Detection of attenuated, noninfectious spirochetes in Borrelia burgdorferi-infected mice after antibiotic treatment.
Xenodiagnosis by ticks was used to determine whether spirochetes persist in mice after 1 month of antibiotic therapy for vectorborne Borrelia burgdorferi infection. Immunofluorescence and polymerase chain reaction (PCR) were used to show that spirochetes could be found in Ixodes scapularis ticks feeding on 4 of 10 antibiotic-treated mice up to 3 months after therapy. These spirochetes could not be transmitted to naive mice, and some lacked genes on plasmids correlating with infectivity. By 6 months, antibiotic-treated mice no longer tested positive by xenodiagnosis, and cortisone immunosuppression did not alter this result. Nine months after treatment, low levels of spirochete DNA could be detected by real-time PCR in a subset of antibiotic-treated mice. In contrast to sham-treated mice, antibiotic-treated mice did not have culture or histopathologic evidence of persistent infection. These results provide evidence that noninfectious spirochetes can persist for a limited duration after antibiotics but are not associated with disease in mice.
Bockenstedt
Linda K
LK
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8031, USA. linda.bockenstedt@yale.edu
Mao
Jialing
J
Hodzic
Emir
E
Barthold
Stephen W
SW
Fish
Durland
D
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D025065:Borrelia burgdorferi / Q000187:drug effects* / Q000472:pathogenicity; D004269:DNA, Bacterial / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D007165:Immunosuppression Therapy; D008193:Lyme Disease / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D020525:Xenodiagnosis
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial