Klebsiella pneumoniae: characteristics of carbapenem resistance and virulence factors

Abstract

Klebsiella pneumoniae, known as a major threat to public health, is the most common factor of nosocomial and community acquired infections. In this study, 50 K. pneumoniae clinical specimens isolated from bronchial, urea, blood, catheter, rectal, bile, tracheal and wound cultures were collected. These isolates were identified and carbapenem resistance was determined via an automated system, CHROMagar Orientation and CHROMagar KPC. The carbapenemase gene regions (blaIMP, blaVIM, blaOXA, blaNDM and blaKPC) and presence of virulence factors (magA, k2A, rmpA, wabG, uge, allS, entB, ycfM, kpn, wcaG, fimH, mrkD, iutA, iroN, hly ve cnf-1) of these isolates were determined by using Multiplex-PCR. The OXA-48 carbapenemase gene regions were determined in 33 of 50 K. pneumoniae strains. In addition, NDM-1 resistance in one, OXA-48 and NDM-1 resistance in four unusual K. pneumoniae isolates were detected. Virulence gene regions that were encountered among K. pneumoniae isolates were 88% wabG, 86% uge, 80% ycfM and 72% entB, related with capsule, capsule lipoprotein and external membrane protein, responsible for enterobactin production, respectively. Even though there was no significant difference between resistant and sensitive strains due to the virulence gene regions (P≥0.05), virulence factors in carbapenem resistant isolates were found to be more diverse. This study is important for both, to prevent the spread of carbapenem resistant infections and to plan for developing effective treatments. Moreover, this study is the first detailed study of the carbapenem resistance and virulence factors in K. pneumoniae strains.

耐碳青霉烯类肺炎克雷白杆菌临床分布及整合素1与其耐药关系的研究

“…10 The mechanism for drug resistance of CRKP is mainly related to two aspects: the excessive expression of Amp Combined with pore protein loss, and the production of carbapenem enzymes. 11 In addition to carbapenem and beta lactam resistance, CRKP was found frequently to carry resistant genes to other antibiotics, and easily develop into multiple-drug resistance bacterium.…”

Outbreak by Hypermucoviscous Klebsiella pneumoniae ST11 Isolates with Carbapenem Resistance in a Tertiary Hospital in China

“…The presence of resistance genes were detected by PCR amplification followed by Sanger sequencing using the primers and conditions described elsewhere (Pagani et al, 2003; Jiang et al, 2005; Li, H. et al, 2014; Validi et al, 2016). Seventeen virulence-associated genes, including aerobactin, iroN, kfuB, rmpA, wcaG, alls, ybtS, ureA, uge, wabG, ycf , entB, iutA, vatD, magA, fimH , and mrkD , were determined by PCR using the primers described previously for carbapenem-resistant HMKP isolates (Yu et al, 2006, 2008; Turton et al, 2010; Candan and Aksoz, 2015). Bacterial strains harboring these virulence genes from our previous studies were used as positive controls in the PCRs.…”

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

“…It has important roles in protecting against complement, including preventing C1q binding to bacteria, which inhibits subsequent activation of the complement pathway, as well as binding C3b away from the outer bacterial membrane and, thus, abrogating bacterial lysis by the complement membrane attack complex. jority of reports stating that wabG is harbored by 88 to 100% of K. pneumoniae isolates, although one report found wabG in only 5.3% of isolates (268,(270)(271)(272)(273)(274). K. pneumoniae strains lacking this gene are unable to generate the LPS outer core or to retain capsular antigen and are attenuated in intraperitoneal, pneumonic, and UTI rodent models of infection (275).…”