Factors Triggering the Bacteriophage-Mediated Transduction Mechanism with the Accompanied SCCmec Excision in Lysogenic S. aureus Populations: a study investigating the factors triggering

Kristine Ferning, Laura Martinenghi & Maria Abboud

Studenteropgave: Basisprojekt


Staphylococcus aureus infections have spread worldwide in hospital, community and livestock settings. These infections have become a global health burden due to gained antibiotic resistance obtained from the acquisition of a mobile genetic element, called SCCmec, carrying the resistant mecA gene. Much research has been conducted to illuminate the contents of this element, yet its transfer among S. aureus strains still remains unclear and will in this investigation be studied in light of the research question:

What factors trigger the bacteriophage-mediated transduction mechanism with the accompanied SCCmec excision in a lysogenic population of methicillin-resistant S. aureus?

Previous studies suggest that the mechanism by which this element is transferred is transduction. However, recently, a mechanism has been proposed for resistance spread (by Hanne Ingmer et al. in 2016), called “Auto-Transduction”, in which lysogenic bacteriophages provide their host bacteria with genetic benefits by “stealing” evolutionarily preferential genes, such as the mecA gene, from surrounding bacteria.

This study experimentally investigates these two types of horizontal gene transfer by first lysing different strains of MRSA and MSSA, using both DNA-damaging antibiotics (rifampin and norfloxacin) and UV light, thereby causing bacteriophage induction. Afterwards, the bacteriophage lysates were tested for transducing properties by letting them infect selected bacterial populations. Our results suggest auto-transduction as the mean by which SCCmec transfer is more common among staphylococcal populations than standard transduction, suggesting that prophages and bacteria coexist more symbiotically than previous studies propose, providing each other with the necessary benefits to ensure survival - even under stressful environments.

UddannelserBasis - International Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
Udgivelsesdato29 maj 2017
Antal sider26
VejledereOle Skovgaard