Department of Medical Microbiology, School of Medicine, Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran.
Student Research Committee, Birjand University of Medical Sciences, Birjand, Iran.
Diagn Microbiol Infect Dis. 2025 Jan;111(1):116595. doi: 10.1016/j.diagmicrobio.2024.116595. Epub 2024 Nov 4.
This study assessed antimicrobial susceptibility, biofilm formation, hypervirulence traits, and virulence-related genes in K. pneumoniae. 119 isolates underwent antibiotic susceptibility testing using the Kirby-Bauer method, biofilm assessment through Congo red agar and Microtiter plate assays, PCR for various genes, and the String test for hypermucoviscosity. Clinical characteristics and virulence factors of hypervirulent (hvKP) were compared to classic K. pneumoniae (cKP) strains. Among the isolates, 77.3% were multi-drug resistant (MDR), and 83.2% showed biofilm-forming ability, with a higher MDR incidence in biofilm producers. A significant correlation was found between biofilm formation and the presence of the bla gene. Genes luxS, mrkA, pgaA, and wzm were significantly related to biofilm production. Three K. pneumoniae (2.5%) were identified as hvKP, with higher prevalence of capsular serotypes K1/K2 and virulence-related genes iuc, rmpA, and rmpA2 than cKP. The study underscores the importance of surveillance and stewardship in combating MDR, biofilm-forming, highly virulent K. pneumoniae.
本研究评估了肺炎克雷伯菌的抗菌药物敏感性、生物膜形成、超毒力特征和与毒力相关的基因。119 株分离株采用 Kirby-Bauer 法进行抗生素敏感性测试，通过刚果红琼脂和微量滴定板测定法评估生物膜，通过 PCR 检测各种基因，以及通过 String 测试检测高黏液性。比较了超毒力（hvKP）和经典肺炎克雷伯菌（cKP）菌株的临床特征和毒力因子。在这些分离株中，77.3%为多药耐药（MDR），83.2%具有生物膜形成能力，生物膜生产者的 MDR 发生率更高。生物膜形成与 bla 基因的存在之间存在显著相关性。luxS、mrkA、pgaA 和 wzm 基因与生物膜产生显著相关。有 3 株肺炎克雷伯菌（2.5%）被鉴定为 hvKP，与 cKP 相比，其荚膜血清型 K1/K2 和与毒力相关的基因 iuc、rmpA 和 rmpA2 的发生率更高。该研究强调了监测和管理在对抗 MDR、生物膜形成、高度毒力肺炎克雷伯菌方面的重要性。
