Biochemistry and Biotechnology Laboratory LR01ES05, Faculty of Sciences of Tunis, University Tunis El Manar, 2092, El Manar II, Tunisia.
Biological Macromolecules, Center for Protein Engineering, InBioS University of Liege, Institut de Chimie B6a Quartier Agora Allée du 6 Août, 11 Sart Tilman, B4000, Liege, Belgium.
Curr Microbiol. 2023 Mar 29;80(5):152. doi: 10.1007/s00284-023-03268-2.
Fifty-four carbapenem non-susceptible Klebsiella pneumoniae (CNSKP) isolates were collected from a Tunisian hospital over a period of 13 consecutive months. Carbapenemase production and the prevalence of carbapenemase-encoding genes were investigated using combined-disk test (CDT), modified Carba NP (mCarba NP) test, and UV-spectrophotometry method complemented by PCR experiments and sequencing. Carbapenemase production was detected by the mCarba NP test and CDT in 92.59% and 96.29% of the 54 CNSKP isolates, respectively; while imipenem hydrolysis was detected using UV-spectrophotometry in the crude extracts of 44 isolates. bla bla, and bla carbapenemase-encoding genes were found in 48, 31, and 22 isolates, respectively. Remarkably, bla bla, and bla genes were reported. The co-occurrence of carbapenemase-encoding genes in a single isolate was detected in 62.96% of the isolates. The analysis of clonal relationships between the isolates by pulsed field gel electrophoresis revealed that the majority of them were genetically unrelated. Our investigation provides molecular data on enzymatic mechanism of carbapenem non-susceptibility among 54 CNSKP showing the dominance of bla and comprises the first identification of bla bla, and bla genes in a Tunisia hospital.
54 株耐碳青霉烯类肺炎克雷伯菌（CNSKP）分离株来自突尼斯一家医院在 13 个月的连续时间内采集。使用联合盘试验（CDT）、改良的 Carba NP（mCarba NP）试验和 UV 分光光度法，结合 PCR 实验和测序，检测碳青霉烯酶的产生和碳青霉烯酶编码基因的流行情况。mCarba NP 试验和 CDT 分别检测到 54 株 CNSKP 分离株中 92.59%和 96.29%的碳青霉烯酶产生；而 44 株分离株的粗提物中用 UV 分光光度法检测到亚胺培南水解。bla bla 和 bla 碳青霉烯酶编码基因分别在 48、31 和 22 株分离株中检出。值得注意的是，bla bla 和 bla 基因被报道。在 62.96%的分离株中检测到单个分离株中存在碳青霉烯酶编码基因的共存。通过脉冲场凝胶电泳对分离株进行克隆关系分析表明，它们大多数在遗传上没有关系。我们的研究提供了 54 株耐碳青霉烯类肺炎克雷伯菌的酶促机制的分子数据，显示 bla 的优势，并包含在突尼斯医院首次鉴定 bla bla 和 bla 基因。
