Fig 4. Bacterial load in joint samples.

A 102 base pair fragment of ospA gene was amplified from the joint DNA samples. The minimal sensitivity of PCR was 40 bacterial cells. The results are expressed as the number of bacteria genomes per 100 ng of extracted DNA. Each symbol represents an individual animal and the samples were analysed in triplicate. In Experiment II, one joint sample of ΔdbpAB infected mice was qPCR negative at 15 weeks of infection, in Experiment III five joint samples of ΔdbpAB infected animals were qPCR negative at two weeks, and in Experiment IV three joint samples of ΔdbpAB infected and ceftriaxone treated (at six weeks of infection) mice were qPCR negative at 15 weeks. The line indicates the median of positive results in each group. “Cef” Ceftriaxone treatment, “aTα” anti-TNF-alpha treatment. ** P ≤ 0.01