Microbe-Human

What is Heomoniphilus aegyptious known for?

It is an infectious agent that causes pink eye by entering the skin.

What are spirochetes and what is their route of entry into the body?

Spirochetes, such as those causing syphilis, corkscrew through the skin and enter via the urogenital portal. It penetrates an unbroken surface and can cross the placenta

What does the acronym TORCH stand for?

Toxoplasmosis, other diseases, rubella, cytomegalovirus, herpes-simplex; infections screened for in pregnant women.

What does a smaller infectious dose (ID) indicate about a pathogen?

It indicates greater virulence.

What are antiphagocytic factors?

Factors that help pathogens evade phagocytosis, including leukocidens(toxic to WBC; produced by streptococcus and staphylococcus) and an extracellular surface layer like a capsule, or some can survive inside a phagocyte and ride it like mycobacterium.

What are extracellular enzymes?

Secreted enzymes by pathogens that break down tissues or dissolve host defense barriers; Examples: mucinase, keratinase, collagenase, hylauroniase, coagulase (cause blood to clot), kinase(break down clot)

What is toxigenicity?

The power of a pathogen to produce toxins.

What are toxinoses?

A variety of diseases caused by toxigenicity.

What are toxemias?

Toxinoses in which the toxin is spread through the blood from the site of infection.

What is intoxication?

Toxinoses caused by the ingestion of toxins(botulism)

What do endotoxins cause and which type of bacteria produce them?

Endotoxins cause fever and are produced by gram-negative bacteria and are released by bacteria that are lysed.

How are exotoxins characterized?

They are unstable with heat, produced by both gram-negative and gram-positive bacteria, and secreted from live cells.

What is necrosis?

It refers to the accumulation of damage leading to cell and tissue death.

What is a focalized infection?

An infection that begins in a specific area but can spread and produce effects in distant sites; produces a toxin

Difference between acute and chronic infection?

Acute infection comes fast and goes away fast but chronic infection comes slowly and stays long

What defines a syndrome in the context of disease?

A syndrome occurs when a disease can be identified by a specific complex of signs and symptoms.

What is fever classified as?

A sign- temperature can be measured

What are signs of an infection

• Edema(swelling caused by excess fluid trapped in body’s tissues), Granulomas and abscesses, lymphadentis(inflammation of lymph nodes)

• Fever, swelling

• Soreness and pain

Define lesion.

The site of of infection or disease

What does leukocytosis refer to?

An increased amount of white blood cells (WBCs).

What does leukopenia refer to?

Decreased amount of WBCs.

What is septicemia?

A general state in which microorganisms are multiplying in the blood and are present in large numbers.

What is the difference between bacteremia and viremia?

Bacteremia refers to the presence of bacteria in the blood, while viremia refers to the presence of viruses; they are not nesscarilly multiplying

What does latency in persistence of microbes mean?

A dormant state where the microbe can periodically become active and cause recurrent disease.

What does sequelae mean?

Long term or permanent damage to tissues or organs

What are the five exit portals?

Respiratory and Salivary (coughing and sneezing, talking and laughing), skin scales, fecal exit, urogenital tract, and removal of blood/bleeding

What are the 6 possible stages of infection progression?

Incubation(initial exposure to microbe), prodromal(starting to get sick), invasion/acute please(height of infection), convalescence(getting better), recovery-where you’re done, or continuation- where you’re chronic carriers

What are convalescent carriers?

Individuals who can still transmit a pathogen during the recovery phase of an illness.

What are chronic carriers?

They harbor and can transmit a pathogen for a long, indefinite period, such as months or years, after their initial infection.

Define a vector.

A live animal that transmits an infectious agent from one host to another- majority are anthropods.

What defines a biological vector?

A vector that is infected and has pathogens internalized.

What defines a mechanical vector?

the vector is not infected, they are passive carriers, pathogens are external

What is zoonosis?

Infectious diseases indigenous to animals that are naturally transmissible to humans.

What are humans usually in reference to zoonosis?

Dead End Host

Example of disease where we are not dead end host.

Influenza- transmissible from person to person

What is horizontal transmission?

Disease spread through a population from one infected individual to another.

What is vertical transmission?

Transmission from parent to offspring through ovum, sperm, placenta or milk

What is the significance of a fomite in transmission?

A fomite is an inanimate object that can transmit pathogens through direct transmission.

What are droplet nuclei?

Tiny dried particles that remain in the air after larger respiratory droplets evaporate; Indirect transmisson

What are aerosols in the context of disease transmission?

Suspensions of tiny solid or liquid particles in the air that can facilitate disease spread.