Highly virulent colistin-susceptible Salmonella Havana ST1524 carrying the mcr-9.1 gene in food

Author(s)

Monte, Daniel F. M. ; Fuga, Bruna ; Pariona, Jesus G. M. ; Vasquez-Ponce, Felipe ; Becerra, Johana ; Keelara, Shivaramu ; Thakur, Siddhartha ; Fedorka-Cray, Paula ; Lincopan, Nilton ; Landgraf, Mariza

• Document type: Journal article
• Source: Microbial Pathogenesis; v. 199, p. 6-pg., 2024-12-27.

Abstract

Salmonella enterica subsp. enterica serovar Havana is a potential pathogenic serotype that can cause human foodborne illness. Therefore, we have conducted a microbiological and genomic surveillance study of Salmonella Havana from food in Brazil. Strikingly, we identified a colistin-susceptible Salmonella Havana strain (NC_STy4) carrying the mcr-9 gene, in salted chicken breast. Genomic analysis revealed that Salmonella Havana strain belonged to the international sequence type (ST) ST1524, circulating at the human-animal-environmental interface. Although the resistome analysis confirmed the presence of mcr-9 and aac(6')-Iaa genes, as well as a parC (Thr57 -> Ser) mutation, this strain exhibited a pansuceptible phenotype. Noteworthy, Salmonella Havana NC_STy4 exhibited a highly virulent behavior, killing 100 % of Galleria mellonella larvae at 13 h post-infection. In this regard, invasins (invA, ibeB), non-fimbrial adherence (misL), fimbrial adherence (fimH), magnesium uptake (mgtB and mgtC), regulation (phoP, phoQ, and pipB), secretion system (ssaHJKLNOQRU), and translocated effector (sopB/sigD and sopE2) virulence genes were predicted. IncHI2 and IncHI2A plasmids were also identified. While these findings underscore the urgent need for surveillance and monitoring foodborne pathogens carrying a wide virulome, colistin-susceptible Salmonella isolates may be silent reservoirs of the mcr genes. (AU)

• FAPESP's process: 16/03044-7 - Genetic diversity, virulence genes and antimicrobial resistance of Salmonella spp. isolated from poultry slaughterhouse
• Grantee: Daniel Farias Marinho Do Monte
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07914-8 - FoRC - Food Research Center
• Grantee: Bernadette Dora Gombossy de Melo Franco
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 17/15967-5 - Whole-genome sequencing approach to study multidrug-resistant Salmonella enterica isolates from Brazilian slaughterhouse
• Grantee: Daniel Farias Marinho Do Monte
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate