title: Evaluation of the preventive capacities of a topically applied azithromycin formulation against Lyme borreliosis in a murine model.
abstract: OBJECTIVE
  Systemic antibiotic treatment of Lyme borreliosis is effective during the early stages of the infection, while chronic manifestations of the disease may remain refractory and difficult to treat. This study was carried out in order to evaluate the potential of topically applied azithromycin to eliminate the spirochaetal organisms in the skin of the freshly bitten host and thereby prevent Lyme borreliosis.
  
  
  METHODS
  Laboratory mice were challenged with Borrelia burgdorferi sensu stricto by needle inoculation or via infected ticks as vectors. Then, an azithromycin-containing formulation was applied once daily to the sites of exposure for three consecutive days. In the case of needle inoculation, a 5% azithromycin formulation was applied starting 1 h, 3 days and 5 days after infection. In the case of tick exposure, 4%, 10% and 20% azithromycin formulations were applied, starting directly after the detachment of the engorged ticks. Subsequently, the infection status of the mice was determined.
  
  
  RESULTS
  Concentrations of azithromycin in murine skin were >3800-fold higher than the published minimal inhibitory concentration for B. burgdorferi as soon as 3 h after the first application. After needle inoculation, spirochaetes were not detectable in all infected mice after treatment, if the first application started 1 h or even after 3 days post-infection. Furthermore, no borrelial organisms were detected after topical treatment when ticks were used for spirochaete inoculation.
  
  
  CONCLUSIONS
  Our data indicate that topical treatment with a formulation containing azithromycin is a promising approach to prevent Lyme borreliosis shortly after a tick bite.
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology, Cell Technology/GLP, Leipzig, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Knauer
authors.forename: Inke
authors.initials: I
authors.lastname: Krupka
authors.forename: Christiane
authors.initials: C
authors.lastname: Fueldner
authors.forename: Joerg
authors.initials: J
authors.lastname: Lehmann
authors.forename: Reinhard K
authors.initials: RK
authors.lastname: Straubinger
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis / Q000379:methods*; D017963:Azithromycin / Q000008:administration & dosage*; D025065:Borrelia burgdorferi / Q000302:isolation & purification; D005260:Female; D008193:Lyme Disease / Q000517:prevention & control*; D051379:Mice; D008809:Mice, Inbred C3H; D012867:Skin / Q000382:microbiology; D013987:Ticks; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin