Genotypic diversity, pathogenic potential and the resistance profile ofSalmonellaTyphimurium strains isolated from humans and food from 1983 to 2013 in Brazil. Issue 11 (November 2015)

• Record Type: Journal Article
• Authors: Almeida, Fernanda; Medeiros, Marta Inês Cazentini; Rodrigues, Dália dos Prazeres; Falcão, Juliana Pfrimer
• Is Part Of: Journal of medical microbiology. Volume 64:Issue 11(2015)
• Publication Date: 2015-11
• Subjects: Medical microbiology -- Periodicals; 616.9041
• DOI: 10.1099/jmm.0.000158
• Languages: English
• ISSNs: 0022-2615

Abstract

Abstract : N/A: 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.