10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 2 2013 (April - June) lessThan i greaterThan Acinetobacter baumannii lessThan /i greaterThan has recently become one of the most important nosocomial pathogens worldwide due to its resistance to nearly all available antibiotic including carbapenems. The most common mechanisms of carbapenem resistance are acquired OXA-type carbapenem-hydrolyzing class D β-lactamases (CHDLs) and metallo-β-lactamases (MBLs). The study determined the presence of CHDLs and MBLs encoding genes among lessThan i greaterThan A. baumannii lessThan /i greaterThan recovered from Ramathibodi Hospital, Mahidol University, Thailand during May 2008 to March 2010. A total of 353 isolates of non-susceptible carbapenems lessThan i greaterThan A. baumannii lessThan /i greaterThan were examined by Double-disk synergy test (DDST) of phenotypic MBLs detection and the simplex PCR assay of CHDLs and MBLs encoding genes were confirmed the positive phenotypic isolates. Twenty-six isolates of lessThan i greaterThan A. baumannii lessThan /i greaterThan were positive DDST phenotypic method and the lessThan i greaterThan bla lessThan /i greaterThan lessThan sub greaterThan IMP-14a lessThan /sub greaterThan , lessThan i greaterThan bla lessThan /i greaterThan lessThan sub greaterThan OXA-23 lessThan /sub greaterThan -like, lessThan i greaterThan bla lessThan /i greaterThan lessThan sub greaterThan OXA-24 lessThan /sub greaterThan -like, and lessThan i greaterThan bla lessThan /i greaterThan lessThan sub greaterThan OXA-58 lessThan /sub greaterThan -like were detected. It is first reported in Southeast Asia that demonstrated the combination of various carbapenem resistant genes among lessThan i greaterThan A. baumannii lessThan /i greaterThan isolates. NOPPADON JUMROON AND PITAK SANTANIRAND Metallo-β-lactamases, Carbapenem-hydrolyzing class D β-lactamases, Acinetobacter baumannii, and Carbapenem. 908-917