Phenotypic Variation of Tobramycin and Ofloxacin Resistance of Pseudomonas aeruginosa by Repeated Exhibition

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Andry Maharo Andrianarivelo
Christian Emmanuel Mahavy
Blandine Andrianarisoa
Tsiry Rasamiravaka


Pseudomonas aeruginosa has the ability to resist almost all available antibiotics by rapidly accumulating multiple resistance mechanisms and thus lead to a therapeutic impasse and higher mortality in infected patients.

The objective of this study was to assess the phenotypic variation in resistance to tobramycin and ofloxacin from Pseudomonas aeruginosa by repeated exhibition after determination of the minimum inhibitory concentration.

This is a prospective and descriptive study carried out in the Laboratory of Microbiology of Fundamental and Applied Biochemistry (Faculty of Sciences, Antananarivo) during the month of January 2020. The strains studied were the virulent wild strain of Pseudomonas aeruginosa PAO1 supplied by the Laboratory and two clinical strains of Pseudomonas aeruginosa from the Microbiology Laboratory of the Joseph Ravoahangy Andrianavalona University Hospital Center, Antananarivo.

The strains of P. aeruginosa were cultured in the liquid culture medium (which is Luria Bertani, added with a buffer system of 3- (N-morpholino) propanesulfonic acid (LB-MOPS) which will stabilize the pH and a solid culture medium which is Columbia agar. Repeated exhibition to Tobramycin and Ofloxacin from these strains have been made. The MIC is determined by a visual evaluation of the turbidity of the various wells of the microplate.

The MIC value of Pseudomonas aeruginosa with tobramycin and ofloxacin is very variable for the initial MIC until the 5th generation after repeated exhibition. More Pseudomonas aeruginosa is exposed to an antibiotic many times, the more it develops resistance to this antibiotic, even being sensitive at the start. That is to say, clinically, the dose prescribed for the antibiotic has been greatly exceeded if Pseudomonas aeruginosa is repeatedly exposed to the same antibiotic.

Resistance, P. aeruginosa, tobramycin, ofloxacin, repeated exhibition.

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How to Cite
Andrianarivelo, A. M., Mahavy, C. E., Andrianarisoa, B., & Rasamiravaka, T. (2020). Phenotypic Variation of Tobramycin and Ofloxacin Resistance of Pseudomonas aeruginosa by Repeated Exhibition. Journal of Advances in Microbiology, 20(4), 1-9.
Original Research Article


Pavageau JB. Study of the antibiotic resistance gram negative bacteria Pseudomonas aeruginosa and Klebsiella pneumoniae: Which actual and future therapeutic solutions against the resistant bacterial infections? Doctoral Thesis in Pharmacy. Grenoble: Grenoble Alpes University. 2017;152.

Ntsogo Enguene VY. New approach in the fight against antibiotic resistance of bacteria colonizing the lungs of patients with cystic fibrosis: Reconstitution of an efflux pump of Pseudomonas aeruginosa. Doctoral Thesis: Medicine, Toxicology. Chemistry and Imagery. Paris: Paris Descartes University. 2016;319.

Azam Mohd W, Khan Asad U. Updates on the pathogenicity status of Pseudomonas aeruginosa. Drug Discovery Today. 2019;24(1):350359.

Driscoll JA, Brody SL, Kollef MH. The epidemiology, pathogenesis and treatment of Pseudomonas aeruginosa infections. Drugs. 2007;67(3):351-368.

French Ministry of Solidarity and Health; 2016.
Available: Accessed in February 2020

Olivares E. Evaluation of the impact of antibiotics on the formation of biofilms by Pseudomonas aeruginosa: Place of the antibiotic. Doctoral Thesis: Life and Health. Strasbourg: University of Strasbourg. 2017;175.

Rasamiravaka T, Randrianierenana A, Andrianarisoa B, Raherimandimby M. Effect of pH on the antimicrobial susceptibility of planktonic-grown Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus ATCC strains. BMR Microbiol. 2018;4(1):1-4.

Antibiotic Committee of the French Society of Microbiology. Recommendation. 2019;142.

Boutiba Ben Boubaker I. Mechanisms of resistance to fluoroquinolones. Faculty of Medicine of Tunis. 2019;71.

Montalegre R. Assessment of the risk of emergence of resistance of Pseudomonas aeruginosa to various antipyocyanic antibiotics in intensive care. Doctoral Thesis: Medical Biology. Toulouse: Toulouse III University - Paul Sabatier. 2016;94.

ANSM; 2019.
(Accessed: February 2020)

Akasaka T, Tanaka M, Yamaguchi A, Sato K. Type II topoisomerase mutations in fluoroquinolone-resistant clinical strains of Pseudomonas aeruginosa isolated in 1998 and 1999: Role of target enzyme in mechanism of fluoroquinolone resistance. Antimicrob Agents Chemother. 2001;45(8): 2263 2268.

Lee JK, Lee YS, Park YK, Kim BS. Alterations in the GyrA and GyrB subunits of topoisomerase II and the ParC and ParE subunits of topoisomerase IV in ciprofloxacin resistant clinical isolates of Pseudomonas aeruginosa. Int J Antimicrob Agents. 2005;25(4):290-295.

Mérens A, Delacour H, Plésiat P, Cavallo J-D, Jeannot K. Pseudomonas aeruginosa and resistance to antibiotics. Rev Francoph Lab. 2011;435:49-62.

Vettoretti L. Adaptation of resistance mechanisms by active efflux in Pseudomonas aeruginosa strains in cystic fibrosis. Doctoral Thesis: Life and Health Sciences. Burgundy: University of Franche-Comté. 2009;238.

Adabi M, Talebi-Taher M, Arbabi L, Afshar M, Fathizadeh S, Minaeian S, et al. Spread of efflux pump over expressing-mediated fluoroquinolone resistance and multidrug resistance in Pseudomonas aeruginosa by using an efflux pump inhibitor. Infect Chemother. 2015;47(2):98.

Gougeon A. Bacteremia of Pseudomonas aeruginosa: Analysis of 181 bacteremic episodes documented in two hospitals in the North of France. Doctoral Thesis: Medical Biology. Lille: University of Lille 2. 2017;141.

Belotti P, Thabet L, Laffarque A, André C, Coulange-Mayonnove L, Arpin C, et al. Description of an original integron encompassing blaVIM-2, qnrVC1 and genes encoding bacterial group II intron proteins in Pseudomonas aeruginosa. J Antimicrob Chemother. 2015;70.

Monlezun L. Structural and functional studies of the MexAB-OprM efflux pump involved in antibiotic resistance in Pseudomonas aeruginosa. Doctoral Thesis: Human Medicine and Pathology. Paris V: René Descartes University. 2012;262.

Toumi A. Les Aminosides, Infectious Diseases Service-Fattouma Bourguiba - Monastir CHU. 2008;80.

Wright GD. Aminoglycoside-modifying enzymes. Curr Opin Microbiol. 1999;2(5): 499-503.

Le B, O’Hara K, Wong S. Lipopolysaccharide changes in impermeability-type aminoglycoside resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother. 1984;26(2): 250-255.

El’Garch F, Jeannot K, Hocquet D, Llanes-Barakat C, Plesiat P. Cumulative effects of several non enzymatic mechanisms on the resistance of Pseudomonas aeruginosa to aminoglycosides. Antimicrob Agents Chemother. 2007;51(3):1016-1021.

Llanes C, Hocquet D, et al. Clinical strains of Pseudomonas aeruginosa over producing MexAB-OprM and MexXY efflux pumps simultaneously. Antimicrob Agents Chemother. 2004;48(5):1797-1802.

Baba Ahmed-KTZ, Arlet G. News of antibiotic resistance in gram negative bacilli in Algeria. Pathol. Biol. 2014;62:169-178.

Hocquet D, El’Garch F, Vogne C, Plesiat P. Mechanism of adaptive resistance of Pseudomonas aeruginosa to aminoglycosides. Pathol. Biol. 2003; 51(89):443-448.