| Congresso Brasileiro de Microbiologia 2023 | Resumo: 569-1 | ||||
Resumo:Since polymyxins are one of last resort antibiotics used against carbapenem resistant human pathogens, the dissemination of polymyxin resistance mediated by mcr together with carbapenemase genes, has become a concern worldwide mainly in Enterobacterales. There are currently only five studies in PubMed NCBI reporting Enterobacter spp. carrying mcr-9 gene, and only one isolate carrying mcr-9, blaKPC and blaNDM was reported, in China. This study aims to report a mcr-9.1, blaNDM and blaKPC co-carrying Enterobacter hormaechei subsp. xiangfangensis, a member of the Enterobacter cloacae complex (ECC). The multidrug-resistant isolate GECL0077, identified as Enterobacter hormaechei subsp. xiangfangensis by MALDI-TOF MS, was recovered from a urine culture collected in 2020 from a kidney transplanted inpatient at a tertiary care hospital in Porto Alegre, Rio Grande do Sul state, Brazil. Due to the multidrug resistance phenotype, the isolate was screened for the presence of carbapenemases by high resolution melting-qPCR and it was selected for sequencing. The DNA prep IlluminaTM kit was used to prepare the libraries that were submitted to WGS by MiSeq Illumina. The MinION long-read sequencing libraries were prepared by using the rapid barcoding sequencing kit (SQK-RBK004; Oxford Nanopore). De novo short-reads and hybrid assemblies were done using CLC Genomic Workbench 23. Antimicrobial resistance genes were identified in silico using the QIAGEN Microbial Insight-Antimicrobial Resistance database (QMI-AR). For plasmid assembling, the hybrid contig was annotated in Prokka and curated manually in Geneious using BLAST. Brig was used for circular comparison among our plasmids with those deposited in GenBank. According to the susceptibility profile determined by the disk diffusion method, the isolate was resistant to ceftazidime, cefepime, meropenem, piperacillin/tazobactam, norfloxacin and sulfametoxazol/trimetoprim. The minimal inhibitory concentration (MIC), determined by the broth microdilution method, for polymyxin B was 0.06 mg/L, which categorizes the isolate as susceptible. Whole-genome sequencing revealed that the isolate GECL0077 carry mcr-9.1, blaKPC and blaNDM and belong to ST171. The mcr-9.1 was identified in a megaplasmid of 419,830 bp (pLB_MCR8255) and was classified as IncHI2A/IncHI2. The genetic environment surrounded by this gene is characterized by insertion sequences (IS903B, IS1R and IS26). The qseC and qseB genes are not present in pLB_MCR8255 and this is correlated to the inability to promote resistance to colistin. The E. hormaechei isolate reported in China (ST93), which carries the mcr-9.1 gene, was also susceptible to polymyxin B and lacks these two genes. The blaNDM-1 gene was integrated to the bacterial chromosome in a Tn3000. The blaKPC-2 was identified in an IncL/M plasmid of 86,141bp (pLB_KPC8255) in the genetic environment of the Tn3 family. In Brazil, the presence of mcr-9 gene has been reported in isolates of Enterobacter hormaechei subsp. xiangfangensis from transtracheal aspirate sample and Enterobacter spp. HC193 from urine culture, belonging to plasmid type IncHI2 and IncFIB, respectively. However, this is the first report of an isolate co-harboring plasmids carrying mcr-9, blaKPC and bacterial chromosome gene blaNDM. The prevalence and genetic features of these coexisting plasmids should be monitored to facilitate the establishment of effective strategies to control their further spread Palavras-chave: mcr-9.1, Enterobacter cloacae complex, IncHI2/IncH12A, IncL/M Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundo de Incentivo à Pesquisa e Eventos (FIPE). | |||||