Genomic characterization of Salmonella enterica serovar Choleraesuis from Brazil reveals a swine gallbladder isolate harboring colistin resistance gene mcr-1.1

Author(s)

Vilela, Felipe Pinheiro ; Rodrigues, Dalia dos Prazeres ; Ferreira, Joseane Cristina ; da Costa Darini, Ana Lucia ; Allard, Marc William ; Falcao, Juliana Pfrimer

• Document type: Journal article
• Source: Brazilian Journal of Microbiology; v. 53, n. 4, p. 8-pg., 2022-08-19.

Abstract

Salmonella enterica serovar Choleraesuis (S. Choleraesuis) is a swine-adapted serovar associated to invasive infections in humans. In Brazil, data of strains of this serovar are scarce. In the present study, six S. Choleraesuis strains of animal (n = 5) and human (n = 1) origin from Brazil were screened for phenotypic antimicrobial resistance using disk-diffusion assay and using whole-genome sequencing data to search for antimicrobial resistance genes, plasmids, prophages, and Salmonella pathogenicity islands (SPIs). Its genetic relatedness was evaluated by MLST and SNP analysis. A single isolate from swine gallbladder harbored the colistin resistance gene mcr-1.1 into a IncX4 plasmid. In the six strains analyzed, resistance was found to tetracycline, nalidixic acid, ciprofloxacin, ampicillin, piperacillin, streptomycin, cefazoline, gentamycin, sulfamethoxazole-trimethoprim, and choloramphenicol, along with resistance genes aac(6')-Iaa, aac(3)-IV, aph(3'')-Ib, aph(6)-Id, aph(4)-Ia, aadA1, aph(3')-IIa, bla(TEM-1A), floR, sul1, sul2, tet(B), drfA1, erm(B), mph(B), lnu(G), qacE, and gyrA point mutation Serine83 -> Tyrosine and parC Threonine57 -> Serine. Furthermore, IncF and IncH plasmids, ten SPIs, and seven prophage types were detected. All strains were assigned to ST145 and five belonged to a common SNP cluster of S. Choleraesuis strains from Brazil. The presence of S. Choleraesuis isolated from animals harboring relevant antimicrobial resistance profiles and virulence determinants reinforced the urge for enhanced surveillance to avoid its transmission to humans through food items. (AU)

• FAPESP's process: 19/19338-8 - Genomic, transcriptomic and phenotypic characterization of Campylobacter jejuni strains isolated from diverse source during 20 years in Brazil
• Grantee: Juliana Pfrimer Falcão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/06947-6 - Molecular characterization of the genotypic diversity, resistance profile and pathogenic potential of Salmonella Infantis strains isolated from multiple sources in Brazil
• Grantee: Felipe Pinheiro Vilela
• Support Opportunities: Scholarships in Brazil - Master