<p>Dynamic Epidemiology and Virulence Characteristics of Carbapenem-Resistant <em>Klebsiella pneumoniae</em> in Wenzhou, China from 2003 to 2016</p>

Abstract

Purpose: To investigate transitions in resistance mechanisms, virulence characteristics and molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) during 2003-2016 in a major Eastern Chinese medical center. Patients and Methods: From a total of 2299 K. pneumoniae clinical strains collected from 2003 to 2016, 214 were found to be CRKP isolates and were selected for further study. Characterization of these was conducted by molecular detection of antibiotic resistance markers and virulence determinants, modified carbapenem inactivation method and multilocus sequence typing (MLST). Results: In this study, the prevalence of CRKP was increasing over the 14-year period, mirroring a national trend. These CRKP strains were resistant to most of the tested, clinically relevant drugs. The majority of these CRKP strains were positive for carbapenemases, with the Klebsiella pneumoniae carbapenemase (KPC) found to be the dominant type (207/210, 98.6%). The carrier rates of virulence genes uge, entB, fimH, mrkD and ureA increased in 2016, while the ybtA, iucA and irp2 showed a relatively constant trend. From MLST data, ST11 (88.8%, 190/ 214) was the preponderant sequence type (ST), followed by ST15 (1.9%, 4/214) and ST656 (1.4%, 3/214). Several strains with less common STs (ST690, ST895, ST1823 and ST1384) were also detected, and these too showed high levels of antimicrobial resistance. Conclusion: The average national rise in CRKP across China is mirrored in this in-depth analysis of a single hospital, while the prevalence of hypervirulent CRKP (such as ST15) was relatively low as of 2016. Continuous monitoring is necessary to keep track of CRKP and should include the prospect of newly emerging strains with less common STs and the prospect of detecting carbapenem-resistant, carbapenemase-negative Klebsiella pneumoniae.

<p>Emergence of NDM-5-Producing Carbapenem-Resistant <em>Klebsiella pneumoniae</em> and SIM-Producing Hypervirulent <em>Klebsiella pneumoniae</em> Isolated from Aseptic Body Fluid in a Large Tertiary Hospital, 2017–2018: Genetic Traits of <em>bla</em>NDM-Like and <em>bla</em>SIM-Like Genes as Determined by NGS</p>

“…Thus, to find more accurate gene markers and identify the hvKP is crucial and urgent. 33 What is more, the hvKP strains frequently cause invasive infections, such as PLA, 6,19 which are consistent with our study. In ST1764 hvKP, alls genes were found, yet not kfuABC genes.…”

“…The major cause in carbapenem-resistance was CRKP strains carrying different resistance genes. 33 57.1% of all CRKP carried NDM gene, similar to a study from Northwestern China 16 and different with the previous studies stating that KPC is prevalent in the US, some of Europe region and most of China. 7,34 We also identified NDM-1 and NDM-5 types of metallo-β-lactamases genes.…”

“…6 Thus, hv and HM are not necessarily related. 33 hvKP strain carried a high number of siderophores. Aerobactin is the most important factor of hv.…”

“…These genes were associated with PLA and could increase virulence. 6,43 Other virulence factors and genomic features also contribute to the enhancement of the virulence, 33 which should be focused on in the subsequent studies.…”

Fecal Klebsiella pneumoniae Carriage Is Intermittent and of High Clonal Diversity

“…HvKp clones circulating in the community are associated with particular capsule types, mainly K1, K2, K20, and K57 ( Lee et al, 2016 ) and certain sequence types (STs) like ST23, ST65, ST86, ST375, and ST380 ( Bialek-Davenet et al, 2014 ; Lin et al, 2014 ; Lee et al, 2017 ). The convergence of carbapenem-resistance and virulence resulted in the emergence of carbapenem-resistant hvKP strains in China, which is expected to become a serious future public health issue ( Zhao et al, 2020 ).…”