Purpose This study was undertaken to characterise the virulence factors in clinical strains of Klebsiella pneumoniae and analyse their association with various infections caused and also to determine the association between virulence factors and antimicrobial resistance profile. Materials and Methods A total number of 370 clinically significant, non-duplicate isolates of K. pneumoniae isolated from both hospitalised patients and patients attending clinics were included in this study. Polymerase chain reaction (PCR) was carried out for the detection of various virulence genes such as mucoviscosity-associated gene A (magA), gene associated with allantoin metabolism (allS), Klebsiella ferric iron uptake(Kfu), capsule-associated gene A (K2A), regulator of mucoid phenotype A (rmpA), enterobactin (entB), yersiniabactin (YbtS), aerobactin, Fimbrial adhesin (FimH) and uridine-diphosphate galacturonate 4-epimerase (uge). Antimicrobial susceptibility testing and PCR-based detection of beta-lactamase-encoding genes such as extended-spectrum beta-lactamases, AmpCs and carbapenemases were performed. Univariate analysis was done to find the association between virulence genes and mortality. Results The siderophore, entB, was present in most (90.5%) of the isolates. Of the 370 isolates, 345 carried multiple virulence genes; 15 harboured single virulence genes and 10 did not harbour any of the studied virulence genes. The most common combination of occurrence was entB and FimH. A mortality rate of 12.75% (38/298) was observed among hospitalised patients. None of the virulence genes had any significant association with mortality. Conclusion Pathogenic K. pneumoniae can harbour single to multiple virulence genes. Invasive infection with even a single virulence gene-harbouring K. pneumoniae can lead to poor outcomes. Both multidrug-resistant (MDR) and non-MDR K. pneumoniae can harbour a variety of virulence genes. None of the virulence genes have a significant association with mortality.

中文翻译：

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与肺炎克雷伯菌致病性相关的毒力基因的特征。

目的 本研究旨在表征肺炎克雷伯菌临床菌株的毒力因子，分析其与引起的各种感染的关联，并确定毒力因子与抗菌素耐药性之间的关联。材料和方法 本研究包括从住院患者和就诊患者中分离出的总共 370 株具有临床意义的非重复肺炎克雷伯菌分离株。采用聚合酶链式反应（PCR）检测粘液粘度相关基因A（magA）、尿囊素代谢相关基因（allS）、克雷伯菌三价铁摄取基因（Kfu）、荚膜相关基因A（ K2A)、粘液表型 A (rmpA)、肠杆菌素 (entB)、耶尔森菌素 (YbtS)、需氧菌素、菌毛粘附素 (FimH) 和尿苷二磷酸半乳糖醛酸 4-差向异构酶 (uge) 的调节剂。对 β-内酰胺酶编码基因（如广谱 β-内酰胺酶、AmpC 和碳青霉烯酶）进行了抗菌药物敏感性测试和基于 PCR 的检测。进行单变量分析以找出毒力基因与死亡率之间的关联。结果铁载体 entB 存在于大多数（90.5%）分离株中。在 370 个分离株中，345 个携带多个毒力基因；15 个含有单一毒力基因，10 个不含有任何所研究的毒力基因。最常见的组合是 entB 和 FimH。住院患者的死亡率为 12.75% (38/298)。没有一个毒力基因与死亡率有任何显着关联。结论 致病性肺炎克雷伯菌可携带单个或多个毒力基因。即使是带有单一毒力基因的肺炎克雷伯菌的侵袭性感染也可能导致不良后果。多重耐药（MDR）和非多重耐药肺炎克雷伯菌都可能携带多种毒力基因。没有一个毒力基因与死亡率有显着关联。