Staphylococcus capitis isolated from bloodstream infections: a nationwide 3-month survey in 38 neonatal intensive care units.

To increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds.

Multi-virulence-locus sequence typing of Staphylococcus lugdunensis generates results consistent with a clonal population structure and is reliable for epidemiological typing.

Staphylococcus lugdunensis is an emergent virulent coagulase-negative staphylococcus responsible for severe infections similar to those caused by Staphylococcus aureus. To understand its potentially pathogenic capacity and have further detailed knowledge of the molecular traits of this organism, 93 isolates from various geographic origins were analyzed by multi-virulence-locus sequence typing (MVLST), targeting seven known or putative virulence-associated loci (atlLR2, atlLR3, hlb, isdJ, SLUG_09050, SLUG_16930, and vwbl). The polymorphisms of the putative virulence-associated loci were moderate and comparable to those of the housekeeping genes analyzed by multilocus sequence typing (MLST).

The major autolysin of Staphylococcus lugdunensis, AtlL, is involved in cell separation, stress-induced autolysis and contributes to bacterial pathogenesis.

Staphylococcus lugdunensis is a human skin commensal organism, but it is considered as a virulent Staphylococcus species. In a previous study, we described the first S. lugdunensis autolysin, AtlL.

Characterization of AtlL, a bifunctional autolysin of Staphylococcus lugdunensis with N-acetylglucosaminidase and N-acetylmuramoyl-l-alanine amidase activities.

The nucleotide sequence of atlL, a gene encoding a putative Staphylococcus lugdunensis peptidoglycan hydrolase, was determined using degenerate consensus PCR and genome walking. This 3837-bp gene encodes a protein, AtlL, that appears as a putative bifunctional autolysin with a 29-amino acid putative signal peptide and two enzymatic putative centres (N-acetylmuramoyl-l-alanine amidase and N-acetylglucosaminidase) interconnected with three imperfect repeated sequences displaying glycine-tryptophan motifs. In order to determine whether both lytic domains were functional, and verify their exact enzymatic activities, gene fragments harbouring both putative domains, AM (N-acetylmuramoyl-l-alanine amidase enzymatic centre plus two repeated sequences) and GL (N-acetylglucosaminidase enzymatic centre plus one repeated sequence), were isolated, subcloned, and expressed in Escherichia coli.