Gupta Prachi, Singh Amit, Gupta Anuj, Singh Dharmendra Prasad, Nautiyal Sulekha
Microbiology, Graphic Era Institute of Medical Sciences, Dehradun, IND.
Microbiology, Uttar Pradesh University of Medical Sciences, Etawah, IND.
Cureus. 2025 May 12;17(5):e83998. doi: 10.7759/cureus.83998. eCollection 2025 May.
Introduction due to its recognition as a major cause of healthcare-associated infections, is posing a huge therapeutic challenge for clinicians globally. The present study aimed to study the phenotypic and genotypic characteristics of carbapenem-resistant (CRAB). Methods A total of 121 clinical isolates of were identified using VITEK 2 (bioMérieux, France) from January 2017 to June 2018. Antimicrobial susceptibility testing was performed by modified Kirby-Bauer disc diffusion. CRAB isolates were subjected to modified Hodge test (MHT), combined disk test (CDT), and double disk synergy test (DDST) for the detection of carbapenemase production, followed by determination of minimum inhibitory concentration (MIC) of meropenem and imipenem by agar dilution and E-test, respectively. Molecular characterisation was done by polymerase chain reaction (PCR) for the detection of blaOXA (blaOXA-51, blaOXA-23, blaOXA-24, and blaOXA-58) and blaMBL (blaVIM, blaIMP, blaNDM, blaSIM, blaSPM, and blaGIM) genes. Results The study showed that 34.71% of isolates were CRAB. On MHT, 64.29% isolates were identified as carbapenemase producers. DDST and CDT show 40.48% of CRAB isolates as metallo-β-lactamase (MBL) producers, and one isolate was identified as an MBL producer by DDST only. MIC and MIC values of meropenem were 16 and 32µg/mL, respectively. MIC and MIC values of imipenem were 12 and >32µg/mL, respectively. blaOXA-51 was detected in all the isolates. blaOXA-23 was detected in 73.81% and blaNDM in 21.43% of isolates. blaVIM, blaOXA-58, blaSIM, blaIMP, and blaSPM were also detected in 7.14%, 4.76%, 2.38%, 2.38%, and 2.38% isolates, respectively. Neither blaOXA-24 nor blaGIM was detected in any of the study isolates. Conclusion A high level of carbapenem resistance was found in blaOXA-23 was the most common carbapenamase gene, followed by blaNDM.
引言 由于其被公认为医疗保健相关感染的主要原因，正给全球临床医生带来巨大的治疗挑战。本研究旨在研究耐碳青霉烯类鲍曼不动杆菌（CRAB）的表型和基因型特征。方法 2017年1月至2018年6月期间，使用VITEK 2（法国生物梅里埃公司）共鉴定出121株临床分离株。采用改良的 Kirby-Bauer 纸片扩散法进行药敏试验。对CRAB分离株进行改良 Hodge 试验（MHT）、联合纸片试验（CDT）和双纸片协同试验（DDST）以检测碳青霉烯酶的产生，随后分别通过琼脂稀释法和E试验测定美罗培南和亚胺培南的最低抑菌浓度（MIC）。通过聚合酶链反应（PCR）进行分子特征分析，以检测blaOXA（blaOXA-51、blaOXA-23、blaOXA-24和blaOXA-58）和blaMBL（blaVIM、blaIMP、blaNDM、blaSIM、blaSPM和blaGIM）基因。结果 研究表明，34.71%的鲍曼不动杆菌分离株为CRAB。在MHT中，64.29%的分离株被鉴定为碳青霉烯酶产生菌。DDST和CDT显示40.48%的CRAB分离株为金属β-内酰胺酶（MBL）产生菌，且仅有一株分离株通过DDST被鉴定为MBL产生菌。美罗培南的MIC和MIC值分别为16和32μg/mL。亚胺培南的MIC和MIC值分别为12和>32μg/mL。所有分离株均检测到blaOXA-51。73.81%的分离株检测到blaOXA-23，21.43%的分离株检测到blaNDM。分别有7.14%、4.76%、2.38%、2.38%和2.38%的分离株还检测到blaVIM、blaOXA-58、blaSIM、blaIMP和blaSPM。在任何研究分离株中均未检测到blaOXA-24和blaGIM。结论 在鲍曼不动杆菌中发现了高水平的碳青霉烯耐药性，blaOXA-23是最常见的碳青霉烯酶基因，其次是blaNDM。
