Epidemiology and Virulence of Klebsiella pneumoniae

Abstract

Strains of Klebsiella pneumoniae are frequently opportunistic pathogens implicated in urinary tract and catheter-associated urinary-tract infections of hospitalized patients and compromised individuals. Infections are particularly difficult to treat since most clinical isolates exhibit resistance to several antibiotics leading to treatment failure and the possibility of systemic dissemination. Infections of medical devices such as urinary catheters is a major site of K. pneumoniae infections and has been suggested to involve the formation of biofilms on these surfaces. Over the last decade there has been an increase in research activity designed to investigate the pathogenesis of K. pneumoniae in the urinary tract. These investigations have begun to define the bacterial factors that contribute to growth and biofilm formation. Several virulence factors have been demonstrated to mediate K. pneumoniae infectivity and include, but are most likely not limited to, adherence factors, capsule production, lipopolysaccharide presence, and siderophore activity. The development of both in vitro and in vivo models of infection will lead to further elucidation of the molecular pathogenesis of K. pneumoniae. As for most opportunistic infections, the role of host factors as well as bacterial traits are crucial in determining the outcome of infections. In addition, multidrug-resistant strains of these bacteria have become a serious problem in the treatment of Klebsiella infections and novel strategies to prevent and inhibit bacterial growth need to be developed. Overall, the frequency, significance, and morbidity associated with K. pneumoniae urinary tract infections have increased over many years. The emergence of these bacteria as sources of antibiotic resistance and pathogens of the urinary tract present a challenging problem for the clinician in terms of management and treatment of individuals.

Biofilm formation and antibiotic resistance inKlebsiella pneumoniaeurinary strains

“…A variety of virulence factors, especially fimbriae, antiphagocytic capsule (CPS), LPS, membrane transporters and siderophores (Clegg and Murphy ), allow the survival of K. pneumoniae and its immune evasion during infection. The ability of K. pneumoniae to form biofilm (Vuotto et al .…”

“…A variety of virulence factors, especially fimbriae, antiphagocytic capsule (CPS), LPS, membrane transporters and siderophores (Clegg and Murphy 2016), allow the survival of K. pneumoniae and its immune evasion during infection. The ability of K. pneumoniae to form biofilm Chung 2016) protects the pathogen from the host immune responses as well as from antibiotics (Jagnow and Clegg 2003;Bandeira et al 2014), enhancing its persistence on epithelial tissues and medical device surfaces.…”

Whole genome sequencing snapshot of multi-drug resistant Klebsiella pneumoniae strains from hospitals and receiving wastewater treatment plants in Southern Romania

“…Moreover, K. pneumoniae is a good indicator of the transmission between clinical and environmental AR reservoirs, being an ubiquitous microorganism found in soil, surface water and on plants [8], but also one of the most important Gram-negative opportunistic pathogens, frequently associated with both hospital and community acquired severe infections. [9,10]; Moreover, K. pneumoniae could cumulate resistance (e.g. MDR, carbapenemase production) and hypervirulence (e.g.…”

La batalla contra las superbacterias: No más antimicrobianos, no hay ESKAPE

“…Klebsiella pneumoniae es un miembro de la familia Enterobacteriaceae, donde también se agrupa Escherichia coli: es un bacilo Gram (-) y se considera una bacteria intrínsecamente virulenta debido a la presencia de adhesinas y de una cápsula que actúa como un factor antifagocítico (Clegg & Murphy, 2016). Se considera un patógeno oportunista y se asocia comúnmente con infecciones de las vías urinarias y de las vías respiratorias.…”

“…El panorama completo es aún más complicado, ya que, en el laboratorio, cepas altamente virulentas de K. pneumoniae son capaces de formar un biofilm, una matriz polimérica compuesta por polisacáridos y proteínas que le confieren protección contra elementos exógenos del medio, como los antimicrobianos (Clegg & Murphy, 2016). En la naturaleza, son capaces de asociarse con otras especies bacterianas que comparten una distribución espacial similar: por ejemplo, se han reportado asociaciones con P. aeruginosa, Proteus mirabilis y Candida albicans, entre otros.…”