RESUMO
The use of phenicol antibiotics in animals has increased. In recent years, it has been reported that the transferable gene mediates phenicol-oxazolidinone resistance. This study analyzed the prevalence and characteristics of phenicol-oxazolidinone resistance genes in Enterococcus faecalis and Enterococcus faecium isolated from food-producing animals and meat in Korea in 2018. Furthermore, for the first time, we reported the genome sequence of E. faecalis strain, which possesses the phenicol-oxazolidinone resistance gene on both the chromosome and plasmid. Among the 327 isolates, optrA, poxtA, and fexA genes were found in 15 (4.6%), 8 (2.5%), and 17 isolates (5.2%), respectively. Twenty E. faecalis strains carrying resistance genes belonged to eight sequence types (STs), and transferability was found in 17 isolates. The genome sequences revealed that resistant genes were present in the chromosome or plasmid, or both. In strains EFS17 and EFS108, optrA was located downstream of the ermA and ant(9)-1 genes. The strains EFS36 and EFS108 harboring poxtA-encoding plasmid cocarried fexA and cfr(D). These islands also contained IS1216E or the transposon Tn554, enabling the horizontal transfer of the phenicol-oxazolidinone resistance with other antimicrobial-resistant genes. Our results suggest that it is necessary to promote the prudent use of antibiotics through continuous monitoring and reevaluation.
Assuntos
Anti-Infecciosos/farmacologia , Cloranfenicol/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Enterococcus faecalis/genética , Enterococcus faecium/genética , Carne/microbiologia , Oxazolidinonas/farmacologia , Animais , Bovinos/microbiologia , Biologia Computacional , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/isolamento & purificação , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/isolamento & purificação , Análise de Alimentos , Transferência Genética Horizontal , Genes Bacterianos/efeitos dos fármacos , Genoma Bacteriano , Tipagem de Sequências Multilocus , Plasmídeos , República da Coreia , Suínos/microbiologia , Sequenciamento Completo do GenomaRESUMO
As interest in probiotics increases, the need for accurate description of probiotic compositions present in commercial products is also increasing. Since Bifidobacterium longum used as probiotics is labeled at species or subspecies levels, a detection method for distinguishing B. longum subsp. longum, infantis, and suis is needed. Thus, we designed three LAMP primer sets for B. longum subspecies. Each primer set was specific for the target subspecies. The detection level was 0.2 pg for each target DNA (about 102 CFU/mL). To apply these LAMP assays to on-site detection, a direct DNA extraction method was optimized and combined with LAMP assay. Finally, direct LAMP assays were used to monitor the presence of B. longum subspecies in 16 probiotic products. They could specifically and sensitively detect target subspecies within approximately 45 min. These rapid on-site detection methods are useful for identifying B. longum subspecies in probiotic products.
