Data on brucellosis in several Alaskan caribou herds during 1962–65 is summarized. During this time agglutination-reactor prevalence rates (1:20 or higher) gradually declined in the Nelchina (6.5 percent to 1.0 percent) and Arctic (30 percent to 12 percent) caribou herds. A simultaneous decline (5 percent to 3.4 percent) in the prevalence of placental retention and/or excessive bleeding at parturition was also observed on the Arctic calving grounds in northwest Alaska in 1963 and 1965. Various additional conditions have been observed, from each of which brucella organisms were isolated on several occasions. These include orchitis-epididymitis, bursitis-synovitis and metritis, singly or in combination. In some cases, the observed lesions no doubt resulted in one or more of the following signs: sterility, lameness, and/or abortion with (probable) subsequent death of the female following putrefaction of retained placental structures. During 1963 about 25 percent of 107 cows showing placental retention and/or “excessive bleeding” were unaccompanied by calves when seen a few days post-partum.

The Russian and American points of view regarding naming the causative organism of rangiferine brucellosis are briefly reviewed. Brucella suis biotype rangiferi is proposed as a compromise, based on both the principles of bacterial taxonomy and the natural ecology of the organism.

Airborne rabies virus was isolated from Frio Cave, Texas, using a mechanical air sampler. Several types of samplers have been used, but only an electrostatic precipitation device has collected measurable quantities of virus. Prior to this, the only known reported isolations of airborne rabies virus had occurred when susceptible animals were confined in bat caves for long periods of time. The use of a mechanical sampler can facilitate quantitation of virus in caves.

Growth of a leptospire isolated from frog kidney tissue was stimulated by the addition of glucose to a bovine albumin polysorbate 80 medium, did not grow in the absence of polysorbate 80, but did respire on a complex of polysorbate 80 and bovine albumin. Growth was completely inhibited by 2-deoxy-D-glucose in a glucose-free bovine albumin polysorbate 80 medium. A requirement for vitamins B₁ (thiamine) and B₁₂ was demonstrated. Oxythiamine and the thiazole fragment of thiamine were nearly equivalent to vitamin B₁ in growth supporting activity while thyamine pyrophosphate, thyamine monophosphate, the pyrimidine fragment of vitamin B₁ and pyrithiamine were much less effective. The isolate was continually propagated at 31.5, 29, 20, 15, and 9 C. Growth could be initiated at 33.5–34 C. but serial subculture failed. Growth was not initiated at 35 u.c. The organism had a cellular but no extracellular tributyrinase.