| Autor: |
Silva DNS; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil., Beltrame CO; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil., Botelho AMN; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil., Martini CL; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil., Esteves MAC; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil., Guedes IA; Laboratório Nacional de Computação Científica, Ministério de Ciências, Tecnologia e Inovações, Avenida Getúlio Vargas 333, Quitandinha, Petrópolis 25651-075, RJ, Brazil., Dardenne LE; Laboratório Nacional de Computação Científica, Ministério de Ciências, Tecnologia e Inovações, Avenida Getúlio Vargas 333, Quitandinha, Petrópolis 25651-075, RJ, Brazil., Figueiredo AMS; Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, Cidade Universitária, Rio de Janeiro 21941-902, RJ, Brazil. |
| Abstrakt: |
Multidrug resistance is commonly acquired by transferring DNA from one bacterium to another. However, the mechanisms that enhance the acquisitions of foreign genes are poorly understood, as well as the dynamics of their transmission between hosts in different environments. Here, genomic approaches were applied to evaluate the enrichment of the S. aureus chromosome with resistance traits in groups of genomes with or without anti-restriction genes and to analyze some evolutionary aspects of these acquisitions. Furthermore, the role played by an anti-restriction gene in improving multiresistance in MRSA was investigated by molecular cloning. A strong association was observed between the presence of anti-restriction gene homologs and patterns of multidrug resistance. Human isolates, mainly ST239-SCC mec III, carry ardA -H1, and from animal sources, mainly CC398, carry ardA -H2. Increased DNA transfer was observed for clones that express the ardA -H1 allele, corroborating its role in promoting gene transfer. In addition, ardA -H1 was expressed in the dsDNA format in the BMB9393 strain. The evolution of successful multidrug-resistant MRSA lineages of the ST239 and ST398 was initiated not only by the entry of the mec cassette but also by the acquisition of anti-restriction gene homologs. Understanding the mechanisms that affect DNA transfer may provide new tools to control the spread of drug resistance. |
