Department of Microbiology, Juntendo Universitygrid.258269.2 Graduate School of Medicine, Tokyo, Japan.
Department of Clinical Microbiology, Kathmandu University School of Medical Sciences, Dhulikhel, Nepal.
Microbiol Spectr. 2022 Aug 31;10(4):e0114322. doi: 10.1128/spectrum.01143-22. Epub 2022 Jul 7.
Seven drug-resistant strains of Stenotrophomonas maltophilia were isolated from patients at two university hospitals in Nepal. S. maltophilia JUNP497 was found to encode a novel class A β-lactamase, KBL-1 (Kathmandu β-lactamase), consisting of 286 amino acids with 52.98% identity to PSV-1. Escherichia coli transformants expressing were less susceptible to penicillins. The recombinant KBL-1 protein efficiently hydrolyzed penicillins. The genomic environment surrounding was a unique structure, with the upstream region derived from strains in China and the downstream region from strains in India. S. maltophilia JUNP350 was found to encode a novel 6'-N-aminoglycoside acetyltransferase, AAC(6')-Iap, consisting of 155 amino acids with 85.0% identity to AAC(6')-Iz. E. coli transformants expressing were less susceptible to arbekacin, amikacin, dibekacin, isepamicin, neomycin, netilmicin, sisomicin and tobramycin. The recombinant AAC(6')-Iap protein acetylated all aminoglycosides tested, except for apramycin and paromomycin. The genomic environment surrounding was 90.99% identical to that of S. maltophilia JV3 obtained from a rhizosphere in Brazil. Phylogenetic analysis based on whole genome sequences showed that most S. maltophilia isolates in Nepal were similar to those isolates in European countries, including Germany and Spain. The emergence of drug-resistant S. maltophilia has become a serious problem in medical settings worldwide. The present study demonstrated that drug-resistant S. maltophilia strains in Nepal harbored novel genes encoding a class A β-lactamase, KBL-1, or a 6'-N-aminoglycoside acetyltransferase, AAC(6')-Iap. Genetic backgrounds of most S. maltophilia strains in Nepal were similar to those in European countries. Surveillance of drug-resistant S. maltophilia in medical settings in Nepal is necessary.
从尼泊尔两家大学医院的患者中分离出 7 株耐多药嗜麦芽窄食单胞菌。发现嗜麦芽窄食单胞菌 JUNP497 编码一种新型 A 类β-内酰胺酶，KBL-1（加德满都β-内酰胺酶），由 286 个氨基酸组成，与 PSV-1 的同源性为 52.98%。表达 的大肠杆菌转化体对青霉素的敏感性降低。重组 KBL-1 蛋白能有效水解青霉素。 周围的基因组环境是一个独特的结构，上游区域来自中国的菌株，下游区域来自印度的菌株。发现嗜麦芽窄食单胞菌 JUNP350 编码一种新型 6'-N-氨基糖苷乙酰转移酶，AAC(6')-Iap，由 155 个氨基酸组成，与 AAC(6')-Iz 的同源性为 85.0%。表达 的大肠杆菌转化体对阿贝卡星、阿米卡星、地贝卡星、异帕米星、新霉素、奈替米星、西索米星和妥布霉素的敏感性降低。重组 AAC(6')-Iap 蛋白乙酰化了所有测试的氨基糖苷类药物，除了巴龙霉素和帕罗霉素。 周围的基因组环境与从巴西根际分离到的嗜麦芽窄食单胞菌 JV3 完全相同。基于全基因组序列的系统发育分析表明，尼泊尔的大多数嗜麦芽窄食单胞菌分离株与德国和西班牙等欧洲国家的分离株相似。 耐多药嗜麦芽窄食单胞菌的出现已成为全球医疗环境中的一个严重问题。本研究表明，尼泊尔耐多药嗜麦芽窄食单胞菌菌株携带新型基因，编码一种 A 类β-内酰胺酶，KBL-1，或一种 6'-N-氨基糖苷乙酰转移酶，AAC(6')-Iap。尼泊尔大多数嗜麦芽窄食单胞菌菌株的遗传背景与欧洲国家相似。在尼泊尔的医疗环境中监测耐多药嗜麦芽窄食单胞菌是必要的。
