食品中伯克霍尔德菌属快速鉴定及耐药性分析

Rapid identification and drug resistance of Burkholderia in food

目的探究伯克霍尔德菌属快速鉴定方法,以及食品中伯克霍尔德菌属的分布特点及耐药现状。方法依据模式菌株的RNA聚合酶β亚基编码基因(rpoB)序列设计引物,扩增食品分离株的rpoB序列,构建基于rpoB的系统发育树。同时利用基质辅助激光解吸飞行时间质谱(MALDI-TOF MS)对食品分离株进行快速鉴定。利用微量肉汤稀释法对食品分离株进行耐药表型检测。结果在种水平,rpoB与基因组鉴定一致率可达100.00%。而MALDI-TOF MS的鉴定准确性为73.47%(36/49),洋葱伯克霍尔德菌复合群(Bcc)存在种间误判的情况。食品分离的Bcc菌株对大多数抗生素的最小抑菌浓度(MIC)远高于B.gladioli,但对头孢他啶的MIC却相反。结论可利用MALDI-TOF MS在属水平对伯克霍尔德菌属进行快速准确的鉴定,再利用rpoB鉴定到种。食品中检出耐多药的伯克霍尔德菌高致病种,提示应加强对食品中伯克霍尔德菌属的监测。

Objective To explore the rapid identification method of Burkholderia,and the distribution in food and drug resistance of Burkholderia.Methods Primers were designed according to RNA polymerase beta-subunit encoding gene(rpoB)of type strains,and the rpoB gene of strains isolated from food was amplified,then a phylogenetic tree was built based on rpoB gene.Matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF MS)was used for the rapid identification of food isolates.Resistance phenotype was detected with micro-broth dilution method.Results At species level,the concordance rate of rpoB gene and genome identification could reach 100.00%.The accuracy of MALDI-TOF MS was 73.47%(36/49),and there were misjudgments among the species of Burkholderia cepacia complex(Bcc).The strains isolated from food showed multidrug resistance,and the MIC of most antibiotics to Bcc strains was much higher than that to B.gladioli,but ceftazidime had opposite MIC.Conclusion MALDI-TOF MS can be used for rapid and accurate identification of Burkholderia at genus level,and then the species was identified by rpoB gene.Multidrug-resistant species of Burkholderia has been detected in food,suggesting that the surveillance for Burkholderia in food should be strengthened.