Mechanisms of quinolones resistance in Acinetobacter baumannii and homology analysis among the strains / 国际检验医学杂志

ABSTRACT

Objective To explore the mechanisms of quinolones resistance in Acinetobacter baumannii and homology analysis a-mong the strains .Methods 25 strains of quinolones-resistant Acinetobacter baumannii isolated clinically were collected .Kirby-Bauer(K-B) detection was utilized to detect the sensitivity of conventional drugs ,and polymerase chain reaction (PCR) was em-ployed to detect quinolone resistance-related genes gyrA and parC which were verified by restriction enzyme digestion and sequen-cing ,repetitive extragenic palindrome(REP)-PCR was adopted to analyze the strain homology .Results Multiple resistances to 12 kinds of antibacterial agents were found among the 25 strains of Acinetobacter baumannii which were sensitive only to minocycline and amikacin ,with sensitive rates were 48 .0% and 32 .0% ,respectively ,and were all sensitive to polymyxin B [minimal inhibitory concentration(MIC)≤2 μg/mL] .gyrA and parC genes were found in the all strain .Mutation TCA→TTA(Ser→Leu) at coden 83 in gyrA gene existed in 25 strains ,mutation TCG→TTG(Ser→Leu) at coden 80 in parC gene existed in 23 strains ,mutation GAA→GGA(Glu→Gly) at coden 84 in parC gene existed in 2 strains .REP-PCR showed that the strains had high degree of homology . Conclusion Quinolone-resistant Acinetobacter baumannii has high degree of homology ,existing gyrA and parC gene mutations .