Pyakurel Susil, Ansari Mehraj, Kattel Smriti, Rai Ganesh, Shrestha Prasha, Rai Kul Raj, Sah Anil Kumar, Rai Shiba Kumar
Department of Microbiology, Shi-Gan International College of Science and Technology, Kathmandu, Nepal.
Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences, Fuzhou, China.
Trop Med Health. 2021 Sep 26;49(1):78. doi: 10.1186/s41182-021-00368-2.
Although carbapenem is the last-resort drug for treating drug-resistant Gram-negative bacterial infections, prevalence of carbapenem-resistant bacteria has substantially increased worldwide owing to irrational use of antibiotics particularly in developing countries like Nepal. Therefore, this study was aimed to determine the prevalence of carbapenemase-producing K. pneumoniae and to detect the carbapenemase genes (blaNDM-2 and blaOXA-48) in at a tertiary care hospital in Nepal.
A hospital-based cross-sectional study was carried out from June 2018 to January 2019 at the Microbiology Laboratory of Annapurna Neurological Institute and Allied Sciences, Kathmandu, Nepal. Different clinical samples were collected and cultured in appropriate growth media. Biochemical tests were performed for the identification of K. pneumoniae. Antibiotic susceptibility testing (AST) was performed by the Kirby-Bauer disc diffusion method. The modified Hodge test (MHT) was performed to detect carbapenemase producers. The plasmid was extracted by the modified alkaline hydrolysis method. Carbapenemase-producing K. pneumoniae were further confirmed by detecting blaNDM-2 and blaOXA-48 genes by PCR using specific forward and reverse primers followed by gel electrophoresis.
Out of the total 720 samples, 38.9% (280/720) were culture positive. K. pneumoniae was the most predominant isolate 31.4% (88/280). Of 88 K. pneumoniae isolates, 56.8% (50/88) were multi-drug resistant (MDR), and 51.1% (45/88) were MHT positive. Colistin showed the highest sensitivity (100%; 88/88), followed by tigecycline (86.4%; 76/88). blaNDM-2 and blaOXA-48 genes were detected in 24.4% (11/45) and 15.5% (7/45) of carbapenemase-producing K. pneumoniae isolates, respectively.
The rate of MDR and carbapenemase production was high in the K. pneumoniae isolates. Colistin and tigecycline could be the drug of choice for the empirical treatments of MDR and carbapenemase-producing K. pneumoniae. Our study provides a better understanding of antibiotic resistance threat and enables physicians to select the most appropriate antibiotics.
尽管碳青霉烯类药物是治疗耐药革兰氏阴性菌感染的最后一道防线，但由于抗生素的不合理使用，尤其是在尼泊尔等发展中国家，耐碳青霉烯类细菌在全球范围内的流行率大幅上升。因此，本研究旨在确定尼泊尔一家三级护理医院中产碳青霉烯酶肺炎克雷伯菌的流行率，并检测碳青霉烯酶基因（blaNDM - 2和blaOXA - 48）。
2018年6月至2019年1月，在尼泊尔加德满都安纳布尔纳神经科学研究所及相关科学中心的微生物实验室进行了一项基于医院的横断面研究。收集不同的临床样本并在合适的生长培养基中培养。进行生化试验以鉴定肺炎克雷伯菌。采用 Kirby - Bauer 纸片扩散法进行抗生素敏感性试验（AST）。采用改良 Hodge 试验（MHT）检测产碳青霉烯酶菌株。通过改良碱性水解法提取质粒。使用特异性正向和反向引物通过PCR检测blaNDM - 2和blaOXA - 48基因，随后进行凝胶电泳，进一步确认产碳青霉烯酶的肺炎克雷伯菌。
在总共720个样本中，38.9%（280/720）培养呈阳性。肺炎克雷伯菌是最主要的分离菌株，占31.4%（88/280）。在88株肺炎克雷伯菌分离株中，56.8%（50/88）为多重耐药（MDR），51.1%（45/88）MHT呈阳性。黏菌素显示出最高的敏感性（100%；88/88），其次是替加环素（86.4%；76/88）。在产碳青霉烯酶的肺炎克雷伯菌分离株中，分别有24.4%（11/45）和15.5%（7/45）检测到blaNDM - 2和blaOXA - 48基因。
肺炎克雷伯菌分离株中多重耐药率和产碳青霉烯酶率较高。黏菌素和替加环素可能是治疗多重耐药和产碳青霉烯酶肺炎克雷伯菌经验性治疗的首选药物。我们的研究有助于更好地了解抗生素耐药性威胁，并使医生能够选择最合适的抗生素。
