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Antimicrobial susceptibility, microbiological and epidemiologic characteristics of hypermucoviscous Klebsiella pneumoniae strains in a tertiary hospital at Hangzhou in China.

Research paper by Chen C Qiong, Zhou Z Jia-Wei, Qiu Q Chun-Ning, Wang W Min-Min, Wang W Xian-Jun, Ruan R Zhi, Fan F Jian-Zhong

Indexed on: 10 Jun '18Published on: 10 Jun '18Published in: Journal of Global Antimicrobial Resistance



Abstract

Hypermucoviscous Klebsiella pneumoniae (HMKP) has been increasingly recovered in clinical isolates. This study sought to examine the microbiological and epidemiologic characteristics of HMKP strains in a tertiary hospital at Hangzhou in China. HMKP isolates were collected and identified via matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). A string test was performed for the hypermucoviscous phenotype. Antimicrobial susceptibility to antibiotic agents was determined. Multilocus sequence typing, capsular serotypes and virulence-associated genes of HMKP isolates were assessed. Forty-two HMKP strains with positive string tests were collected. Thirty-two (76.2%) HMKP isolates were carbapenem-susceptible (CS-HMKP) and ten (23.8%) HMKP isolates were carbapenem-resistant (CR-HMKP). CS-HMKP strains were more susceptible to antibiotics than CR-HMKP strains. K1 (50%) and K2 (12.5%) were the main capsular serotypes of all HMKP isolates. K57 was first reported in the CR-HMKP strain. ST163 was the main sequence type (50%) of CS-HMKP strains, while ST11 was a unique sequence type of CR-HMKP strains. The regulator of the mucoid phenotype gene rmpA and other virulence factors (allS, kfu, iutA, entB, iroN, fimH and wabG) were present in more than 80% of the HMKP strains. Patients with CR-HMKP strains had a higher mortality rate than those with CS-HMKP strains. K1 and K2 were the main capsular serotypes of these HMKP strains. The emergence of carbapenem-resistant HMKP should be a concern, as it had an increased mortality rate, especially with ST11 CR-HMKP strains, demonstrating the global epidemic of carbapenem resistance. Copyright © 2018. Published by Elsevier Ltd.