Variable manifestations, diverse seroreactivity and post-treatment persistence in non-human primates exposed to Borrelia burgdorferi by tick feeding

Abstract

The efficacy and accepted regimen of antibiotic treatment for Lyme disease has been a point of significant contention among physicians and patients. While experimental studies in animals have offered evidence of post-treatment persistence of Borrelia burgdorferi, variations in methodology, detection methods and limitations of the models have led to some uncertainty with respect to translation of these results to human infection. With all stages of clinical Lyme disease having previously been described in nonhuman primates, this animal model was selected in order to most closely mimic human infection and response to treatment. Rhesus macaques were inoculated with B. burgdorferi by tick bite and a portion were treated with recommended doses of doxycycline for 28 days at four months post-inoculation. Signs of infection, clinical pathology, and antibody responses to a set of five antigens were monitored throughout the ~1.2 year study. Persistence of B. burgdorferi was evaluated using xenodiagnosis, bioassays in mice, multiple methods of molecular detection, immunostaining with polyclonal and monoclonal antibodies and an in vivo culture system. Our results demonstrate host-dependent signs of infection and variation in antibody responses. In addition, we observed evidence of persistent, intact, metabolically-active B. burgdorferi after antibiotic treatment of disseminated infection and showed that persistence may not be reflected by maintenance of specific antibody production by the host.

The generality of post-antimicrobial treatment persistence of replicatively-attenuatedBorrelia burgdorferiin a mouse model

“…On the other hand, all saline-treated mice were culture-positive. Our studies (46, 47, 50) and those of others (45, 49, 81) in mice, dogs (29, 52) and non-human primates (53, 54) have all reached similar conclusions: spirochetes are persisting, but are paradoxically non-cultivable. It was suggested that the persisting remnants of B. burgdorferi in the tissues of infected mice after antimicrobial treatment is DNA or DNA-containing structures rather than live bacteria (76, 82, 83).…”

“…Our results indicate that disseminated spirochetes of two different B. burgdorferi strains can persist in mice at 12 and 18 months following antimicrobial treatment. Non-cultivable spirochetes persist in mice (93), dogs (29), and non-human primates (54) inoculated with alternate strains of B. burgdorferi , so we are confirming that persistence and resurgence are not unique to N40.…”

“…It is apparent that not all isolates or strains can be easily cultured, and this is especially apparent during long-term infection. It is becoming increasingly clear that in B. burgdorferi infected and antimicrobial treated animals, spirochetes were non-cultivable but viable, as have been demonstrated by xenodiagnoses (46, 47, 50, 54), immunohistology (46, 47, 75), and transcriptional activity of mRNA (47, 50, 54). Here we demonstrated that morphologically intact B. burgdorferi that survived antimicrobial treatment in disease-susceptible C3H mice as well in disease-resistant B6 mice could be acquired by larval ticks.…”

“…Chronic cases require prolonged treatment, and treatment is often less effective (15, 42-44). Several reports have provided evidence of B. burgdorferi presence in collagenous tissues, following antimicrobial therapy during chronic infection in different animal models, including mice (45-50), dogs (29, 51, 52), and non-human primates (48, 53, 54), and in spontaneous cases in humans (17-21). What is unique about all of these studies is that spirochetes can be detected by PCR for B. burgdorferi -specific DNA (BbDNA), but not by culture.…”

“…What is unique about all of these studies is that spirochetes can be detected by PCR for B. burgdorferi -specific DNA (BbDNA), but not by culture. There is also strong scientific evidence that uninfected ticks were able to acquire B. burgdorferi that survive various antimicrobial treatments and transmit them to naïve hosts following the molt to the next stage (45-47, 50, 54).…”