Characteristics of Klebsiella pneumoniae detected in patients with hepatic abscess in Wenzhou

ObjectiveTo investigate the microbiological characteristics, capsule type, virulence gene and drug resistance of Klebsiella pneumoniae detected in patients with hepatic abscess. The differences of K. pneumoniae with different virulence characteristics detected in patients with hepatic abscess were compared.

MethodsThe clinical data of 165 hepatic abscess patients with K. pneumoniae infection in our hospital from 2015 to 2017 were retrospectively analyzed, and 102 strains of K. pneumoniae with high virulence were confirmed by using wire drawing test. The strains were divided into high virulence group and common group. The classification and virulence gene rmpA of serum capsule were detected by using PCR amplification. VITEK 2 Compact automatic microbiological assay instrument was used for drug susceptibility test and the results were statistically analyzed.

ResultsAmong patients with hepatic abscess, the community acquired infection rate of K. pneumoniae was higher. Up to 83.33% of the infected patients had no underlying disease and 81.60% of hepatic abscess cases were caused by highly virulent K. pneumoniae strain with high mucous phenotype, and the capsule type were mainly serum K-1 and K-2, which carried rmpA gene. Common K. pneumoniae was mainly mucous free, and the capsule type was non-serum K-1 or K-2 type, a few of them carried rmpA gene. The resistance of K. pneumoniae with high virulence to 10 common used antibiotics was low, and 3 strains of K. pneumoniae with high virulence producing Extended Spectyum β Lactamases (ESBLs) were detected. No K. pneumoniae strain resistant to carbapenem was detected.

ConclusionThe main pathogen of hepatic abscess was K. pneumoniae with high virulence and high level mucous, and mainly with serum type K-1 and K-2, Severe community-acquired infection of highly virulent K. pneumoniae causing liver abscess occurred in patients with normal immunity. The resistance of to common used antibiotics was low. Three strains of K. pneumoniae with high virulence producing ESBLs were detected, and they showed upward trend in drug resistance, to which more attention should be paid in clinical practice.