Clinical and Molecular Analysis of <b><i>Klebsiella pneumoniae </i></b>Causing Liver Abscess in China

Abstract

Objective: Hypervirulent Klebsiella pneumoniae (hvKP) has been characterized as the major pathogen associated with the development of liver abscesses. Although the prevalence of K. pneumoniae in liver abscesses in Chinese patients is on the rise, methods for the early laboratory identification and recognition of hvKP are lacking, and hvKP detection and surveillance are thus limited. Methods: A retrospective study was conducted in 240 patients with cultures that were positive for K. pneumoniae, who were hospitalized in the Hospital of Beijing area from May 2013 to August 2014. The clinical and molecular characteristics of K. pneumoniae strains that cause liver abscesses were studied. Thirty-eight (16.7%) of 240 patients positive for K. pneumoniae cultures had liver abscesses. Results: Among these K. pneumoniae isolates, 92.1% (35/38) and 84.2% (32/38) were rmpA and aerobactin (abc) positive, respectively, as indicated by multiplex PCR, while 81.6% (31/38) were string test positive. Intriguingly, K. pneumoniae isolates that were positive for rmpA, abc, or string test accounted for almost all isolates (97.3%; n = 37/38) and thus were defined as hvKP in this study. Based on the new criteria for hvKP, none of these hvKP strains were positive for extended spectrum β-lactamases. Conclusions: Compared to the string test alone, integrating rmpA and abc detection with the string test is robuster and more extensive in the identification of liver abscess-causing hvKP strains. Multiplex PCR assays may therefore accelerate the early laboratory detection of hvKP.

Clinical and microbiological characteristics of hypervirulent Klebsiella pneumoniae (hvKp) in a hospital from North China

“…, we found that the main capsular serotype of hvKp in this hospital is K2 (17, 28.81%), K57 (15, 25.42%) and K1 (14, 23.73%), and the rate of K57 type was even slightly higher than that of the K1 type. K57 has also been reported in other reports with different detection rates, such as 9.6% (8/84)[25], 13.6% (3/22) [17], 10.4% (10/96) [26] and 18.9% (7/37)[27], suggesting that the serotype distribution of hvKp varied in different regions. The 59 strains of hvKp were also subjected to PFGE molecular typing analysis, and the results suggested that the same serotype strains can almost be classified into the same cluster, but the same cluster can be divided into different band types according to different genetic backgrounds, indicating that PFGE molecular typing technology can further differentiate various strains based on genetic characters.…”

Antimicrobial Resistance of Hypervirulent Klebsiella pneumoniae: Epidemiology, Hypervirulence-Associated Determinants, and Resistance Mechanisms

“…Whole-genome sequencing of 30 hvKP isolates from different geographic origins revealed that all hvKP were rmpA positive (Struve et al, 2015 ). Several studies from China also showed that 92–100% of hvKP isolates were positive for rmpA (Liu et al, 2014 ; Sun et al, 2016 ; Wu et al, 2017 ). Regardless of the investigated infection site, most hvKP isolates appear to have the rmpA gene (Ku et al, 2008 ; Yu et al, 2008 ; Lee et al, 2010 ; Decré et al, 2011 ; Qu et al, 2015 ; Guo et al, 2016 ; Zhang et al, 2016 ; Wu et al, 2017 ; Zhan et al, 2017 ).…”

“…Many reports showed that an iucABCD - iutA gene was more common in hvKP strains than in cKP strains (Table 1 and Table S1 ). In China, many studies have reported the high prevalence (69–96%) of aerobactin in hvKP isolates (Guo et al, 2016 , 2017 ; Sun et al, 2016 ; Yan et al, 2016 ; Ye et al, 2016 ; Zhang et al, 2016 ; Zhao et al, 2016 ; Wu et al, 2017 ; Zhan et al, 2017 ). A study in Taiwan also showed that the prevalence of aerobactin was 100% in capsular K1 and K2 isolates and 86% in non-K1/K2 isolates.…”

Microbiological and Clinical Characteristics of Hypermucoviscous Klebsiella pneumoniae Isolates Associated with Invasive Infections in China

“…Alarmingly, increasing studies reported that multi-drug-resistant, even carbapenem-resistant hvKP isolates have been emerged (Yang et al, 2014 ; Yao et al, 2015 ; Zhang et al, 2015 ), which is becoming an important threat to public health. Recently, many studies from China described the prevalence, clinical presentations and epidemiology of hvKP isolates (Liu et al, 2014 ; Yang et al, 2014 ; Qu et al, 2015 ; Yao et al, 2015 ; Sun et al, 2016 ; Zhao et al, 2016 ). However, the limitations of these studies included limited number of K. pnuemoniae involved, short span of investigation and focusing a specific infection.…”