this acid on the growth of Shigella spp , while the results found a curing effect on the resistance genes of both species of Shigella.