Immune Defenses and Infectious Diseases Study Guide

A comprehensive set of flashcards covering key concepts from the study guide on immune defenses and infectious diseases, designed for exam preparation.

What are the components of innate immune defense in the respiratory tract?

Nasal hairs, mucus, cilia, lysozyme, lactoferrin, cationic antimicrobial peptides, macrophages.

What distinguishes adaptive immune defense from innate?

Adaptive immune defense requires time to develop and includes secretory IgA, B-cells/antibodies, T-cells, and activated macrophages.

What is the most common cause of the common cold?

Rhinovirus.

What follows a viral upper respiratory tract infection commonly leading to Otitis Media?

Bacteria traveling up the Eustachian tube.

What bacteria are most commonly associated with Otitis Media?

Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis.

What is Otitis Externa commonly referred to as?

Swimmer’s ear.

Which organisms are most often responsible for Otitis Externa?

Staphylococcus aureus, Pseudomonas aeruginosa.

What is the effect of diphtheria toxin on host cells?

Blocks translation by ADP-ribosylating Elongation Factor-2, leading to cell death.

What can form from the diphtheria infection that blocks the airway?

Pseudomembrane.

What pathogens are covered in the DTP/DTaP vaccine?

Diphtheria (toxoid), Tetanus, Pertussis (acellular antigens).

What is the key antigen associated with Rheumatic fever?

M protein.

What is the characteristic toxin produced in Scarlet fever?

Erythrogenic/pyrogenic toxin.

What is the role of hemagglutinin in influenza?

Helps virion attach to and penetrate host cells.

How do neuraminidase inhibitors affect influenza viruses?

They block the release of new viruses from infected host cells.

What is antigenic drift in influenza viruses?

Mutation in H/N genes producing seasonal influenza strains.

What distinguishes antigenic shift from antigenic drift?

Antigenic shift involves reassortment of genome segments and occurs with co-infection.

Which type of influenza has a higher severity and can cause pandemics?

Influenza A.

What is the most prevalent cause of respiratory infection in newborns?

Respiratory Syncytial Virus (RSV).

What receptor does COVID-19 use to infect host cells?

ACE2 receptor.

Which organisms are classified as pathogens affecting the respiratory system?

Viruses: Influenza, RSV, Rhinovirus, Adenovirus, Coronaviruses, Parainfluenza, SARS-CoV-2; Bacteria: GAS, S. pneumoniae, H. influenzae, C. diphtheriae, B. pertussis, Mycoplasma; Fungi: Histoplasma capsulatum, Pneumocystis jiroveci.

Name an acid-fast bacterium associated with TB.

Mycobacterium tuberculosis.

What role does a granuloma play in tuberculosis?

Walls off TB organisms and contains the infection.

What can lead to the reactivation of tuberculosis?

Depressed immune system, HIV/AIDS, old age, corticosteroid use.

What does the Mantoux test detect?

Induration and erythema in response to purified protein derivative for TB.

Which vector is associated with the plague?

Fleas.

What is the reservoir for Tularemia?

Wild rodents.

What is the mortality rate of untreated pneumonic plague?

90% without treatment.

What is Pneuomocystis jiroveci commonly associated with in patients?

AIDS.

What is 'Walking pneumonia' caused by?

Mycoplasma pneumoniae.

What bacteria is known for causing severe pneumonia and has a water reservoir?

Legionella pneumophila.

What pathogen is commonly associated with dental caries?

Streptococcus mutans.

Which virus is associated with mumps?

Rubulavirus.

What bacterium is frequently associated with gastric ulcers?

Helicobacter pylori.

What is the most common infectious cause of bloody diarrhea?

EHEC or Shigella.

Which bacteria are commonly responsible for traveler's diarrhea?

ETEC (Enterotoxigenic E. coli).

What is the most common food-borne diarrheal pathogen?

Campylobacter.

What causes rapid onset food poisoning?

Preformed toxins from Staphylococcus aureus, Bacillus cereus, Clostridium perfringens.

What bacteria are responsible for gastroenteritis?

Salmonella enterica typhimurium.

What differentiates Salmonella enterica typhi?

Causes typhoid fever.

What is MacConkey agar selective for?

Gram-negative bacteria.

What do lactose fermenters appear like on MacConkey agar?

Pink colonies.

What classification do Enterobacteriaceae fall under?

Gram-negative rods and facultative anaerobes.

What does Shiga toxin do to the intestinal epithelium?

Blocks translation and damages the epithelium leading to bloody diarrhea.

Which toxins increase cAMP and cause water loss associated with watery diarrhea?

Cholera toxin and ETEC LT/ST.

What is a common trigger for C. difficile infections?

Antibiotic treatment.

What are the vaccines available for Hepatitis?

A and B vaccines.

Which virus necessitates the presence of Hepatitis B to infect?

Hepatitis D.

What is the most common reason for liver transplants?

Hepatitis C.

What is the target organ for Schistosoma?

Liver, specifically the portal venous system.

What is the HIV lifecycle component responsible for attachment?

GP120.

What does reverse transcriptase do in the HIV lifecycle?

Converts RNA into DNA.

What is HAART?

Multi-drug therapy targeting several steps of the HIV lifecycle.

What does TSST-1 cause in terms of immune response?

Massive nonspecific T-cell activation leading to toxic shock syndrome.

What pathogen is the most common cause of bacterial endocarditis?

Staphylococcus aureus.

How is Malaria primarily transmitted?

Through mosquito bites.

What kind of infections can Herpes viruses cause?

Lifelong latent infections with reactivation.

What are the stages of syphilis?

Primary: painless chancre; Secondary: rash (palms/soles); Tertiary: gummas, neurologic/cardiac damage.

Which strains of HPV are known to cause cervical cancer?

Certain high-risk strains.

What does Gardasil-9 protect against?

Nine HPV strains including cancer-causing and wart-causing strains.

What is the bacteria associated with cat scratch disease?

Bartonella.

What disease is caused by Treponema pallidum?

Syphilis.

What pathogen is associated with chickenpox and shingles?

Varicella-zoster virus (VZV).

What bacteria can cause cat/dog bite infections?

Pasteurella.

Which protozoan is known for sexually transmitted infections with discharge?

Trichomonas vaginalis.

Which bacteria is the most common cause of STIs?

Chlamydia trachomatis.

What is the bacteria responsible for chancroid?

Haemophilus ducreyi.

What do HSV-1/2 primarily cause?

Cold sores and genital ulcers.

Which virus is associated with hemorrhagic fever?

Ebola.

What is the pathogenic mechanism of Bacillus anthracis in inhalational disease?

Causes severe respiratory symptoms leading to high mortality without treatment.

What is the outcome of untreated Tularemia pneumonia?

30-60% fatality.

What is a notable characteristic of Mycoplasma pneumoniae?

It lacks a cell wall.