RamA, a transcriptional regulator conferring florfenicol resistance in Leclercia adecarboxylata R25
Autor: | Licheng Zhu, Danying Zhou, Yuanyuan Ying, Cong Cheng, Qiyu Bao, Mei Zhu, Aifang Li, Junwan Lu |
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Rok vydání: | 2019 |
Předmět: |
Florfenicol
Drug resistance Microbial Sensitivity Tests Molecular cloning Biology Microbiology 03 medical and health sciences chemistry.chemical_compound Gene Knockout Techniques Bacterial Proteins Enterobacteriaceae Drug Resistance Multiple Bacterial RNA Ribosomal 16S Escherichia coli Cloning Molecular Gene Gene knockout Leclercia adecarboxylata 030304 developmental biology Regulator gene Genetics Thiamphenicol 0303 health sciences Whole Genome Sequencing 030306 microbiology Comparative genomics Computational Biology General Medicine ramA Resistance-nodulation-division Anti-Bacterial Agents Complementation chemistry Trans-Activators Original Article Efflux |
Zdroj: | Folia Microbiologica |
ISSN: | 1874-9356 |
Popis: | Due to the inappropriate use of florfenicol in agricultural practice, florfenicol resistance has become increasingly serious. In this work, we studied the novel florfenicol resistance mechanism of an animal-derived Leclercia adecarboxylata strain R25 with high-level florfenicol resistance. A random genomic DNA library was constructed to screen the novel florfenicol resistance gene. Gene cloning, gene knockout, and complementation combined with the minimum inhibitory concentration (MIC) detection were conducted to determine the function of the resistance-related gene. Sequencing and bioinformatics methods were applied to analyze the structure of the resistance gene-related sequences. Finally, we obtained a regulatory gene of an RND (resistance-nodulation-cell division) system, ramA, that confers resistance to florfenicol and other antibiotics. The ramA-deleted variant (LA-R25ΔramA) decreased the level of resistance against florfenicol and several other antibiotics, while a ramA-complemented strain (pUCP24-prom-ramA/LA-R25ΔramA) restored the drug resistance. The whole-genome sequencing revealed that there were five RND efflux pump genes (mdtABC, acrAB, acrD, acrEF, and acrAB-like) encoded over the chromosome, and ramA located upstream of the acrAB-like genes. The results of this work suggest that ramA confers resistance to florfenicol and other structurally unrelated antibiotics, presumably by regulating the RND efflux pump genes in L. adecarboxylata R25. |
Databáze: | OpenAIRE |
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