Antibiotic Resistance Pattern and Detection of Some ESBL Genes amongDiarrheagenic E. coli O157:H7.

Abstract

During the period of 20th of May to1st of November 2013, twenty five isolatesof E. coliO157:H7 were identified among 200 samples taken from children under ten years oldsuffer from diarrhea (68 males and 132 females) admitted to Rapareen Pediatric hospitalsin Erbil City. Isolates were identified from stool sample by using cultural, morphological,biochemical characteristics and serological test. Antibiotic sensitivity testing was donefor all isolates by using fourteen antibiotic types The resistance rate of the isolatestoward these antibiotics were 100 % for AMP, 96% for MET, 76% for CTX, 72% for TEand KF, 68% for TMP, 56% for FEP, 52% for C and SXT, 48% for CRO, 28% for AK,20% for CIP, while the lowest percent 16% was for CN, and all isolates were sensitivefor IPM. Extended spectrum ß-lactamase (ESBL) production was done for all isolates.Out of 25 E. coli O157:H7isolates, 8(32%) were ESBL producers, while17(68%) werenon ESBL producers. The plasmid profile of 25 isolates conducted by using gelelectrophoresis, the results revealed different bands with molecular weight rangingbetween (2kbp- more than 10kbp) in size. The transformation process conductedsuccessfully for (E1 and E15) and the results showed that the resistance genes forampicillin, Cephalothin, Cefepime, metronidazole and trimethoprimwere located onplasmid DNA for E1 isolate, while for E15 isolate, the ampicillin, Cephalothin,Cefepime, ceftriaxone, Cefotaxime, metronidazole and trimethoprimlocated on plasmid.The results of transformation confirmed by gel electrophoresis, and showed that oneplasmids of E1 and two plasmid E15 had been transformed successfully with molecularweight of more than 10 Kbp. All E. coli O157:H7isolates were screened for the presenceof ESBL genes including (blaCTX-M - blaSHV-and blaTEM) on plasmid DNA usingpolymerase chain reaction (PCR) assay. Results showed that all isolates were positive forthe existence of ( blaSHV-and blaTEM), while 88% of the isolates contained( blaCTXM).