Natural transformation allows transfer of SCCmec-mediated methicillin resistance in Staphylococcus aureus biofilms

Mais Maree (1) , Le Thuy Thi Nguyen , Ryosuke Ohniwa (2, 1) , Masato Higashide , Tarek Msadek (2) , Kazuya Morikawa (1)

1 Université de Tsukuba = University of Tsukuba
2 Biologie des Bactéries pathogènes à Gram-positif - Biology of Gram-Positive Pathogens

SCCmec is a large mobile genetic element that includes the mecA gene and confers resistance to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA). There is evidence that SCCmec disseminates among staphylococci, but the transfer mechanisms are unclear. Here, we show that two-component systems mediate the upregulation of natural competence genes in S. aureus under biofilm growth conditions, and this enhances the efficiency of natural transformation. We observe SCCmec transfer via natural transformation from MRSA, and from methicillin-resistant coagulase-negative staphylococci, to methicillinsensitive S. aureus. The process requires the SCCmec recombinase genes ccrAB, and the stability of the transferred SCCmec varies depending on SCCmec types and recipients. Our results suggest that natural transformation plays a role in the transfer of SCCmec and possibly other mobile genetic elements in S. aureus biofilms.

Domaines: Sciences du Vivant [q-bio]

Mais Maree, Le Thuy Thi Nguyen, Ryosuke Ohniwa, Masato Higashide, Tarek Msadek, et al.. Natural transformation allows transfer of SCCmec-mediated methicillin resistance in Staphylococcus aureus biofilms. Nature Communications, 2022, 13 (1), pp.2477. ⟨10.1038/s41467-022-29877-2⟩. ⟨pasteur-03671424⟩