@article{mbs:/content/journal/micro/10.1099/mic.0.26942-0, author = "Makris, George and Wright, John D. and Ingham, Eileen and Holland, Keith T.", title = "The hyaluronate lyase of Staphylococcus aureus – a virulence factor?", journal= "Microbiology", year = "2004", volume = "150", number = "6", pages = "2005-2013", doi = "https://doi.org/10.1099/mic.0.26942-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26942-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "HL, hyaluronate lyase", keywords = "HA, hyaluronic acid", keywords = "TS, temperature sensitive", keywords = "NAG, N-acetyl-d-glucosamine", abstract = "The hyaluronate lyase (HL) gene of Staphylococcus aureus 8325-4 (hysA) was inactivated in vitro with the insertion of the erythromycin determinant, ermC, from plasmid pE194. The hysA : : ermC mutation was introduced into S. aureus via a temperature-sensitive shuttle vector, where it underwent homologous recombination with the wild-type (w.t.) allele. The insertion of ermC in the chromosomal hysA locus was confirmed by Southern blot hybridization and the loss of HL activity was demonstrated macroscopically by a plate assay. The importance of HL for pathogenicity was assessed by comparing the virulence of the HL− mutant strain to that of the w.t. in an established mouse abscess model of S. aureus infection. A significantly higher cell recovery was obtained from lesions infected with the w.t. strain compared to the lesions infected with the HL− strain (P =0·01). Although the lesion areas from both groups were not significantly different (P=0·9) they were of different morphology. A colorimetric assay was used to measure HL activity from culture supernatants of the S. aureus 8325-4 strains w.t., WA250 (agr) and PC1839 (sar) grown in a chemically defined medium. HL activity reached a maximum in the w.t. strain during mid-exponential phase (t=5 h) and while it showed a 16-fold decrease in the agr mutant it increased 35-fold in the sar mutant background. These results strongly suggest that HL is a virulence factor which is important in the early stages of subcutaneous infections.", }