The Detection of Hypermucoviscous Carbapenem-Resistant <i>Klebsiella pneumoniae</i> from a Tertiary Teaching Hospital in Malaysia and Assessment of Hypermucoviscous as Marker of Hypervirulence
Zhi Xian Kong, Rina Karunakaran, Kartini Abdul Jabar, Sasheela Ponnampalavanar, Chun Wie Chong, Cindy Shuan Ju Teh
Abstract
Background: Hypermucoviscous carbapenem-resistant Klebsiella pneumoniae (hmCRKp) is emerging globally and approaching the worst-case scenario in health care system. Aims: The main objective in this study was to determine the hypermucoviscous characteristics among the carbapenem-resistant K. pneumoniae (CRKp) isolated from a teaching hospital in Malaysia. The association of hypermucoviscous phenotype with the virulence traits and clinical presentations were also investigated. Methods: A retrospective study was conducted in University Malaya Medical Centre (UMMC). The presence of hypermucoviscous K. pneumoniae was identified among a collection of CRKp clinical isolates (first isolate per patient) from 2014 to 2015 using string test. Correlation between clinical and microbial characteristics of the hmCRKp was investigated. Results: A total of nine (7.5%) hmCRKp were detected among 120 CRKp isolates. Majority of the isolates were hospital acquired or health care-associated infections. None of the patients had typical pyogenic liver abscess. All of the hmCRKp isolates harbored carbapenemase genes and were multidrug resistant. K1/K serotype, peg-344 , allS , and magA were not identified among hmCRKp isolates, whereas aerobactin siderophore receptor gene ( iutA ), iroB , rmpA , and rmpA2 were detected. Only three hmCRKp isolates were resistant to serum bactericidal. Conclusions: All the isolates presented inconclusive evidence for the interpretation of hypervirulence. Therefore, more study should be performed in the future to have a better understanding of the virulence mechanisms in correlation with the clinical and microbial determinants.