Molecular analysis of virulence factors of hypermucoviscous <em>Klebsiella pneumoniae</em> in a diabetes patient with multifocal intramuscular and musculoskeletal abscesses

Sun Jun 30, 2019 17:24

via Journal of Infection and Chemotherapy

Publication date: Available online 29 June 2019
Source: Journal of Infection and Chemotherapy
Author(s): Masataka Kudo, Takashi Matono, Masatomo Morita, Hidemasa Izumiya, Makoto Ohnishi, Junichi Hasegawa, Migiwa Izumi, Mai Yoshino, Ken Arai, Hiroshi Imura

Abstract

Unusual community-acquired invasive Klebsiella pneumoniae infection has been reported worldwide, particularly in Asia. Recently, several virulence-associated genes of the isolates have been investigated. We report a case of multifocal intramuscular and musculoskeletal abscesses caused by K. pneumoniae in a 61-year-old male diabetes patient. A string test of the K. pneumoniae isolate, which was recovered from abscesses obtained by surgical debridement and drainage, was positive. We used whole-genome sequencing to analyze the virulence-associated gene profile of the isolate. The isolate belonged to the K2 genotype with sequence type 375. The isolate harbored rmpA and rmpA2, which induce serum resistance (hypermucoviscosity). The isolate also carried siderophores, i.e., aerobactin and salmochelin, which are associated with enhanced bacterial growth. The isolate did not harbor K1-unique virulence factors, such as colibactin, microcin, and yersiniabactin. Our K2 strain harbored a combination of virulence plasmid-associated genes—rmpA/A2 and siderophores (aerobactin and salmochelin). Hence, we advocate that essential molecular virulence factors of isolates that cannot be identified by a string test and capsular serotyping alone may exist.