Virulence factors of the group A streptococci and genes that regulate their expression

Hynes, Wayne L.

doi:10.2741/1491

Cited by 37 publications

(33 citation statements)

References 317 publications

(385 reference statements)

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“…Another gram-positive bacterium, Clostridium perfringens produces hyaluronidases that are also thought to contribute to the spreading of bacteria in tissues (2). Based on these observations and the tendency for GAS to spread rapidly in soft tissue, it has been widely assumed that its hyaluronidase serves a similar function (7,14,20,27). Although standard texts often attribute bacterial spread in tissue to the function of this enzyme, there is no experimental data to support this assumption.…”

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confidence: 99%

Role of Hyaluronidase in Subcutaneous Spread and Growth of Group A Streptococcus

Starr¹,

Engleberg

2006

Infect Immun

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Group A streptococcus (GAS) depends on a hyaluronic acid (HA) capsule to evade phagocytosis and to interact with epithelial cells. Paradoxically, GAS also produces hyaluronidase (Hyl), an enzyme that cleaves HA. A common assumption is that Hyl digests structurally identical HA in human tissue to promote bacterial spread. We inactivated the gene encoding extracellular hyaluronidase, hylA, in a clinical Hyl ؉ isolate. Hyl ؉ and an isogenic Hyl ؊ mutant were injected subcutaneously into mice with or without high-molecular-weight dextran blue. The Hyl ؊ strain produced small lesions with dye concentrated in close proximity. The Hyl ؉ strain produced identical lesions, but the dye diffused subcutaneously. However, Hyl ؉ bacteria were not isolated from unaffected skin stained by dye diffusion. Thus, Hyl digests tissue HA and facilitates spread of large molecules but is not sufficient to cause subcutaneous diffusion of bacteria or to affect lesion size. GAS capsule expression was assayed periodically during broth culture and was reduced in Hyl ؉ strains relative to Hyl ؊ strains at the onset and the end of active capsule synthesis but not during peak synthesis in mid-exponential phase. Thus, Hyl is not sufficiently active to remove capsule during peak synthesis. To demonstrate a possible nutritional role for Hyl, GAS was shown to grow with N-acetylglucosamine but not D-glucuronic acid (both components of HA) as a sole carbon source. However, only Hyl ؉ strains could grow utilizing HA as a sole carbon source, suggesting that Hyl may permit the organism to utilize host HA or its own capsule as an energy source.

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confidence: 99%

Role of Hyaluronidase in Subcutaneous Spread and Growth of Group A Streptococcus

Starr¹,

Engleberg

2006

Infect Immun

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“…Such proteins have been shown to play important roles in pathogenesis, such as resistance to phagocytosis, adherence to plasma and extracellular matrix proteins, and degradation of host proteins [17]. As LPXTG motif-containing proteins are covalently attached to the cell wall, we were surprised to see these proteins in the cellassociated protein fraction, as we did not expect them to be released from the cell wall during protein preparation.…”

Section: General Remarksmentioning

confidence: 91%

Group A streptococcus cell‐associated pathogenic proteins as revealed by growth in hyaluronic acid‐enriched media

et al. 2007

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Northumbria University has developed Northumbria Research Link (NRL) to enable users to access the University's research output. Copyright © and moral rights for items on NRL are retained by the individual author(s) and/or other copyright owners. Single copies of full items can be reproduced, displayed or performed, and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided the authors, title and full bibliographic details are given, as well as a hyperlink and/or URL to the original metadata page. The content must not be changed in any way. Full items must not be sold commercially in any format or medium without formal permission of the copyright holder. The full policy is available online: http://nrl.northumbria.ac.uk/policies.html This document may differ from the final, published version of the research and has been made available online in accordance with publisher policies. To read and/or cite from the published version of the research, please visit the publisher's website (a subscription may be required.) Group A streptococcus (GAS), also know as Streptococcus pyogenes, is a human pathogen and can cause several fatal invasive diseases such as necrotising fasciitis, the so-called flesh-eating disease, and toxic shock syndrome. The destruction of connective tissue and the hyaluronic acid (HA) therein, is a key element of GAS pathogenesis. We therefore propagated GAS in HA-enriched growth media in an attempt to create a simple biological system that could reflect some elements of GAS pathogenesis. Our results show that several recognised virulence factors were up-regulated in HA-enriched media, including the M1 protein, a collagen-like surface protein and the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, which has been shown to play important roles in streptococcal pathogenesis. Interestingly, two hypothetical proteins of unknown function were also up-regulated and detailed bioinformatics analysis showed that at least one of these hypothetical proteins is likely to be involved in pathogenesis. It was therefore concluded that this simple biological system provided a valuable tool for the identification of potential GAS virulence factors. RESEARCH ARTICLE Group

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“…S. pyogenes produces, or at least have the potential to produce, a number of different proteolytic enzymes that can play important roles during infections [12]. Some medicinal plant extracts including, Helichrysum italicum and Nepeta cataria showed inhibitory effects on some bacterial enzymes that contribute to the pathogenic properties [19].…”

Section: Discussionmentioning

confidence: 99%

“…pyogenes infections may leads to the delay sequelae of rheumatic fever and glomerulonephritis [12]. Increased antibiotic resistance in S. pyogenes [13] and antibiotic treatment failure for S. pyogenes infections [14] have been reported and become a serious clinical problem.…”

Section: Introductionmentioning

confidence: 99%

Bactericidal, Bacteriolytic, and Antibacterial Virulence Activities of <i>Boesenbergia pandurata</i> (Roxb) Schltr Extract against <i>Streptococcus pyogenes</i>

Limsuwan¹,

Voravuthikunchai²

2014

Trop. J. Pharm Res

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Virulence factors of the group A streptococci and genes that regulate their expression

Cited by 37 publications

References 317 publications

Role of Hyaluronidase in Subcutaneous Spread and Growth of Group A Streptococcus

Role of Hyaluronidase in Subcutaneous Spread and Growth of Group A Streptococcus

Group A streptococcus cell‐associated pathogenic proteins as revealed by growth in hyaluronic acid‐enriched media

Bactericidal, Bacteriolytic, and Antibacterial Virulence Activities of <i>Boesenbergia pandurata</i> (Roxb) Schltr Extract against <i>Streptococcus pyogenes</i>

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