Identification and characterisation of hyaluronate lyase from Streptococcus suis.
ABSTRACT Hyaluronate lyase, which catalyses the degradation of hyaluronic acid (HA), has been described from several pathogenic streptococcal species. We describe, for the first time, identification and purification of hyaluronate lyase from the zoonotic pig pathogen Streptococcus suis. We have cloned the hyaluronate lyase gene from S. suis and used it to generate an allelic replacement knock-out mutant of S. suis serotype 7 that can no longer biosynthesise the enzyme. Interestingly, a limited strain survey indicates that hyaluronate lyase activity is not present in all disease isolates of S. suis. Polyclonal anti-hyaluronate lyase anti-serum raised against our recombinant hyaluronate lyase has been used in Western blots, showing that hyaluronate lyase activity is always associated with the presence of protein of the expected size, whereas lack of hyaluronate lyase activity is due to truncation or absence of the enzyme. We show that hyaluronate lyase activity is required for S. suis to use HA polymer as a carbon source and that supplying exogenous recombinant hyaluronate lyase to all S. suis strains tested allowed fermentation of the resultant HA breakdown products.
- SourceAvailable from: Søren J Sørensen
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- "An additional ATCC 35586 sequence (2533) also annotated as a hyaluronoglucosidase lacks the catalytic domain (results not shown). The functionality might be linked to hyaluronic acid degradation or spread in host tissues as proposed for instance for Streptococcus suis (Allen et al., 2004). "
ABSTRACT: The genus Carnobacterium belongs to the lactic acid bacteria and Carnobacterium maltaromaticum is commonly found in modified atmosphere packed and vacuum packed fish and meat products as well as in live fish. This species has been described as a fish pathogenic organism but human clinical isolates have only been obtained at one occasion. To investigate the virulence potential we sequenced the entire genome of strain ATCC 35586, isolated from a diseased salmon. When comparing the translated gene products of ATCC 35586 to those of Gram positive bacterial pathogens and probiotics as well as the related Carnobacterium sp. AT7 we identified a range of putative virulence genes including genes encoding products involved in adhesion to fibronectin and collagen, capsule synthesis, cell wall modification, iron scavenging mechanisms, haemolysis, invasion and resistance to toxic compounds. Of particular interest was the presence of internalin encoding gene homologues to some of those found in Listeria spp. and Lactobacillus plantarum. Furthermore, the ATCC 35586 strain possesses a gene encoding a product similar to the central Listeria monocytogenes transcriptional regulator PrfA, that in this organism controls virulence gene expression by binding to conserved DNA binding sites. Based on the consensus DNA sequence of this binding site, we identified a total of 65 genes in the ATCC 35586 genome that in the upstream region carry a PrfA binding motif. Among these is one of the internalin encoding genes; two genes encoding products involved in capsule biosynthesis as well as various genes encoding products with metabolic functions. In contrast to L. monocytogenes, the ATCC 35586 strain did not encode other PrfA dependent virulence factors such as listeriolysin O, phospholipases A and B, ActA, listeriolysin O, zinc metallo protease and internalins A and B. In conclusion, C. maltaromaticum ATCC 35586 carries putative virulence genes that may explain its reported ability to infect fish. The findings of this study give no reason for concern regarding human health by the presence of this species in food products.International journal of food microbiology 06/2011; 152(3):107-15. DOI:10.1016/j.ijfoodmicro.2011.05.012 · 3.16 Impact Factor
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ABSTRACT: The diffusion of toxins from the site of a bite into the circulation is essential for successful envenomation. Degradation of hyaluronic acid in the extracellular matrix (ECM) by venom hyaluronidase is a key factor in this diffusion. Hyaluronidase not only increases the potency of other toxins but also damages the local tissue. In spite of its important role, little attention has been paid to this enzyme. Hyaluronidase exists in various isoforms and generates a wide range of hyaluronic acid degradation products. This suggests that beyond its role as a spreading factor venom hyaluronidase deserves to be explored as a possible therapeutic target for inhibiting the systemic distribution of venom and also for minimizing local tissue destruction at the site of the bite.Cell Biochemistry and Function 01/2006; 24(1):7-12. DOI:10.1002/cbf.1261 · 2.13 Impact Factor
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ABSTRACT: Infections caused by Streptococcus suis are considered a global problem in the swine industry. In this animal species, S. suis is associated with septicemia, meningitis, endocarditis, arthritis and, occasionally, other infections. Moreover, it is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infection in humans have been reported, a large outbreak due to S. suis serotype 2 emerged in the summer of 2005 in Sichuan, China. A similar outbreak was observed in another Chinese province in 1998. Symptoms reported in these two outbreaks include high fever, malaise, nausea and vomiting, followed by nervous symptoms, subcutaneous hemorrhage, septic shock and coma in severe cases. The increased severity of S. suis infections in humans, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, underscores the critical need to better understand the factors associated with pathogenesis of S. suis infection. From the 35 capsular serotypes currently known, serotype 2 is considered the most virulent and frequently isolated in both swine and humans. Here, we review the epidemiological, clinical and immunopathological features of S. suis infection in humans.Animal Health Research Reviews 07/2007; 8(1):29-45. DOI:10.1017/S1466252307001247