Colistin-resistant Pseudomonas aeruginosa clinical strains with defective biofilm formation

Abstract

Aim: Colistin is the only effective antibiotic in some cases of resistance to all tested antibiotics, even carbapenem. On the other hand, biofilm formation is one of the antibiotic resistance mechanisms in this bacterium. The aim of this study was to examine biofilm formation in colistin-resistant for the first time. Method: Two groups of were included in this study: 1) colistin-resistant and 2) colistin-susceptible. Biofilm formation was determined in these groups using the micro-tube test well as PCR to detect the genes involved in biofilm formation ( and ). The plasmids for colistin resistance, and , were also determined. ATCC 27853 was used as a control for all tests.Results: Strong biofilm formation was observed only in colistin-susceptible strains, and and were not detected in colistin-resistant strains. The control strain ATCC 27853 possesses and and is categorized as a strong biofilm formation group. According to the results of this study, colistin resistance is associated with defective biofilm formation, as reported by other studies on .

Keywords

• Pseudomonas aeruginosa
• colistin resistance
• biofilm