Microbial lipases as virulence factors

Stehr, Frank; Kretschmar, Marianne; Kröger, Cathrin; Hube, Bernhard; Schäfer, Wilhelm

doi:10.1016/s1381-1177(03)00049-3

Cited by 80 publications

(68 citation statements)

References 34 publications

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“…In addition to HysA, S. aureus possesses other mechanisms for penetrating the host. One example is a secreted cysteine protease, staphopain A, which is able to induce vascular leakage during a guinea pig infection (56), and this effect can be augmented by the addition of another secreted cysteine protease, staphopain B. Additionally, lipases have been observed to enhance S. aureus tissue penetration (57). Taken together these results indicate that HysA is part of a class of S. aureus secreted proteins that act in a coordinated fashion as spreading factors by breaking down host tissues to facilitate bacterial dissemination (22).…”

Section: Discussionmentioning

confidence: 99%

Staphylococcus aureus Hyaluronidase Is a CodY-Regulated Virulence Factor

et al. 2014

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Staphylococcus aureus is a Gram-positive pathogen that causes a diverse range of bacterial infections. Invasive S. aureus strains secrete an extensive arsenal of hemolysins, immunomodulators, and exoenzymes to cause disease. Our studies have focused on the secreted enzyme hyaluronidase (HysA), which cleaves the hyaluronic acid polymer at the ␤-1,4 glycosidic bond. In the study described in this report, we have investigated the regulation and contribution of this enzyme to S. aureus pathogenesis. Using the Nebraska Transposon Mutant Library (NTML), we identified eight insertions that modulate extracellular levels of HysA activity. Insertions in the sigB operon, as well as in genes encoding the global regulators SarA and CodY, significantly increased HysA protein levels and activity. By altering the availability of branched-chain amino acids, we further demonstrated CodY-dependent repression of HysA activity. Additionally, through mutation of the CodY binding box upstream of hysA, the repression of HysA production was lost, suggesting that CodY is a direct repressor of hysA expression. To determine whether HysA is a virulence factor, a ⌬hysA mutant of a community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 strain was constructed and found to be attenuated in a neutropenic, murine model of pulmonary infection. Mice infected with this mutant strain exhibited a 4-log-unit reduction in bacterial burden in their lungs, as well as reduced lung pathology and increased levels of pulmonary hyaluronic acid, compared to mice infected with the wild-type, parent strain. Taken together, these results indicate that S. aureus hyaluronidase is a CodY-regulated virulence factor.

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Section: Discussionmentioning

confidence: 99%

Staphylococcus aureus Hyaluronidase Is a CodY-Regulated Virulence Factor

et al. 2014

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“…Microbial lipases are secreted by several other pathogenic microorganisms and may have a role as virulence factors (Stehr et al 2003). Lipase secretion activity and pathogenicity are usually positively correlated in Beauveria bassiana (Feng 1998;Kaur & Padmaja 2009;Robledo-Monterrubio et al 2009) and the lipases of bacteria and fungi have also been described as being active during host infection (Gribbon et al 1997;Smoot 1997;Stehr et al 2003;Gá cser et al 2007; Beys da Silva et al 2010).…”

Section: Introductionmentioning

confidence: 99%

The entomopathogen Metarhizium anisopliae can modulate the secretion of lipolytic enzymes in response to different substrates including components of arthropod cuticle

et al. 2010

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“…Haemolysins involved in invasion, are considered to be a significant virulence factor of P. aeruginosa as indicated previously (Majtán et al, 1991;Woods et al, 1986). The most important role of bacterial extracellular lipases may be the digestion of host cellular lipids for nutrient acquisition, which results in adhering to host tissue and neighboring cells (Stehr et al, 2003). Lecithinase enzymes modulate the host immune system (Cheng et al, 1995) and play roles in cell-to-cell spread (VazquezBoland et al, 1992).…”

Section: Discussionmentioning

confidence: 99%

Virulence profiles of clinical and environmental Pseudomonas aeruginosa isolates from Central Morocco

Maroui¹,

Aboulkacem²,

Timinouni³

et al. 2016

Afr. J. Microbiol. Res.

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The pathogenic potential of Pseudomonas aeruginosa comes from the expression of many secreted and cell surface virulence factors, and its biofilm formation. This study aimed to investigate and compare the virulence profiles of 123 clinical and environmental P. aeruginosa isolated in Meknes (Morocco). Using suitable culture media, phenotypic screening evaluated the production of β-haemolysin, caseinase, lipase, lecithinase, pyocyanin and pyoverdin, as well as the ability to swim, swarm and twitch. Biofilm formation kinetics was assessed using microtiter test plates. Data analysis was performed using Statistic Package of the Social Science software (version 21.0). High percentages of strains expressed caseinase (99.2%), β-heamolysin (95.1%), lipase (100%) and lecithinase (100%). 95.9% of isolates produced either pigment. All strains were able to swim, warm and twitch, at different levels. All strains were biofilm producers, and the evolution of adherent biomass over time varies greatly from strain to strain. Significant positive correlations were observed between proteolytic and hemolytic activities; biofilm formation and twitching; as well as swimming, swarming and twitching motilities. Twitching and swimming were significantly higher in environmental strains, which were also quickly adhered and formed denser biofilms. Clinical strains showing significantly higher proteolytic activity were isolated from cardiology ward, and those with higher twitching and denser biofilm were from the thoracic service. Inpatient strains were significantly earlier producer of denser biofilm than outpatient ones. P. aeruginosa strains tested have a collection of virulence markers required to cause disease in different tissues. Such bacteria present a serious therapeutic challenge for treatment of both community-acquired and nosocomial infections.

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Microbial lipases as virulence factors

Cited by 80 publications

References 34 publications

Staphylococcus aureus Hyaluronidase Is a CodY-Regulated Virulence Factor

Staphylococcus aureus Hyaluronidase Is a CodY-Regulated Virulence Factor

The entomopathogen Metarhizium anisopliae can modulate the secretion of lipolytic enzymes in response to different substrates including components of arthropod cuticle

Virulence profiles of clinical and environmental Pseudomonas aeruginosa isolates from Central Morocco

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