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تقييم بعض جينات المقاومة للمضادات الحيوية في عزلات الكلبسيلا == Evaluation of Some Antibiotic Resistance Genes In Klebsiella Isolates

Author name: زاهد سعدون عزيز
Supervisor name: عباس شاكر جواد المحنة | سلمان عزيز عدوس
General topic: Biology
Specific topic: Microbiology
Degree: Doctorate
University: University of Kufa - College Of Science - Department Of Biology
Language: English
University location: Najaf
First pages: 24T2951 - p.pdf
Abstract: هدفت الدراسة الحالية الى تقييم انتشار جينات البيتا لاكتاميز ? - lactamases ومنها جينات البيتا لاكتاميز الواسعة الطيف lactamases - Extended Spectrum ? وجينات اخرى مثل جينات المقاومة للكوينولونات Quinolones المرتبطة بالبلازميدات plasmid mediated quinolones | The study aimed to evaluate the prevalence of plasmid mediated ? - lactamases including Extended Spectrum ? - lactamases and non - lactamases and study the horizontal gene transfer. A total of 800 of urine samples were taken from patient suffering from urinary tract infections had been collected during a period from February, to September of 2012, from the hospitals of AL - Najaf province. All the samples were cultured on MacConkey agar. From those 300 samples gave positive bacterial growth , 250 were lactose fermentative isolates, which were submitted to conventional tests including IMVIC and motility tests ultimately lactose fermentative, non motile isolates were candidate to Vitek 2 system to confirm the identification. the results revealed that there were 42 (16.8%) of isolates identified as Klebsiellae represented by Klebsiella pnumoniae ssp pneumoniae, 9(3.6%) of isolates diagnosed as Raoultella ornithinolytica, and 1(0.4%) for both K. pnumoniae ssp.ozeanae and Raoultella planticola. Screening tests were performed , disk diffusion test revealed different pattern of resistance, screening of ESBLS by MacConkey agar medium supplemented with 2 mg /l of Ceftazidime showed that 31 (58.5%) of isolates were initially ESBLS producers.Phenotypes confirmatory tests were conducted to different classes of antimicrobial agents, Disk synergism test revealed that 20(37.74%) of isolates were ESBLS positive, while Disk combination test by Ceftazidime + clav and Cefepime + clav revealed that 28(52.83%) and 43(81.13%) were ESBLS producers respectively, disk replacement test pointed that positive isolates were 26(49%), vitek2 system revealed 33(62%) of isolates were ESBLS producers.Imipenem - Ceftazidime antagonism test revealed that there was no isolate produce induced AmpC beta - lactamase, AmpC disc test revealed that no one of isolates were AmpC producer.The result of MHT(Modified Hodge test) revealed that all isolates were not Carbapenemases producers. Molecular study of different antimicrobial resistance genes were performed, the results reveald high percent of occurence as follow : blaTEM genes (90.6%), blaSHV gene(81.13%), blaCTX - M genes (88.6%), sul genes (88.6%), aac(6')Ib - cr genes (84.9%) and qnr - B genes (41.5%).the study also highlighted an association between studied genes. Finally many attempts to study of gene transfer by conjugation were conducted but all of them were failed, except one isolate (No. 5) was succeeded with frequency of conjugation (0.5×10 - 7). This study concluded that there were high prevalence of some plasmid mediated genes of isolates with clear multi gene resistance patterns as compared with some other genes which propose the high selective pressure of these genes and isolates might acquired resistance by mobile elements such as plasmids and integrons.
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