Podcast
Questions and Answers
What is the most common primary pathogen in bronchitis?
What is the most common primary pathogen in bronchitis?
Which symptom is considered the most prominent in bronchitis?
Which symptom is considered the most prominent in bronchitis?
Which of the following is NOT considered a virulence factor of Bordetella pertussis?
Which of the following is NOT considered a virulence factor of Bordetella pertussis?
What is the primary mode of transmission for whooping cough?
What is the primary mode of transmission for whooping cough?
Signup and view all the answers
Which of the following organisms is most commonly associated with acute tracheobronchitis?
Which of the following organisms is most commonly associated with acute tracheobronchitis?
Signup and view all the answers
What effect does the pertussis toxin have on adenylate cyclase activity?
What effect does the pertussis toxin have on adenylate cyclase activity?
Signup and view all the answers
What is a common complication seen due to the action of tracheal cytotoxin in whooping cough?
What is a common complication seen due to the action of tracheal cytotoxin in whooping cough?
Signup and view all the answers
Which of the following is a secondary bacterial infection associated with bronchitis?
Which of the following is a secondary bacterial infection associated with bronchitis?
Signup and view all the answers
What is the most common cause of ventilator-associated pneumonia?
What is the most common cause of ventilator-associated pneumonia?
Signup and view all the answers
Which organism is most likely associated with lung abscess formation?
Which organism is most likely associated with lung abscess formation?
Signup and view all the answers
Which of the following factors enhances colonization of the upper respiratory tract by Streptococcus pneumoniae?
Which of the following factors enhances colonization of the upper respiratory tract by Streptococcus pneumoniae?
Signup and view all the answers
What percentage of the healthy population harbors virulent pneumococci in the nasopharynx?
What percentage of the healthy population harbors virulent pneumococci in the nasopharynx?
Signup and view all the answers
Which condition is NOT a predisposing factor for pneumococcal infections?
Which condition is NOT a predisposing factor for pneumococcal infections?
Signup and view all the answers
Which of the following symptoms is associated with pneumococcal meningitis?
Which of the following symptoms is associated with pneumococcal meningitis?
Signup and view all the answers
What type of pneumonia is commonly caused by Streptococcus pneumoniae in children?
What type of pneumonia is commonly caused by Streptococcus pneumoniae in children?
Signup and view all the answers
What virulence factor of Streptococcus pneumoniae is responsible for its anti-phagocytic properties?
What virulence factor of Streptococcus pneumoniae is responsible for its anti-phagocytic properties?
Signup and view all the answers
What characterizes the paroxysmal cough associated with whooping cough?
What characterizes the paroxysmal cough associated with whooping cough?
Signup and view all the answers
Which pathogen is the most common cause of community-acquired pneumonia?
Which pathogen is the most common cause of community-acquired pneumonia?
Signup and view all the answers
What is a typical treatment during the catarrhal stage of whooping cough?
What is a typical treatment during the catarrhal stage of whooping cough?
Signup and view all the answers
Which of the following is NOT a symptom of whooping cough?
Which of the following is NOT a symptom of whooping cough?
Signup and view all the answers
What distinguishes atypical pneumonia from typical pneumonia?
What distinguishes atypical pneumonia from typical pneumonia?
Signup and view all the answers
Where does hospital-acquired pneumonia typically occur in relation to patient hospitalization?
Where does hospital-acquired pneumonia typically occur in relation to patient hospitalization?
Signup and view all the answers
Which of the following vaccines is commonly administered with the acellular pertussis vaccine?
Which of the following vaccines is commonly administered with the acellular pertussis vaccine?
Signup and view all the answers
Which of the following is a common bacterial pathogen associated with hospital-acquired pneumonia?
Which of the following is a common bacterial pathogen associated with hospital-acquired pneumonia?
Signup and view all the answers
What is a potential long-term problem for those who survive pneumococcal pneumonia?
What is a potential long-term problem for those who survive pneumococcal pneumonia?
Signup and view all the answers
Which of the following is a complication associated with pneumococcal pneumonia?
Which of the following is a complication associated with pneumococcal pneumonia?
Signup and view all the answers
Which pneumonia type is most commonly associated with older age, chronic lung disease, and diabetes?
Which pneumonia type is most commonly associated with older age, chronic lung disease, and diabetes?
Signup and view all the answers
Which vaccine is recommended for all children younger than 5 years old to prevent pneumococcal disease?
Which vaccine is recommended for all children younger than 5 years old to prevent pneumococcal disease?
Signup and view all the answers
Which treatment options are utilized for pneumococcal pneumonia due to penicillin resistance?
Which treatment options are utilized for pneumococcal pneumonia due to penicillin resistance?
Signup and view all the answers
What type of agar is used for the culture of sputum to diagnose Klebsiella pneumoniae?
What type of agar is used for the culture of sputum to diagnose Klebsiella pneumoniae?
Signup and view all the answers
Which is a common procedure for identifying antibiotic sensitivity in Klebsiella pneumoniae?
Which is a common procedure for identifying antibiotic sensitivity in Klebsiella pneumoniae?
Signup and view all the answers
What is a common empirical treatment for Klebsiella pneumoniae until sensitivity test results are known?
What is a common empirical treatment for Klebsiella pneumoniae until sensitivity test results are known?
Signup and view all the answers
Study Notes
Bacterial Lower Respiratory Tract Infection
-
Learning Objectives:
- Identify common causes of lower respiratory tract infections
- Recognize clinical signs of lower respiratory tract infections
- Describe lab diagnostics for various respiratory infections
- Detail treatment and prevention of infectious respiratory diseases
Lower Respiratory Tract Infections: Causative Agents
-
Bronchitis:
- Influenza virus
- Parainfluenza virus
- Respiratory syncytial virus
- Human metapneumovirus
- Chlamydophila pneumoniae
- Mycoplasma pneumoniae
- Bordetella pertussis (acute tracheobronchitis, whooping cough)
-
Bronchiolitis:
- Respiratory syncytial virus
- Parainfluenza virus 1-3
-
Pneumonia:
- Respiratory syncytial virus
- Influenza virus
- Adenovirus
- SARS-CoV-2
- Streptococcus pneumoniae
- Staphylococcus aureus
- Haemophilus influenzae type b
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
- Chlamydophila pneumoniae
- Mycoplasma pneumoniae
- Legionella species
Bronchitis: Clinical Manifestations
- Cough (most prominent symptom)
- Upper respiratory symptoms (nasal congestion, sore throat, low-grade fever)
- Expiratory wheezes (on physical examination)
Whooping Cough (Pertussis):
- Causative Agent: Bordetella pertussis
- Characteristics: Gram-negative capsulated coccobacilli
- Transmission: Droplets produced during coughing
Pertussis Pathogenesis
- Bacteria adhere to ciliated epithelial cells
- Bacteria multiply, increasing mucus secretion
- Ciliated epithelial cells are paralyzed and destroyed
- Other toxins cause systemic reactions
Pertussis Virulence Factors
- Pili: help organisms attach to cilia
- Pertussis toxin (A-B toxin): increases cAMP, mucus, and severe cough
- Adenylate cyclase toxin: increased mucus, inhibits leukocyte movement, and phagocytosis
- Tracheal cytotoxin: kills ciliated epithelial cells
- Capsule
- Endotoxin
Bronchitis: Clinical Findings
- Incubation period: 7-10 days
- Initial phase: mild upper respiratory symptoms
- Severe paroxysmal cough (1-4 weeks): high-pitched "whoop" sound
- Copious mucus production
- Vomiting, exhaustion after coughing fits
Pneumonia: Classification
-
Typical Pneumonia:
- Sudden onset, chills, malaise, high fever
- Productive cough
- Lobar infiltrate on chest X-ray
-
Atypical Pneumonia:
- Gradual onset, low-grade fever
- Dry, non-productive cough
- Headache, sore throat
- Diffuse lung infiltrates
Community-Acquired Pneumonia:
- Common causes: Streptococcus pneumoniae, respiratory viruses, Klebsiella pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Legionella species, Chlamydia pneumoniae
Hospital-Acquired Pneumonia:
- Occurs 48 hours or more after hospital admission (not present on admission)
- Common causes: Gram-negative bacilli (e.g., E. coli, K. pneumoniae, P. aeruginosa), Gram-positive cocci (e.g., S. aureus)
- Often caused by antimicrobial-resistant organisms
Pneumococcal Pneumonia
- Causative agent: Streptococcus pneumoniae
- Gram-positive coccobacilli, arranged in pairs/chains
- Virulent strains are capsulated
- Over 85 types based on capsular antigens
Pneumococcal Pneumonia: Transmission
- 5%-50% of healthy people carry virulent organisms in the nasopharynx
- Infection is often endogenous - aspiration of pneumococci from the nasopharynx.
Pneumococcal Pneumonia: Virulence Factors
- Polysaccharide capsule: anti-phagocytic
- IgA protease: enhanced colonization of upper respiratory mucosa
- Pneumolysin (hemolysin/cytolysin): damages respiratory epithelium
Pneumococcal Pneumonia: Complications
- Empyema (infection around lungs)
- Pericarditis (inflammation of the heart lining)
- Endobronchial obstruction with atelectasis and abscess
Pneumococcal Pneumonia: Treatment
- Penicillin resistant in some isolates
- Macrolides and Fluoroquinolones are alternative treatments
Prevention
-
Pneumococcal vaccination recommended for: children under 2, adults over 65, and high-risk individuals
-
Acellular pertussis vaccine: given with diphtheria and tetanus toxoids (DTaP). Boosters at 1.5 years and school age
-
Pneumococcal conjugate vaccine (PCV13): For age 2 and under, and high risk individuals.
-
Pneumococcal polysaccharide vaccine (PPSV23): for age 65 and older.
-
Chemoprophylaxis: Azithromycin for 5 days
Klebsiella Pneumoniae:
- Community-acquired pneumonia (Friedlander's pneumonia)
- Health care associated infections (majority of Klebsiella infections), including:
- Ventilator associated pneumonia (VAP)
- Urinary tract infection
- Surgical site infections (SSIs)
Klebsiella Pneumoniae: Laboratory Diagnosis
- Culture of sputum on Blood MacConkey agar
- Lactose fermenter
- Further identification by biochemical tests, BR test, and slide agglutination
Klebsiella Pneumoniae: Treatment
- Antibiotic selection based on resistance testing
- Aminoglycoside (e.g., gentamicin) and third generation cephalosporin (e.g., cefotaxime) are empiric choices until results of testing are known
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz focuses on bacterial lower respiratory tract infections including bronchitis, bronchiolitis, and pneumonia. You'll learn about common causes, clinical signs, lab diagnostics, treatment, and prevention strategies. Test your knowledge on infectious respiratory diseases and their management.
