1. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Lecture prepared by Mindy Miller-Kittrell, University of Tennessee, Knoxville M I C R O B I O L O G Y WITH DISEASES BY BODY SYSTEM SECOND EDITION Chapter 22 Microbial Diseases of the Respiratory System

2. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structures of the Respiratory System Function of the Respiratory System – Exchange of gases between the atmosphere and the blood Respiratory system divided into two main parts – Upper respiratory system – Collects air, filters contaminants from the air, and delivers it to the lower respiratory organs – Lower respiratory system

3. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structures of the Respiratory System Structures of the Upper Respiratory System, Sinuses, and Ears – Components of the upper respiratory system – Nose – external portion of the respiratory system – Nasal cavity – lined with hairs and a ciliated mucous membrane to filter and trap particles and microbes – Pharynx – lined with a ciliated mucous membrane that pushes contaminants into the digestive system – Tonsils – aggregations of lymphoid tissue – Mucus – contains antimicrobial chemicals

4. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structures of the Respiratory System Structures of the Lower Respiratory System – Components of the lower respiratory system – Larynx – contains the vocal cords – Trachea, bronchi, bronchioles – series of tubes that allow movement of air through to the lungs – Alveoli – Air sacs of the lungs where oxygen from air enters the blood while carbon dioxide diffuses from the blood into the alveoli to be exhaled – Diaphragm – muscle involved in breathing – Protective components include a ciliated mucous membrane, alveolar macrophages, and secretory antibodies

5. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structures of the Respiratory System

6. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structure of the Respiratory System Normal Microbiota of the Respiratory System – Lower respiratory system – Typically microorganisms are not present – Upper respiratory system – Normal microbiota limit growth of pathogens – Normal microbiota may be opportunistic pathogens – Examples of normal microbiota – Haemophilus influenzae can colonize the nose – Staphylococcus aureus is present as normal microbiota in some individuals without causing disease – Diphtheroids can colonize the nose and nasal cavity

7. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Streptococcal Respiratory Diseases – Signs and symptoms – Sore throat, difficulty swallowing; may progress to scarlet or rheumatic fever – Pathogen and virulence factors – Caused by Group A streptococci ( S. pyogenes ) – Virulence factors include M proteins, hyaluronic acid capsule, streptokinases, C5a peptidase, pyrogenic toxins, streptlysins – Pathogenesis – Typically occur when normal microbiota are depleted, large inoculum is introduced, or adaptive immunity is impaired

8. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Streptococcal Respiratory Diseases – Epidemiology – Spread via respiratory droplets – Occurs most often in winter and spring – Diagnosis, treatment, and prevention – Often confused with viral pharyngitis – Penicillin is an effective treatment

9. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears

10. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Diptheria – Signs and symptoms – Sore throat, oozing fluid that hardens into a pseudomembrane that can obstruct airways – Pathogen and virulence factors – Caused by Cornybacterium diphtheriae – Virulent C. diptheriae produce diphtheria toxin, which prevents polypeptide synthesis and causes cell death

11. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears

12. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears

13. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Diphtheria – Pathogenesis and epidemiology – Spread person to person via respiratory droplets or skin contact – Immunocompromised or nonimmune individuals develop symptomatic infections – Diagnosis, treatment, and prevention – Diagnosis based on presence of a pseudomembrane – Treated by administration of antitoxin and antibiotics – Immunization is an effective prevention

14. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Sinusitis and Otitis Media – Signs and symptoms – Sinusitis: pain and pressure of the affected sinus accompanied by malaise – Otitis media: severe pain in the ears – Pathogen and virulence factors – Caused by various bacteria such as Streptococcus pneuomoniae, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis

15. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Upper Respiratory System, Sinuses, and Ears Sinusitis and Otitis Media – Pathogenesis and epidemiology – Bacteria in the pharynx spread to the sinuses via their connection with the throat – Sinusitis is more common in adults; otitis media is more common in children – Diagnosis, treatment, and prevention – Symptoms often diagnostic – No known way to prevent sinusitis

16. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Upper Respiratory System Common Cold – Signs and symptoms – Sneezing, runny nose, congestion, sore throat, malaise, and cough – Pathogens and virulence factors – Rhinoviruses are the most common cause, although numerous viruses cause colds – Pathogenesis – Cold viruses replicate in and then kill infected cells

17. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Upper Respiratory System Common Cold – Epidemiology – Transmitted via coughing/sneezing, fomites, or person-to- person contact – Diagnosis, treatment, and prevention – Signs and symptoms are usually diagnostic – Treatment is mainly supportive – Pleconaril can reduce duration of symptoms – Hand antisepsis is important preventive measure

18. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Lower respiratory organs are usually axenic When bacterial infection of the lower respiratory system occurs life-threatening illness can result

19. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Bacterial Pneumonias – Inflammation of the lungs accompanied by fluid–filled alveoli and bronchioles – Can be described by the affected region or the organism causing the disease – E.g., lobar pneumonia involves entire lobes of the lungs – Bacterial pneumonias are the most serious and the most frequent in adults

20. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Pneumoccocal Pneumonia – Signs and symptoms – Fever, chills, congestion, cough, chest pain, and short, rapid breathing – Pathogen and virulence factors – Caused by Streptococcus pneumoniae – Virulence factors include adhesins, capsule, pneumolysin – Pathogenesis and epidemiology – Infection occurs by inhalation of bacteria – Bacterial replication causes damage to the lungs – Diagnosis, treatment, and prevention – Penicillin is the drug of choice for treatment – Vaccination is method of prevention

21. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

22. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Primary Atypical (Mycoplasmal) Pneumonia – Signs and symptoms – Atypical symptoms including fever, malaise, sore throat, excessive sweating – Pathogen and virulence factors – Caused by Mycoplasma pneumoniae – Virulence factors include an adhesion protein – Epidemiology – Nasal secretions among individuals in close contact spread the bacteria – Diagnosis, treatment, and prevention – Treated with tetracycline and erythromycin – Prevention is difficult because individuals can be infective despite lack of symptoms

23. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

24. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Klebsiella Pneumonia – Signs and symptoms – Typical pneumonia symptoms combined with a thick, bloody sputum and recurrent chills – Pathogen and virulence factors – Caused by Klebsiella pneumoniae – Virulence factors include a capsule – Pathogenesis and epidemiology – Immunocompromised individuals at greatest risk for infection – Diagnosis, treatment, and prevention – Treated with antimicrobials – Prevention involves good aseptic technique by health care workers

25. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

26. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Other Bacterial Pneumonias – Cause – Haemophilus influenzae, Staphylococcus aureus, Yersinia pestis, and Chlamydia species – Portal of entry – inhalation, also via blood with Y. pestis – Signs/Symptoms – typical pneumonia symptoms with frothy, bloody sputum in the case of Y. pestis – Incubation period – variable depending on cause, although Y. pestis can produce symptoms in hours – Susceptibility – typically young children most susceptible – Treatment – antibiotic treatment – Prevention – good hygiene; vaccine available for H. influenzae

27. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

28. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Legionnaires’ Disease – Signs and symptoms – Typical pneumonia symptoms and possible complications of the gastrointestinal tract, CNS, liver, and kidneys – Pathogen and virulence factors – Caused by Legionella pneumophila – Pathogenesis – L. pneumophila kills human cells, causing tissue damage and inflammation

29. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Legionnaires’ Disease – Epidemiology – The elderly, smokers, and immunocompromised individuals are at increased risk for infection – Diagnosis, treatment, and prevention – Quinolones or macrolides are the drugs of choice for treatment – Reduction of bacterial presence in water is successful control measure

30. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

31. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

32. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Tuberculosis – Pathogenesis – M. tuberculosis can remain viable for long periods in aerosol drops – Three types of tuberculosis – Primary tuberculosis – initial case of tuberculosis disease – Secondary tuberculosis – reestablished tuberculosis – Disseminated tuberculosis – tuberculosis involving multiple systems – Epidemiology – Immunocompromised individuals are most at risk – Tuberculosis is the leading killer of HIV+ individuals

33. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

34. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

35. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Pertussis (Whooping Cough) – Signs and symptoms – Initially cold-like, then characteristic cough develops – Pathogen and virulence factors – Bordetella pertussis is the causative agent – Virulence factors include various toxins including pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, and tracheal cytotoxin – Pathogenesis – Four phases – incubation, catarrhal, paroxysmal, and convalescent

36. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Pertussis (Whooping Cough) – Epidemiology – Highly contagious; the bacteria spread through the air in airborne droplets – Diagnosis, treatment, and prevention – Symptoms are usually diagnostic – Treatment is primarily supportive – Prevention is with the DTaP vaccine

37. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System

38. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Inhalational Anthrax – Signs and symptoms – Resemble a cold or flu but progress to severe coughing, shortness of breath, shock, and death – Pathogen and virulence factors – Bacillus anthracis is the causative agent – Virulence factors include a capsule and secretion of anthrax toxin – Pathogenesis and epidemiology – Anthrax not spread from person to person – Acquired by contact or inhalation of endospores

39. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Bacterial Diseases of the Lower Respiratory System Inhalation Anthrax – Diagnosis, treatment, and prevention – Diagnosis based on identification of bacteria in sputum – Early and aggressive treatment with antimicrobials necessary – Anthrax vaccine available to military personnel, researchers, and health care workers dealing with anthrax patients

40. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

41. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Influenza – Signs and symptoms – Sudden fever, pharyngitis, congestion, cough, myalgia – Pathogens and virulence factors – Influenza virus types A and B are the causative agents – Hemagglutinin and neuraminidase mutations are responsible for production of new strains – Mutations occur via two main processes – Antigenic drift – Antigenic shift

42. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

43. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

44. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Influenza – Pathogenesis – Symptoms of influenza are produced by the immune response to the virus – Flu patients are susceptible to secondary bacterial infections due to virally produced damage to the lung epithelium – Epidemiology – Transmitted via inhalation of airborne viruses or by self- inoculation – Complications occur most often in the elderly, children, and those with chronic diseases

45. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

46. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Influenza – Diagnosis, treatment, and prevention – Signs and symptoms during a community-wide outbreak are often diagnostic – Two drugs recommended to treat influenza – Oseltamivir and zanamivir – Treatment also involves supportive care to relieve symptoms – Immunization with a multivalent vaccine

47. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

48. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Respiratory Syncytial Virus Infection – Most common childhood respiratory disease – Signs and symptoms – Fever, runny nose, and coughing in babies or immunocompromised individuals – Mild coldlike symptoms in older children and adults – Pathogen – Respiratory syncytial virus (RSV) – Pathogenesis – Formation of syncytia can help viruses evade the immune system and also infect new cells

49. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

50. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Respiratory Syncytial Virus Infection – Epidemiology – Transmission occurs via close contact with infected persons – Diagnosis, treatment, and prevention – Diagnosis of RSV infection made by immunoassay combined with signs of respiratory distress – Supportive treatment for young children – Prevention includes aseptic technique of health care workers and day care employees

51. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

52. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System

53. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Viral Diseases of the Lower Respiratory System Other Viral Respiratory Diseases – Other viruses cause respiratory disease in children, the elderly, or immunocompromised individuals – Cytomegalovirus – Metapneumovirus – Estimated to be the second most common cause of viral respiratory disease behind rhinoviruses – Parainfluenza viruses – Three strains cause croup and viral pneumonia – Occur primarily in young children

54. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System

55. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System Coccidiodomycosis – Signs and symptoms – Resembles pneumonia or tuberculosis – Infection can become systemic in immunocompromised persons – Pathogen and virulence factors – Caused by Coccidioides immitis – Pathogen assumes yeast form at human body temperature – Pathogenesis – Enters the body through inhalation of arthroconidia from the soil

56. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System

57. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System

58. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System Coccidiodomycosis – Epidemiology – Found almost exclusively in southwestern U.S. and northern Mexico – Diagnosis, treatment, and prevention – Diagnosed by presence of spherules in clinical specimens – Amphotericin B is the drug of choice for treatment – Protective masks can prevent exposure to arthroconidia for those in occupations with high risk

59. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System Blastomycosis – Signs and symptoms – Flulike symptoms – Systemic infections can produce painless lesions on the face and upper body or purulent lesions on various organs – Pathogen and virulence factors – Caused by Blastomyces dermatitidis – Pathogen assumes yeast form at human body temperature

60. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System Blastomycosis – Pathogenesis and epidemiology – Enters the body through inhalation of dust carrying fungal spores – Incidence increasing among immunocompromised – Diagnosis, treatment, and prevention – Diagnosis based on identification of B. dermatitidis in clinical samples – Treated with Amphotericin B – Relapse common in AIDS patients

61. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System

62. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System

63. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System Pneumocystis Pneumonia (PCP) – Signs and symptoms – difficulty breathing, anemia, hypoxia, and fever – Pathogen – caused by Pneuocystis jiroveci – Pathogenesis and epidemiology – Infection occurs by inhalation of droplets containing the fungus – Common disease in AIDS patients – Diagnosis, treatment, and prevention – Treat with trimethoprim and sulfamethoxazole – Impossible to prevent infection with P. jiroveci

64. Copyright © 2009 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mycoses of the Lower Respiratory System