respiratory

• Diphtheria

  Non spore forming rods that are club-shaped and arranged in V or L shaped, giving rise to "Chinese characters"
• Diphtheria


  • Transient flora of the throat
  • Inflammation begins in the respiratory tract leading to sore throat and fever
  • Most prominent sign are thick, gray,adherent pseudomembrane over tonsils and throat
• Streptococcal Pharyngitis (Strep Throat)

  Acute bacterial infection of throat
• Streptococcal Pharyngitis (Strep Throat)

  Infection has the potential to spread to the middle ear, sinuses, ears
• Streptococcus pyogenes

  Pathogen that causes Streptococcal Pharyngitis, also known as group A streptococcus, gas, strep
• Reservoirs and Modes of Transmission for Streptococcal Pharyngitis

  • Direct contact
  • Hands, aerosol droplets, secretions from patients and nasal carriers, contaminated dust, lint, handkerchiefs have been linked to food-borne of streptococcal pharyngitis
• Legionella Pneumophila

  Acute bacterial pneumonia
• Pontiac fever

  Influenza-like, less severe form of legionellosis, not associated with pneumonia or death
• Legionnaires disease "legionellosis"


  Atypical pneumonia characterized by very high fever and severe pneumonia
• Legionella Pneumophila

  • More likely to affect elderly persons, with pre existing respiratory disease, diabetes, cellulitis, renal disease, or malignancy; immunocompromised or people who smoke or drink heavily
• Legionella pneumophila


  Etiologic agent of Legionella Pneumophila
• Reservoirs and Modes of Transmission for Legionella Pneumophila


  • Environmental water
• Laboratory Diagnosis for Legionella Pneumophila

  1. Sputum and blood specimens should be sent to microbiology lab for C&S

  2. Legionella spp. Stain poorly and require cysteine and other nutrients to grow

  3. Recommended culture medium is charcoal yeast extract agar

  4. Immunodiagnostic procedures are available such as antigen detection in your urine
• Mycoplasmal Pneumonia (Primary Atypical Pneumonia)


  Smallest free-living organism that can self replicate
• Mycoplasmal Pneumonia (Primary Atypical Pneumonia)

  • Part of the normal flora of the mouth
  • Lack of cell wall and cell membrane contains sterol
  • Cause of atypical pneumonia or walking pneumonia
• Treatment for Mycoplasmal Pneumonia

  macrolide or tetracycline
• Klebsiella pneumoniae

  Opportunistic pathogen that causes nosocomial infections
• Klebsiella pneumoniae

  • Found in large intestines but also present in soil and water
  • Produces primary lobar pneumonia that has production of thick, bloody sputum "currant jelly" sputum
• Tuberculosis (TB)

  Acute or chronic mycobacterial infection of lower respiratory tract
• Military tuberculosis

  Widespread tuberculosis involving many lesions throughout the body
• Mycobacterium tuberculosis


  Etiologic agent of Tuberculosis, a bacterium that belongs to the group of bacilli, rod-shaped, slow growing and acid-fast bacilli, referred to as tubercle bacillus
• Mycobacterium tuberculosis


  • Peculiar cell wall structures that provide strong impermeable barrier to noxious compounds and drugs
• Reservoirs and Modes of Transmission for Tuberculosis

  • Rarely primates, cattle
  • Transmission: airborne droplets by infected people during coughing, singing, talking
  • Bovine tuberculosis results from infected cattle or ingestion of unpasteurized, contaminated milk or dairy products
• Laboratory Diagnosis for Tuberculosis

  1. Demonstration of acid-fast bacilli (AFB) in sputum specimens provides a rapid, presumptive diagnosis

  2. Isolation of M. tuberculosis on Lowenstein-Jensen or Middlerbook culture media takes 3-6 weeks because the organism's long generation time (18-24 hours)

  3. Includes automated and semi automated instruments, molecular diagnostic procedures and gas-liquid chromatography

  4. Susceptibility testing, Tuberculosis are multidrug resistant

  5. Mantoux purified protein derived (PPD) tuberculin test, positive result may indicate past infection, present infection, or receipt of BCG vaccine

  6. Pulmonary tuberculosis may be seen on chest radiographs
• Whooping Cough (Pertussis)

  Highly contagious, acute bacterial childhood (usually) infection
• Parapertussis


  Similar but milder disease to Whooping Cough (Pertussis)
• Bordetella pertussis


  Pathogen that causes Whooping Cough, a small, encapsulated, nonmotile, Gram- coccobacilli that produces endotoxin and exotoxin
• Bordetella parapertussis


  Pathogen that causes Parapertussis
• Bordetella bronchiseptica


  Relative organism that causes respiratory infections in animals, includes kennel cough in dogs
• Laboratory Diagnosis for Whooping Cough (Pertussis)

  1. Special media such as Bordert-Gengoug agar (potato-based medium) or Regan-Lowe agar (charcoal blood medium) are used to isolate B. pertussis

  2. Molecular diagnostic and immunodiagnostic are available
• Scarlet Fever

  Inflammation occurs with streptococcal pharyngitis caused by streptococcus pyogenes strains producing pyogenic exotoxin known as "erythrogenic toxin"
• Sinusitis

  Inflammation of the mucosal lining of 1 or more paranasal sinuses
• Antimicrobial therapy for Sinusitis


  Done to achieve clinical improvement
• Common cold (acute rhinitis)


  Common illness in both children and adults
• Viruses is the most common etiological agent of common cold
• Antibiotics have no role of common cold
• Rhinoviruses


  Main cause of common colds, non-enveloped RNA viruses that have more than 100 serologic types, affect the nose and conjunctiva, can withstand adverse environmental conditions and can survive external environment for many hours but are killed with gastric acid when swallowed
• Coronaviruses (URTI)


  The second main cause of common cold, enveloped RNA virus, infections occur worldwide mainly transmitted by respiratory aerosol
• SARS (severe acute respiratory syndrome)


  New disease atypical pneumonia caused by the etiological agent CoV-SARS
• SARS

  • Civet cat was likely reservoir of Cov-SARS
  • Severe forms of atypical pneumonia characterized by fever, non-productive cough, dyspnea and hypoxia, chills, rigors, malaise, and headache commonly occur, incubation period 2-10 days
  • No antiviral therapy or vaccine available, attempts of using ribavirin and steroids in the treatment but efficacy is still undetermined