14 Questions
What is the causative agent of epiglottitis?
Both A and B
What type of agar is used to culture samples for diphtheria?
Blood tellurite agar
What is a common symptom of upper respiratory tract infections?
Coughing
What is the purpose of a nasal swap sample in laboratory diagnosis?
To diagnose upper respiratory tract infections
Which antibiotic is commonly used to treat pertussis?
Erythromycin
What is the primary purpose of a VITEK test?
To identify bacterial antibiotic susceptibility
Which of the following is NOT a normal flora of the upper respiratory tract?
Streptococcus pyogenes
What is the main mechanism of host defense in the respiratory tract?
All of the above
Which of the following pathogens is responsible for laryngeal TB of URT?
Mycobacterium tuberculosis
What is the main cause of tonsillitis and pharyngitis in children?
Streptococcus pyogenes
Which of the following is a common mode of transmission of upper respiratory tract infections?
Contact with hands and utensils
Which of the following diseases is NOT associated with the upper respiratory tract?
Meningitis
Which of the following pathogens is responsible for sinusitis?
All of the above
What is the primary function of the mucociliary escalator in the respiratory tract?
To trap pathogens and remove them from the respiratory tract
Study Notes
Upper Respiratory Tract Infection
- The upper respiratory tract consists of nasal cavity, sinuses, pharynx, and larynx.
- Normal flora of the upper respiratory tract includes:
- Streptococcus
- Staphylococcus
- Neisseria spp.
- Diphtheroids
- Haemophilus spp.
- Bacteroides
- Candida spp.
- Mycoplasma
- Fusobacterium
- Actinomyces
Host Defense Mechanisms of the Respiratory Tract
- Coughing and sneezing
- Presence of normal flora
- Nasal hair
- Cilia
- Mucociliary escalator
- Secretion of IgA antibody
- Macrophages eradicate microbes in the lungs
Pathogens of the Upper Respiratory Tract
- Streptococcus pyogenes (strep A)
- Staphylococcus aureus
- Corynebacterium diphtheria
- Haemophilus influenzae (immunocompromised patients)
- Streptococcus pneumoniae (sinusitis)
- Moraxella catarrhalis (sinusitis)
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Bordetella pertussis
- Legionella pneumophila
- Mycobacterium tuberculosis (laryngeal TB of URT)
- Some enterobacteria
Transmission of Infection
- Coughing
- Sneezing
- Contact with hands
- Utensils
Diseases of the Upper Respiratory Tract
- Tonsillitis and pharyngitis
- Laryngitis (Strep pneumoniae, H. influenzae, M. catarrhalis)
- Sinusitis (H. influenzae, S. pneumoniae, S. aureus, M. catarrhalis, S. pyogenes and some gram-negative)
- Diphtheria (C. diphtheria)
- Whooping cough (Bordetella pertussis)
- Epiglottitis (H. influenza, parainfluenza, Strep pneumoniae, Staph aureus, Klebsiella spp)
- Otitis media (S. pneumoniae, H. influenza, M. catarrhalis)
Symptoms of Upper Respiratory Tract Infections
- Coughing
- Sore throat (pain)
- Fever
- Myalgia
- Fatigue
- Pain when swallowing
Laboratory Diagnoses
- Samples: throat swab, nasal swab, nasopharyngeal swab (for otitis media, ear swab)
- Culture: blood agar and chocolate agar, incubated aerobically for 24h at 37°C
- If requested, culture on blood tellurite for diphtheria (black colonies)
- Confirmatory tests: catalase, coagulase, optichin disk (Strep. pneumoniae), bacitracin disk (strep A), Lancefield grouping (hemolytic strep)
- VITEK, serology, PCR (direct smears are not routinely done)
Treatment of URT Infections
- Self-limiting
- Penicillin
- Cephalosporin
- Amoxicillin
- Erythromycin, clarithromycin, azithromycin, and trimethoprim can be used for pertussis
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
