Studies of experimental streptococcal mastitis: II. Inoculation of Varying Numbers of Living Streptococcus agalactiae into the Teat Canal of Goats

Abstract

The inoculation of doses of living Str. agalactiae varying from approximately 1,000 to 100,000 million and contained in a volume of 10 ml. into the teat canal of goats produced a sharp systemic reaction that lasted two or three days, followed by a streptococcal mastitis that was clinically, biochemically and bacteriologically closely similar to bovine streptococcal mastitis. The degree and type of reaction could not be correlated with the number of living organisms inoculated. An examination of the infecting strain of Str. agalactiae showed that 45 out of 258 isolations from milk were more lethal for mice after growth in the udder. The serum of one of 13 goats tested nine days after inoculation with Str. agalactiae gave increased mouse protection. During the first six hours the leucocyte counts of goats inoculated with living organisms fell as an arithmetical progression. The onset of the systemic reaction was delayed in two goats accidentally infected with what were believed to be very small numbers of living streptococci.