No abstract

To determine the seroprevalence of Lyme disease in gray wolves (Canis lupus) from various counties of Minnesota and Wisconsin (USA), 589 serum samples were collected from 528 wolves from 1972 to 1989. An indirect fluorescent antibody (IFA) test was used to detect the presence of antibodies against Borrelia burgdorferi. Titers of greater than or equal to 1:100 were considered positive. Results were confirmed by testing a few selected sera by Western blotting. Of the 589 sera tested, 15 (3%) had IFA titers of greater than or equal to 1:100. Three of the positive samples were collected from Douglas County in Wisconsin and twelve were from Minnesota counties. This study indicates that wolves are exposed to B. burgdorferi and are susceptible to Lyme disease.

EcoRI-digested DNA from Borrelia burgdorferi was ligated into the dephosphorylated vector pWR590 and transformed into Escherichia coli DH5a. When the gene library was screened, 20 clones reacted with pooled dog sera with high titers (immunofluorescent antibody titer, .1,280) to this spirochete. One clone expressed a 110-kDa antigen that reacted strongly with the high-titered pooled sera from dogs with Lyme borreliosis and serum from goats immunized with B. burgdorferi. The 110-kDa protein was expressed with and without isopropyl-o-D-thiogalactosidase, indicating the protein is not a fusion protein with I8-galactosidase. Monospecific antisera to the 110-kDa antigen recognized a 75-kDa Borrelia protein. Of the sera that reacted with B. burgdorferi by immunoblotting; 57, 100, and 83% of human, dog, and horse serum samples, respectively, reacted with the 110-kDa protein. Sera from individuals that tested negative with a B. burgdorferi lysate with immunoblotting showed no reaction with the 110-kDa protein. The 110-kDa antigen appears to be useful for the diagnosis of Lyme borreliosis.

SUMMARYTwo groups of calves were dosed orally with 104, 105, and 106S. typhimurium at approximately 2 days of age and at 14–21 days of age. No obvious clinical signs were observed with this strain, but younger calves excreted the salmonellas in the faeces for longer periods than older animals. The younger animals also excreted more salmonellas per gram of faeces in the first week following dosing. These observations may explain why salmonella cross-infection is likely to occur where very young calves are congregated. Following cessation of excretion of salmonellas in the faeces and subsequent slaughter of calves, examination of all the mesenteric, caecal, and colic lymph nodes showed these to be the most useful sites for recovery of salmonellas.Provided good nutrition and hygienic conditions prevail, calves retained on their farm of origin for longer periods are more likely to recover from neonatal salmonella infections.