Complete substitution of the Brazilian endemic clone by other methicillin-resistant Staphylococcus aureus lineages in two public hospitals in Rio de Janeiro, Brazil

Complete substitution of the Brazilian endemic clone by other methicillin-resistant Staphylococcus aureus lineages in two public hospitals in Rio de Janeiro, Brazil

Brazilian Journal of Infectious Diseases, November 2016

27875687

Raiane Cardoso Chamon, Sthefanie da Silva Ribeiro, Thaina Miranda da Costa, Simone Aranha Nouér, Katia Regina Netto dos Santos

Staphylococcus aureus is an important cause of bloodstream infections (BSI). Therefore, the main purpose of this work was to characterize a collection of 139 S. aureus isolates from BSI in two public hospitals in relation to their antimicrobial susceptibility profile, SCCmec types, and clonal relationship. Methicillin resistance and resistance to other 12 agents were accessed by the disk diffusion test. Minimum inhibitory concentration (MIC) to mupirocin was also determined. The SCCmec types were accessed by multiplex PCR, and the clonal relationship was determined by pulsed field gel electrophoresis method and restriction modification system characterization. Besides, multilocus sequence typing (MLST) was performed for representative methicillin-resistant S. aureus (MRSA) isolates. The military hospital showed a dissemination of the USA100/ST5/CC5/SCCmec II lineage associated to multidrug resistance, including mupirocin resistance, and the teaching hospital presented polyclonal and non-multidrug resistant MRSA isolates. Complete substitution of the Brazilian endemic clone (BEC) by other lineages was found in both hospitals. These findings can highlight differences in policy control and prevention of infections used in the hospitals and a change in the epidemiological profile of MRSA in Brazilian hospitals, with the replacement of BEC, a previously well-established clone, by other lineages.