Klebsiellaspp. as Nosocomial Pathogens: Epidemiology, Taxonomy, Typing Methods, and Pathogenicity Factors

Abstract

SUMMARY Bacteria belonging to the genus Klebsiella frequently cause human nosocomial infections. In particular, the medically most important Klebsiella species, Klebsiella pneumoniae, accounts for a significant proportion of hospital-acquired urinary tract infections, pneumonia, septicemias, and soft tissue infections. The principal pathogenic reservoirs for transmission of Klebsiella are the gastrointestinal tract and the hands of hospital personnel. Because of their ability to spread rapidly in the hospital environment, these bacteria tend to cause nosocomial outbreaks. Hospital outbreaks of multidrug-resistant Klebsiella spp., especially those in neonatal wards, are often caused by new types of strains, the so-called extended-spectrum-β-lactamase (ESBL) producers. The incidence of ESBL-producing strains among clinical Klebsiella isolates has been steadily increasing over the past years. The resulting limitations on the therapeutic options demand new measures for the management of Klebsiella hospital infections. While the different typing methods are useful epidemiological tools for infection control, recent findings about Klebsiella virulence factors have provided new insights into the pathogenic strategies of these bacteria. Klebsiella pathogenicity factors such as capsules or lipopolysaccharides are presently considered to be promising candidates for vaccination efforts that may serve as immunological infection control measures.

Isolation and characterization of a lytic bacteriophage φKp-lyy15 of Klebsiella pneumoniae

“…This organism is an important causative agent of nosocomial and opportunistic infection in humans, such as pneumonia, urinary tract infections, bacteremia, and intra-abdominal infections (Podschun and Ullmann, 1998;Fang et al, 2007). Infections caused by K. pneumoniae are frequently life threatening in infants, the elderly and immunocompromised individuals (Ko et al, 2002).…”

Changes of antimicrobial resistance and extended-spectrum β-lactamase production in Klebsiella spp. strains

“…play a significant role. 18 The number of Klebsiella spp. isolated at the CMH has increased during the followed period of 5 years by 45%, becoming the fifth most frequent pathogen.…”

Study of biodiversity of Klebsiella sp.

“…(Rangarajan et al 2001), Yersinia (Ibrahim et al 1994), Salmonella (Chang et al 1997), Serratia (Dauga et al 1990), Erwinia (Kwon et al 1997) etc. Members of the Klebsiella genus are well known clinical pathogens and have been described specifically for their pathogenicity (Podschun et al 1998). Some species play an important role in nitrogen fixation (Ladha et al 1983).…”