Overexpression of mfpA Gene Increases Ciprofloxacin Resistance in Mycobacterium smegmatis. (22nd March 2021)

• Record Type: Journal Article
• Authors: Falco, Aura; Aranaga, Carlos; Ocampo, Ivan; Takiff, Howard
• Other Names: Nardoni Simona Academic Editor.
• Is Part Of: International journal of microbiology. Volume 2021(2021)
• Publication Date: 2021-03-22
• Subjects: Microbiology -- Periodicals; Microbiology; Microbiology -- Periodicals; Electronic journals; Periodicals; 579
• DOI: 10.1155/2021/6689186
• Languages: English
• ISSNs: 1687-918X

Abstract

Abstract : Fluoroquinolones (FQs) are antibiotics useful in the treatment of drug-resistant tuberculosis, but FQ-resistant mutants can be selected rapidly. Although mutations in the DNA gyrase are the principal cause of this resistance, pentapeptide proteins have been found to confer low-level FQ resistance in Gram-negative bacteria. MfpA is a pentapeptide repeat protein conserved in mycobacterial chromosomes, where it is adjacent to a group of four highly conserved genes termed a conservon . We wished to characterize the transcriptional regulation of the mfp A gene and relate its expression to ciprofloxacin resistance in M. smegmatis . Reverse transcription PCR showed that mfp A gene is part of an operon containing the conservon genes. Using a transcriptional fusion, we showed that a promoter was located 5′ to the mfp EA operon. We determined the promoter activity under different growth conditions and found that the expression of the operon increases slightly in late growth phases in basic pH and in subinhibitory concentrations of ciprofloxacin. Finally, by cloning the mfp A gene in an inducible vector, we showed that induced expression of mfp A increases the ciprofloxacin Minimal Inhibitory Concentration. These results confirm that increased expression of the mfp A gene, which is part of the mfp EA operon, increases ciprofloxacin resistance in M. smegmatis .