摘要
目的了解广东省沙门菌对喹诺酮耐药特征及其基因突变情况。方法选用2010—2011年广东省非伤寒沙门菌监测收集的4种主要血清型沙门菌,采用半定量药敏检测法测定2010—2011年收集的沙门菌临床株对萘啶酸和环丙沙星的最小抑菌浓度(MIC);通过PCR扩增鼠伤寒沙门菌株的gyrA和parC的基因,并对序列进行测定,对比野生株,发现突变位点及突变类型。结果共对2010—2011年收集的496株鼠伤寒沙门菌、鼠伤寒沙门菌变种、肠炎沙门菌和斯坦利沙门菌进行耐药性分析,75.4%(374/496)沙门菌对萘啶酸耐药,其中鼠伤寒沙门菌、鼠伤寒沙门菌变种、肠炎沙门菌、斯坦利沙门菌耐药率分别为82.5%(207/251)、84.0%(84/100)、79.5%(70/88)、22.8%(13/57);5.4%(27/496)沙门菌对环丙沙星耐药,其中鼠伤寒沙门菌、鼠伤寒沙门菌变种、肠炎沙门菌的耐药率分别为8.0%(20/251)、5.0%(5/100)、2.3%(2/88)。71.7%(180/251)鼠伤寒沙门菌发生基因突变,其中86.1%(155/180)发生gyrA上突变,37.2%(67/180)发生parC上突变,23.3%(42/180)发生双基因突变。环丙沙星耐药株、中敏株、敏感株分别有7株(35.0%,7/20)、1株(3.1%,1/32)、6株(3.0%,6/199)发生gyrA Ser83位点突变,3组间Ser83位点突变率差异有统计学意义(P<0.01);环丙沙星耐药株、中敏株、敏感株分别有15株(75.0%,15/20)、21株(65.6%,21/32)、111株(55.8%,111/199)发生gyrA Asp87位点突变,3组间突变率差异无统计学意义(P>0.05)。5株parC Ser80位点突变株均突变为Arg,此突变的菌株均伴有Ser83Phe及Asp87Asn;9株parC Thr57突变株均对萘啶酸耐药。结论广东省沙门菌对萘啶酸普遍耐药,对环丙沙星仍普遍敏感;gyrA和parC中可能影响沙门菌耐药的突变位点应进一步确认其对耐药的影响。
Objective To investigate the quinolone resistance to Salmonella and mutation relevant to quinolone resistance in Guangdong Province. Methods We select four main Salmonella serovars from Non-typhi Salmonella surveillance in Guangdong between 2010 and 2011 to determine the minimum inhibitory concentration of nalidixic acid and ciprofloxacin by semi-quantitative susceptibility test and detect mutants in gyrA and parC by sequencing. Results Salmonella typhimurium,Salmonella I 4,5,12： i：-,Salmonella enteritidis,and Salmonella stanley from 2010 to 2011 were selected for the antimicrobial susceptibility test. We found 75. 4%（ 374 /496） of Salmonella were resistant to nalidixic acid,of which resistant rates of Salmonella typhimurium,Salmonella I 4,5,12： i：-,Salmonella enteritidis and Stanley salmonella to nalidixic acid were 82. 5%（ 207 /251）,84. 0%（ 84 /100）,79. 5%（ 70 /88）,and 22. 8%（ 13 /57）,respectively. 5. 4% of Salmonella were resistant to ciprofloxacin. 8. 0% of Salmonella typhimurium was resistant to ciprofloxacin, followed by Salmonella I 4,5,12： i：-（ 5. 0%） and Salmonella enteritidis（ 2. 3%）. Mutants were detected in 71. 7% of Salmonella typhimurium isolates. 86. 1% of the mutants were detected in gyrA and 37. 2% in parC,and 23. 3% in both genes. Locus mutation at Ser83 in gyrA was observed in 35. 0% of the ciprofloxacin-resistant isolates,3. 1% of intermediate isolates and 3. 0% of the susceptible isolates（ P〈0. 01）. Locus mutation at Asp87 in gyrA was observed in 75. 0% of the ciprofloxacin-resistant isolates,65. 6% of intermediate isolates and 55. 8% of the susceptible isolates（ P〈 0. 05）. Arg was detected in all five isolates with mutants at Ser80 in parC. Nine isolates with Thr57 mutants in parC were all resistant to nalidixic acid. Conclusion Generally Salmonella isolates in Guangdong were highly resistant to nalidixic acid,but sensitive to ciprofloxacin. Mutants in gyrA and parC which might affect quinolone resistance in Salmonella isolates should be confirmed by further experiments.
出处
《华南预防医学》
2013年第6期27-32,共6页
South China Journal of Preventive Medicine
基金
广东省食品安全卫生应急技术研究中心基金(粤科函社字[2011]733号)
关键词
沙门菌
喹诺酮
最小抑菌浓度
耐药
Salmonella
Quinolone
Minimum inhibitory concentration
Drug resistance
