Schwerpunkt 3: Infektionsimmunologie an der Tierärztliche Hochschule Hannover

A. Fleming in 1929

Zoonoses can be transmitted (under natural conditions) between animals and humans (also through the environment)

• climate change influencing arthropods
• exotic pets
• exotic foods (bush meat)
• companion animals (Haustier)
• Alteration in livestock management practices (Änderung in Viehhaltung)
• Acquisition of new virulence traits (Erwerb neuer virulenter Eigenschaften)
• Pathogen adaption to new host species
• changes in land use
• tourism
• translocation of infected animals or persons

• symbiosis/mutualism: ecological interaction between 2 or more species where each species has a net benefit
• commensalism: long-term biological interaction where one species benefits while the other neither benefits or is harmed
• parasitism: relationship between two species where the parasite lives in or on the host and causes harm and is adapted to this way of life

• the phenotype of a pathogen is specific for all virulent strains of this species
• inactivation of coding virulence(-associated) genes leads to attenuation (loss) of virulence
• complementation of these genes restores virulence of the mutant

mono-causal (dangerous) infectious disease with tendency to spread among a population affecting many individuals

• Morbidity: diseased cases/population/period
• Mortality: fatalities/population/period
• Letality: fatalities/cases
• Prevalence: infections/time point
• Incidence: new infections/time period

• endemic: no time limit, spatial limit, low morbidity
• epidemic: time limit, spatial limit, high morbidity
• pandemic: time limit, no spatial limit, high morbidity

=> break down of fibrin clots formed by coagulation by converting plasminogen into active plasmin

-> promotes bacterial escape from fibrinous thrombi and enables transmigration through extracellular matrix and vascular barriers

• obligate intracellular bacteria can not reproduce outside their host cells because their metabolism relies on host molecules
• facultative intracellular bacteria are capable of living and reproducing either inside and outside cells.

• protection against recognition by immune system
• partial protection against antibiotics
• nutrient rich habitat
• overcome of barriers -> possibility to spread into deeper
• dissemination --> spread into the blood stream

1. detection by microscopy
2. detection by culture
3. proof of pathogenicity

=> for detection/classification of microorganisms as pathogens