PKN1 and chlamydia trachomatis infectious disease: Prevalence of anti-OmpA and anti-Pkn1 antibodies was significantly higher (P < 0.001) in sera of chlamydia-infected animals than in sera from uninfected animals (A450 mean values: 0.67 v/s 0.29 and 0.69 v/s 0.27, respectively; Figure 2).