MICRO 200 Chapter 22

Ciliary escalator

The layer of cilia in the respiratory tract which uses mucus to trap foreign substances, while tiny hair like structures beat in coordinated waves to move this mucus towards the throat where it is expelled.

Rhinitis

Inflammation of the nasal lining, leading to sneezy, runny nose, and itchy

Rhinovirus

most frequent cause of the common cold. A positive sense, single stranded RNA virus

Rhinorrhea

commonly known as a runny nose

Coronavirus

a group of RNA viruses that cause respiratory tract infections ranging from the common cold ton death. Has one of the largest genome sizes of RNA viruses

M protein

a major virulence factor on the surface of Group A Streptococcus (S. pyrogenes) that help the bacteria resist the human immune system by inhibiting phagocytosis and causing rheumatic fever. Binds to fibrinogen, interfering with the complement system

Hyaluronic acid

a natural sugar molecule in the body that retains water. Mediates the immune response involving pro or anti inflammatory cytokines

superantigen

a microbial protein that causes the immune system to over activate, leading to the activation of a large number of T cells.

Tumor necrosis factor

a cytokine made by immune cells that triggers inflammation to fight infection and can cause cell death (necrosis) in tumors. Overproduction can lead to chronic inflammation and autoimmune diseases.

pseudomembrane

a false layer of exudate that forms a biofilm. Easily peeled off, revealing healthy tissue underneath. Composed of white blood cells, fibrin, bacteria, and debris

pertussis /whooping cough

a highly contagious bacterial respiratory infection known for severe coughing fits. Characterized by violent cough, caused by damaged cilia. Has two stages

adenovirus

a large group of viruses which cause a variety of infections, most typically a mild cold or flu like symptoms

respiratory syncytial virus

An infection which produces giant, multinucleated cells (syncytia). A negative sense RNA enveloped virus. Most prevalent cause of respiratory infections

otitis media

Common sequela to the common cold. Due to inflammation of the eustachian tubes and fluid build up in the middle ear. Usually caused by Streptococcus pneumoniae, Non communicable

Treatment is mostly ‘watchful waiting’ for the first 72 hours

effusion

the abnormal buildup of fluid in bodily cavities

eustachian tube

A narrow passage connecting the middle ear to the back of the throat

biofilm

a film of microorganisms which adheres to surfaces and each other. Held together by ‘glue’ made of sugars and proteins

pharyingitis

Inflammation of the throat causing pain and swelling. Viral infections tend to be more mild, bacterial are more intense

scarlet fever

A complication after an infection with S. pyrogens- specifically a strain that has been infected with a bacteriophage. Gains the ability to produce an exotoxin known as erythrogenic toxin. Characterized by sandpaper rash and high fevers

glomerulonephritis

Believed to be a result of streptococcal proteins forming antigen-antibody complexes and depositing in the basement membrane of the glomeruli in the kidney. Characterized by nephritis, blood in urine, increased blood pressure, and occasionally heart failure.

Streptococcus pyrogenes

A gram-positive coccus that grows in chains. It’s non-motile and forms capsules and slime layers. A facultative anaerobe. Contain antigens that resemble the heart, joint, and brain, allowing the microbe to evade detection.

Fusobacterium necrophorum

A recently recognized bacteria to cause pharyngitis. Can cause a peritonsillar abscess, which can further lead to sepsis (Lemierre’s syndrome). Gram negative. Infections are also missed because most cultures test for S. pyogenes instead

M protein

A major virulence factor on Group A streptococcus that helps bacteria resist the immune system by inhibiting phagocytosis. May lead to rheumatic fever

Erythrogenic Toxin

A toxin produced by S. pyogenes after they receive the gene from a temperate bacteriophage

Catarrhal stage

First stage of Whooping cough. Displays cold-like symptoms, especially a runny nose

paroxysmal stage

The second stage of Whooping cough. Characterized by severe and uncontrollable coughing

filamentous hemagglutinin

A fibrous structure that aids in adhesion to respiratory cells during infection of Whooping cough

dyspnea

a symptom, shortness of breath

rales

a sign, a popping/rattling/bubbling sound heard in the lungs during breathing. Often indicative of pneumonia or heart failure

croup

a clinical description of acute coughing, wheezing, and difficulty breathing. Often due to RSVD

Neuraminidase

An enzyme on the surface of influenza that breaks down the protective mucus coating of the respiratory tract. One of the two glycoproteins of the surface of influenza.

antigenic drift

The random mutation of the glycoproteins on influenza where the antibody binds

antigenic shift

When a host is infected with two different influenza viruses at once, the two can infect the same cell and swap gene strands

tubercle

A small lesion on the lungs (or other tissues)

caseouse lesions

When tissue dies and has a soft, white appearance. A key characteristic of tuberculosis

extrapulmonary TB

When tuberculosis affects organs outside the lungs after spreading through the blood stream

consumption

The old, historical name for tuberculosis

Mantoux test

Also known as a tuberculin skin test. A small amount of tuberculin solution is injected under the skin. 48-72 hours later the skin is observed. A positive result indicated a person has been infected with tuberculosis

Induration

A medical term for the hardening or thickening of tissue

BCG

Bacillus Calmette-Guerin. A live strain of a bovine tuberculosis bacterium that has been made avirulemt. Not given in the United States

MDR-TB

Multidrug-resistant tuberculosis. Defined as being resistant to at least isoniazid and rifampin. Requires 18-24 months of treatment. Results in a cocktail of drugs to treat that can have severe side effects

XDR-TB

Extensively drug-resistant tuberculosis. Strains that are resistant to MDR-TB drugs and two additional drugs. mortality rate is about 70% within months of diagnosis

Pneumonia

an inflammatory condition of the lung, where fluids fill the alveoli.

Histoplasmosis

a dimorphic fungus with a wide range of manifestations. Used to be referred to as Darling’s disease, Ohio Valley Fever, and spelunker’s disease. Human to human contact has not been documented

Pneumocystis jirovecci (PCP)

A fungus a part of the normal biota. Can cause serious pneumonia in immunocompromised people. Multiplies intracellularly and extracellularly. Causes epithelial cells to slough off. Symptoms are a cough, fever, shallow breath, and cyanosis

Cyanosis

blueish coloration of the skin due to a lack of oxygen in blood

Hantavirus pulmonary syndrome

Initial symptoms resemble common viral infections. Then, severe pulmonary edema forms and causes acute respiratory distress. Transmitted through dust contaminated with bodily fluids of infected rodents

Myalgia

Muscle aches

Hemagglutinin

One of the two glycoproteins on the surface of influenza. Contributes to virulence by binding to host cell receptors and enabling viral penetration