Microbe-Human Interactions, Immunity, and Infectious Diseases Study Guide

This set of flashcards focuses on key concepts from the study of microbe-human interactions, immunity, infectious diseases, and specific pathogens as covered in lecture notes.

What is the difference between Transient and Resident Flora?

Transient flora are temporary microbes influenced by hygiene, while resident flora are stable microbes established on specific body areas.

What are True Pathogens?

True pathogens cause disease in anyone, regardless of immune status.

What are the common sites of Normal Resident Flora?

Skin, gastrointestinal tract, upper respiratory tract, external genitalia, external eye, and external ear.

What are the steps in the establishment of an infection?

Colonization, infection, then disease.

What are the portals of entry for infections?

Skin, gastrointestinal tract, respiratory tract, urogenital tract, transplacental.

What are some pathogens that can infect during pregnancy?

Toxoplasmosis, syphilis, varicella-zoster virus, parvovirus B19, HIV, rubella, cytomegalovirus, herpes simplex virus.

Define Infectious Dose (ID).

The minimum number of microbes required to establish an infection.

What are virulence factors?

Characteristics or structures of a pathogen that enhance its ability to cause disease.

What is the difference between Endotoxin and Exotoxin?

Endotoxin is released from Gram-negative bacteria when the cell wall is damaged; Exotoxin is secreted by living bacteria and targets specific cells.

What are the stages of clinical infections?

Incubation period, prodromal stage, period of invasion, and convalescent period.

What are cardinal signs of inflammation?

Local: redness, heat, swelling, pain; Systemic: fever, leukocytosis.

What is the difference between a reservoir and a carrier?

A reservoir is the natural habitat of the pathogen; a carrier harbors and spreads the pathogen without symptoms.

What is the distinction between mechanical and biological vectors?

Mechanical vectors transport pathogens without being infected, while biological vectors are involved in the life cycle of the pathogen.

What defines an endemic disease?

Disease present at a steady rate in a specific location.

What is the focus of immunopathology?

The study of disease states associated with underreactivity and overreactivity of the immune response.

What are the four types of hypersensitivity reactions?

Type I (Immediate), Type II (Cytotoxic), Type III (Immune Complex-Mediated), Type IV (Delayed-Type Hypersensitivity).

What is anaphylaxis?

A systemic, explosive reaction often involving airway obstruction and circulatory collapse.

What are the blood types and their associated antigens and antibodies?

Type A: A antigens, anti-B antibodies; Type B: B antigens, anti-A antibodies; Type AB: A and B antigens, no antibodies; Type O: no antigens, anti-A and anti-B antibodies.

What is the importance of the Rh factor?

It determines blood type (Rh-positive or Rh-negative) and can lead to hemolytic disease in newborns.

What are the characteristics of Staphylococcus aureus?

Found on skin and mucous membranes, with virulence factors including coagulase and various toxins.

What distinguishes Streptococcus pneumoniae from other streptococci?

It is a diplococcus with a capsule and can cause pneumonia and meningitis.

How do you differentiate between Staphylococci and Streptococci?

By using the catalase test; Staphylococci are catalase-positive, Streptococci are catalase-negative.

What are the virulence factors of Neisseria gonorrhoeae?

Pili and IgA protease.

What disease does Clostridium perfringens cause?

Gas gangrene.

What is Mycobacterium tuberculosis known for?

Its cell wall containing mycolic acids and its association with primary tuberculosis.