title: Genotypic diversity, pathogenic potential and the resistance profile of Salmonella Typhimurium strains isolated from humans and food from 1983 to 2013 in Brazil.
abstract: Salmonella enterica subsp. enterica serovar Typhimurium is one of the leading serovars that causes salmonellosis worldwide. However, few studies have molecularly characterized S. Typhimurium strains in Brazil. In this study, we genotyped 92 S. Typhimurium strains isolated from humans (43) and food (49) between 1983 and 2013 in Brazil using PFGE, multiple-locus variable number of tandem repeats analysis (MLVA) and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Moreover, we assessed the frequency of 12 virulence markers by PCR and the resistance profile against 12 antimicrobials. More than 85.8% of the strains studied carried 11 of the virulence markers or more. Thirty-three strains (25%) were multidrug resistant (MDR). The 92 S. Typhimurium studied were grouped by PFGE as PFGE-A, PFGE-B1 and PFGE-B2; by MLVA as MLVA-A, MLVA-B1 and MLVA-B2; and, finally, by ERIC-PCR as ERIC-A and ERIC-B. The strains isolated from humans before the mid-1990s were allocated to all clusters. The strains isolated from humans after the mid-1990s were distributed in the PFGE-B1, MLVA-B1, MLVA-B2 and ERIC-A clusters. The strains isolated from food were distributed in all clusters, except in PFGE-B2. All typing results suggested that the S. Typhimurium strains of human clinical origin isolated before the mid-1990s were genetically more diverse, which might indicate the selection of a more adapted S. Typhimurium subtype after Salmonella Enteritidis became the most prevalent serovar in Brazil. Regarding strains isolated from food, the results suggest the current circulation of more than one subtype. Furthermore, the high frequency of virulence genes and the presence of MDR strains reinforces their potential hazard for humans and the risk of their presence in foods in Brazil.
authors: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas - Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n°, Ribeirão Preto, SP, Brasil.
authors: Fernanda
authors: F
authors: Almeida
authors: Centro de Laboratório Regional de Ribeirão Preto - Instituto Adolfo Lutz, Rua Minas 877, Ribeirão Preto, SP, Brasil.
authors: Marta Inês Cazentini
authors: MIC
authors: Medeiros
authors: Laboratório de Enterobactérias, FIOCRUZ/Fundação Instituto Oswaldo Cruz, Avenida Brasil, 4365, Pavilhão Rocha Lima, 3°andar, Manguinhos, 21040-360 Rio de Janeiro, RJ, Brasil.
authors: Dália Dos Prazeres
authors: DDP
authors: Rodrigues
authors: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas - Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n°, Ribeirão Preto, SP, Brasil.
authors: Juliana Pfrimer
authors: JP
authors: Falcão
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001938:Brazil; D024881:Drug Resistance, Bacterial; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D037521:Virulence Factors