宁波地区耐碳青霉烯类高毒力肺炎克雷伯菌的分子生物学特征研究

目的 研究宁波地区耐碳青霉烯类高毒力肺炎克雷伯菌(carbapenem-resistant hypervirulent Klebsiella pneumoniae, CR-hvKP)分子流行特征,为宁波地区CR-hvKP院内防控及临床治疗提供理论依据。方法 从宁波地区3家医院收集150株耐碳青霉烯类肺炎克雷伯菌,用PCR筛选出CR-hvKP;再用PCR检测其耐药基因和毒力基因。结果 150株耐碳青霉烯类肺炎克雷伯菌中检出14株CR-hvKP,占比为9.33%;主要标本类型为血流感染6株和痰液5株;临床科室分布以ICU(5株)为主,其次为呼吸科(3株)和血液科(3株)。14株CR-hvKP拉丝试验阳性,荚膜血清型以K2为主,整合子均为intI1型;碳青霉烯类耐药基因以KPC-2为主,且发现3株同时携带KPC-2和NDM-1耐药基因;14株CR-hvKP均携带rmpA、kpn、entB、wabG、ureA、fimH毒力基因,其中2株aerobactin基因阳性。结论 宁波地区出现的CR-hvKP以K2荚膜型为主,耐药情况严重,且同时携带耐药及毒力基因,提示临床须合理使用抗生素,加强耐药监测及院感防控,以减少CR-hvKP的传播。

Epidemiological characteristics of carbapenem-resistant hypervirulent Klebsiella pneumonia in Ningbo

This study was aimed at studying the molecular epidemiological characteristics of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) in the Ningbo Area, to provide a reference for the rational clinical use of drugs, and the prevention and control of CR-hvKP in hospitals. A total of 150 carbapenem-resistant hypervirulent Klebsiella pneumoniae strains were collected from three hospitals in the Ningbo Area, the CR-hvKP strains were screened through polymerase chain reaction detection of carbapenemase resistance genes and virulence genes. A total of 14 CR-hvKP strains were isolated from 150 carbapenem-resistant Klebsiella pneumoniae strains, accounting for 9.33%, mainly from the whole blood (six strains) and sputum (five strains). The clinical departments collecting the isolates were mainly the cardiovascular surgery intensive care unit (five strains), the respiratory department (three strains) and the hematology department (three strains). Among the 14 CR-hvKP strains, 14 strains were positive for the string test. The main type was the K2 capsule type (nine strains), and the integrons of all strains were intI1 type. Among them, 13 strains carried the Klebsiella pneumoniae carbapenemase 2 (KPC-2) gene, and three strains carried both KPC-2 and NDM-1 genes. The virulence gene detection of 14 CR-hvKP strains showed that rmpA, Kpn, entB, wabG, urea and fimH were all positive, and in two strains, aerobactin virulence genes were positive. The CR-hvKP strains in Ningbo were mainly of K2 capsule type, which are resistant to multiple antibiotics and simultaneously carry multiple drug resistance and virulence genes, thus suggesting a clinical need to use antibiotics rationally, and strengthen drug resistance monitoring and hospital infection prevention control to limit the spread of CR-hvKP.