非洲钝缘蜱(Ornithodoros moubata)和豚鼠、鸡胚对精河株斑点热立克次体易感性的比较

THE SUSCEPTIBILITY OF ORNITHODOROS MOUBATA TO INFECTION WITH THE JINGHE STRAIN OF SPOTTED FEVER RICKETTSIAE IN COMPARISON WITH GUINEA PIG AND CHICK EMBRYO

豚鼠和鸡胚对大部分人类致病性立克次体都易感。但鸡胚接种需要严格的无菌条件,否则极易为杂菌污染,而且胚龄要求较严,在现场工作中保证供应也较困难,故一般不宜用作第一代分离之用。在现场分离立克次体,至今仍主要使用豚鼠,有的立克次体病用小白鼠。

For the purpose of comparison between the susceptibility of Ornithodoros moubata and guinea pig to infection with the Jinghe strain of rickettsiae,22 blood samples taken from infected guinea pigs on different post-infection days,and 12 samples in different dilutions taken from an infected guinea pig three days after infection,were inoculated into ticks and guinea pigs simultaneously.Twenty-three and 22 out of the total 34 samples were found to be positive in the inoculated ticks and guinea pigs respectively.The results showed no difference in susceptibility between this tick species and guinea pig to the Jinghe strain of rickettsiae,suggesting that O.moubata can be used for the isolation of rickettsiae in the epidemiological survey of tick-borne spotted fever in linghe and other places in Hsinjiang.The difference between the IDof O.moubata and chick embryo suggested that chick embryo had a higher susceptibility than tick to the infection with the strain used However,it was noted that the strain used in this experiment had already been passaged several dozens of times and adapted to the chick embryo.It may be hypothesized that the result may not reflect the difference in susceptibility to the infection with a newly isolated strain or the strains present in nature.