Role of MexA-MexB-OprM efflux pump system in chronic Pseudomonas Aeruginosa pulmonary infection in mice

Abstract

In order to investigate the role of the MexA-MexB-OprM efflux pump system in the pathogenesis of Pseudomonas aeruginosa (PA)-induced pulmonary infection, pulmonary infection models were established by intratracheal injection of K767 (wild type), nalB (MexA-MexB-OprM up-regulated mutant), and ΔmexB (knockout) strains, separately. All mice were treated with Meropenem (intraper Δ itoneal injection, 100 mg/kg body weight, twice every day), and strain-related pathology, bacteria count, cytokine level, myeloperoxidase (MPO, indicator of neutrophil recruitment) activity, and macrophage inflammatory protein-2 (MIP-2) expression were evaluated at early (3rd day post-infection) and late (7th and 14th day post-infection) stages of infection. E-test showed that ΔmexB was more significantly Δ sensitive to panipenan (ETP), meropenem (MP) and imipenem (IP) than K767 and nalB strains. There was no significant difference in sensitivity to cefepime (TM) among the three stains. In contrast to the K767 and nalB groups, the ΔmexB group showed decreased bacteria burden over time and less exte Δ nsive pathological change. Additionally, MPO activity and levels of inflammatory cytokines (IL-1b, IL-12, and TNF-α) were increased at the early stage (day 3) and decreased at the later stage (day 14). Serum MIP-2 expression level was steadily increased in all three groups from early to late stages, but significantly higher in ΔmexB group than in K767 and nalB groups ( Δ P<0.05). In conclusion, the MexA-MexB-OprM efflux pump system might play an important role in PA-induced chronic pulmonary infection. High expression of the MexA-MexB-OprM efflux pump could increase antibacterial resistance and promote infection.

Keywords

Pseudomonas aeruginosa / MexA-MexB-OprM efflux pump / pulmonary infections / MexB / antibacterial resistance

References

[1] MajumdarS., KirbyA., BerryN., et al.. An outbreak of imipenem-resistant Pseudomonas aeruginosa in an intensive care unit. J Hosp Infect, 2004, 58(2): 160-161

[2] HigginsP.G., FluitA.C., MilatovicD., et al.. Antimicrobial susceptibility of imipenem-resistant Pseudomonas aerugi nosa. Antimicrob Agents Chemother, 2002, 50(2): 299-301

[3] MesarosN., NordmannP., Roussel-DelvallezM., et al.. Pseudomonas aeruginosa: resistance and therapeutic options at the turn of the new millennium. Clin Microbiol Infect, 2007, 13(6): 560-578

[4] LivermoreD.M.. Of Pseudomonas, porins, pumps and carbapenems. Antimicrob Chemother, 2001, 47(3): 247-250

[5] AeschlimannJ.R.. The role of multidrug efflux pumps in the antibiotic resistance of Pseudomonas aeruginosa and other Gram-negative bacteria. Pharmacotherapy, 2003, 23(7): 916-924

[6] KriengkauykiatJ., PorterE., LomovskayaO., et al.. Use of an efflux pump inhibitor to determine the prevalence of efflux pump-mediated fluoroquinolone resistance and multidrug resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother, 2005, 49(2): 565-570

[7] Kukavica-IbruljI., BragoziA., ParoniM., et al.. In vivo growth of Pseudomonas aeruginosa strains PAO1 and PA14 and the hypervirulent strain LESB58 in a rat model of chronic lung infection. J Bacteriol, 2008, 190(8): 2804-2813

[8] MariaM.D., BorrellN., PerezJ.L., et al.. Detection and susceptibility testing of hypermutable Pseudomonas aeruginosa strains with the E test and disk diffusion. Antimicrob Agents Chemother, 2004, 48(7): 2665-2672

[9] WangY., CelaE., GagnonS., et al.. Estrogen aggravates inflammation in Pseudomonas aeruginosa pneumonia in cystic fibrosis mice. Respir Res, 2010, 30(11): 166

[10] ArakiN., YanagiharaK., MorinagaY., et al.. In vivo efficacy of doripenem (DRPM) against Pseudomonas aeruginosa in murine chronic respiratory tract infection model. J Infect Chemother, 2011, 17(3): 318-321

[11] SongZ., KharazmiA., WuH., et al.. Effects of ginseng treatment on neutrophil chemiluminescence and immunoglobulin G subclasses in a rat model of chronic Pseudomonas aeruginosa pneumonia. Clin Diagn Lab Immunol, 1998, 5(6): 882-887

[12] JinX., LinZ., XieX., et al.. The delayed response of Toll-like receptors may relate to Pseudomonas aeruginosa keratitis exacerbating rapidly at the early stages of infection. J Clin Microbiol Infect Dis, 2010, 29(2): 231-238

[13] DengJ.C., ChengG., NewsteadM.W., et al.. Sepsis-induced suppression of lung innate immunity is mediated by IRAK-M. J Clin Inv, 2006, 116(9): 2532-2542

[14] StratevaT., YordanovD.. Pseudomonas aeruginosa-a phenomenon of bacterial resistance. Med Microbiol, 2009, 58Pt9: 1133-1148

[15] LiX.Z., NikaidoH., PooleK., et al.. Role of MexA-MexB-OprM in antibiotic efflux in Pseudomonas aeruginosa. Antimicrob Agents Chemother, 1995, 39(9): 1948-1953

[16] VojtováV., KolárM., UvízlR., et al.. Antibiotic utilization and Pseudomonas aeruginosa resistance in intensive care units. New Microbiol, 2011, 34(3): 291-298

[17] LiX.Z., BarréN., PooleK., et al.. Influence of the MexA-MexB-OprM multidrug efflux system on expression of the MexC-MexD-OprJ and MexE-MexF-OprN multidrug efflux systems in Pseudomonas aeruginosa. J Antimicrob Chemother, 2000, 46(6): 885-893

[18] WagnerJ.G., RothR.A.. Neutrophil migration mechanisms, with an emphasis on the pulmonary vasculature. Pharmacol Rev, 2000, 52(3): 349-374

[19] ReinigerN., LeeM.M., ColemanF.T., et al.. Resistance to Pseudomonas aeruginosa chronic lung infection requires cystic fibrosis transmembrane conductance regulator-modulated interleukin-1 (IL-1) release and signaling through the IL-1 receptor. Infect Immun, 2007, 75(4): 1598-1608

[20] WuH., SongZ., GivskovM., et al.. Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection. Microbiology, 2001, 147Pt5: 1105-1113

[21] HazlettL.D.. Corneal response to Pseudomonas aeruginosa infection. Prog Retin Eye Res, 2004, 23(1): 1-30

[22] NiM., ZhangD., QiJ., et al.. Analysis of AmpC beta-lactamase gene in Pseudomonas aeruginosa. J Huazhong Univ Sci Technol Med Sci, 2005, 25(1): 17-19

[23] ChengX., WangP., WangY., et al.. Identification and distribution of the clinical isolates of imipenem-resistant Pseudomonas aeruginosa carrying metallo-beta-lacta mase and/or class 1 integron genes. J Huazhong Univ Sci Technol Med Sci, 2008, 28(3): 235-238