Rezvan Goodarzi1, Rasoul Yousefimashouf1, Mohammad Taheri1, Fatemeh Nouri2, Babak Asghari3. 1. Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran. 2. Department of Pharmaceutical Biotechnology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran. 3. Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran. babak.asghari1980@gmail.com.
Abstract
BACKGROUND: This study aimed to investigate the association between biocides' reduced susceptibility and the presence of efflux pump genes including cepA, qacEΔ1 and qacE in multidrug-resistant (MDR) Pseudomonas aeruginosa. METHODS AND RESULTS: The MDR P. aeruginosa isolates were collected and identified from different clinical samples. The minimum inhibitory concentrations (MIC) of four biocides (chlorhexidine gluconate 1%, benzalkonium chloride 1%, Kohrsolin® extra, and SEPTI-Turbo) were determined by microbroth dilution with and without carbonyl cyanide m-chlorophenyl hydrazone (CCCP). Polymerase chain reaction (PCR) was performed for detecting the efflux pump genes. In total, 92 MDR P. aeruginosa isolates were collected. The reduced susceptibility (8-128 µg/ml) was seen against chlorhexidine gluconate 1%, benzalkonium chloride 1%, Kohrsolin® extra, and SEPTI-Turbo in 63 (68.5%), 59 (64.1%), 64 (69.6%), and 65 (70.6%) isolates, respectively. The Kohrsolin® extra was the most effective biocide. The cepA, qacE, and qacEΔ1 were detected in 56 (60.9%), 1 (1.1%), and 34 (36.9%) isolates, respectively. There was a significant association between the presence of biocide resistance genes and reduced susceptibility to studied biocides (P = 0.00001). The CCCP had no effect on benzalkonium chloride 1% and Kohrsolin® extra, but reduced the MICs of chlorhexidine gluconate 1% and SEPTI- Turbo by 2 to 128 fold. CONCLUSIONS: The P. aeruginosa isolates exhibited varying degrees of tolerance to biocides. The cepA was the most prevalent gene. There was a significant connection between the occurrence of the efflux pump genes cepA and qacEΔ1 with reduced biocide susceptibility.
BACKGROUND: This study aimed to investigate the association between biocides' reduced susceptibility and the presence of efflux pump genes including cepA, qacEΔ1 and qacE in multidrug-resistant (MDR) Pseudomonas aeruginosa. METHODS AND RESULTS: The MDR P. aeruginosa isolates were collected and identified from different clinical samples. The minimum inhibitory concentrations (MIC) of four biocides (chlorhexidine gluconate 1%, benzalkonium chloride 1%, Kohrsolin® extra, and SEPTI-Turbo) were determined by microbroth dilution with and without carbonyl cyanide m-chlorophenyl hydrazone (CCCP). Polymerase chain reaction (PCR) was performed for detecting the efflux pump genes. In total, 92 MDR P. aeruginosa isolates were collected. The reduced susceptibility (8-128 µg/ml) was seen against chlorhexidine gluconate 1%, benzalkonium chloride 1%, Kohrsolin® extra, and SEPTI-Turbo in 63 (68.5%), 59 (64.1%), 64 (69.6%), and 65 (70.6%) isolates, respectively. The Kohrsolin® extra was the most effective biocide. The cepA, qacE, and qacEΔ1 were detected in 56 (60.9%), 1 (1.1%), and 34 (36.9%) isolates, respectively. There was a significant association between the presence of biocide resistance genes and reduced susceptibility to studied biocides (P = 0.00001). The CCCP had no effect on benzalkonium chloride 1% and Kohrsolin® extra, but reduced the MICs of chlorhexidine gluconate 1% and SEPTI- Turbo by 2 to 128 fold. CONCLUSIONS: The P. aeruginosa isolates exhibited varying degrees of tolerance to biocides. The cepA was the most prevalent gene. There was a significant connection between the occurrence of the efflux pump genes cepA and qacEΔ1 with reduced biocide susceptibility.