ABSTRACT
In veterinary medicine, the traditional reason for showing interest in specific infectious agents has been their ability to cause disease, that is, their pathogenicity. This is, of course, also vital in laboratory animal medicine, as only healthy animals should be used for experiments. However, the impact of infections goes far beyond this: Infections may interfere with research, even in the absence of clinical symptoms or pathological changes. Specific bacteria may have a direct impact on the immunology, the physiology, the reproduction, other parts of the microbiology, and the oncology.1 Even if the study includes a test group and a control group, infections are still important because specific bacteria
6.1 Mechanisms of pathogenicity and research interference from specific bacteria ..................................................................................... 103 6.1.1 Pathogenicity versus research interference .......................... 103 6.1.2 Epidemiological terms ............................................................. 104 6.1.3 Host-bacterial interaction influencing pathogenicity
and research interference ........................................................ 104 6.1.3.1 Adhesins and receptors............................................. 106 6.1.3.2 Toxins ........................................................................... 108
6.1.4 Host-environment interaction influencing pathogenicity and research interference ............................... 109
6.2 Mechanisms of pathogenicity and research interference from the commensal gut microbiota ............................................................110 6.2.1 Host-microbial interactions within immunity .....................110
