摘要：
Objective To describe the clinical characteristics of hypervirulent Klebsiella pneumoniae (hvKP) infection.To analyze the antibiotic susceptibility of hvKP to provide the empiric antibiotic options.To investigate capsule serotype and sequence type (ST) of hvKP and their correlation with clinical profiles.Methods hvKP was defined as bacteria isolated from patients with community-acquired pyogenic liver abscess (CA-PLA) with co-infection sites outside liver or a bloodstream infection in a host without underlying biliary tract diseases.Patients with CA-PLA hospitalized in the First Hospital of China Medical University were retrospectively analyzed from January 2011 to December 2017.Antibiotic susceptibility was detected by automatic bacterial identification and antibiotic susceptibility analysis system in vitro.Polymerase chain reaction method and gene sequencing were used to detect the main capsule serotype and ST.Results A total of 140 cases with hvKP infection were enrolled.The co-infections outside liver abscess included 98 bloodstream infections,53 pneumonia,11 perianal abscess,10 urinary system infections,3 subphrenic abscess,3 endophthalmitis,2 spleen abscess,and other miscellaneous infections including 1 peritonitis,1 skin and soft tissue infection,1 myelitis,1 colitis,1 psoas major abscess and 1 myocardial abscess.Among the 140 cases,106 presented with single co-infection site,32 with 2 sites,and 2 with 3 sites.HvKP manifested high antibiotic susceptibility up to 80％ for most commonly used antibiotics.Capsule serotyping of 4,3 revived isolates indicated that K1 serotype accounted for 53.49％ (23/43),K2 34.88 (15/43),K54 2.33％ (1/43),K57 2.33％ (1/43),and other serotypes 6.98％(3/43).There was no significant distribution among K1,K2,K54,and K57 of hvKP capsule serotypes in patients with or without diabetes mellitus (P＞0.05).Multilocus sequence typing (MLST) suggested that ST23 and ST65 were predominant accounting for 39.53％ (17/4.3) and 25.58％ (11/4.3) respectively.No serotype or ST predominance was seen in any of the clinical infections.Conclusion HvKP is related to a wide spectrum of infectious diseases,including multiple extrahepatic sites and bloodstream infections besides CA-PLA with high antibiotic susceptibility.K1 and K2 are the predominant capsule serotypes,and ST 23 and ST65 are the predominant sequence types.%目的 研究高毒力肺炎克雷伯杆菌(hvKP)感染的临床表型及其荚膜血清型和多位点序列分型.方法 基于临床将无胆道基础疾病的社区获得性化脓性肝脓肿(CA-PLA)伴肝外共感染部位或血流感染患者分离到的肺炎克雷伯杆菌定义为hvKP.回顾性分析2011年1月1日-2017年12月31日中国医科大学附属第一医院符合上述定义的hvKP感染的临床表型,采用全自动细菌鉴定及药敏分析系统检测hvKP体外药敏结果;聚合酶链反应(PCR)和基因测序检测hvKP荚膜血清型、多位点序列分型(MLST).结果 收集符合上述定义的hvKP感染病例140例,肝脓肿外的其他共感染疾病为血流感染98例,肺部感染53例,泌尿系感染10例,膈下脓肿3例,眼内炎3例,脾脏脓肿2例,腹膜炎、皮肤软组织感染、脊髓脓肿、结肠炎、腰大肌脓肿、肛周脓肿、心肌脓肿各1例.140例患者中伴1个肝外共感染疾病者106例,伴2个共感染疾病者32例,伴3个共感染疾病者2例.hvKP对常用抗菌药物敏感性超过80％.对复活的43株hvKP进行荚膜血清型检测,K1型占53.49％(23/43),K2型占34.88％(15/43),K54型和K57型各占2.33％(1/43),其他血清型占6.98％(3/43);未发现某种荚膜血清型在hvKP的临床表型上有分布优势规律.伴与不伴糖尿病患者hvKP荚膜血清型分型差异均无统计学意义(P＞0.05).hvKP MLST结果显示,ST23型占39.53％ (17/43),ST65型占25.58％ (11/43),ST86型占9.30％ (4/43),ST412、ST29、ST1660、ST380、ST1364、ST700、ST2159型各占2.33％(1/43),未分型占9.30％ (4/43),无疾病分布优势.结论 hvKP导致的感染性疾病广泛,包括肝脓肿外多部位和血流感染;对抗菌药物保持高度敏感;其荚膜血清型分型主要为K1型和K2型;MLST以ST23型和ST65型为主.
