Methodology for the Study of Horizontal Gene Transfer in <em>Staphylococcus aureus</em>

Abstract

One important feature of the major opportunistic human pathogen Staphylococcus aureus is its extraordinary ability to rapidly acquire resistance to antibiotics. Genomic studies reveal that S. aureus carries many virulence and resistance genes located in mobile genetic elements, suggesting that horizontal gene transfer (HGT) plays a critical role in S. aureus evolution. However, a full and detailed description of the methodology used to study HGT in S. aureus is still lacking, especially regarding natural transformation, which has been recently reported in this bacterium. This work describes three protocols that are useful for the in vitro investigation of HGT in S. aureus: conjugation, phage transduction, and natural transformation. To this aim, the cfr gene (chloramphenicol/florfenicol resistance), which confers the Phenicols, Lincosamides, Oxazolidinones, Pleuromutilins, and Streptogramin A (PhLOPSA)-resistance phenotype, was used. Understanding the mechanisms through which S. aureus transfers genetic materials to other strains is essential to comprehending the rapid acquisition of resistance and helps to clarify the modes of dissemination reported in surveillance programs or to further predict the spreading mode in the future.

Prevalence, Enterotoxigenic Potential and Antimicrobial Resistance of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Algerian Ready to Eat Foods

“…They can be encoded in prophages, plasmids, or chromosomal pathogenicity islands. The location of the se and sel genes on mobile genetic elements presents an additional risk factor in S. aureus food intoxication, due to possible horizontal gene transfer [14].…”

Susceptibility and molecular characterization of mec A- and mec B-positive community acquired methicillin-resistant Staphylococcus aureus isolates from students

“…Horizontal gene transfers occurs through conjugation, transduction and natural transformation. Conjugation can be stimulated in S. aureus, transduction is efficient in the organism, and it is capable of natural transformation [1,32,33] The mecB usually found on chromosome and plasmids of Macrococcus caseolyticus [39] was observed in some isolates in this study. Four groups of mecA have been identified, mecA1, mecA2, mecB, mecC.…”

Self-limiting paratransgenesis

“…Bacteria that do not inherit a plasmid may have a fitness advantage in that they multiply faster. In addition, plasmid loss rate as bacteria multiply depends on plasmid rate of replication that in turn determines P lasmid C opy N umber per bacterium (PCN) [ 16 , 17 ]. In support of this assertion, plasmid pHL662 that has a PCN 14.6 is lost faster ( Fig 1 ) than plasmid punc-119c that has a PCN 37.8 ( S3 Table ).…”