Mishra Kajal, Banerjee Tuhina, Yadav Ghanshyam, Kumar Ashok, Pratap Arvind, Chaurasiya Sandhya, Rakshit Pue
Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Department of Anaesthesiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Microbiol Spectr. 2025 Sep 2;13(9):e0019825. doi: 10.1128/spectrum.00198-25. Epub 2025 Aug 8.
This prospective, cross-sectional study was undertaken to identify the emerging phylogeny groups (KpI, KpII, KpIII) and characterize their drug resistance. Phylogeny groups of 150 clinical isolates of biochemically identified were detected by targeting their chromosomal class A, β-lactamase genes , , and , respectively, and their flanking gene (). Antimicrobial susceptibility testing was done by disk diffusion and broth microdilution methods and statistically analyzed. Carbapenemases (Classes A, B, and D) were detected by multiplex PCR. Colistin resistance mechanisms to detect alteration in /, two-component signaling pathways, and were done by PCR and sequencing. Of the total, KpI, were 93 (62%), KpII, were 36 (24%), and KpIII, were 21 (14%). Carbapenem resistance was in 77 (51.3%); 52 (55.9%), 17 (47.2%), and 8 (38%) in KpI, KpII, and KpIII, respectively. Colistin resistance was in 16 (10.6%), 11 (68.75%) in KpI and 5 (31.25%) in KpIII. was resistant to polymyxin B as compared with KpI ( = 0.0008). (63, 81.8%) was the commonest. Co-harboring of multiple carbapenemase genes was significant in all the phylogroups ( < 0.001). The majority of the cases of were males ( = 0.0139) and in the intensive care unit ( = 0.0091). Several non-synonymous mutations were observed in the colistin-resistant isolates in and genes, with the phylogenetic tree revealing different evolutionary relationships among the isolates. There is considerable emergence of and as prominent human pathogens along with drug resistance, which requires attention.IMPORTANCEThese epidemiological data add to the extremely scarce literature on the occurrence of the two phylogeny groups of , namely and , in infections and highlight their widespread dissemination as prominent human pathogens, beyond agriculture and environment as their common habitat. There was significant drug resistance in the phylogeny groups, including colistin resistance in , which was studied for the first time.
本前瞻性横断面研究旨在识别新兴的系统发育组（KpI、KpII、KpIII）并描述其耐药性特征。通过分别靶向150株经生化鉴定的临床分离株的染色体A类β-内酰胺酶基因、、及其侧翼基因（），检测其系统发育组。采用纸片扩散法和肉汤微量稀释法进行药敏试验并进行统计学分析。通过多重PCR检测碳青霉烯酶（A、B和D类）。通过PCR和测序检测黏菌素耐药机制，以检测/、双组分信号通路和的改变。其中，KpI有93株（62%），KpII有36株（24%），KpIII有21株（14%）。碳青霉烯耐药的有77株（51.3%）；KpI、KpII和KpIII中分别为52株（55.9%）、17株（47.2%）和8株（38%）。黏菌素耐药的有16株（10.6%），KpI中有11株（68.75%），KpIII中有5株（31.25%）。与KpI相比，对多黏菌素B耐药（P = 0.0008）。（63株，81.8%）最为常见。在所有系统发育组中，多种碳青霉烯酶基因的共携带情况均具有显著性（P < 0.001）。大多数病例为男性（P = 0.0139）且在重症监护病房（P = 0.0091）。在黏菌素耐药分离株的和基因中观察到若干非同义突变，系统发育树显示分离株之间存在不同的进化关系。作为突出的人类病原体以及耐药性，和的出现相当可观，需要引起关注。重要性这些流行病学数据补充了关于感染中、这两个系统发育组出现情况的极为稀少的文献，并突出了它们作为突出的人类病原体的广泛传播，超出了它们作为常见栖息地的农业和环境范围。在系统发育组中存在显著的耐药性，包括中首次研究的黏菌素耐药性。
