Advanced Biomedical Research

Efflux pump regulatory genes mutations in multidrug resistance Pseudomonas aeruginosa isolated from wound infections in Isfahan hospitals

Authors

1 Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Infectious Disease Research, Imammosa Kazem Hospital, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Multidrug resistance Pseudomonas aeruginosa (MDR-P. aeruginosa) is a worldwide threat for public health. Hyperexpression of efflux pump systems (MexAB-OprM and MexCD-OprJ), which is a well-known mechanisms for MDR emerging, is controlled by regulatory genes, mexR and nfxB, respectively. The aim of this study was to evaluate point mutations in mexR and nfxB genes in MDR- P. aeruginosa isolated from wound infections.
Materials and Methods: A total of 34 P. aeruginosa cultures obtained from wound infections were analyzed. Among them eight isolates identified as MDR-P. aeruginosa and were subjected to determination of mutations in mexR and nfxB genes.
Results: We detected eight-point mutations in mexR and 12-point mutations in nfxB. The most common mutations were common G327-A (eight isolates), G384-A (eight isolates), G411-A (eight isolates). Mutations in A371-C and A372-C were the predominant substitution which was seen in nfxB. Amino acid substitutions were also found at position 124 and 126 for NfxB and MexR, respectively.
Conclusions: P. aeruginosa isolates with mutation in efflux pump regulatory genes such as mexR and nfxB could be a main factor contributed to antibiotic resistance and must be considered in antibiotic treatment.

Keywords

1. Forbes BA, Sahm DF, Weissfeld AS. Bailey and Scott's Diagnostic Microbiology. 12 th ed. USA: Elsevier; 2007. p. 340-50.  Back to cited text no. 1
    
2. Strateva T, Yordanov D. Pseudomonas aeruginosa: A phenomenon of bacterial resistance. J Med Microbiol 2009;58:1133-48.  Back to cited text no. 2
    
3. Lister PD, Wolter DG, Hanson ND. Antibacterial-resistant Pseudomonas aeruginosa: Clinical impact and complex regulation of chromosomally encoded resistance mechanisms. Clin Microbiol Rev 2009;22:582-610.  Back to cited text no. 3
    
4. Schweizer HP. Efflux as mechanism of resistance to antimicrobials in Pseudomonas aeruginosa and related bacteria: Unanswered questions. Genet Mol Res 2003;2:48-62.  Back to cited text no. 4
[PUBMED]    
5. Alekshun MN, Levy SB. Molecular mechanisms of antibacterial multidrug resistance. Cell 2007;128:1037-150.  Back to cited text no. 5
    
6. Ozer B, Duran N, Onlen Y, Savas L. Efflux pump genes and antimicrobial resistance of Pseudomonas aeruginosa strains isolated from lower respiratory tract infections acquired in an intensive care unit. J Antibiot (Tokyo) 2012;65:9-13.  Back to cited text no. 6
    
7. Llanes L, Hocquet D, Vogne C, Baitich DB, Neuwirth C, Plesiat P. Clinical strains of Pseudomonas aeruginosa overproducing MexAB-OprM and MexXY efflux pumps simultaneously. Antimicrob Agents Chemother 2004;48:1797-802.  Back to cited text no. 7
    
8. Poole K, Tetro K, Zhao Q, Neshat S, Heinrichs DE, Bianco N. Expression of the multidrug resistance operon mexA-mexBoprMin Pseudomonas aeruginosa: mexR encodes a regulator of operon expression. Antimicrob Agents Chemother 1996;40:2021-8.  Back to cited text no. 8
    
9. Jeannot K, Elsen S, Kohler T, Delden CV, Plesiat P. Resistance and virulence of Pseudomonas aeruginosa clinical strains overproducing the MexCD-OprJ efflux pump. Antimicrob Agents Chemother 2008;52:2455-62.  Back to cited text no. 9
    
10. Adewoye L, Sutherland A, Srikumar R, Poole K, The MexR repressor of the mexAB-oprM multidrug efflux operon in Pseudomonas aeruginosa: Characterization of mutations compromising activity. J Bacteriol 2002;184:4308-12.  Back to cited text no. 10
    
11. Dumas JL, Delden CV, Perron K, Kohler T. Analysisofantibiotic resistance gene expression in Pseudomonas aeruginosa by quantitative real-time-PCR. FEMS Microbiol Lett 2006;254:217-25.  Back to cited text no. 11
    
12. Higgins PG, Fluit AC, Milatovic D, Verhoef J, Schmitz FJ. Mutations in GyrA, ParC, MexR and NfxB in clinical isolates Pseudomonas aeruginosa. Int J Antimicrob Agents 2003;21:409-13.  Back to cited text no. 12
    
13. Magiorakos AP, Srinivasan A, Carey RB, Carmeli Y, Falagas ME, Giske CG, et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: An international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect 2012;18:268-81.  Back to cited text no. 13
    
14. Pena C, Zorrilla SG, Oriol I, Tubau F, Dominguez MA, Pujol M. Impact of multidrug resistance on Pseudomonas aeruginosa ventilator-associated pneumonia outcome: Predictors of early and crude mortality. Eur J Clin Microbiol Infect Dis 2013;32:413-20.  Back to cited text no. 14
    
15. Morales E, Cots F, Sala M, Comas M, Belvis F, Riu M. Hospital costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition. BMC Health Serv Res 2012;12:1-8.  Back to cited text no. 15
    
16. Mahon C, Lehman D, Manuselis G. Text Book of Diagnostic Microbiology, 4 th ed. USA: Elsevier; 2011. p. 480-90.  Back to cited text no. 16
    
17. Tyler SD, Strathdee CA, Rozee KR, Johnson WM. Oligonucleotide primers designed to differentiate pathogenic Pseudomonas on the basis of the sequencing of genes coding for 16S-23S rRNA internal transcribed spacers. Clin Diagn Lab Immunol 1995;2:448-53.  Back to cited text no. 17
    
18. National Committee for Clinical Laboratory Standards, Ed.,"Prefomance standards for antimicrobial disk susceptibility tests," Approved Standards M100- S22, National Committee for Clinical Laboratory Standards, Wayne, Pa, USA, 2012.  Back to cited text no. 18
    
19. Gorgani N, Ahlbrand S, Patterson A, Pourmand N. Detection of point mutations associated with antibiotic resistance in Pseudomonas aeruginosa. Int J Antimicrob Agents 2009;34:414-8.  Back to cited text no. 19
    
20. Jeannot K, Elsen S, Kohler T, Attree I, Delden CV, Plesiat P. Resistance and virulence of Pseudomonas aeruginosa clinical strains overproducing the MexCD-OprJ efflux pump. Antimicrob Agents Chemother 2008;52:2455-62.  Back to cited text no. 20
    
21. Breidenstein EB, Nunez CD, Hancock RE. Pseudomonas aeruginosa: All roads lead to resistance. Trends Microbiol 2011;19:419-26.  Back to cited text no. 21
    
22. Hirsch EB, Tam VH. Impact of multidrug-resistant Pseudomonas aeruginosa infection on patient outcomes. Expert Rev Pharmacoecon Outcomes Res 2010;10:441-51.  Back to cited text no. 22
    
23. Soto SM. Role of efflux pumps in the antibiotic resistance of bacteria embedded in a biofilm. Virulence 2013;4:1-7.  Back to cited text no. 23
    
24. Livermore DM. Multiple mechanisms of antimicrobial resistance in Pseudomonas aeruginosa: Our worst nightmare?. Clin Infect Dis 2002;34:634-40.  Back to cited text no. 24
[PUBMED]    
25. Hooper DC. Efflux pumps and nosocomial antibiotic resistance: A primer for hospital epidemiologists. Clin Infect Dis 2005;40:1811-7.  Back to cited text no. 25
[PUBMED]    
26. Anderson C, Jalal S, Aili D, Wang Y, Islam S, Jarl A. Critical biophysical properties in Pseudomonas aeruginosa efflux gene regulator MexR are targeted by mutations conferring multidrug resistance. Protein Sci 2010;19:680-92.  Back to cited text no. 26
    
27. Tomas M, Doumith M, Warner M, Turton JF, Beceiro A, Bou G. Efflux pumps, OprD Porin, AmpC β-Lactamase, and multiresistance in Pseudomonas aeruginosa isolates from cystic fibrosis patients. Antimicrob Agents Chemother 2010;54:2219-24.  Back to cited text no. 27
    
28. Henrichfreise B, Wiegand I, Pfister W, Wiedemann B. Resistance mechanisms of multiresistant Pseudomonas aeruginosa strains from germany and correlation with hypermutation. Antimicrob Agents Chemother 2007;51:4062-70.  Back to cited text no. 28
    
29. Suman G, Khan M, Sabitha K, Jamil K. Mutation in mexR-gene leading to drug resistance in corneal keraitis in human. Indian J Exp Biol 2006;44:929-36.  Back to cited text no. 29
    
30. Hocquet D, Bertrand X, Kohler T, Talon D, Plesiat P. Genetic and phenotypic variations of a resistant Pseudomonas aeruginosa epidemic clone. Antimicrob Agents Chemother 2003;47:1887-94.  Back to cited text no. 30
    
31. Jalal S, Ciofu O, Høiby N, Gotoh N, Wretlind B. Molecular mechanisms of fluoroquinolone resistance in Pseudomonas aeruginosa isolates from cystic fibrosis patients. Antimicrob Agents Chemother 2000;44:710-2.  Back to cited text no. 31
    
32. Morita Y, Cao L, Gould VC, Avison MB, Poole K. NalD encodes a second repressor of the MexAB-OprM multidrug efflux operon of Pseudomonas aeruginosa. J Bacteriol 2006;188:8649-54.  Back to cited text no. 32
    
33. Sobel ML, Hocquet D, Cao L, Plesiat P, Poole K. Mutations in PA3574 (nalD) lead to increased MexAB-OprM expression and multidrug resistance in laboratory and clinical isolates of Pseudomonas aeruginosa. Antimicrob Agents Chemother 2005;49:1782-6.  Back to cited text no. 33
Advanced Biomedical Research
Volume 2014, May
May 2014
Pages 1-5