Infection and Drug Resistance (May 2024)
Molecular Characteristics of Virulence Genes in Carbapenem-Resistant and Carbapenem-Sensitive Klebsiella Pneumoniae in Relation to Different Capsule Serotypes in Ningbo, China
Abstract
Min Jiang,1,* Hui Zhang,2,* Wenjun Lu,3 Xuedan Qiu,1 Chenyao Lin,1 Rongqing Zhao,1 Qingcao Li,1 Qiaoping Wu1 1Clinical Laboratory, The Affiliated LiHuiLi Hospital of Ningbo University, Ningbo, Zhejiang Province, People’s Republic of China; 2Clinical Laboratory, Ninghai County Chengguan Hospital, Ningbo, Zhejiang Province, People’s Republic of China; 3Intensive Care Units, The Affiliated LiHuiLi Hospital of Ningbo University, Ningbo, Zhejiang Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qingcao Li; Qiaoping Wu, The Affiliated LiHuiLi Hospital of Ningbo University, 1111 Jiangnan Road, Ningbo, Zhejiang Province, 315040, People’s Republic of China, Tel +86-574-55835786, Fax +86-574-55835781, Email [email protected]; [email protected]: Klebsiella pneumoniae (KP) is a common nosocomial pathogen. Capsules are an important component of KP’s virulence, among which the K1, K2, K5, K20, K54, and K57 serotypes are predominant and exhibit varying degrees of virulence.Methods: The capsule and virulence genes of 150 carbapenem-resistant Klebsiella pneumoniae (CRKP) and 213 carbapenem-sensitive Klebsiella pneumoniae (CSKP) isolates were examined by polymerase chain reaction (PCR). The isolates were tested for hypermucoviscosity by string tests. Phylogenetic relationships between KP isolates were analyzed using multilocus sequence typing (MLST) and a Galleria mellonella infection model confirmed the differences in virulence.Results: A total of 111 of 363 isolates of KP were detected, the highest detected serotypes were K1, K5, and K2, and CSKP was detected more frequently than CRKP. There was a greater prevalence of K1 and K2 serotypes in CSKP, while in CRKP, K5 serotypes were more prevalent. K1 isolates had the highest detection rates for hypermucoviscosity Klebsiella pneumoniae (hmKP) and hypervirulent Klebsiella pneumoniae (hvKP), and carried the most virulence genes. K54 isolates had the lowest detection rate of hmKP while K5 isolates had the lowest detection rate of hvKP and carried the fewest virulence genes. MLST results for serotypes K1, K20, and K57 showed significant homogeneity, while those for serotypes K2, K5, and K54 showed diversity. The Galleria mellonella infection model showed that the K1 serotype was the most virulent and the K54 serotype was the weakest.Conclusion: CSKP isolates were detected more frequently than CRKP isolates for capsular serotype detection. K1 isolates had the most virulence gene and strongest virulence, K5 isolates carried the fewest virulence genes, and K54 isolates had the weakest virulence. Furthermore, significant homogeneity was observed among K1, K20, and K57 isolates.Keywords: Klebsiella pneumoniae, capsular serotypes, virulence, MLST
