ISSN:
1432-8798
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary With sixteen virus strains of cattle origin representing all seven types of foot-and-mouth disease virus (FMDV), infectivity for cattle by intramuscular (i.m.) inoculation was significantly related to plaque size on primary calf kidney cell cultures; the larger plaque viruses were more infectious. This relationship was not observed when these virus strains were inoculated into cattle tongues, mice or cell cultures (by CPE technique). For the 16 strains, the approximate minimum infective doses, expressed in bovine ID50 units, varied from 10 to 10,000 units for i.m. inoculation and from 0.01 to 2.0 units for tongue inoculation of cattle. The tongue route of inoculation for FMDV in cattle was from 100 to 200,000 times more sensitive for producing infection than i.m. inoculation. Of 195 cattle given various doses of FMDV by i.m. inoculation, 154 were infected, 13 were only antigenically stimulated or immunized and 28 were not clinically or serologically affected; with some strains, virus doses of as much as 15,000 bovine ID50 units failed to elicit a detectable response. Five of the FMD viruses that had 20 or more serial passages by cattle tongue inoculation produced smaller plaques in calf kidney cell cultures and were less infectious for cattle by i.m. inoculation than four field strains that had two to three laboratory passages and probably had natural passage primarily in cattle. Thus, serial passage of FMD viruses by cattle tongue inoculation may not be the ideal method for retaining field strain characteristics. Also, the hosts of natural passage may influence results.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01250142
Permalink
