Evaluation of bla OXA-48-like point mutation carbapenemase-producing Enterobacterales in Prapokklao Hospital, Thailand

Carbapenemase-producing (CPE) isolates increasingly carry oxacillinase-48 (OXA-48)-like enzymes encoded by , which can confer high levels of carbapenem resistance. This aims to determine the prevalence of CPE and genetic variation among -carrying isolates recovered from Prapokklao Hospital in Chanthaburi Province, Thailand in 2016-2017. In total, 122 carbapenem-resistant (CRE) isolates were recovered from clinical samples. CRE were evaluated using standard biochemical tests and MIC test strips. Carbapenemase production was assessed through the modified Hodge test (MHT), modified carbapenem inactivation method (mCIM), and EDTA-modified carbapenem inactivation method (eCIM). Detection of mutations was conducted via PCR and confirmed by Sanger sequencing. Among these CRE isolates, 72 (59.02%), 44 (36.07%), 3 (2.46%), and 3 (2.46%) were , , , and , respectively. The MHT identified carbapenemase production in 108 isolates (88.52%). Based on the mCIM, 81 isolates (66.39%) were carbapenemase producers. Seventy-three isolates (59.84%) were eCIM-positive, indicating metallo-β-lactamase production. Three distinct genetic variants of the gene were identified among the isolates, including the wild-type and two point mutation types harboring the mutations E168Q and S171A (mutation type 1) and E168Q, S171A, and R214S (mutation type 2). Multiple-sequence alignment and analysis revealed variation of R214 located in the β5-β6 loop. This study identified point mutation groups and carbapenemase production, predominantly metallo-β-lactamases, among CRE isolates, especially and . These findings highlight the importance of implementing stringent infection control measures and active antimicrobial resistance surveillance to combat the spread of difficult-to-treat, metallo-β-lactamase-producing CRE in healthcare settings. In this study, we aimed to investigate genetic variation and CPE among bla carrying isolates recovered from Prapokklao Hospital, Chanthaburi Province, Thailand, during 2016-2017. A total of 122 carbapenem-resistant Enterobacterales (CRE) were recovered from clinical samples in Prapokklao Hospital. All CRE samples were confirmed by standard biochemical tests and minimum inhibitory concentration (MIC) test strips (E-test). The carbapenemase production was determined using the modified Hodge test (MHT), the modified carbapenem inactivation method (mCIM), and EDTA-CIM (eCIM). Three single mutations (E168Q, S171A, and R214S) were characterized in this study. This mut