Molecular Detection of Plasmid-mediated Gens in Colistin Resistant Pseudomonas aeruginosa Isolates in North of Iran

BACKGROUND AND OBJECTIVES Pseudomonas aeruginosa is environmental bacterium with ability of making human infections like bacteremia, ventilator-associated pneumonia, urinary tract infections and skin soft tissue infections. The major problem is appearance of drug-resistant strains which makes the treatment process difficult in the face with this bacterium. The polymyxins, colistin (polymyxin E) and polymyxin B, are antimicrobial agents with broad-spectrum activity against Gram negative bacteria and it is considered as a last-resort antibiotic in treatment of P. aeruginosa. The emergence of colistin-resistant Pseudomonas aeruginosa is a serious worldwide concern and it became of a great threat for patients with severe infection with P. aeruginosa. Possible mechanisms for colistin resistance were studied by detection of mcr- ۱ and mcr-۲ genes which are transferable plasmids. Therefore, the aim of this study was to detect plasmid-mediated mcr-۱ and ۲ genes in colistin-resistant P. aeruginosa isolates in North of Iran.MATERIALS AND METHODS A total of ۱۹۰ clinical isolates of P. aeruginosa were collected from the two largest tertiary care hospitals in Babol, Iran. All bacterial isolates were phenotypically screened for colistin resistance using the colistin broth disk elution (CBDE) method. Moreover, mcr-۱-۲ gene was detected through polymerase chain reaction (PCR).RESULTS AND DISCUSSION Colistin resistance was found in ۷.۹% (۱۵/۱۹۰) of P. aeruginosa isolates. Also, ۲.۱% of isolates were intermediate resistant. Among ۱۵ colistin resistant isolates, the mcr-۱ and mcr- ۲ gene was not detected in any P. aeruginosa.CONCLUSION This is the first report on the prevalence of the colistin-resistant Pseudomonas aeruginosa from humans in North of Iran which indicates an alarm for the manner and amount of antibiotics prescribed and used.

کلیدواژه ها:

Pseudomonas aeruginosa ، colistin ، mcr-۱ ، mcr-۲ ، PCR