Clinical characteristics of patients with pneumonia caused by Klebsiella pneumoniae in Taiwan and prevalence of antimicrobial-resistant and hypervirulent strains: a retrospective study

Chih-Han Juan,Chia-Hsin Chou,Tsung-Ying Tsai,Shih-Yu Fang,Yi-Tsung Lin

doi:10.1186/s13756-019-0660-x

Abstract

BackgroundWe aimed to compare the clinical characteristics of patients with community-acquired pneumonia (CAP), healthcare-associated pneumonia (HCAP), and hospital-acquired pneumonia (HAP) caused by Klebsiella pneumoniae and analyze the antimicrobial resistance and proportion of hypervirluent strains of the microbial isolates.MethodsWe conducted a retrospective study on patients with pneumonia caused by K. pneumoniae at the Taipei Veterans General Hospital in Taiwan between January 2014 and December 2016. To analyze the clinical characteristics of these patients, data was extracted from their medical records. K. pneumoniae strains were subjected to antimicrobial susceptibility testing, capsular genotyping and detection of the rmpA and rmpA2 genes to identify hypervirulent strains.ResultsWe identified 276 patients with pneumonia caused by K. pneumoniae, of which 68 (24.6%), 74 (26.8%), and 134 (48.6%) presented with CAP, HCAP, and HAP, respectively. The 28-day mortality was highest in the HAP group (39.6%), followed by the HCAP (29.7%) and CAP (27.9%) groups. The HAP group also featured the highest proportion of multi-drug resistant strains (49.3%), followed by the HCAP (36.5%) and CAP groups (10.3%), while the CAP group had the highest proportion of hypervirulent strains (79.4%), followed by the HCAP (55.4%) and HAP groups (41.0%).ConclusionPneumonia caused by K. pneumoniae was associated with a high mortality. Importantly, multi-drug resistant strains were also detected in patients with CAP. Hypervirulent strains were prevalent in all 3 groups of pneumonia patients, even in those with HAP.

Highlights

We aimed to compare the clinical characteristics of patients with community-acquired pneumonia (CAP), healthcare-associated pneumonia (HCAP), and hospital-acquired pneumonia (HAP) caused by Klebsiella pneumoniae and analyze the antimicrobial resistance and proportion of hypervirluent strains of the microbial isolates
Clinical characteristics of pneumonia patients caused by K. pneumoniae During the study period, a total of 276 consecutive patients with monomicrobial K. pneumoniae-caused pneumonia was identified
We focused on pneumonia caused by K. pneumoniae and discovered that the proportion of multi-drug resistant (MDR) strains in HCAP patients was lower than that in HAP patients (36.5% versus 49.3%, p = 0.076), but significantly higher than that in CAP patients (36.5% versus 10.3%, p < 0.001)

Summary

Introduction

We aimed to compare the clinical characteristics of patients with community-acquired pneumonia (CAP), healthcare-associated pneumonia (HCAP), and hospital-acquired pneumonia (HAP) caused by Klebsiella pneumoniae and analyze the antimicrobial resistance and proportion of hypervirluent strains of the microbial isolates. Juan et al Antimicrobial Resistance and Infection Control (CAP and HCAP) caused by K. pneumoniae was associated with high 28-day mortality (29.7% of patients) and that the nasopharynx may be a reservoir of K. pneumoniae [4]. The polysaccharide capsule of K. pneumoniae is the most important virulence factor of the pathogen; certain capsular types, such as K1, K2, K5, K20, K54, and K57, are associated with community-onset pyogenic infections [4, 10, 11]. The diagnostic accuracy of such biomarkers that differentiate hypervirulent from classical K. pneumoniae strains has recently been validated [14]

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