Transduction of plasmid determinants in Staphylococcus aureus and Escherichia coli

Temperate Phages of Staphylococcus aureus

Most Staphylococcus aureus isolates carry multiple bacteriophages in their genome, which provide the pathogen with traits important for niche adaptation. Such temperate S. aureus phages often encode a variety of accessory factors that influence virulence, immune evasion and host preference of the bacterial lysogen. Moreover, transducing phages are primary vehicles for horizontal gene transfer. Wall teichoic acid (WTA) acts as a common phage receptor for staphylococcal phages and structural variations of WTA govern phage-host specificity thereby shaping gene transfer across clonal lineages and even species. Thus, bacteriophages are central for the success of S. aureus as a human pathogen.

Transfer of Antibiotic Resistance in Staphylococcus aureus

Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic elements and occurs primarily by conjugation or bacteriophage transduction, with the latter traditionally being perceived as the primary route. Recent work on conjugation and transduction suggests that transfer by these mechanisms may be more extensive than previously thought, in terms of the range of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen.

Understanding the rise of the superbug: investigation of the evolution and genomic variation of Staphylococcus aureus

The bacterium Staphylococcus aureus is a common cause of human infection, and it is becoming increasingly virulent and resistant to antibiotics. Our understanding of the evolution of this species has been greatly enhanced by the recent sequencing of the genomes of seven strains of S. aureus. Comparative genomic analysis allows us to identify variation in the chromosomes and understand the mechanisms by which this versatile bacterium has accumulated diversity within its genome structure.

Antimicrobial resistance of Staphylococcus aureus: genetic basis

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Generation of transducing particles in Staphylococcus aureus

Transduction of plasmid pC194 and bacteriophage phi 11de varied inversely with the multiplicity of infection. As the multiplicity of infection decreased from 10(-1) to 10(-5) PFU/CFU, the transduction frequency of pC194 increased 10(4)-fold; the transduction frequency of phi 11de increased 300-fold with a 100-fold decrease in multiplicity of infection. Physical and genetic analysis of the transduced DNA showed that pC194 resided in the phage particle as a random, circularly permuted linear concatemer. In DNA prepared from phage that cotransduced pC194 and phi 11de, pC194 resided in the transducing phage primarily as a linear multimer of 15.8 kilobases, or about 5.4 pC194 monomers. The pC194 multimer was randomly inserted into the phi 11 genome.