|
hxegards tudyo pathogenesis ofhogcholex-a (HQ, theennacIthe vrnis, it rget organ, awl the virerriia axe the thx test aspect which axe generally conskkmi to It the most irnpnnt orn rerpnring thorough inugation. Thus far, the da concerning these aspect were mainly obtains from experiment using pigs, so that many factors still remain unknown, This irnpdiment to tir gogress <INC researches was mainly due to difficulties In the assay of the NC virus and its antibody n a sysanatic mannt.
In the previous paper, the evaluation fo the fluorescent antibody-cell culture t (FA(Uflwas na by comparison th & END rrethcd to cletsmine it rehabAhty as a pnxeduxe fcc detecting and titration NC virus. In & present siy, a comparison of viral multiplication in pigs Eetwn virulent arid atiuati NC virus was made by the FA(Xfl’ and END method to ehcidat the rrazhanism of NC virus infection. The experimental data are summarii as follows:
1 . parative strdies of the multiplication of NC virus in pigs were perforirni tetwn virulent and attenuati strains.
To siimmari, from the virulent cases, the virus was detctd from the tisil and splen as early as 24-hour pcGt-inccuiation ,and from the mandihilar and some other lymph nodes on& 2alday. Thevirus was then&niin&paxotidgknds and o&r lymph nodes as well as in & spAi and tonsil of two pigs and the lung of ore pig ldEai on the 3rd day pst-inocu]ation. Fouxtn pigs of which two were )cilbi each clay from the 4th through tie 7th day pc€t-incculation all had virus inspairnens thsuefromthrotthe&dy.Thevirusin&Uoodvmsdeatlaslatasonthe 3rd or4th day pxst-incciJation.
For tie attnuaJ cases, the virus was initially dend only from & tonsil on the 3rd day. Excepting the constant psitive isolation from tonsils, the virus,thereaft, was inomsistently deeoel from the mawlibular awl iresentric lymph nodes air! the parc*id glands. Vms isolation from & spln was pzitive in only 2 pigs through the whole experiment.
To compare tie patterns of NC virus infection, both virulent and mcdifith wuses were dett from tonsils amsistntly with relatively high vthis t. This suggest that tonsils dopAayanir ntrole earlystageof HCvirus infection. his also noeworthy that both the mandiNrlar lymoph nodes arid tie parotid glands had a comparatively high detton rat of the virus in spit of hind leg incculation.
ToThe result of this experiment indkai that the pattern of NC infection can It divided into 3 phases it lymphatic phase, viiernic phase and visceral phase. The mfection of the atenuatrl virus seerrti to lack a vixernic awl a visceral phase, arid showed only a lymphatic phase which is sorrnhat similar to the initial stage of the vnlent vns infection.
2.14o HC vmis was &ezti from the mwous rneznhane oNe digestive tr&t m the ininal a penitent. It was, however, deat from the memhtes of almost all pait oNe stomach and Inttinal t-act th& repeat experiment. Such a discrepancy of the result Irtween the two experiment might he acrxcnnl fcc by the virus isolatioon eh*t. It is evident that care must he usal in &eung tie virus from the digestive tt
3 .HC virus was cktzti from Wood of pigs infecrd with visubit ‘Anis as tat as the
3rd or 4th day pcrst-incculatiou by the BID methcd. The virus tzs zemainal hilager than that of any other organs examined but the BID pltiorrnxon was negative at the lower dilutions of serum. It was cons that the END peienomenon might have ken inerfexal with by circulating int-feron. Careful stu&es for tie deiion of intrferon were mace and it was found that interferon was present in tie bkxxl as early as 24-hours post-Inccu]afl and some remained for 7 days.
4 .HC virus culd he ckeced by the FACUI employing PK- 15 cells from thc6e sea ontaining intferon. This th&atl that Ge PK- 15 cell hit has a lower sensitivity to interferon than the primary ST cell.
From these data, tie author cIfexs psible suggestions to help clarify the pathogenesiss of hog cholera.
(Not: This paper was a part of his doctoral thesis submit] to the Azabu Veterinary (Illege, Japan, by the writ in 1968.)
|