bacterial pneumonia


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bacterial pneumonia

  1. 1. Lower Respiratory tractInfectionsDr Seema IrfanAssistant ProfessorDepartment of Pathology and Microbiology
  2. 2. Lower Respiratory tract Infections
  3. 3. Normal host defense• Nasopharynx• Conducting airways• Lower respiratory tract Nasal hair Turbinates Mucocilliary apparatus IgA secretion Cough, epiglottis reflex, sharpangle branching, mucocilliaryapparatus, Immunoglobulin(IgA) Alveolar lining fluid Alveolar macrophages Polymorph Cell mediated immunity Cytokines
  4. 4. PneumoniaDefinition → Inflammation of the alveoliand terminal airspaces in response toinvasion by an infectious agent
  5. 5. Pathogenesis• Factor responsible for development ofpneumonia– Defect in host defense– Overwhelming inoculum
  6. 6. Breech of body barriers• Cigarette smoking• Viral infection• Trauma to chest wall• Pulmonary edema• Alteration in the level of consciousness– Stroke– Seizures– Sedation– Alcohol abuse– Even normal sleep
  7. 7. Mode of transmission• Air born• Aspiration of upper respiratory flora• Metastatic seeding through blood
  8. 8. Aetiology• Viral• Bacterial• Mycobacterial• Fungal• Protozoal• Others
  9. 9. Community Acquired PneumoniaTypicalS.pneumoniaeH.InfluenzaeM.catarrhalisK.PneumoniaeS.aureusPseudomonasaeruginosaAnaerobes; BacteroidesAtypicalMycoplasma pneumoniaeChlamydia pneumoniaeCoxiella burnettii,Legionella pneumophila,RSV, Influenza, VZ,Adeno, Measles & Hantavirus, Fungi, Worms,Pneumocystis
  10. 10. Community AcquiredPneumoniaetiology S.pneumoniaeH.influenzaeM.pneumoniae C.pneumoniaeL.pneumophiliaAnaerobesOther
  11. 11. Pneumonia History →• Fever/Chills, cough, sob, chest pain• Physical Exam → Varies based on age of childNewbornsPatients do not cough → more commonly presentwith tachypnea, retractions, gruntingAdults• Auscultation of the lung fields may yield thefollowing:– Crackles, wheezing, diminished breath sounds,tubular breath sounds, or pleural friction rub
  12. 12. Hospital Acquired Pneumonia• Common organisms:– Enteric gram negative rods– P.aeruginosa– Acinetobacter spp.– Burkholderia cepacia– Stenotrophomonas maltophila• Ventilator associated pneumonia• Aspiration pneumonia
  13. 13. Ventilator associated pneumonia(VAP)• VAP refers to pneumonia that arises more than48–72 hours after endotracheal intubation.• Most concerning aspect of VAP is the high rateof associated mortality.• Risk factors :– patient related (male sex, preexisting pulmonarydisease, or multiple organ system failure)– treatment related (intubation or enteral feeding)Modifiable risk factors for HAP are obvioustargets for improved management andprophylaxis in several studies.
  14. 14. Chest x-ray (Acute Lobar pneumonia)
  15. 15. Bacterial pneumoniaAcute Chronic• Streptococus pneumoiae M.tuberculosis• Haemophilus influenzae Nocardia species• Moraxella catarrhalis• Klebsella pneumoniae andother enterobacteriaceae• Staphylococcuc aureus• Pseudomonas aeroginosa• Legionella pneumophila• Mycoplsma pneumoniae• Chlamydia pneumoniae
  16. 16. PneumoniaDiagnosis →Sputum Culture → usually not helpful → poorcorrelation with lower respiratory pathogensTracheal aspirate: Quantitative cultureBroncho-alveolar levage→ most useful inimmunocompromised patients believed to haveunusual organisms or patients who are severely illLung Aspirate → underused but can be very helpfulone series reports 52% positive cultures using thisapproachBlood & pleural fluid cultures positive in <20% cases
  17. 17. Sputum:• One of the most common types of specimensubmitted to the laboratory for bacterialexamination.• Difficult to obtain because of contamination withsaliva.• Many of the bacteria which are known to causelower respiratory tract infections may be presentin the oropharynx as part of the normal flora• The examination of a direct smear from thespecimen can be very helpful in diagnosingrespiratory infections and in determining theusefulness of the information provided by theculture.
  18. 18. Unsatisfactory sputum samples
  19. 19. Satisfactory sputum samples
  20. 20. Reporting• The average number of each type of cellper low power field in a representativearea of the smear is recorded.• Less than 1 and up to 9 cells per field arereported as “Few”• 10 to 25 cells are reported as “Moderate”• Any number in excess of 25 is reported as“Numerous”
  21. 21. Culture media• Chocolate agar• CN agar• MacConkey’s agar
  22. 22. Streptococus pneumoiae
  23. 23. Cross section of Streptococcuspneumoniae
  25. 25. Identification of Streptococcuspneumoniae
  26. 26. Sensitivity by disc diffusion method
  27. 27. Haemophilus influenzae Menengitis
  28. 28. Colony morphology Haemophilusinfluenzae
  29. 29. Haemophilus influenzae
  30. 30. Haemophilus influenzae
  31. 31. Haemophilus influenzae
  32. 32. sattelitism
  33. 33. Moraxella catarrhalis
  34. 34. Colony morphology of Moraxellacatarrhalis
  35. 35. Moraxella catarrhalis
  36. 36. Klebsiella pneumoniae
  37. 37. Colony morphology of Klebsiellapneumoniae
  38. 38. Chest X-ray(nosocomialpneumonia)
  39. 39. Sputum gram stain
  40. 40. Pseudomonas aeroginosa
  41. 41. Atypical bacterial pneumonia• Mycoplasma, Legionella, Chlamydia• Unusual presentation• Extrapulmonary features• CXR often normal early in infection• WBC normal• Diagnosis-serology, urine• Treatment-macrolides, newer quinolones
  42. 42. Tuberculosis• Aetiology: Mycobacterium tuberculosis• Subacute infection– Chronic cough +/- haemoptysis– Fever– Weight loss– Night sweats• Extrapulmonary and atypical pulmonarypresentations more common in immuno-compromised host• Risk 100-fold higher in HIV/AIDS
  43. 43. Chest X-ray showing cavitation
  44. 44. Air born infection
  45. 45. TB diagnosis• Sputum x 3 for AFBSmear• TB culture– Sputum– Bronchoscopy– Other fluid if involved egpleural, CSF etc• Mantoux test
  46. 46. Acid fast staining of Mycobacteriumtuberculosis
  47. 47. Colony morphology of Mycobacteriumtuberculosis
  48. 48. Fungal pneumonia• Endemic fungi– Histoplasmosis– Blastomycosis– Cryptococcosis• Aspergillus• Candida