scholarly journals Pseudomonas aeruginosa cells adapted to benzalkonium chloride show resistance to other membrane-active agents but not to clinically relevant antibiotics

2002 ◽  
Vol 49 (4) ◽  
pp. 631-639 ◽  
Author(s):  
M. F. Loughlin ◽  
M. V. Jones ◽  
P. A. Lambert
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Benzalkonium Chloride

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

Microbiology ◽  
2010 ◽  
Vol 156 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Paul H. Mc Cay ◽  
Alain A. Ocampo-Sosa ◽  
Gerard T. A. Fleming
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Continuous Culture ◽  
Benzalkonium Chloride ◽  
Efflux Pump ◽  
Fold Increase ◽  
Original Strain ◽  
Limiting Nutrient ◽  
Continuous Culture System ◽  
Subinhibitory Concentrations ◽  
Limited Culture

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.

scholarly journals Prevalence of Resistance Genes to Biocides in Antibiotic-Resistant Pseudomonas Aeruginosa Clinical Isolates

2021 ◽  
Author(s):  
Farzad Khademi ◽  
Shahram Habibzadeh ◽  
Hamid Vaez ◽  
Mohsen Arzanlou ◽  
Somayeh Safarirad ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Resistance Genes ◽  
Benzalkonium Chloride ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Chlorhexidine Digluconate ◽  
Biocide Resistance

Abstract Background: Biocides are frequently used as preservative, disinfectant and sterilizer against many microorganisms in hospitals, industry and home. However, the resistance rate of Pseudomonas aeruginosa (P. aeruginosa) strains to biocides is increasing. The aim of this study was to evaluate the antimicrobial activity of four frequently used biocides against P. aeruginosa and to determine the prevalence of genes involved in biocide resistance. Methods: A total of 76 clinical isolates of P. aeruginosa strains were used in the present study. The minimum inhibitory concentrations (MICs) of four biocides, i.e. chlorhexidine digluconate, benzalkonium chloride, triclosan and formaldehyde, against P. aeruginosa strains were determined using agar dilution method. In addition, the prevalence of biocide resistance genes was determined using the polymerase chain reaction (PCR) method.Results: In the present study, the highest MIC90 value was observed for benzalkonium chloride (MIC90=1024 μg/mL), followed by formaldehyde (MIC90=512 μg/mL), triclosan (MIC90=512 μg/mL) and chlorhexidine digluconate (MIC90=64 μg/mL). Furthermore, the prevalence of qacEΔ1, qacE, qacG, fabV, cepA and fabI genes were 73.7% (n=56), 26.3% (n=20), 11.8% (n=9), 84.2% (n=64), 81.5% (n=62) and 0% (n=0), respectively. A significant association was observed between the presence of biocide resistance genes and MICs (p<0.05). Furthermore, there was no significant association between the presence of biocide resistance genes and antibiotic resistance (p>0.05), except for levofloxacin and norfloxacin antibiotics and qacE and qacG genes (p<0.05). Conclusion: Our results revealed that chlorhexidine digluconate is the most effective biocide against P. aeruginosa isolates in Ardabil hospitals. However, we recommend continuous monitoring of the antimicrobial activity of biocides and the prevalence of biocide-associated resistance genes for a better prevention of microorganism dissemination and infection control in hospitals.

Actively detached Pseudomonas aeruginosa biofilm cell susceptibility to benzalkonium chloride and associated resistance mechanism

2019 ◽  
Vol 201 (6) ◽  
pp. 747-755
Author(s):  
Simon Oussama Khelissa ◽  
Marwan Abdallah ◽  
Charafeddine Jama ◽  
Nour-Eddine Chihib
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Benzalkonium Chloride ◽  
Resistance Mechanism

scholarly journals Adaptive response of single and binary Pseudomonas aeruginosa and Escherichia coli biofilms to benzalkonium chloride

2011 ◽  
Vol 52 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Idalina Machado ◽  
Susana Patrícia Lopes ◽  
Ana Margarida Sousa ◽  
Maria Olívia Pereira
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Adaptive Response ◽  
Benzalkonium Chloride
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