Lee H-C, Chuang Y-C, Yu W-L, Lee N-Y, Chang C-M, Ko N-Y, Wang L-R, Ko W-C
Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
J Intern Med. 2006 Jun;259(6):606-14. doi: 10.1111/j.1365-2796.2006.01641.x.
Klebsiella pneumoniae, a Gram-negative bacillus usually forming glistening mucoid colonies with viscid consistency on the culture plate, is a common pathogen causing various clinical infection patterns. However, little is known about the clinical implications of this mucoid character.
The purposes of this study, therefore, were to investigate the frequency of hypermucoviscosity (HV) in bacteraemic isolates of K. pneumoniae, and determine the significance of any association between HV and various clinical manifestations.
Retrospective observational study.
Patients diagnosed with K. pneumoniae bacteraemia at a community-based university hospital between June 1999 and June 2001 were enrolled in this analysis.
Clinical data concerning comorbid diseases and infection patterns was collected. K. pneumoniae bacteraemic isolates were examined for the presence of HV using a modified string test. The clinical impact of HV and risk factors for the invasive syndrome were assessed using statistical analysis. Polymerase chain reaction (PCR) was performed to detect magA, a gene related to HV phenotype.
Overall, 200 (64.9%) of the 308 cases of K. pneumoniae bacteraemia were community-acquired infections. Compared with hospital-acquired K. pneumoniae bacteraemia (HA-KpB), community-acquired K. pneumoniae bacteraemia (CA-KpB) was more likely to be monomicrobial in nature (83.5% vs. 64.8%; P < 0.001) and caused by HV strains (41.5% vs. 14.8%; P < 0.001). The prevalence rate of magA among HV phenotypical K. pneumoniae strains was 24.1%. Patients infected with HV-positive strains were more likely to have the distinctive invasive syndrome (i.e. liver abscess, meningitis, pleural empyaema or endophthalmitis) than those infected with HV-negative variants (37.3% vs. 6.8%; P < 0.001). Multivariate logistic regression analysis, adjusted for age, showed that HV phenotype in K. pneumoniae strains (OR 8.86; 95% CI, 3.70-21.25; P < 0.001) was positively associated with the development of the invasive syndrome in CA-KpB cases.
The HV phenotype of K. pneumoniae bacteraemic isolates was associated with the development of a distinctive invasive syndrome. Identification of the HV phenotype should prompt clinicians to initiate aggressive investigations for invasive diseases.
肺炎克雷伯菌是一种革兰氏阴性杆菌，在培养平板上通常形成具有粘性的闪亮粘液样菌落，是引起各种临床感染类型的常见病原体。然而，关于这种粘液样特征的临床意义知之甚少。
因此，本研究的目的是调查肺炎克雷伯菌血流感染分离株中高粘液性（HV）的频率，并确定HV与各种临床表现之间任何关联的意义。
回顾性观察研究。
1999年6月至2001年6月期间在一家社区大学医院被诊断为肺炎克雷伯菌血流感染的患者纳入本分析。
收集有关合并症和感染类型的临床数据。使用改良的拉丝试验检查肺炎克雷伯菌血流感染分离株中是否存在HV。使用统计分析评估HV的临床影响和侵袭性综合征的危险因素。进行聚合酶链反应（PCR）以检测与HV表型相关的基因magA。
总体而言，308例肺炎克雷伯菌血流感染病例中有200例（64.9%）为社区获得性感染。与医院获得性肺炎克雷伯菌血流感染（HA-KpB）相比，社区获得性肺炎克雷伯菌血流感染（CA-KpB）在本质上更可能是单一微生物感染（83.5%对64.8%；P<0.001），并且由HV菌株引起（41.5%对14.8%；P<0.001）。在HV表型的肺炎克雷伯菌菌株中magA的流行率为24.1%。与感染HV阴性变体的患者相比，感染HV阳性菌株的患者更有可能出现独特的侵袭性综合征（即肝脓肿、脑膜炎） 、胸膜脓胸或眼内炎）（37.3%对6.8%；P<0.001）。在对年龄进行校正的多变量逻辑回归分析中，肺炎克雷伯菌菌株中的HV表型（OR 8.86；95%CI，3.70-21.25；P<0.001）与CA-KpB病例中侵袭性综合征的发生呈正相关。
肺炎克雷伯菌血流感染分离株的HV表型与独特侵袭性综合征的发生有关。识别HV表型应促使临床医生对侵袭性疾病展开积极调查。
