عنوان المقالة:Detection of Metallo-β-Lactamases and Inhibitor Resistant Temoniera Enzyme in β-Lactam Resistant Klebsiella Spp. and Enterobacter Cloacea Isolated from Wound Infections : A Genetic Study Detection of Metallo-β-Lactamases and Inhibitor Resistant Temoniera Enzyme in β-Lactam Resistant Klebsiella Spp. and Enterobacter Cloacea Isolated from Wound Infections : A Genetic Study
The emergence of acquired metallo-beta-lactamases (MBLs) is of clinical concern since they confer resistance to all available beta-lactams except aztreonam. This study had been undertaken for detecting the ability of Klebsiella species and Enterobacter cloacea to produce inhibitor-resistant Temoniera beta-lactamases (IRT) and metallo-β-lactamase. Further, for determining the genetic elements encoding for such enzymes whether chromosomally or conjugated plasmid mediated. Furthermore, for detect the potency of some curing agents on conjugated plasmids DNA. The study was performed on 75 wound patients admitted to Department of Surgery, Ramadi Teaching Hospital during the period from February to July, 2010. Rapid iodometric β-lactamase production test in addition to phenotypic and confirmatory tests for production of IRT, and metallo-β-lactamase were performed. Plasmid DNA extraction, conjugation and curing experiments were performed. Our result showed that Fourty isolates were bacteriologically identified as Klebsiellae spp. including 26 (34.7%) Klebsiellae pneumoniae and 14 (18.7%) Klebsiellae oxytoca, 10 (13.3%) Enterobacter cloacea, and etc. In the screening test for IRT production, 6 (24%) isolates of K. pneumoniae were resistant to inhibition by clavulanic acid. In the screening test for metallo-beta-lactamase production, the study revealed that 1(10%), 1(4%) isolates of Klebsiella oxytoca and K. pneumoniae respectively were produced this enzyme. In the genetic part of study, Five (83.3%) of inhibitor-resistant TEM β-lactamase and 2 (100%) of metallo-β-lactamase producer isolates of Klebsiella spp., were plasmid mediated while the remaining were chromosomally mediated. The result of curing experiments showed successful curing for all the study isolates by both methods. The study suggested that the production of β-lactamases of type IRT, and metallo appeared to be the major mechanisms of resistance of Klebsiellae spp. and Enterobacter cloacea to β-lactams. Also, conjugative plasmids were found to be the main genetic elements encoding for such enzymes produced by these bacteria. Finally, the study suggested that sodium dodecyl sulphate was of higher potency than elevated growth temperature in the curing of plasmid DNA.
الأستاذ الدكتور مشتاق طالب صالح الندا | Dr. Mushtak T. S. Al-Neda | 8223