With the identification of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2004, research on that topic has been intensified worldwide during the last decade. In Germany, the research consortium MedVet-Staph, which includes researchers from human and veterinary medicine, has started in 2011. One of the tasks within MedVet-Staph is the identification of novel and uncommon resistance genes.

In the years before MedVet-Staph, several novel and uncommon resistance genes have been identified in LA-MRSA. These comprised the multiresistance gene cfr, which confers combined resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins and streptogramin A antibiotics, the trimethoprim resistance gene dfrK, the lincosamide-pleuromutilin-streptogramin A resistance gene vga(C) and the macrolide-lincosamide-streptogramin B resistance gene erm(T). In 2011, the first and so far only staphylococcal apramycin resistance gene, apmA, has been identified on large multiresistance plasmids. Moreover, small plasmids of an unusual structure carrying the genes apmA or dfrK were identified in 2012. In addition, the pleuromutilin-lincosamide-streptogramin A resistance gene vga(E), first described in 2011, was detected in LA-MRSA from cattle, poultry and food of poultry origin in 2012. A variant of vga(E) was identified on plasmids in porcine coagulase-negative staphylococci. In 2013, the pleuromutilin-lincosamide-streptogramin A resistance gene lsa(E) and the spectinomycin resistance gene spw were described. Both genes were part of different types of multiresistance gene clusters of enterococcal origin. These multiresistance gene clusters were initially found in human MRSA ST398 and in MSSA and MRSA ST9 of human and animal origin. Most recently, relics of these multiresistance gene clusters have also been detected in the chromosomal DNA of various coagulase-negative staphylococci. The latest novel resistance gene, the spectinomycin resistance gene spd, has been described in 2014. This gene was detected in MRSA CC398 of various origins from Belgium, The Netherlands, Germany and Austria, but also in porcine MSSA ST433 from Germany. A new variant of the spd gene has recently been identified on structurally diverse plasmids in porcine Staphylococcus hyicus and coagulase-negative staphylococci from Germany.