Interactions between Microbes and Humans

These flashcards cover the key concepts related to the interactions between microbes and humans, including the human microbiome, mechanisms of infection, and disease transmission.

What is the human microbiome?

The sum of all microbes found on and in a human, required for proper health and functioning.

What are the effects of normal microbiota in humans?

They aid in digestion, exhibit antagonistic effects against invading microbes, and can be correlated with various morbidities.

Define pathogenicity.

Pathogenicity refers to an organism’s ability to cause disease.

What distinguishes true pathogens from opportunistic pathogens?

True pathogens can cause disease in healthy individuals, whereas opportunistic pathogens cause disease when the host's immune system is compromised.

What is virulence?

It refers to the severity of disease, determined by an organism's ability to establish itself in the host and cause damage.

Name some defensive strategies of pathogens.

Adhesins, capsules, enzyme secretion, and antigenic variation.

What are exoenzymes?

Enzymes that damage host tissue to facilitate the spread of infection.

What are exotoxins?

Proteins released by Gram(+) bacteria that are highly toxic to the host.

What role do capsules play in microbial infection?

Capsules help bacteria evade phagocytosis by the host's immune system.

How does Helicobacter pylori survive in the acidic environment of the stomach?

By secreting urease to produce ammonia, which neutralizes stomach acid.

Define communicable disease.

A disease that can be transmitted from one host to another.

What is the difference between morbidity and mortality?

Morbidity reflects the burden of disease in a population, while mortality refers to the rate of death due to the disease.

What is epidemiology?

The study of the frequency and distribution of disease and other health-related factors in defined populations.

What is the significance of a vectorborne mode of transmission?

It involves the transmission of disease through arthropods.

Differentiate between an endemic and a pandemic disease.

An endemic disease is consistently present at a steady incidence rate in a population, while a pandemic is an epidemic spreading rapidly across multiple continents.

What are the characteristics of asymptomatic carriers?

They are individuals who carry the disease without showing symptoms.

What is the role of adhesins in microbial infection?

Adhesins are cell surface molecules that help microbes adhere to host cell surfaces at entry points.