No abstract

Due to their crucial role in pathogenesis and virulence, phages of Staphylococcus aureus have been extensively studied. Most of them encode and disseminate potent staphylococcal virulence factors. In addition, their movements contribute to the extraordinary versatility and adaptability of this prominent pathogen by improving genome plasticity. In addition to S. aureus, phages from coagulase-negative Staphylococci (CoNS) are gaining increasing interest. Some of these species, such as S. epidermidis, cause nosocomial infections and are therefore problematic for public health. This review provides an overview of the staphylococcal phages family extended to CoNS phages. At the morphological level, all these phages characterized so far belong to the Caudovirales order and are mainly temperate Siphoviridae. At the molecular level, comparative genomics revealed an extensive mosaicism, with genes organized into functional modules that are frequently exchanged between phages. Evolutionary relationships within this family, as well as with other families, have been highlighted. All these aspects are of crucial importance for our understanding of evolution and emergence of pathogens among bacterial species such as Staphylococci.

The clinically important vancomycin antibiotic inhibits the growth of pathogens such as Staphylococcus aureus by blocking cell wall synthesis through specific recognition of nascent peptidoglycan terminating in D-Ala-D-Ala. Here, we demonstrate the ability of single-molecule atomic force microscopy with antibiotic-modified tips to measure the specific binding forces of vancomycin and to map individual ligands on living bacteria. The single-molecule approach presented here provides new opportunities for understanding the binding mechanisms of antibiotics and for exploring the architecture of bacterial cell walls.