Efflux pump activity in fluoroquinolone and tetracycline resistant Salmonella and E. coli implicated in reduced susceptibility to household antimicrobial cleaning agents

Thorrold, Catherine Ann; Letsoalo, Maupi E.; Duse, Adrian; Marais, Elsé

doi:10.1016/j.ijfoodmicro.2006.08.008

Cited by 49 publications

(30 citation statements)

References 22 publications

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“…However, lesser attention has been focused on reverse hypothesis which suggests that antibioticresistant organisms become tolerant to other antibacterial agents (e.g. disinfectants) due to the action of efflux pumps [11]. Overall, our results provide supportive evidence to the reverse hypothesis with reference to P. aeruginosa.…”

Section: Discussionsupporting

confidence: 67%

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Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin

Pagedar

Singh

Batish

2011

J. Basic Microbiol.

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The present study was undertaken to investigate the role of efflux pump activity (EPA) in conferring adaptive and cross resistances against ciprofloxacin (CF) and benzalkonium chloride (BC) in dairy isolates of Pseudomonas aeruginosa. Biofilm formation potential was correlated with development of adaptive resistance in originally resistant strains. Irrespective of parent strains's susceptibility, isolates developed substantial adaptive resistance against CF and BC. Significant difference was observed in ability of non resistant isolates to develop adaptive resistance against CF and BC (P < 0.02) and subsequent cross resistance. EPA was quantified using EtBr (Ethidium Bromide) model and its role was more prominent [confirmed by its inhibition using efflux pump inhibitor (EPI) 2,4-dinitrophenol (DNP)], in conferring adaptive resistance (P = 0.147) than cross resistance (P = 0.343). Reduction in adaptive resistances due to EPI was more evident in originally non resistant strains, which reaffirms EPA as probable mechanism of adaptive resistance. The present study perhaps first of its kind, suggests an active role of EPA in conferring adaptive and cross resistances in food related P. aeruginosa isolates and supports reverse hypothesis that antibiotic-resistant organisms eventually become tolerant to other antibacterial agents as well.

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Section: Discussionsupporting

confidence: 67%

“…In P. aeruginosa, multi-drug resistance has been reported to enhance motility, biofilm formation potential and virulence in comparison to sensitive isolates [9,10]. As per reverse hypothesis, antibiotic resistant organism develops cross resistance to other antimicrobial agent due to EPA, although the hypothesis has not been scrutinized extensively [11].…”

mentioning

confidence: 99%

Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin

Pagedar

Singh

Batish

2011

J. Basic Microbiol.

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“…They can extrude a range of antibacterial compounds. Resistance to fluoroquinolones has been shown to be mediated in P. aeruginosa by efflux pump systems (Poole, 2005;Thorrold et al, 2007).…”

Section: Sequence Analysis Of the Qrdr Region Of Gyra And Parcmentioning

confidence: 99%

“…There is increasing concern that the use of biocides [such as benzalkonium chloride (BKC) and other quaternary ammonium compounds] in these environments may be contributing to the development of microorganisms with decreased susceptibilities to antibiotics and disinfectants (Rutala et al, 1997;Russell et al, 1998;Russell, 1999Russell, , 2002McBain & Gilbert, 2001;Fraise, 2002;Langsrud et al, 2003;Thorrold et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Effect of subinhibitory concentrations of benzalkonium chloride on the competitiveness of Pseudomonas aeruginosa grown in continuous culture

2010

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This study investigates the link between adaptation to biocides and antibiotics in Pseudomonas aeruginosa. An enrichment continuous culture of P. aeruginosa NCIMB 10421 (MIC 25 mg BKC l−1) was operated (D=0.04 h−1, 792 h) with added benzalkonium chloride (BKC). A derivative, PA-29 (696 h), demonstrated a >12-fold decrease in sensitivity to the biocide (MIC >350 mg BKC l−1). The variant demonstrated a 256-fold increase in resistance to ciprofloxacin, with a mutation in the gyrA gene (Thr-83→Ile). Similarly, culturing of the original strain in a continuous-culture system with ciprofloxacin selection pressure led to the evolution of BKC-adapted populations (MIC 100 mg BKC l−1). Efflux pump activity predominantly contributed to the developed phenotype of PA-29. An amino acid substitution (Val-51→Ala) in nfxB, the Mex efflux system regulator gene, was observed for PA-29. Overexpression of both MexAB-OprM and MexCD-OprJ was recorded for PA-29. Similarly, mexR, a repressor of the Mex system, was downregulated. Competition studies were carried out in continuous culture between PA-29 and the original strain (in the presence of subinhibitory concentrations of BKC). The outcome of competition was influenced by the concentration of biocide used and the nature of limiting nutrient. The inclusion of 1 mg BKC l−1 in the medium feed was sufficient to select (S=0.011) for the BKC-adapted strain in magnesium-limited culture. Conversely, the presence of 10 mg BKC l−1 in the medium supply was insufficient to select for the same organism (S=−0.017) in the glucose-limited culture. These results indicate the importance of environmental conditions on selection and maintenance of biocide adaptation.

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“…Active efflux from the cell is a common mechanism for biocide and antibiotic resistance in many bacteria (5,30,48,51,55,65), especially in organisms such as P. aeruginosa (15). We have previously demonstrated that triclosan is an excellent substrate for many of the clinically significant multidrug efflux pumps of the resistance nodulation cell division (RND) family of P. aeruginosa, including MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexJK-OpmH (15).…”

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confidence: 99%

Identification and Characterization of TriABC-OpmH, a Triclosan Efflux Pump of Pseudomonas aeruginosa Requiring Two Membrane Fusion Proteins

et al. 2007

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Pseudomonas aeruginosa achieves high-level (MIC > 1 mg/ml) triclosan resistance either by constitutive expression of MexAB-OprM, an efflux pump of the resistance nodulation cell division (RND) family, or expression of MexCD-OprJ, MexEF-OprN, and MexJK-OpmH in regulatory mutants. A triclosan-resistant target enzyme and perhaps other mechanisms probably act synergistically with efflux. To probe this notion, we exposed the susceptible ⌬(mexAB-oprM) ⌬(mexCD-oprJ) ⌬(mexEF-oprN) ⌬(mexJK) ⌬(mexXY) strain PAO509 to increasing triclosan concentrations and derived a resistant strain, PAO509.5. This mutant overexpressed the PA0156-PA0157-PA0158 pump, which only effluxed triclosan, but not closely related compounds, antibiotics, and divalent cations, and was therefore renamed TriABC. Constitutive expression of the triABC operon was due to a single promoter-up mutation. Deletion of two adjacent genes, pcaR and PA0159, encoding transcriptional regulators had no effect on expression of this operon. TriABC is the only P. aeruginosa RND pump which contains two membrane fusion proteins, TriA and TriB, and both are required for efflux pump function. Probably owing to tight transcriptional coupling of the triABC genes, complementation of individual mutations was only partially achievable. Full complementation was only observed when a complete triABC operon was provided in trans, either in single or multiple copies. TriABC associated with OpmH, but not OprM, for assembly of a functional triclosan efflux pump. TriABC is the fifth RND pump in P. aeruginosa shown to efficiently efflux triclosan, supporting the notion that efflux is the primary mechanism responsible for this bacterium's high intrinsic and acquired triclosan resistance.

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Efflux pump activity in fluoroquinolone and tetracycline resistant Salmonella and E. coli implicated in reduced susceptibility to household antimicrobial cleaning agents

Cited by 49 publications

References 22 publications

Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin

Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin

Effect of subinhibitory concentrations of benzalkonium chloride on the competitiveness of Pseudomonas aeruginosa grown in continuous culture

Identification and Characterization of TriABC-OpmH, a Triclosan Efflux Pump of Pseudomonas aeruginosa Requiring Two Membrane Fusion Proteins

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