Microbiology-Chapter 22

These flashcards encompass key terms and definitions related to diseases of the respiratory tract, providing a comprehensive overview for exam preparation.

Upper Respiratory Tract

Includes nose, nasal cavities, pharynx, and associated structures like ears, tonsils, and sinuses.

Lower Respiratory Tract

Includes larynx, trachea, bronchi, bronchioles, and lungs (alveoli).

Pleurae

Membrane that surrounds the lungs.

Diaphragm

Major muscle used for breathing, located below the lungs.

Normal Flora of Respiratory Tract

Microbes that inhabit the upper respiratory tract, which can act as opportunistic pathogens.

Pharyngitis

Infection in the throat, commonly known as a sore throat.

Laryngitis

Infection in the larynx.

Tonsillitis

Infection of the tonsils.

Rhinosinusitis

Sinus infection, also referred to as sinusitis.

Epiglottitis

Infection of the epiglottis, considered a medical emergency.

Streptococcal Pharyngitis

Also known as strep throat, caused by Group A beta-hemolytic streptococcus (Streptococcus pyogenes).

Diphtheria

Bacterial disease caused by Corynebacterium diphtheriae which can result in a pseudomembrane in the throat.

Tuberculosis

Infection caused by Mycobacterium tuberculosis, known for its slow growth and ability to become dormant.

Legionnaire's Disease

Caused by Legionella pneumophila, often linked to water sources, leading to pneumonia.

Pertussis

Also known as whooping cough, caused by Bordetella pertussis, characterized by severe coughing.

Pneumonia

Inflammation/infection of the lungs, often causing fluid-filled alveoli and bronchioles.

Hantavirus Pulmonary Syndrome

Respiratory viral disease transmitted through inhalation of virus in dried mouse urine or feces.

Common Cold

Viral upper respiratory infection caused by various viruses, predominantly rhinovirus.

Sinusitis

Inflammation of the sinus cavities, often preceded by an upper respiratory infection.

Otitis Media

Middle ear infection, commonly secondary to upper respiratory infections.

Scarlet Fever

A strain of strep throat accompanied by a red rash and fever, caused by erythrogenic toxin.

Fungal Infections

Infections of the respiratory system, often seen in immunocompromised patients, caused by various fungi.

Respiratory Syncytial Virus (RSV)

Common childhood respiratory disease that can lead to severe infections like bronchiolitis.

Influenza

Viral respiratory disease caused by influenzavirus, known for its high mutation rate and seasonal outbreaks.

What does the DPT vaccine target?

The DPT vaccine targets diphtheria, pertussis, and tetanus, preventing these serious bacterial infections.

Why do we get fewer colds as we age?

As we age, our immune system becomes more experienced, having encountered many viruses over time, which enhances its ability to recognize and combat common cold viruses.

why are colds more common in Fall/Winter?

Cold weather conditions promote dry air and decreased humidity, which can dry out mucous membranes in the respiratory tract. This increased susceptibility allows viruses to spread more easily, resulting in more frequent colds.

Describe how tuberculosis infection progresses (including the immune system cell that harbors the bacteria).

Tuberculosis infection begins when the bacteria Mycobacterium tuberculosis enter the lungs and are engulfed by macrophages. The bacteria can survive within these immune cells, leading to a chronic infection that may remain dormant or result in active disease if the immune response weakens.

What do MDR and XDR stand for regarding tuberculosis infections?

MDR stands for Multidrug-Resistant, indicating strains of tuberculosis that are resistant to at least isoniazid and rifampicin, the two most potent TB drugs. XDR stands for Extensively Drug-Resistant, referring to strains resistant to MDR TB drugs plus additional resistance to fluoroquinolones and at least one of the second-line injectable drugs.

How are the different strains of influenza identified?

Different strains of influenza are identified by their surface antigens, hemagglutinin (H) and neuraminidase (N), leading to designations like H1N1 or H3N2.

What type of influenza appears to be the most virulent?

Influenza Type A appears to be the most virulent and is responsible for seasonal epidemics and pandemics.

Describe why the flu immunization must be altered annually.

The flu immunization must be altered annually due to the rapid mutation of influenza viruses (antigenic drift), which leads to changes in their surface antigens. This variability requires updates to the vaccine formulation to ensure effectiveness against the most prevalent circulating strains.

What is 'in' a flu shot?

A flu shot generally contains inactivated or weakened influenza virus strains, along with other components to enhance immune response.

Pneumococcal pneumonia

-Gram positive diplococcus

-Most common cause of bacterial pneumonia

-Rust colored sputum

-High fever, chills, chest pain, cough

-Pneumococcal vaccine

Atypical pneumonia

-walking pneumonia

-caused by mycoplasma pneumoniae, chlamydophilia pneumonia, legionella pneumophilia

-Mycoplasma pneumoniae lacks a cell wall, so beta lactam drugs do not work because they target cell walls

Legionaires’ Disease

caused by legionella pneumophilia (gram-negative intracellular pathogen)

- severe atypical pneumonia

-spread through inhalation of aerosolized water (AC units, hot tubs)

-not spread person to person

-high fever, GI symptoms common

Pertussis

-Whopping cough

-caused by bordetella ——

-Gram-negative coccobacillus

-releases — toxin affecting cilia

-prevention: DTaP or Tdap vaccine

Tuberculosis

-caused by mycobacterium ——- (acid fast rod with mycolic acid in its cell wall)

-chronic cough, weight loss, night sweats, bloody sputum

-treat with long term drug therapy

Inhalation Anthrax

-caused by bacillus ———

-gram positive endospore forming rod

-spores are inhaled, germinate in lungs, septic shock occurs, widened mediastinum on xray

Respiratory Syncytial Virus (RSV)

-most common cause of bronchiolitis and pneumonia in infants

-causes syncytia (fused giant cells)

-treatment with ribavirin or supportive care.

Influenza

-causes by influenza virus (A, B, and C)

-H&N spike proteins

-new vaccine each year to combat antigenic drift and shift. (continuous small mutations)

-antigenic shift only occurs in influenza type A on a pandemic level where there is a large sudden shift

Hantavirus Pulmonary Syndrome (HPS)

-spread through inhalation of mouse urine

-begins like the flu, sudden respiratory failure, can become deadly if lungs fill with fluid

-prevent with rodent control