Evaluation of Expression of NorA Efflux Pump in Ciprofloxacin Resistant Staphylococcus Aureus Against Hexahydroquinoline Derivative by Real-Time PCR


Staphylococcus aureus causes a wide variety of infections worldwide. Methicillin-resistant S. aureus is one of most common causes of nosocomial and community acquired infections. The fluoroquinolones are an important class of antibiotics that used to treat infections caused by S. aureus. Today, a significant increase in the rate of ciprofloxacin resistance in methicillin-resistant S. aureus strains is concerning. The norA efflux pump is considered as contributors to antibiotic resistance. Here, we aimed to evaluate the expression of norA efflux pump in the presence of hexahydroquinoline derivative in methicillin and ciprofloxacin resistant S. aureus. We were determined minimum inhibitory concentration of ciprofloxacin and hexahydroquinoline derivative and their combination by broth microdilution method against ciprofloxacin resistant S. aureus. The expression of the norA efflux pump gene was evaluated by quantitative Real-time PCR. This study showed that minimum inhibitory concentrations of ciprofloxacin in the presence of hexahydroquinoline derivative in comparison to ciprofloxacin were decreased. Quantitative Real-time PCR identified the increased expression of norA efflux pump gene in methicillin and ciprofloxacin resistant S. aureus strain. The increased expression of norA efflux pump gene may have resulted in the effort of S. aureus to survive. The results showed that the hexahydroquinoline derivative enhanced the antibacterial effect of ciprofloxacin against methicillin and ciprofloxacin resistant S. aureus. Therefore, the derivatives may be used as inhibitors of antibiotic resistance for combination therapy.

Costa SS, Falcao C, Viveiros M, et al. Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus. BMC Microbial 2011;11(1):241.

Havaei SA, Moghadam SO, Pourmand MR, et al. Prevalence of genes encoding bi-component leukocidins among clinical isolates of Methicillin-Resistant Staphylococcus aureus. Iran J Publ Health 2010;39(1):8-14.

Kurlenda J, Grinholc M. Alternative therapies in Staphylococcus aureus diseases. Acta biochim Pol 2012;59(2):171-84.

Neuhauser MM, Weinstein RA, Rydman R, et al. Antibiotic resistance among gram-negative bacilli in US intensive care units: implications for fluoroquinolone use. JAMA 2003;289(7):885-8.

Sahm DF, Critchley IA, Kelly LJ, et al. Evaluation of current activities of fluoroquinolones against gramnegative bacilli using centralized in vitro testing and electronic surveillance. Antimicrob Agents Chemother 2001;45(1):267-74.

Harnett N, Brown S, Krishnan C. Emergence of quinolonen resistance among clinical isolates of methicillin-resistant Staphylococcus aureus in Ontario, Canada. Antimicrob Agents Chemother 1991;35(9):1911-3.

Mesak LR, Davies J. Phenotypic changes in ciprofloxacinresistant Staphylococcus aureus. Res Microbiol 2009;160(10):785-91.

Acar JF, Goldstein FW. Trends in bacterial resistance to fluoroquinolones. Clin Infect Dis 1997;24(1):S67-73.

Schmitz FJ, Fluit AC, Brisse S, et al. Molecular epidemiology of quinolone resistance and comparative in vitro activities of new quinolones against European Staphylococcus aureus isolates. FEMS Immunol Med Mic 1999;26(3-4):281-7.

Drlica K, Malik M. Fluoroquinolones: action and resistance. Curr Top Med Chem 2003;3(3):249-82.

Jacoby GA. Mechanisms of resistance to quinolones. Clin Infect Dis 2005;41(Suppl 2):S120-6.

Savjani JK, Gajjar AK, Savjani KT. Mechanisms of resistance: useful tool to design antibacterial agents for drug-resistant bacteria. Mini-Rev Med Chem 2009;9(2):194-205.

Marquez B. Bacterial efflux systems and efflux pumps inhibitors. Biochimie 2005;87(12):1137-47.

Braga LC, Leite AA, Xavier KG, et al. Synergic interaction between pomegranate extract and antibiotics against Staphylococcus aureus. Can J Microbiol 2005;51(7):541-7.

Schito GC. The importance of the development of antibiotic resistance in Staphylococcus aureus. Clin Microbiol Infect 2006;12(Suppl 1):3-8.

Wright GD. Bacterial resistance to antibiotics: enzymatic degradation and modification. Adv Drug Deliver Rev 2005;57(10):1451-70.

Chan BCL, Ip M, Lau C, et al. Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase. J Ethnopharmacol 2011;137(1):767-73.

Gibbons S. Plants as a source of bacterial resistance modulators and anti-infective agents. Phytochem Rev 2005;4(1):63-78.

Shin S, Pyun MS. Anti-Candida effects of estragole in combination with ketoconazole or amphotericin B. Phytother Res 2004;18(10):827-30.

Stavri M, Piddock LJV, Gibbons S. Bacterial efflux pump inhibitors from natural sources. J Antimicrob Chemoth 2007;59(6):1247-60.

Shahverdi AR, Rafii F, Tavassoli F, et al. Piperitone from Mentha longifolia var. chorodictya Rech F. reduces the nitrofurantoin resistance of strains of enterobacteriaceae. Phytother Res 2004;18(11):911-14.

Rafii F, Shahverdi AR. Comparison of essential oils from three plants for enhancement of antimicrobial activity of nitrofurantoin against enterobacteria. Chemotherapy 2007;53(1):21-5.

Shahverdi AR, Monsef-Esfahani HR, Tavasoli F, et al. Trans-cinnamaldehyde from Cinnamomum zeylanicum bark essential oil reduces the clindamycin resistance of Clostridium difficile in vitro. J Food Sci 2007;72(1):55-8.

Laue H, Weiss L, Bernardi A, et al. In vitro activity of the novel diaminopyrimidine, iclaprim, in combination with folate inhibitors and other antimicrobials with different mechanisms of action. J Antimicrob Chemoth 2007;60(6):1391-4.

Lak P, Amini M, Safavi M, et al. Enhancement of the antibacterial activity of ciprofloxacin against Staphylococcus aureus by 3-alkyl esters and 3-aryl esters of hexahydroquinoline derivatives. Arznei-Forschung 2008;58(9):464-8.

Wayne PA. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing. 21th Inform Suppl 2011;31(1):M100-S21.

Couto I, Costa SS, Viveiros M, et al. Efflux-mediated response of Staphylococcus aureus exposed to ethidium bromide. J Antimicrob Chemoth 2008;62(3):504-13.

Ding Y, Onodera Y, Lee JC, et al. NorB, an efflux pump in Staphylococcus aureus strain MW2, contributes to bacterial fitness in abscesses. J Bacteriol 2008;190(21):7123-9.

Yousefi M, Pourmand MR, Shahverdi AR, et al. Minimum inhibitory concentration of ciprofloxacin in combination with hexahydroquinoline derivatives against Staphylococcus aureus. Tehran Univ Med J 2012;70(9):525-30.

Kumar A, Khan IA, Koul S, et al. Novel structural analogues of piperine as inhibitors of the NorA efflux pump of Staphylococcus aureus. J Antimicrob Chemoth 2008;61(6):1270-6.

German N, Kaatz GW, Kerns RJ. Synthesis and evaluation of PSSRI-based inhibitors of Staphylococcus aureus multidrug efflux pumps. Bioorg Med Chem Lett 2008;18(4):1368-73.

IssueVol 52, No 6 (2014) QRcode
Staphylococcus aureus Ciprofloxacin Hexahydroquinoline derivative NorA efflux pump

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
Pourmand MR, Yousefi M, Salami SA, Amini M. Evaluation of Expression of NorA Efflux Pump in Ciprofloxacin Resistant Staphylococcus Aureus Against Hexahydroquinoline Derivative by Real-Time PCR. Acta Med Iran. 1;52(6):424-429.