Microbiology Chapter 19

What are the two parts of the respiratory tract?

Upper respiratory tract and lower respiratory tract.

List the components of the upper respiratory tract.

Mouth, nose, nasal cavity, sinuses, throat (pharynx), epiglottis, larynx.

List the components of the lower respiratory tract.

Trachea, bronchi, bronchioles, alveoli.

What anatomical features protect the respiratory tract from infection?

Nasal hair, cilia, mucus.

What are the second and third lines of defense in the respiratory tract?

Complement, antimicrobial peptides, chemocytokines, macrophages, secretory IgA.

What is microbial antagonism?

The function of normal biota that reduces the chances of pathogens establishing themselves by competing for resources and space.

What are common causative agents of pharyngitis?

Viruses, Streptococcus pyogenes, mechanical irritation.

What are the signs and symptoms of pharyngitis?

Pain, inflammation of the throat, reddened and/or swollen mucosa.

What serious complications can arise from untreated streptococcal throat infections?

Scarlet fever and rheumatic fever.

How is Streptococcus pyogenes transmitted?

Via respiratory droplets or direct contact with mucus secretions.

What is the antibiotic of choice for treating Streptococcus pyogenes infections?

Penicillin.

What are the causative agents of the common cold?

Over 200 different viruses including rhinoviruses, coronaviruses, adenoviruses, and respiratory syncytial virus.

What are the symptoms of the common cold?

Sneezing, scratchy throat, runny nose, fever in children.

What are the causative agents of sinusitis?

Various viruses, bacteria, fungi, and noninfectious causes like allergies.

What is the treatment for bacterial sinusitis?

Broad-spectrum antibiotics.

What leads to acute otitis media?

Viral infections of the upper ear causing inflammation of eustachian tubes and fluid buildup.

What vaccines can prevent acute otitis media?

Prevnar (pneumococcal pneumonia) and Hib (Haemophilus influenzae).

What defines pneumonia?

An inflammatory condition of the lung in which fluid fills the alveoli.

What is the most common causative agent of community-acquired pneumonia?

Streptococcus pneumoniae.

What is 'walking pneumonia' caused by?

Mycoplasma pneumoniae and Chlamydophila pneumoniae.

What is a significant risk factor for pneumonia in children?

Pneumonia is the leading cause of death from infectious diseases in children under 5.

What role does the HIB vaccine play in respiratory health?

It has reduced the incidence of Haemophilus influenzae infections.

What is the role of alveolar macrophages in the lower respiratory tract?

They help to clear pathogens and debris from the alveoli.

What is the significance of secretory IgA in the respiratory tract?

It plays a crucial role in mucosal immunity by preventing pathogen adherence.

What is the typical treatment for fungal infections causing sinusitis?

Antifungals and/or surgery.

What is the common method for diagnosing streptococcal pharyngitis?

Rapid diagnostic tests of pharyngeal swab specimens.

What is the bacitracin disc test used for?

To distinguish S. pyogenes from other beta-hemolytic streptococci.

What is the fatality rate of scarlet fever in the past?

Up to 95%.

What are the symptoms of scarlet fever?

Sandpaper-like rash and high fever.

What disease is caused by SARS-CoV-2?

COVID-19

What severe condition can COVID-19 lead to in children?

MIS-C (multi-system inflammatory syndrome in children)

What are common signs and symptoms of COVID-19?

Symptoms can range from none to severe, potentially leading to death.

What organ systems can SARS-CoV-2 damage?

It can damage blood vessels, heart, kidneys, brain, and other organs.

What is a significant post-COVID symptom reported by patients?

Post-COVID symptoms can last for weeks to months.

What triggers widespread damage in SARS-CoV-2 infections?

Activation of bradykinins.

What is the role of interferon in the immune response to SARS-CoV-2?

The virus has proteins that block interferon production, crippling the innate immune response.

What is Streptococcus pneumoniae commonly known as?

Pneumococcus

What factors increase the risk of disease from Streptococcus pneumoniae?

Old age, season, underlying viral respiratory disease, diabetes, chronic substance abuse.

What is atypical pneumonia caused by?

Mycoplasma and Chlamydophila.

What is a characteristic of 'walking pneumonia'?

Lack of acute illness in most patients.

What is Pneumocystitis pneumonia caused by?

Pneumocystitis (carinii) jiroveci, a fungus.

Who is most at risk for Pneumocystitis pneumonia?

AIDS patients.

What is the primary transmission method for respiratory viruses causing pneumonia?

Aerosol droplets.

What is the mortality rate for healthcare-associated pneumonia?

30 to 50%.

What are common symptoms of influenza?

Headache, chills, dry cough, body aches, fever, stuffy nose, sore throat, extreme fatigue.

What are the causative agents of influenza?

Influenza A, B, and C viruses.

How is influenza primarily transmitted?

Inhalation of virus-laden aerosols and droplets.

What is the CDC's recommendation for influenza vaccination?

Everyone over the age of 6 months should receive a vaccination.

What is the treatment for influenza?

Antiviral drugs like Relenza and Tamiflu, effective if taken early.

What is the causative agent of whooping cough?

Bordetella pertussis.

What are the stages of whooping cough?

Incubation, catarrhal, paroxysmal, and convalescent stages.

What is the prevention method for whooping cough?

DTaP vaccine and antibiotic treatment for contacts.

What is tuberculosis often referred to as?

The 'Captain of the Men of Death' and 'White Plague.'

What is the minimum infectious dose of Mycobacterium tuberculosis?

About 10 bacterial cells.

What are the forms of clinical tuberculosis?

Primary, secondary (reinfection), and disseminated/extrapulmonary.

What is a significant complication of extrapulmonary tuberculosis?

Infection can occur in regional lymph nodes, kidneys, long bones, and the brain.

What is the primary method for diagnosing tuberculosis?

Tuberculin testing (Mantoux test).

What is the treatment for active tuberculosis?

Rifampin, isoniazid, ethambutol, and pyrazinamide.

What defines multidrug-resistant tuberculosis (MDR-TB)?

Resistance to at least isoniazid and rifampin.

What is extensively drug-resistant tuberculosis (XDR-TB)?

MDR-TB strains with resistance to two additional drugs.

What is the estimated mortality rate for XDR-TB within months of diagnosis?

70%.