Antimicrobial resistance and genetic background of non-typhoidal Salmonella enterica strains isolated from human infections in Sao Paulo, Brazil (2000-2019)

Author(s):Show less -

Calarga, Aline Parolin ; Pardini Gontijo, Marco Tulio ; Paula de Almeida, Luiz Gonzaga ; Ribeiro de Vasconcelos, Ana Tereza ; Nascimento, Leandro Costa ; Cotrim de Moraes Barbosa, Taise Marongio ; de Carvalho Perri, Thalita Mara ; dos Santos, Silvia Regina ; Tiba-Casas, Monique Ribeiro ; Lemes Marques, Eneida Goncalves ; Ferreira, Cleide Marques ; Brocchi, Marcelo

• Document type: Journal article
• Source: Brazilian Journal of Microbiology; v. 53, n. 3, p. 14-pg., 2022-04-21.

Abstract

Salmonella enterica causes Salmonellosis, an important infection in humans and other animals. The number of multidrug-resistant (MDR) phenotypes associated with Salmonella spp. isolates is increasing worldwide, causing public health concern. Here, we aim to characterize the antimicrobial-resistant phenotype of 789 non-typhoidal S. enterica strains isolated from human infections in the state of Sao Paulo, Brazil, along 20 years (2000-2019). Among the non-susceptible isolates, 31.55, 14.06, and 13.18% were resistant to aminoglycosides, tetracycline, and beta-lactams, respectively. Moreover, 68 and 11 isolates were considered MDR and Extended Spectrum beta-Lactamase (ESBL) producers, respectively, whereas one isolate was colistin-resistant. We selected four strains to obtain a draft of the Genome Sequence; one S. Infantis (ST32), one S. Enteritidis (ST11), one S. I 4,[5],12:i:- (ST19), and one S. Typhimurium (ST313). Among them, three presented at least one of the following antimicrobial resistance genes (AMR) linked to mobile DNA: bla(TEM-1B), dfrA1, tetA, sul1, floR, aac(6')-laa, and qnrE1. This is the first description of the plasmid-mediated quinolone resistance (PMQR) gene qnrE1 in a clinical isolate of S. I 4,[5],12:i:-. The S. Typhimurium is a colistin-resistant isolate, but did not harbor mcr genes, but it presented mutations within the mgrB, pmrB, and pmrC regions that might be linked to the colistin-resistant phenotype. The virulence pattern of the four isolates resembled the virulence pattern of the highly pathogenic S. Typhimurium UK-1 reference strain in assays involving the in vivo Galleria mellonella model. In conclusion, most isolates studied here are susceptible, but a small percentage present an MDR or ESBL-producer and pathogenic phenotype. Sequence analyses revealed plasmid-encoded AMR genes, such as beta-lactam and fluoroquinolone resistance genes, indicating that these characteristics can be potentially disseminated among other bacterial strains. (AU)

• FAPESP's process: 17/10051-2 - Biotechnological potential and phenotypic and molecular characterization of Salmonella enterica mutants
• Grantee: Marcelo Brocchi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/13412-8 - Salmonella enterica: roles of NAPS in pathogenicity and virulence
• Grantee: Marcelo Brocchi
• Support Opportunities: Regular Research Grants