The amino acid sequences and activities of synergistic hemolysins fromStaphylococcus cohnii

Abstract

Staphylococcus cohnii ssp. cohnii and S. cohnii ssp. urealyticus are a coagulase-negative staphylococci considered for a long time as unable to cause infections. This situation changed recently and pathogenic strains of these bacteria were isolated from hospital environments, patients and medical staff. Most of the isolated strains were resistant to many antibiotics. The present work describes isolation and characterization of several synergistic peptide hemolysins produced by these bacteria and acting as virulence factors responsible for hemolytic and cytotoxic activities. Amino acid sequences of respective hemolysins from S. cohnii ssp. cohnii (named as H1C, H2C and H3C) and S. cohnii ssp. urealyticus (H1U, H2U and H3U) were identical. Peptides H1 and H3 possessed significant amino acid homology to three synergistic hemolysins secreted by Staphylococcus lugdunensis and to putative antibacterial peptide produced by Staphylococcus saprophyticus ssp. saprophyticus. On the other hand, hemolysin H2 had a unique sequence. All isolated peptides lysed red cells from different mammalian species and exerted a cytotoxic effect on human fibroblasts.

Identification of a haemolysin-like peptide with antibacterial activity using the draft genome sequence ofStaphylococcus epidermidisstrain A487

“…2). Although the H3C haemolysin is typically produced in combination with the H1C and H2C peptides (Mak et al , 2008), we could find no evidence of an H3C homologue within the draft genome assembly of S. epidermidis A487. The genes encoding the H1C and H2C homologues in strain A487 were located on separate contigs (data not shown).…”

“…The first 19 residues of the 487 peptide sequence shared 57% identity and 63% similarity to the first 15 residues of the known haemolysin H2C (accession number ) of Staphylococcus cohnii ssp. cohnii (Mak et al , 2008) (Fig. 2).…”

“…The H2C haemolysin is one of three synergistic haemolysins (H1C, H2C and H3C) concurrently produced by over 90% of a selection of S. cohnii isolates from Poland (Mak et al , 2008). This group of haemolysins is related to the SLUSH peptides of Staphylococcus lugdenensis and a putative antibacterial peptide (of unknown haemolytic nature) identified in the genome of Staphylococcus saprophyticus (Mak et al , 2008). Accordingly, the peptide identified in this study has been named haemolysin‐like peptide (Hlp) and the corresponding gene, hlp .…”

“…However, confirmation of this will require specific investigation of the activity of the peptide 487 homologues. The lack of an H3C homologue in strain 487 may explain, at least in part, the lack of haemolytic activity as the H1C, H2C and H3C peptides are synergistic haemolysins (Mak et al , 2008). In S. cohnii , the H2C haemolysins have been implicated as potential virulence determinants in this usually benign organism (Mak et al , 2008).…”

Isolation, biochemical characterization, and cloning of a bacteriocin from the poultry-associated Staphylococcus aureus strain CH-91

“…The BacCH91 bacteriocin was purified from culture supernatants of strain CH-91 using a procedure originally designed for bacterial hemolytic peptides (Mak et al 2008). The relatively hydrophobic character of the peptide facilitated effective extraction using an optimized mixture of organic solvents, and a single subsequent chromatography step (reversed-phase HPLC) produced a homogenous bacteriocin preparation.…”