- Transmission of Microbes
The method in which an infectious agent transfers from one organism to another. This can occur by either direct transmission (direct contact between infectious host and susceptible host) or indirect transmission (which involves an intermediate carrier).
Direct transmission is defined as person-to-person transmission of infectious agents through contact.
Indirect transmission includes both vehicle-borne and vector-borne contact.
Indirect transmission can come from fomites or from vectors. A vector is defined as any agent (person, animal, or microorganism) that carries and transmits an infectious pathogen into another living organism. Vectors can be biological or mechanical. Biological vectors occur when the pathogen lives inside the organism. Mechanical vectors are when the pathogen is carried by, but does not live in, an organism.
Identify the type of transmission for each of the following examples:
1. Housefly landing on cow dung, picking up tapeworm eggs on its footpads, taking off and landing on a hotdog bun, and depositing the eggs on the bun.
2. James sneezed into his hands and then touched the door knob to exit Sally’s office. Sally, a few minutes later, touched her door knob to leave her office.
3. Baby Osman sneezes while his father is cuddling him.
4. Julie is bitten by a mosquito that is infected with the malaria parasite Plasmodium vivax.
Matching: Bacterial Shapes
Match the term in Column B to the appropriate description provided in Column A. Enter the correct letter from Column B in the answer blanks.
Column A. Column B.
_____1. Spiral-shaped bacteria A. Tetrads______2. Rod-shaped bacteria B. Strepto-______3. Curved, rod-shaped bacteriaC. Staph-______4. Chains of bacteria D. Diplo______5. Groups of two bacteria E. Bacillus______6. Groups of four circlesF. Spirillum______7. Circular-shaped bacteriaG. Vibrio______8. One bacteriaH. Pleopmorphic______9. Clusters of bacteria I. Cocci______10. The ability to alter shape due to environmental conditionsJ. Mono