The Study On GyrA Gene And ParC Gene Mutation Of Quinolone-resistant Pseudomonas Aeruginosa

Objective To explore the transgenation information of gyrA gene and parC gene in quinolone-resistant Pseudomonas aeruginosa. Methods The gyrA gene sequence and parC gene sequence in Pseudomonas aeruginosa was analyzed with PCR, PCR-RFLP and DNA sequencing. Results Among the 40 quinolones-resistant Pseudomonas aeruginosa isolated from patients in hospital , 23 (57.5%) had a mutation in gyrA codon : Thr83(ACC)→Ile(ATC ), 15 (37.5%) quinolones-resistant Pseudomonas aeruginosa had a mutation in parC codon : Ser87(TCG)→Leu(TTG). 15 (37.5%) strains had both gyrA gene mutation and parC gene mutation, however, 8 strains only had gyrA gene mutation without parC gene mutation; 17(42.5%) strains had neither gyrA gene mutation nor parC gene mutation; 20 quinolones-susceptible Pseudomonas aeruginosa had neither gyrA gene mutation nor parC gene mutation.GyrA gene and parC gene direct sequencings are the same as polymerase chain reaction-restriction fragment lenthgth polymorphisms (PCR-RFLP) methods. Conclusions Following new quinolones are used largely in hospitals, the situation of resistance to quinolones in Pseudomonas aeruginosa is more and more serious.① GyrA mutation Thr83(ACC)→Ile(ATC ) and parC mutation Ser87(TCG)→Leu(TTG) are the mechanism of resistance to quinolones in Pseudomonas aeruginosa isolated from patient in hospital. ②ParC mutation is tightly related with GyrA mutation, To say in other words, there is GyrA mutation when ParC mutate. ③ DNA sequencing confirm: it is reliability that the study on gyrA gene and parC gene mutation of Pseudomonas aeruginosa by PCR-RFLP.