Fig 8.

Supplementation of GlcNAc fails to rescue the rrp1^mut bacterial load in fed ticks but enables transmission via tick bite. (a) RNA samples were extracted from whole fed ticks (after repletion; 5 to 7 days) and subjected to qRT-PCR analysis. The bacterial burdens in ticks were measured by the number of copies of flaB mRNA compared to the number of copies of tick-actin transcript as previously described (37). The data are presented as the means of relative levels of flaB transcript ± SEM for three groups (each group contained 4 replete ticks) for each strain (WT, rrp1^mut mutant, and rrp1^com strain). Asterisks indicate that the differences in bacterial load between the WT strain, the rrp1^mut mutant, and the rrp1^mut mutant supplemented with GlcNAc were statistically significant at a P value of <0.05. (b) Detection of spirochete burdens in C3H mice infected via tick bite using qRT-PCR. At day 14 after tick feeding, mice were sacrificed. Tissues (skin, heart, joint, and bladder) were collected and total RNA from heart and bladder tissues subjected to qRT-PCR analysis as described in Materials and Methods. Statistical analysis showed no significant difference between the WT, the rrp1^com strain, and the rrp1^mut mutant supplemented with GlcNAc at P = 0.05.