Suzi P de Carvalho1, Jéssica B de Almeida1,2, Leandro M de Freitas2, Ana Marcia S Guimarães3, Naíla C do Nascimento4, Andrea P Dos Santos4, Guilherme B Campos2, Joanne B Messick4, Jorge Timenetsky3, Lucas M Marques2,1,3. 1. Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus 45662-900, Bahia State, Brazil. 2. Multidisciplinary Institute of Health, Universidade Federal da Bahia, Rio de Contas Street, Square 17, Number 58, Candeias, Vitória da Conquista, 45029-094, Bahia State, Brazil. 3. Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, 1374 Professor Lineu Prestes Avenue, Sao Paulo, 05508-900, São Paulo State, Brazil. 4. Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA.
Abstract
PURPOSE: Comparative genomic analysis of strains may help us to better understand the wide diversity of their genetic profiles. The aim of this study was to analyse the genomic features of the resistome and virulome of Brazilian first methicillin-resistant Staphylococcus aureus (MRSA) isolates and their relationship to other Brazilian and international MRSA strains. METHODOLOGY: The whole genomes of three MRSA strains previously isolated in Vitória da Conquista were sequenced, assembled, annotated and compared with other MRSA genomes. A phylogenetic tree was constructed and the pan-genome and accessory and core genomes were constructed. The resistomes and virulomes of all strains were identified.Results/Key findings. Phylogenetic analysis of all 49 strains indicated different clones showing high similarity. The pan-genome of the analysed strains consisted of 4484 genes, with 31 % comprising the gene portion of the core genome, 47 % comprising the accessory genome and 22 % being singletons. Most strains showed at least one gene related to virulence factors associated with immune system evasion, followed by enterotoxins. The strains showed multiresistance, with the most recurrent genes conferring resistance to beta-lactams, fluoroquinolones, aminoglycosides and macrolides. CONCLUSIONS: Our comparative genomic analysis showed that there is no pattern of virulence gene distribution among the clones analysed in the different regions. The Brazilian strains showed similarity with clones from several continents.
PURPOSE: Comparative genomic analysis of strains may help us to better understand the wide diversity of their genetic profiles. The aim of this study was to analyse the genomic features of the resistome and virulome of Brazilian first methicillin-resistant Staphylococcus aureus (MRSA) isolates and their relationship to other Brazilian and international MRSA strains. METHODOLOGY: The whole genomes of three MRSA strains previously isolated in Vitória da Conquista were sequenced, assembled, annotated and compared with other MRSA genomes. A phylogenetic tree was constructed and the pan-genome and accessory and core genomes were constructed. The resistomes and virulomes of all strains were identified.Results/Key findings. Phylogenetic analysis of all 49 strains indicated different clones showing high similarity. The pan-genome of the analysed strains consisted of 4484 genes, with 31 % comprising the gene portion of the core genome, 47 % comprising the accessory genome and 22 % being singletons. Most strains showed at least one gene related to virulence factors associated with immune system evasion, followed by enterotoxins. The strains showed multiresistance, with the most recurrent genes conferring resistance to beta-lactams, fluoroquinolones, aminoglycosides and macrolides. CONCLUSIONS: Our comparative genomic analysis showed that there is no pattern of virulence gene distribution among the clones analysed in the different regions. The Brazilian strains showed similarity with clones from several continents.