Correlation between Klebsiella pneumoniae carrying pLVPK-derived loci and abscess formation

Abstract

Klebsiella pneumoniae-caused liver abscess (KLA) is an emerging infectious disease. However, factors other than K1-specific loci that contribute to the pathogenesis of this disease have not been identified. pLVPK is a 219,385-bp plasmid of K. pneumoniae CG43, an invasive K2 strain associated with KLA. We aimed in this study to evaluate the involvement of pLVPK in K. pneumoniae virulence and its clinical significance in abscess formation. A pLVPK-cured CG43 was isolated and its virulence was examined in a mouse model. The prevalence of pLVPK-derived loci terW, iutA, rmpA, silS, and repA was investigated in 207 clinical isolates by screening with specific primers. Loss of pLVPK abolished the ability of K. pneumoniae to disseminate into extraintestinal sites and, consequently, attenuated abscess formation in mice. Primary K. pneumoniae abscess isolates (n = 94) were more likely to be terW (+)-iutA (+)-rmpA (+)-silS (+) than those related to non-abscess infections (n = 113) (62% vs. 27%; p < 0.0001). Logistic regression analysis indicated that the presence of the terW-rmpA-iutA-silS loci was a significant risk factor (odds ratio, 4.12; 95% confidence interval, 2.02-8.4; p < 0.0001) for abscess formation. pLVPK is a determinant for K. pneumoniae virulence and infection with strains carrying the pLVPK-derived terW-rmpA-iutA-silS loci may predispose patients to abscess formation.

Microbiological characteristics of hypermucoviscous Klebsiella pneumoniae isolates from different body fluids

“…pLVPK-derived terW-rmpA-iutA-silS loci are independent pathogenicity factors for abscess formation [25]. pLVPK derivatives could be extrachromosomal and carry the repA gene, or be a chromosome-integrated form [25,34]. Gene deficiency of pLVPK derivatives was found for the first time in the hvKP isolates except K1 type.…”

“…pneumoniae virulence determinant pLVPK is a 219,385-bp plasmid isolated from the invasive K2 strain CG43. pLVPK-derived terW-rmpA-iutA-silS loci are independent pathogenicity factors for abscess formation [25]. pLVPK derivatives could be extrachromosomal and carry the repA gene, or be a chromosome-integrated form [25,34].…”

“…pLVPK-derived genetic loci (terW-iutA-rmpAsilS) and the repA gene were detected by PCR, using specific primers for terW, iutA, rmpA, silS and repA [25]. After 5 minutes at 94°C, there were 35 cycles of 94°C, 30 seconds; the annealing temperature, 30 seconds.…”

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model

“…Recently, a 219-kb pLVPK plasmid from K. pneumoniae was reported to be associated with PLA development; however, not all K. pneumoniae PLA isolates (66%, 23/35) were terW þ -iutA þ -rmpA þ -silS þ . 24 Hence, the development of K. pneumoniae liver abscesses likely results from a combination of all virulence determinants, including the phagocytic-resistant capsule and hypermucoviscosity phenotype as well as the presence of rmpA, aerobactin and other virulence-associated genes. In this study, the presence of LPS (O antigen) in DK1 maintained a level of cytokine induction level similar to that observed after high-dose inoculation of K62.…”

FimK regulation on the expression of type 1 fimbriae in Klebsiella pneumoniae CG43S3

“…Reports of KLAs have also increased in Western and other Asian countries (Pope et al, 2011). Although KLA pathogenic mechanisms remain obscure, several virulence traits, including the vast amount of K1 capsular polysaccharide surrounding the bacteria surface (Fung et al, 2002), magA (Chuang et al, 2006), iron acquisition loci on pLVPK (Tang et al, 2010) and type 1 fimbriae (Struve et al, 2008(Struve et al, , 2009Stahlhut et al, 2012), have been reported. Fimbriae (also called pili) allow bacteria to attach to host cells to establish infection.…”