Allocation of Klebsiella pneumoniae Bloodstream Isolates into Four Distinct Groups byompK36Typing in a Taiwanese University Hospital

Abstract

The OmpK36 porin plays a role in carbapenem resistance and may contribute to bacterial virulence in Klebsiella pneumoniae. This study aimed to investigate the characteristics of different groups of K. pneumoniae separated by ompK36 typing. Among 226 nonduplicate K. pneumoniae bloodstream isolates collected at a Taiwanese hospital in 2011, four ompK36 types, designated types A, B, C, and D, were identified by PCR in 61, 28, 100, and 36 isolates, respectively; 1 isolate was untypeable. Statistical analysis showed significantly higher rates of antimicrobial resistance (all tested antibiotics except meropenem), extended-spectrum ␤-lactamases or DHA-1 (47.5% together), Qnr-type quinolone resistance determinants (50.8%), and IncFIIA-type plasmids (49.2%) in group A than in others. Seventeen isolates were identified as belonging to 3 international high-risk clones (4 sequence type 11 [ST11], 10 ST15, and 3 ST147 isolates); all isolates but 1 ST15 isolate were classified in group A. The significant characteristics of group C were hypermucoviscosity (62.0%) and a higher virulence gene content. This group included all serotype K1 (n ‫؍‬ 30), K2 (n ‫؍‬ 25), and K5 (n ‫؍‬ 3) isolates, 6 of 7 K57 isolates, all isolates of major clones associated with pyogenic liver abscesses (29 ST23, 11 ST65, 5 ST86, 7 ST373, and 1 ST375 isolates), and 16 (94.1%) of 17 isolates causing bacteremic liver abscesses. Twelve (42.9%) of the group B isolates were responsible for bacteremic biliary tract infections. Group D was predominant (83.3%) among 12 K20 isolates. This study suggests that most clinical K. pneumoniae isolates can be allocated into four groups with distinct characteristics based on ompK36 types. K lebsiella pneumoniae is an important human opportunistic pathogen that causes a wide variety of community-acquired and nosocomial infections (1-4). The organism is still one of the leading causes of community-acquired pneumonia (3) and has been described as the major cause of pyogenic liver abscesses (PLA) in some Asia-Pacific countries (2, 4). Serotypes K1 and K2 in K. pneumoniae have been linked to invasive infections (2-9). Using multilocus sequence typing (MLST), Brisse et al. (10) identified two virulent K1 clones of K. pneumoniae, clonal complex (CC) 23 and CC82, which were strongly associated with PLA and respiratory infection, respectively. K. pneumoniae is also an important reservoir of antibiotic resistance determinants (1). Several clones of K. pneumoniae with a high prevalence of carbapenem resistance or extended-spectrum ␤-lactamases (ESBLs) have been distributed worldwide (11-16). The epidemic drug-resistant clones, called "high-risk" clones (11), may play an important role in the dissemination of antimicrobial resistance. The major international high-risk clones identified by MLST belong to sequence type 11 (ST11), ST15, ST147,. ST11 and ST258 were included in clonal group (CG) 258 (11,14), while ST15 and ST147 were grouped in CG15 and CG147 (11, 13, 14), respectively.High-level carbapenem resistance in K. pneumoniae ma...

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

“…However, these two STs were not found in the present study. Previous studies showed that ST268 was only found among K20 isolates (Liu et al, 2014 ; Lin et al, 2015 ; Yan et al, 2015 , 2016 ; Zhang et al, 2016 ). In the present study, we also found that there was an association between ST268 and K20 isolates.…”

Molecular characterization and epidemiology of carbapenem non-susceptible Enterobacteriaceae isolated from the Eastern region of Heilongjiang Province, China

“…In our study, we demonstrated that the sequence type ST76 was the predominant type among CRKP isolates which are bla KPC-2 positive in Heilongjiang Province. To the best of our knowledge, the ST76 clone has been sporadically reported in Taiwan and America [ 45 , 46 ]. In Japan, ST76 has been isolated from meat [ 47 ].…”

Global Evolution of Pathogenic Bacteria With Extensive Use of Fluoroquinolone Agents

“…Though some major international ST (ST11, ST14, ST147, ST258) strains of MDR K. pneumoniae are called sometimes hypervirulent or "high-risk" an abundance of papers show that these isolates carry significantly fewer virulence factors than strains from the really highly virulent STs, primarily ST23 and ST65 (Lascols et al, 2013;Bialek-Davenet et al, 2014;Liu et al, 2014;Qu et al, 2015;Yan et al, 2015;Paczosa and Mecsas, 2016;Gomez-Simmonds and Uhlemann, 2017;Gu et al, 2018;Lam et al, 2018b;Turton et al, 2018). Interestingly -despite the large outfit of virulence factors -ST23 and ST65 strains remain minor STs relative to the major clones of MDR K. pneumoniae in the healthcare setting (Cantón et al, 2012;Chen et al, 2014;Pitout et al, 2015;Gomez-Simmonds and Uhlemann, 2017;Runcharoen et al, 2017).…”