| Congresso Brasileiro de Microbiologia 2023 | Resumo: 282-2 | ||||
Resumo:In recent years, various species of Salmonella spp. have exhibited multidrug resistance, with different antimicrobial resistance genes identified using molecular techniques. This study aimed to assess the presence of antimicrobial resistance genes in Salmonella spp. isolates from chicken carcasses obtained between 2004 and 2019, establishing a temporal comparison. A total of 28 Salmonella spp. isolates were utilized, comprising 12 isolates from 2004, 2005, and 2006 (old group) and 16 isolates from 2019 (new group). Genotypic profiles were obtained via whole genome sequencing. Isolates were cultured in BHI broth at 37°C for 18-24 h, and DNA was extracted using the PureLink™ Genomic DNA Mini Kit (Thermo-Fisher, Waltham, MA, USA). Libraries were prepared using the SureSelectQXT kit (Agilent Technologies, Santa Clara, CA, USA) and sequenced on the Illumina MiSeq platform. Data were analyzed using FastQC for sequence quality, Trimmomatic for undesired sequence removal, and A5-MiSeq for contig and scaffold assembly. Annotations were obtained through UniProtKB database mapping, and gene evaluation employed the ResFinder pipeline. Results showed the Enteritidis serotype predominantly in the old isolate group at 41.66% (5/12), while the Heidelberg serotype prevailed in the new isolate group at 68.75% (11/16). A total of 86 resistance genes were found in both groups, with 36.05% (31/86) conferring resistance to specific antimicrobial classes: 6.97% (6/86) aminoglycosides, 6.97% (6/86) fluoroquinolones, 4.65% (4/86) beta-lactams, 4.65% (4/86) peptide antibiotics, 3.48% (3/86) fosfomycin, 2.32% (2/86) aminocoumarins, 1.16% (1/86) sulfonamides, 1.16% (1/86) phenicols, 1.16% (1/86) tetracyclines, 1.16% (1/86) nitroimidazoles, 1.16% (1/86) triclosan, and 1.16% (1/86) elfamycins. The remaining 63.95% (55/86) represented multidrug resistance genes, with 12.72% (7/55) conferring resistance to up to two antimicrobial classes, 9.09% (5/55) to up to three antimicrobial classes, 3.63% (2/55) to up to four antimicrobial classes, 30.90% (17/55) to five or more antimicrobial classes, and 43.63% (24/55) conferring resistance to metals. Notably, the presence of genes was similar between old and new isolate groups, each harboring 68 genes distributed among specific antimicrobial classes and multidrug resistance. However, genes conferring resistance to cephalosporins, cephamicins, phenicols, sulfonamides, and tetracyclines were exclusively observed in new isolates. Resistance mechanisms were also identified, with the efflux mechanism present in 66.17% (45/68) of old isolate genes and 48.52% (33/68) of new isolate genes. The drug inactivation mechanism occurred in 11.76% (8/68) of old isolate genes and 26.47% (18/68) of new isolate genes, while modification of the drug target was observed in 14.70% (10/68) of old isolate genes and 17.64% (12/68) of new isolate genes. Genes with multiple resistance mechanisms were evenly distributed between old and new groups at 7.35% (5/68) each. This study highlights the significance of genetic sequencing in elucidating resistance mechanisms and monitoring the transmission of antimicrobial resistance genes in foodborne pathogens of animal origin, which are of public health concern. Palavras-chave: food, resistance genes, pathogens, public health Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico – (CNPq). | |||||