The extracellular hyaluronidase gene (hylA) of Streptococcus pyogenes

Hynes, Wayne L.

doi:10.1016/s0378-1097(00)00029-x

Cited by 14 publications

(19 citation statements)

References 17 publications

(23 reference statements)

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“…We found that frequency of hyaluronidase expression among unrelated clinical strains collected from the University of Michigan Hospitals was significantly lower than published results (8). We also observed that the most clinically significantly M types (M1 and M3) do not produce an active enzyme in vitro.…”

Section: Discussioncontrasting

confidence: 58%

“…that are not homologous to hylA at the level of DNA sequence or protein product. Extracellular hyaluronidase activity is attributable to the product of the hylA gene, HylA, whereas HylP and its analogues are believed to be phage associated, facilitating penetration of the capsule by streptococ-cal phages (8,10). Although all GAS have a hylA gene, only a small percentage of clinical strains (Ͻ25%) produce a detectable amount of HylA when grown in vitro (10).…”

mentioning

confidence: 99%

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

Starr¹,

Engleberg

2006

Infect Immun

100

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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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Section: Discussioncontrasting

confidence: 58%

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confidence: 99%

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

Starr¹,

Engleberg

2006

Infect Immun

100

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“…S. agalactiae hylB encodes hyaluronate lyase (hyaluronidase), a putative virulence factor that is involved in cleaving hyaluronic acid, a component of the extracellular matrix in many tissues (30). Hyaluronidases have also been found to be important virulence factors in other gram-positive organisms, such as Streptococcus pyogenes (22). Overall, human isolates showed a significantly lower average hyaluronidase activity than bovine isolates, indicating that S. agalactiae isolates from cattle and human invasive cases also represent phenotypically distinct populations.…”

Section: Discussionmentioning

confidence: 99%

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Sukhnanand¹,

Dogan²,

Ayodele³

et al. 2005

J Clin Microbiol

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Streptococcus agalactiae causes severe invasive disease in humans and mastitis in cattle. Temporally matched bovine milk isolates and clinical human invasive isolates (52 each) collected in New York State over 18 months were characterized by molecular subtyping and phenotypic methods to probe the interspecies transmission potential of this species. EcoRI ribotyping differentiated 17 ribotypes, and DNA sequencing of the housekeeping gene sodA and the putative virulence gene hylB differentiated 7 and 17 allelic types, respectively. Human and bovine isolates were not randomly distributed between ribotypes or hylB and sodA clusters. The combined analysis of all subtyping data allowed the differentiation of 39 clonal groups; 26 groups contained only bovine isolates, and 2 groups contained both human and bovine isolates. The EcoRI ribotype diversity among bovine isolates (Simpson's numerical index of discrimination [mean ؎ standard deviation], 0.90 ؎ 0.05) being significantly higher than that among human isolates (0.42 ؎ 0.15) further supports that these isolates represent distinct populations. Eight human isolates, but no bovine isolates, showed an IS1548 transposon insertion in hylB, which encodes a hyaluronidase. Based on data for 43 representative isolates, human isolates, on average, showed lower hyaluronidase activities than bovine isolates. Isolates with the IS1548 insertion in hylB showed no hyaluronidase activity. Human and bovine isolates did not differ in their abilities to invade HeLa human epithelial cells. Our data show that (i) EcoRI ribotyping, combined with hylB and sodA sequencing, provides a discriminatory subtype analysis of S. agalactiae; (ii) most human invasive and bovine S. agalactiae isolates represent distinct subtypes, suggesting limited interspecies transmission; and (iii) hyaluronidase activity is not required for all human infections.

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“…A fragment of this serine protease was recently described to be present in culture supernatant of S. pyogenes (28). Recently, an LPXTGX-containing hyaluronidase (HylA) in S. pyogenes was described (24). In S. pneumoniae, a similar hyaluronidase containing a typical cell wall sorting signal has been proposed to be cell wall attached (5,25).…”

Section: Construction Of a Tripartite Pattern By Analysis Of Coohtermmentioning

confidence: 99%

Improved Pattern for Genome-Based Screening Identifies Novel Cell Wall-Attached Proteins in Gram-Positive Bacteria

Janulczyk

Rasmussen

2001

Infect Immun

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With a large number of sequenced microbial genomes available, tools for identifying groups or classes of proteins have become increasingly important. Here we present an improved pattern for the identification of cell wall-attached proteins (CWPs), a group of proteins with diverse and important functions in gram-positive bacteria. This tripartite pattern is based on analysis of 65 previously described cell wall-attached proteins and takes into account the three principal requirements for cell wall sorting; a sortase target region (LPXTGX), a membrane-spanning region, and a charged stop-transfer tail. In five different genomes of gram-positive bacteria, the tripartite pattern identified a total of 35 putative CWPs, 19 of which were novel. The specificity and sensitivity of the tripartite pattern are higher than those of the classical pattern, which is based solely on the sortase target region. Several putative CWPs with atypical sortase target regions were identified. In the complete genome of the important human pathogen Streptococcus pyogenes, the tripartite pattern identified 14 putative CWPs. Seven of the putative S. pyogenes proteins were novel, and two of these were a 5 nucleotidase and a pullulanase. This study represents the first whole-genome screening for CWPs, and we conclude that the tripartite pattern is highly suitable for this purpose. Identification of CWPs using this pattern offers important possibilities in the study of the pathogenesis and physiology of gram-positive bacteria.

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The extracellular hyaluronidase gene (hylA) of Streptococcus pyogenes

Cited by 14 publications

References 17 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

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Improved Pattern for Genome-Based Screening Identifies Novel Cell Wall-Attached Proteins in Gram-Positive Bacteria

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