Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed p...Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed primers to amplify the Quinolone-resistance-determining region （QRDR） of gyrA and par（？,, then the PCR products were sequenced and analyzed. In comparision with NCTC5776, a single mutation was found at base 371 in gyrA of strain 38 which changed from C to T, and a single mutation was found at base 350 in gyrA of strain 60 which changed from A to C. No mutation was found in gyrA of the rest The mutation of strain 38 led to an amino acid substitution of Arg99Cys and the mutation of 60 led to an amino acid substitution of Met 92 Leu. No mutation was found in parC QRDR of all the isolates. These results indicats that the DNA gyrase will be the primary target to salmonella of fluoroquinolone.展开更多
By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the r...By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.展开更多
文摘Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed primers to amplify the Quinolone-resistance-determining region （QRDR） of gyrA and par（？,, then the PCR products were sequenced and analyzed. In comparision with NCTC5776, a single mutation was found at base 371 in gyrA of strain 38 which changed from C to T, and a single mutation was found at base 350 in gyrA of strain 60 which changed from A to C. No mutation was found in gyrA of the rest The mutation of strain 38 led to an amino acid substitution of Arg99Cys and the mutation of 60 led to an amino acid substitution of Met 92 Leu. No mutation was found in parC QRDR of all the isolates. These results indicats that the DNA gyrase will be the primary target to salmonella of fluoroquinolone.
基金Supported by the National Natural Science Foundation of China (11171244)
文摘By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.
