OBJECTIVES: We investigated the occurrence and mechanism of amikacin resistance and its association with various beta-lactamase genes in Pseudomonas aeruginosa isolates. METHODS: Of the total 250 consecutive, non-duplicated isolates of P. aeruginosa, 55 isolates showed amikacin resistance. PCR amplification of genes for aminoglycoside (AG)-modifying enzymes [aac(3)-I, aac(3)-II/VI, aac(3)-III/IV, aac(6')-I, aac(6')-II, ant(2'')-I, ant(4')-II and aph(3')-VI], 16S rRNA methylases (rmtA, rmtB, rmtC and armA) and class 1 integrons was performed. In addition, we analysed the association of AG resistance genes with various beta-lactamase genes. RESULTS AND CONCLUSIONS: In Korea, the amikacin resistance rate in P. aeruginosa was high (22%), and it varied among provinces (3.8% to 40%). Four types of AG-modifying enzyme genes [aph(3')-VI, ant(2'')-I, aac(6')-I and aac(3)-II/VI] were found in 48 isolates. Thirty-six strains harboured two or more types of enzymes, of which a combination of aph(3')-VI and ant(2'')-I was the most frequent (24/36 isolates, 66.7%). None harboured aac(3)-I, aac(3)-III/IV, aac(6')-II, ant(4')-II, rmtA, rmtB, rmtC or armA. Forty-two isolates co-harboured beta-lactamase genes (mostly bla(OXA-10)). A class 1 integron was detected in all but one, and all the ant(2'')-I and 26/29 bla(OXA-10) were found in it. In contrast, aph(3')-VI was not found to be associated with the class 1 integron. Considering the possibility of co-selection and dissemination, constant monitoring of resistance evolution is necessary.
OBJECTIVES: We investigated the occurrence and mechanism of amikacin resistance and its association with various beta-lactamase genes in Pseudomonas aeruginosa isolates. METHODS: Of the total 250 consecutive, non-duplicated isolates of P. aeruginosa, 55 isolates showed amikacin resistance. PCR amplification of genes for aminoglycoside (AG)-modifying enzymes [aac(3)-I, aac(3)-II/VI, aac(3)-III/IV, aac(6')-I, aac(6')-II, ant(2'')-I, ant(4')-II and aph(3')-VI], 16S rRNA methylases (rmtA, rmtB, rmtC and armA) and class 1 integrons was performed. In addition, we analysed the association of AG resistance genes with various beta-lactamase genes. RESULTS AND CONCLUSIONS: In Korea, the amikacin resistance rate in P. aeruginosa was high (22%), and it varied among provinces (3.8% to 40%). Four types of AG-modifying enzyme genes [aph(3')-VI, ant(2'')-I, aac(6')-I and aac(3)-II/VI] were found in 48 isolates. Thirty-six strains harboured two or more types of enzymes, of which a combination of aph(3')-VI and ant(2'')-I was the most frequent (24/36 isolates, 66.7%). None harboured aac(3)-I, aac(3)-III/IV, aac(6')-II, ant(4')-II, rmtA, rmtB, rmtC or armA. Forty-two isolates co-harboured beta-lactamase genes (mostly bla(OXA-10)). A class 1 integron was detected in all but one, and all the ant(2'')-I and 26/29 bla(OXA-10) were found in it. In contrast, aph(3')-VI was not found to be associated with the class 1 integron. Considering the possibility of co-selection and dissemination, constant monitoring of resistance evolution is necessary.
Authors: P Rashvand; A Peymani; M Mohammadi; A A Karami; R Samimi; S Hajian; D Porasgari; N Habibollah-Pourzereshki Journal: New Microbes New Infect Date: 2021-04-23