| Congresso Brasileiro de Microbiologia 2023 | Resumo: 80-1 | ||||
Resumo:This study reports the genomic findings of the first report of a Salmonella isolate carrying blaCTX-M-55 gene, recovered from a bacteremic patient from Brazil. Bacterial isolate positive for blaCTX-M-55 gene was submitted to antimicrobial susceptibility testing by disk diffusion and epsilometric test. The isolate was submitted to whole genome sequencing by Illumina technology and downstream analysis. Matching out assays were performed by conjugation, plasmid sizes determined by S1-PFGE and plasmid content were investigated by hybrid assembly after MinIon long reads sequencing. The SNP-analysis was performed by submitting the genomes to CSI phylogeny 1.4 online server (https://cge.cbs.dtu.dk/ services/CSIPhylogeny/). Core genome MLST (cgMLST) was performed in BioNumerics version 8.1 (bioMérieux/Belgium). The comparison was performed using the 219 genomic sequences of Salmonella Agona deposited in the Enterobase database. Isolate 288_18 was identified as sequence type ST13, resistant to ampicillin, cefotaxime, ceftazidime, cefepime, ceftriaxone and aztreonam. A transferable IncFII plasmid sized approximately 67kb was found to carry the blaTEM-1 and blaCTX-M-55 in a module consisting of IS26-blaTEM-1B-WbuC- blaCTX-M-55-IS26. In addition, an 117kb IncI1plasmid was also identified in the 288_18 isolate, but without additional resistance genes. Besides the acquired ESBL gene, a chromosomal point mutation was found in parC gene (parC p.T57S; ACC ➝ AGC; T➝S), related to quinolone resistance. The analysis of SNP’s shows that clinical isolate (288_18) was grouped within a clade formed with ST13 S. Agona isolates from mainly human isolates, followed by animal and food isolates from EUA, England, United Kingdom and Germany. Isolates within this cluster differed by 9-125 SNPs. A minimum spanning tree (MST) based on core-genome MLST showed that the clinical isolate (288_18) is mostly related to strains of human origin from different countries, although it derives from a food strain. To the best of our knowledge, this is the very first report of blaCTM-55 in Salmonella isolated from human infection in Brazil. Occurrence of blaCTX-M-55 in IncFII epidemic plasmid in a relevant clinical human isolate of Salmonella Agona underscores the urgent need for enhanced and effective continuous surveillance for controlling its dissemination.
Palavras-chave: Salmonella Agona, CTX-M-55, IncFII plasmid Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) | |||||