Bacteriology Division, Instituto Adolfo Lutz, 351, Doutor Arnaldo Avenue, São Paulo, Brazil.
Sci Rep. 2023 Feb 9;13(1):2299. doi: 10.1038/s41598-023-29599-5.
This study analyzes the genomic findings of the first report of Salmonella isolate carrying the bla gene, recovered from a bacteremic patient from Brazil. A bacterial isolate positive for the bla gene was submitted to antimicrobial susceptibility testing by disk diffusion and epsilometric test. Whole genome sequencing was performed using Illumina technology. Conjugation assay was performed; plasmid sizes determined by S1-PFGE and plasmid content were investigated by hybrid assembly after MinION long reads sequencing. Isolate 288_18 was identified as sequence type ST13, resistant to ampicillin, cefotaxime, ceftazidime, cefepime, ceftriaxone, and aztreonam. A transferable IncFII plasmid sized approximately 67 kb was found to carry the bla and bla in a module consisting of IS26-bla-WbuC-bla-IS26. In addition, an 117 kb IncI1plasmid was also identified in the 288_18 isolate, but without additional resistance genes. To the best of our knowledge, this is the first report of bla in Salmonella isolated from human infection in Brazil. The occurrence of bla in the 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.
本研究分析了来自巴西菌血症患者的携带 bla 基因的沙门氏菌分离株的首个基因组发现。对 bla 基因阳性的细菌分离株进行了药敏试验，包括纸片扩散法和抑菌环试验。使用 Illumina 技术进行全基因组测序。进行了接合试验；通过 S1-PFGE 确定质粒大小，并通过 MinION 长读测序后的杂交组装研究质粒含量。分离株 288_18 被鉴定为序列型 ST13，对氨苄西林、头孢噻肟、头孢他啶、头孢吡肟、头孢曲松和氨曲南耐药。发现一个可转移的 IncFII 质粒，大小约为 67kb，携带 bla 和 bla 基因，位于由 IS26-bla-WbuC-bla-IS26 组成的模块中。此外，在 288_18 分离株中还鉴定出一个 117kb 的 IncI1 质粒，但没有其他耐药基因。据我们所知，这是巴西首例从人类感染中分离出的携带 bla 的沙门氏菌。在相关的肠炎沙门氏菌临床人类分离株中发现 bla 基因位于流行的 IncFII 质粒上，这突显了迫切需要加强和有效持续监测以控制其传播。
