Microbiology - Lecture 2

Reservoir

Source providic conditions for survival, multiplication & transmission for MO.

Zoonosis

From animal to human

Disease transmission

* %%**Contact**%% - direct, indirect, droplet
* %%**Vehicle**%%- water- food- air- borne
* %%**Vectors**%%- mechanical, biological

Sexually transmitted diseases

* Sensitive to environmental stress (drying)
* Do not survive outside the body
* Require direct intimate contact

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*Syphillis, Gonorrhea, Chlamydia*

Indirect contact transmission

From reservoir via **fomite** - non-living object

Droplet transmission

With water drops, small distance

Vehicle transmission

* %%**Waterborne**%%- contaminated water. *Shigella, E.coli, Norovirus, Hepatis A.*
* %%**Airborne**%% - attached to dust, more than 1m. *Staphylococci, Mycobacterium, M.bovis.*
* %%**Mechanical**%% - on insects. *Salmonella typhi.*

Skin defence

**Mucus sectretion** - with chemicals & antibodies.

**Shedding**

**Immune cells in connective tissue** - dendritic cells phagocytosis

Parental entry

Injection, bites, cuts, wounds.

Defense by innate & adaptive immune system.

Adherence

**Tissue specific, species specific** - mediated by __interactions__ of macromolecules on bacteria and host receptors.