Production of an extracellular toxic complex by various strains of Klebsiella pneumoniae

Straus, David C.

doi:10.1128/iai.55.1.44-48.1987

Cited by 56 publications

(26 citation statements)

References 24 publications

(24 reference statements)

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“…As in many enterobacteria, and as has been especially well studied in E. coli, other factors have also been demonstrated in Klebsiella spp. Although the production of cytotoxins (102,127,149,150,229), enterotoxins (95,(122)(123)(124)(125)148) and hemolysin (4-6, 17) has been sporadically described, these features probably play a rather minor role in Klebsiella.…”

Section: Siderophoresmentioning

confidence: 99%

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

1998

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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.

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Section: Siderophoresmentioning

confidence: 99%

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

1998

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“…2b) were observed in either cells treated with 50 lg mL À1 (protein concentration) OMVs. Two previous studies focusing on the host cell pathology induced by K. pneumoniae showed that extracellular components released or secreted from bacteria are partly associated with host cell cytotoxicity (Straus, 1987;Cano et al, 2009). Thus, we expected that K. pneumoniae OMVs would inhibit growth or induce death in either U937 cells, HEp-2 cells or both.…”

Section: Klebsiella Pneumoniae Omvs Are Not Cytotoxic To Host Cellsmentioning

confidence: 99%

“…Klebsiella pneumoniae produces several virulence factors, including antiphagocytic capsular polysaccharide (Cortés et al, 2002), LPS (Shankar-Sinha et al, 2004;Lawlor et al, 2005), siderophores (Nassif & Sansonetti, 1986) and adhesins, but specific cytotoxic factors for host cells have not yet been determined. Straus (1987) reported that an extracellular toxic complex from K. pneumoniae is responsible for lung damage, and that the production of extracellular toxic complex is correlated with K. pneumoniae virulence. More recently, Cano et al (2009) demonstrated that host cell cytotoxicity is associated with the K. pneumoniae capsular polysaccharide and strains expressing different capsule levels are not equally virulent.…”

Section: Introductionmentioning

confidence: 99%

“…These results suggest that additional bacterial elements released or secreted from bacteria, together with the capsular polysaccharide, are involved in K. pneumoniae pathogenesis. Based on these two studies, we speculated that the extracellular toxic complex described by Straus (1987) may be OMVs and that K. pneumoniae OMVs induce host cell cytotoxicity. In the present study, we examined the production of OMVs from K. pneumoniae and analysed the proteome of K. pneumoniae-derived OMVs.…”

Section: Introductionmentioning

confidence: 99%

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Klebsiella pneumoniae secretes outer membrane vesicles that induce the innate immune response

Lee

et al. 2012

FEMS Microbiol Lett

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Outer membrane vesicles (OMVs) derived from pathogenic Gram‐negative bacteria are an important vehicle for delivery of effector molecules to host cells, but the production of OMVs from Klebsiella pneumoniae, an opportunistic pathogen of both nosocomial and community‐acquired infections, and their role in bacterial pathogenesis have not yet been determined. In the present study, we examined the production of OMVs from K. pneumoniae and determined the induction of the innate immune response against K. pneumoniae OMVs. Klebsiella pneumoniae ATCC 13883 produced and secreted OMVs during in vitro culture. Proteomic analysis revealed that 159 different proteins were associated with K. pneumoniae OMVs. Klebsiella pneumoniae OMVs did not inhibit cell growth or induce cell death. However, these vesicles induced expression of proinflammatory cytokine genes such as interleukin (IL)‐1β and IL‐8 in epithelial cells. An intratracheal challenge of K. pneumoniae OMVs in neutropenic mice resulted in severe lung pathology similar to K. pneumoniae infection. In conclusion, K. pneumoniae produces OMVs like other pathogenic Gram‐negative bacteria and K. pneumoniae OMVs are a molecular complex that induces the innate immune response.

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“…Virulent strains of K. pneumoniae are known to release an extracellular toxic complex from their surfaces during growth. This complex is composed of capsular polysaccharide, LPS and protein and has been implicated in tissue damage of the type seen in lobar pneumonia (Domenico et ai, 1985;Straus, 1987;Straus etai, 1985). The 0-polysaccharide side chains of the LPS molecule are responsible for the resistance of K. pneumoniae serotype 01 to serum bactericidal activity (McCallum etai, 1989;Tomas etai, 1986).…”

Section: Introductionmentioning

confidence: 99%

Structural variation in the O‐specific polysaccharides ofKlebsiella pneumoniaeserotype O1 and O8 lipopolysaccharide: evidence for clonal diversity inrfbgenes

Kelly

Severn

Richards

et al. 1993

Molecular Microbiology

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The O-polysaccharide fraction of the lipopolysaccharide from Klebsiella pneumoniae serotype O8 was found to comprise two galactose-containing homopolymers. Structural analysis, using chemical and high-field nuclear magnetic resonance (NMR) techniques, established that the K. pneumoniae O8 polysaccharides are composed of the linear, disaccharide repeating units [formula: see text] K. pneumoniae O8 mutant RFK-1 was isolated by resistance to phage KO1-2; strain RFK-1 expressed only D-galactan I-OAc. The 1H- and 13C-NMR resonances from this O-polysaccharide indicate that all of the O-acetyl groups within the K. pneumoniae O8 polysaccharide are carried on D-galactan I and O-acetylation occurs only on the beta-D-galactofuranose residues; 60% of the available beta-D-galactofuranose residues are non-acetylated. The O-acetylation of the remaining residues is equally distributed between the O-2 and O-6 positions. The carbohydrate backbone structures in the O8 polysaccharide are identical to D-galactan I and II expressed by K. pneumoniae O1, accounting for the antigenic cross-reaction between strains belonging to serotypes O1 and O8. However, the O1 polysaccharides are not acetylated and the O-acetyl groups present in the K. pneumoniae serotype O8 polysaccharides provide a structural basis for their recognition as distinct serotypes. The rfb (O-polysaccharide biosynthesis) gene cluster of K. pneumoniae serotype O1 determines the synthesis of D-galactan I. rfbKpO1-specific gene probes were used to examine conservation in the rfb gene clusters of other K. pneumoniae serotypes which produce D-galactan I. Six O1 strains were examined and all showed hybridization with rfbKpO1 probes under conditions of high stringency. Three serotype O2 strains produce D-galactan I and these strains also contained DNA sequences recognized by rfbKpO1 probes under high stringency. The physical maps of these homologous rfb chromosomal regions showed some polymorphism. Surprisingly, the rfbKpO8 region from K. pneumoniae serotype O8 was only recognized by rfbKpO1 probes under low-stringency hybridization conditions, providing evidence for two substantially different clonal groups of rfb genes from K. pneumoniae strains with structurally related O-antigens.

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Production of an extracellular toxic complex by various strains of Klebsiella pneumoniae

Cited by 56 publications

References 24 publications

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

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

Klebsiella pneumoniae secretes outer membrane vesicles that induce the innate immune response

Structural variation in the O‐specific polysaccharides ofKlebsiella pneumoniaeserotype O1 and O8 lipopolysaccharide: evidence for clonal diversity inrfbgenes

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