Fig. 4
From: Uptake and fecal excretion of Coxiella burnetii by Ixodes ricinus and Dermacentor marginatus ticks
Transstadial transmission of C. burnetii from nymphs to adult I. ricinus. Nymphs were fed on blood containing 106 GE/ml and were allowed to transform into adults. a Of the PCR C. burnetii-positive adult ticks, one half of a bisected tick was used for cultivation with L-929 cells. Vacuoles typical for Coxiella infections appeared 24 days after inoculation. b Material from the same tick was used for cultivation in cell-free ACCM-2 medium, and C. burnetii DNA was detected by PCR. Negative controls tested in parallel showed no Cq-value in the PCR (not shown). c Eight females molted from previously infected nymphs were divided into two infection groups, each consisting of 4 females and 3 Coxiella-negative males, and fed again on sterile blood. Feces were removed every two days and tested by quantitative PCR. Infection group 1 excreted C. burnetii DNA with their feces, whereas in feces of infection group 2 and in the negative control group no C. burnetii DNA was detected (here shown as 100). Samples in b and c were analyzed in three independent measurements in duplicates, the mean values and standard deviations are indicated