Table 1.
Comparison of the genome of the three Borrelia strains.
Fig 1.
Effect of oxygen levels on growth rate of the 3 strains.
Growth of B. burgdorferi B31, B. afzelii BO23 and B. garinii CIP 103362 in BSK-II medium under anaerobic (5% CO2, 5%H, 90%N2), microaerobic (3–5% O2, 5% CO2, 90%N2+) or aerobic (80% N2,20% O2, 0.05% CO2) conditions at 34°C. Data represent means ± standard deviation.
Fig 2.
Motility of the three strains.
Motility was measured in diluted BSK-II agar plates supplemented with 0.35% agarose. Swarm diameters were measured after 4d of incubation at 34°C in microaerobic conditions. Results reported are the average of three independent experiments. Data represent means ± standard deviation. An asterisk indicates a significant difference using a one-way ANOVA where p < 0.05.
Table 2.
Antibiotic susceptibility of B. burgdorferi, B. afzelii and B. garinii.
Fig 3.
Survival to tert-butyl hydroperoxide.
Early stationary phase cultures were incubated for 1.5h with 0, 1, 2.5, 5, 10 and 25 mM of tert-butyl hydroperoxide. Survival was determined by plating on BSK-II. Plates were incubated at 34°C under microaerobic condition for 7-14d to allow enumeration of CFUs. Untreated samples were used to standardize survival (100%). Data represent means ± standard deviation. An asterisk indicates a significant difference compared to B. burgdorferi B31 using a one-way ANOVA where p < 0.05.
Fig 4.
Rate of growth of B. burgdorferi B31-A3, B. garinii CIP 103362 and B. afzelii BO23 at various osmolarities.
(A) Growth curves of strains were performed in BSK-II at various osmolarities (150 to 850 mOsM) under microaerobic conditions. (B) Graph of final densities of strains at various osmolarities. Growth was monitored daily by plating on BSK-II. Asterisks indicate a significant difference compared to B. burgdorferi B31 using a one-way ANOVA where p < 0.05. Data represent means ± standard deviation.
Table 3.
Mouse infectivity results of B. burgdorferi, B. garinii and B. afzelii strains.
Fig 5.
Immunoblot of B. burgdorferi B31-A3, B. garinii CIP 103362 and B. afzelii BO23 strains incubated with mouse sera.
Borrelia strains were grown in BSK-II to mid-log phase and cell lysates were analyzed by immunoblotting. Cell lysates were incubated with serum obtained from mice either before (Pre-bleed, PB) or 6 weeks after needle inoculation (Post-infection, PI) with B. burgdorferi (lanes 1 to 3), B. garinii (lanes 4 to 6) and B. afzelii (lanes 7 to 9).
Table 4.
Summary of the results.
Table 5.
BSK-II composition and reference, lot number of each ingredient.
Table 6.
Antibiotics used in this study.