Department of Microbiology, Velammal Medical College Hospital and Research Institute, Tamil Nadu, India.
Indian J Med Microbiol. 2024 May-Jun;49:100603. doi: 10.1016/j.ijmmb.2024.100603. Epub 2024 May 7.
To find the prevalence of Ceftazidime-Avibactam (CAZ-AVI) resistant Klebsiella pneumoniae in clinical isolates and to determine the genes responsible for Ceftazidime-Avibactam resistance using PCR.
A total of 89 carbapenem resistant Klebsiella pneumoniae from various clinical samples were included in the study. CAZ-AVI resistance was tested using E-test. CAZ-AVI resistant strains were subjected to conventional PCR for detection of carbapenamase genes bla, bla, bla, bla, bla.
Of the 89 isolates screened for CAZ-AVI resistance, 45(50.5%) isolates were found to be resistant. 42 isolates were subjected to PCR for detection of β lactamase genes.34 isolates were positive for bla and all 42 isolates were positive for bla. Co-expression of NDM-1 and OXA-48 was seen in 34 isolates. Sensitivity of mCIM test to identify a carbapenamse compared to PCR was 61.9%. Sensitivity of eCIM test to identify NDM-1 was 80%.
CAZ-AVI was effective in vitro in 49.4% of the isolates. Indicating that CAZ-AVI is a promising addition to antibiotics against CRE as well as a carbapenem sparing drug in ESBL producing organisms. β-Lactamase-related mutations are the main mechanism leading to CAZ-AVI resistance.
在临床分离株中寻找头孢他啶-阿维巴坦（CAZ-AVI）耐药肺炎克雷伯菌的流行率，并使用 PCR 确定导致头孢他啶-阿维巴坦耐药的基因。
本研究共纳入了来自各种临床样本的 89 株碳青霉烯类耐药肺炎克雷伯菌。使用 E 试验检测 CAZ-AVI 耐药性。对 CAZ-AVI 耐药株进行常规 PCR 检测碳青霉烯酶基因 bla、bla、bla、bla、bla。
在筛查 CAZ-AVI 耐药的 89 株分离株中，发现 45（50.5%）株耐药。对 42 株进行 PCR 检测β-内酰胺酶基因。34 株bla 阳性，42 株bla 均阳性。34 株同时表达 NDM-1 和 OXA-48。mCIM 试验检测碳青霉烯酶的敏感性与 PCR 相比为 61.9%。eCIM 试验检测 NDM-1 的敏感性为 80%。
CAZ-AVI 在 49.4%的分离株中具有体外活性。这表明 CAZ-AVI 是治疗 CRE 的一种有前途的抗生素，也是产 ESBL 菌中碳青霉烯类药物的节约药物。β-内酰胺酶相关突变是导致 CAZ-AVI 耐药的主要机制。
