In fact, the homolog of hyl Efm in Streptococcus pyogenes (spy1600) encoded
in a genetic locus with a similar SB-715992 organization to that of the hyl Efm -region and sharing 42% identity at the amino acid level (61% similarity), was recently shown not to have any detectable hyaluronidase activity. Spy1600 was characterized as a family 84 glycosyl hydrolase with β- N -SAR302503 price acetyl-glucosaminidase specificity after purification and substrate analysis  and expression of spy1600 in S. pyogenes was found to be up-regulated during phagocytosis . For this reason, and because of the almost exclusive occurrence of hyl Efm in isolates from clinical origin in different surveillance studies [14, 22–24], this gene has been postulated as an important pathogenic determinant of hospital-associated E. faecium. However, its exact role in virulence has not been established. In this work, we assess the role of the hyl Efm -region in E. faecium pathogenesis of experimental
peritonitis. Methods Bacterial strains and plasmids Table Selleck Natural Product Library 1 and Figure 1 show the strains and plasmids used in this work and depict the genetic organization of the hyl Efm -region in E. faecium strains and mutants. Table 1 E. faecium strains and plasmids used in this work Strains/Plasmids Relevant Characteristics Reference Strains E. faecium TX16 (DO) Sequenced endocarditis clinical isolate, Emr, Smr. ST-16a http://www.hgsc.bcm.tmc.edu  TX1330RF Fsr and second Rfr derivative of TX1330, a faecal colonizing strain from a healthy human volunteer  TX1330RF (pHylEfmTX16) Derivative of TX1330RF to which the hyl Efm -containing plasmid (pHylEfmTX16) was transferred by conjugation from TX16 (DO) (~250 kb)  TX1330RF (pHylEfmTX16Δ7,534) Mutant with deletion of part or all of 6 genes of the hyl Efm region of TX1330RF(pHylEfmTX16) This work TX1330RF (pHylEfmTX16Δ4genes) Non-polar deletion of 4 genes of the hyl Efm region of TX1330RF(pHylEfmTX16) This work TX1330RF (pHylEfmTX16Δ hyl ) Non-polar
deletion mutant of hyl Efm of TX1330RF(pHylEfmTX16) This work TX1330RF (pHylEfmTX16Δ hyl-down ) Non-polar deletion of hyl Efm plus its downstream gene of TX1330RF(pHylEfmTX16) This work TX1330RF (pHylEfmTX16Δ down ) Non-polar deletion of the gene downstream of hyl Efm of TX1330RF(pHylEfmTX16) This work E. faecalis CK111 OG1Sp upp4 ::P23 repA4  Plasmids pHylEfmTX16 Conjugative and transferable megaplasmid (ca. 250 kb) of TX16 (DO) containing hyl Efm  pCJK47 Conjugative donor plasmid for markerless mutagenesis; oriT pCF10 and pheS * pORI280 derivative; confers Emr  pHOU1 Derivative of pCJK47 in which the erm (C) gene was replaced by aph-2′-ID; confers Gmr This work pHOU2 Derivative of pCJK47 in which the erm (C) gene was replaced by aph-2′-ID and cat was incorporated in the cloning site for allelic replacements; confers Gmr. This work pTEX5501ts E.