J Infect Dis. 2000 Mar;181,3:1069-81. Status of Borrelia burgdorferi infection after antibiotic treatment and the effects of corticosteroids: An experimental study. Straubinger RK, Straubinger AF, Summers BA, Jacobson RH. James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca NY, 14853, USA. rks4@cornell.edu Sixteen specific-pathogen-free beagles were infected with Borrelia burgdorferi. Three groups of 4 dogs were treated with antibiotics for 30 consecutive days starting 120 days after tick exposure; 4 dogs were untreated controls. At day 420 after tick exposure and again before euthanasia, 2 dogs of each group were treated with prednisone for 14 days. All dogs contracted infection and 11 developed acute arthritis 50-120 days after exposure. After day 120, one of 12 antibiotic-treated dogs and 2 of 4 untreated dogs became lame. Antibiotic therapy reduced the freq uency of Borrelia-positivity in subsequent skin biopsy samples. After prednisone treatment, both control dogs developed severe polyarthritis. At euthanasia, single tissues of the antibiotic-treated dogs and multiple tissues of all control dogs were Borrelia-positive by polymerase chain reaction. Viable spirochetes were not recovered from antibiotic-treated dogs. Two antibiotic-treated dogs showed histologic evidence of minimal lesions, whereas all control dogs had mild polyarthritis with periarteritis. 16 dogs were infected with Borrelia burgdorferi. 120 days after tick exposure, 12 dogs were 56treated with antibiotics for 30 days; 4 control dogs were not treated. .At euthanasia, single tissues of the antibiotic-treated dogs and multiple tissues of all control dogs were Borrelia-positive by polymerase chain reaction.[Persistence:] .Do the data indicate an ongoing persistent infection in these animals or only the presence of DNA remnants of dead Borrelia..? From this study and our previous investigations, 20, it appears likely that B. burgdorferi maintains a persistent infection with live organisms albeit at a very low level, p.1079, [Diagnosis:] As demonstrated by the injection of heat-killed B. burgdorferi organisms into the skin of an uninfected animal, DNA of dead organisms was detectable in our hands only for 3 weeks. These results are in concordance with a study in which persistent experimental infection with Treponema pallidum, the spirochetal agent of syphilis, was identified by PCR, 21. Wicher et al.[1998] discovered that DNA of dead Treponema organisms was removed from or degraded within rabbit tissue within 15-30 days after syringe inoculation, p.1079, Our studies show that at least in the dog, blood is an unreliable tissue to demonstrate B. burgdorferi infection., p.108
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