Detection of capsular serotype and virulence gene of Klebsiella pneumonia with hypermucoviscosity phenotype / 中华检验医学杂志

ABSTRACT

Objective To detect the hypermucoviscosity phenotype , capsular serotype and virulence gene of Klebsiella pneumonia (K.pneumonia) from various kinds of clinical specimens and understand the characteristics of different K.pneumonia causing infections.Methods A retrospective study was conducted through collection of 178 K.pneumonia isolates from blood, sputum, bronchoalveolar lavage fluid , urine, normally sterilized fluid , puncture fluid from liver abscess and other abscesses between January 2010 and December 2012 in General Hospital of Chinese PLA.String test was carried out for detection of hypermucoviscosity phenotype.Capsular serotype and virulence gene ( rmpA) were checked by polymerase chain reaction.Analysis was made according to the hypermucoviscosity , capsular serotype , rmpA gene , as well as the sources of K.pneumoniae.Statistic data was analyzed by contingency table analysis and χ2 test.Results Eighty-three out of 178 ( 46.6%) strains of K.pneumonia were hypermucoviscous with positive string test, the positive rate of virulence gene rmpA was 92.8%(77/83).K1/K2/K57 capsular serotypes were the predominant serotypes in the group of puncture fluid from liver abscess and other abscesses (75.0%,27/36)than the group of blood (32.4%,12/37), urine(21.7%,5/23) and normally sterilized fluid(25.0%,5/20), and also more than in the group of sputum , bronchoalveolar lavage fluid (50.0%,22/44),χ2 =21.19,P<0.01.The positive rate of string test in the group of puncture fluid from liver abscess and other abscesses (77.8%, 28/36)was significantly higher than the group of blood (29.7%, 11/37), urine (30.4%, 7/23), or normally sterilized fluid (25.0%, 5/20),χ2 =27.90,P<0.01.The positive rate of rmpA gene in the isolates from puncture fluid of liver abscess and other abscesses was higher than other groups.Conclusions As the pathogens of various kinds of infections , mainly abscess and respiratory infection, hypermucoviscous strains of K.pneumonia were of great clinical significance.Capsular serotype K57, as well as K1 and K2, possessed hypermucoviscosity and hypervirulence in China.