兰州市犬和猫艰难梭菌感染的流行调查研究

Prevalence of Clostridium difficile Infection in Dogs and Cats in Lanzhou City

调查兰州市宠物犬、猫中艰难梭菌(Clostridium difficile)感染的流行情况,为艰难梭菌感染防控提供基础数据。通过细菌分离纯化、16S rRNA测序分析、基质辅助激光解吸电离飞行时间质谱(MALDI^(-)TOF MS)和多重PCR技术对采集到的菌株进行了分离、鉴定和毒素基因检测。结果表明,分离到的艰难梭菌粗糙、扁平,呈“油煎蛋”样典型菌落,革兰氏染色呈阳性;16S rRNA测序结果显示分离菌株与文献报道艰难梭菌的基因序列同源性>99%;MALDI^(-)TOF MS检测结果显示分离菌株有典型的艰难梭菌特征离子峰,与16S rRNA测序结果一致;毒素基因检测结果显示24株分离株中,1株为毒素A阳性/毒素B阳性/二元毒素阳性(A^(+)B^(+)CDT^(+)),15株为A^(+)B^(+)CDT^(-),8株为A^(-)B^(-)CDT^(-)。兰州市居民豢养的犬、猫中艰难梭菌的分离率分别为10.3%(19/185)和8.1%(5/62),呈现较高的感染率,需加强宠物艰难梭菌感染的防控。

The prevalence of Clostridium difficile infection(CDI)in dogs and cats in Lanzhou city was investigated to provide basic data for disease control.Bacterial isolation,16S rRNA gene analysis,matrix^(-)assisted laser desorption ionization^(-)time of flight mass spectroscopy(MALDI^(-)TOF MS),multiplex PCR and toxin genes detection technologies were applied to isolate and identify clostridium difficile in collected samples.The isolated C.difficile was Gram positive,with classic rough,flat and fried egg morphology.16S rRNA sequencing results showed that the gene sequence homology with reported C.difficile was above 99%.The isolated bacteria contained characteristic ions of C.difficile in MALDI^(-)TOF MS detection,which was consistent to 16S rRNA sequencing results.In 24 isolated strains,one was toxin A/toxin B/binary toxin positive(A^(+)B^(+)CDT^(+)),15 were A^(+)B^(+)CDT^(-)and 8 were A^(-)B^(-)CDT^(-).All the above results suggest that CDI was widely prevalent in dogs(10.3%,19/185)and cats(8.1%,5/62)in Lanzhou,and further prevention and controlling measurements are necessary.