1/26/2016 Structure and Function of the Microbes Respiratory System Learning Objective Invisible Invaders Describe how microorganisms are Amazing Allies prevented from entering the respiratory system. Chapter 24 Microbial Diseases of the Respiratory System Structure and Function of the Structures of the upper respiratory system Respiratory System Upper respiratory system -Nose,pharynx,middle ear,and eustachian tubes -Saliva and tears protect mucosal surfaces Sirus Lower respiratory system -Larynx,trachea,bronchial tubes,and alveoli Oral cavity Epiglottis -Respiratory mucus protects mucosal surfaces
1/26/2016 1 Invisible Invaders Amazing Allies Chapter 24 Microbial Diseases of the Respiratory System Structure and Function of the Respiratory System Learning Objective Describe how microorganisms are prevented from entering the respiratory system. Structure and Function of the Respiratory System • Upper respiratory system – Nose, pharynx, middle ear, and eustachian tubes – Saliva and tears protect mucosal surfaces • Lower respiratory system – Larynx, trachea, bronchial tubes, and alveoli – Ciliary escalator moves particles to the throat via ciliary action – Alveolar macrophages destroy microorganisms in the lungs – Respiratory mucus protects mucosal surfaces Structures of the upper respiratory system Sinus Nasal cavity Oral cavity Tongue Sinus Middle ear Auditory (eustachian) tube Opening of Tongue auditory tube Epiglottis Larynx (voice box) Trachea (windpipe) auditory tube Tonsils Pharynx (throat) Spine (backbone) Esophagus
1/26/2016 Structures of the lower respiratory system Normal Microbiota of the Bronchiole Branch from (h Respiratory System Learning Objective Left lung Trache Characterize the normal microbiota of the upper and lower respiratory systems. Normal Microbiota of the Microbial Diseases of the Upper Respiratory System Respiratory System A wide variety of microorganisms Learning Objective colonize the upper respiratory tract Differentiate pharyngitis,laryngitis Normal microbiota suppress pathogens tonsillitis,sinusitis,and epiglottitis. by competing for nutrients and producing inhibitory substances Lower respiratory system is nearly sterile due to the ciliary escalator in the bronchial tubes
1/26/2016 2 Structures of the lower respiratory system Pharynx (throat) Larynx ( b) Bronchiole Branch from the pulmonary vein Branch from the pulmonary artery Blood (voice box) Trachea (windpipe) Right lung Bronchus Bronchiole Pleura Left lung H t Blood capillaries Alveoli Pleura Diaphragm (breathing muscle) Heart Normal Microbiota of the Respiratory System Learning Objective Characterize the normal microbiota of the upper and lower respiratory systems. Normal Microbiota of the Respiratory System • A wide variety of microorganisms colonize the upper respiratory tract • Normal microbiota suppress pathogens by competing for nutrients and pg y roducing inhibitory substances • Lower respiratory system is nearly sterile due to the ciliary escalator in the bronchial tubes Microbial Diseases of the Upper Respiratory System Learning Objective Differentiate pharyngitis, laryngitis, tonsillitis, sinusitis, and epiglottitis
1/26/2016 Microbial Diseases of the Upper Bacterial Diseases of the Upper Respiratory System Respiratory System ·Pharyngitis -Sore throat,inflammation of mucus membranes in the throat Learning Objective ·Laryngitis -Larynx is the site of infection ·Tonsillitis List the causative agent,symptoms, -Inflamed torsils prevention,preferred treatment,and ·Sinusitis laboratory identification tests for streptococcal pharyngitis,scarlet fever -Usually self-limiting diphtheria,cutaneous diphtheria,and otitis media. Bacterial Diseases of the Upper Respiratory System Diphtheria Streptococcal pharyngitis(strep throat) Caused by Corynebacterium diphtheriae -Caused by group A streptococci(GAS) -Gram-positive rod:pleomorphic .Streptococcus pyogenes Forms a tough grayish membrane in the throat -Resistant to phagocytosis -Streptokinases-lyse clots -Fibrin and dead tissue -Streptolysins-cytotoxic to cells -Blocks passage of air to the lungs -Local inflammation,fever,tonsillitis Exotoxin produced by lysogenized bacteri enlarged lymph nodes -Diagnosis-enzyme immunoassay tests ci5botdonogeshe Scarlet fever Cutaneous diphtheria-forms skin ulcer -Erythrogenic toxin produced by Prevented by DTaP vaccine lysogenized5.pyogenes -Diphtheria toxoid
1/26/2016 3 Microbial Diseases of the Upper Respiratory System • Pharyngitis – Sore throat, inflammation of mucus membranes in the throat • Laryngitis – Larynx is the site of infection • Tonsillitis – Inflamed tonsils • Sinusitis – Heavy mucus discharge from the sinuses – If opening is blocked, then pressure and pain occur – U ll lf Usually self-li iti m ng • Epiglottitis – A flap-like structure that prevents ingested material from entering the larynx – Most life-threatening disease of the upper respiratory system; develops rapidly with death in a few hours – Haemophilus influenzae type B Bacterial Diseases of the Upper Respiratory System Learning Objective List the causative agent, symptoms, prevention, preferred treatment, and laboratory identification tests for streptococcal pharyngitis, scarlet fever, di hth i t s di hth i d di phtheria, cu taneous di phtheria, and otitis media. Bacterial Diseases of the Upper Respiratory System • Streptococcal pharyngitis (strep throat) – Caused by group A streptococci (GAS) • St t rep ococcus pyogenes – Resistant to phagocytosis – Streptokinases - lyse clots – Streptolysins - cytotoxic to cells – Local inflammation, fever, tonsillitis, enlarged lymph nodes – Diagnosis - enzyme immunoassay tests • Scarlet fever – Erythrogenic toxin produced by lysogenizedS. pyogenes Diphtheria • Caused by Corynebacterium diphtheriae – Gram-positive rod; pleomorphic • F m g g y mm or ms a tou gh gra yish m e mbrane in the throat – Fibrin and dead tissue – Blocks passage of air to the lungs • Exotoxin produced by lysogenized bacteria – Circulates in the blood; damages the heart and kidneys • Cutaneous diphtheria – forms skin ulcer • Prevented by DTaP vaccine – Diphtheria toxoid
1/26/2016 Otitis Media Acute otitis media,with bulging eardrum Infection of the middle ear -Formation of pus puts pressure on the eardrum Causes -Streptococcus pneumoniae (35%) -Nonencapsulated Haemophilus inflenzde(20-30%) -Moraxella(10-15%) -Staphylococcus aureus (1-2%) Common in childhood due to smaller auditory tube 8 million cases each year in the US Viral Disease of the Upper The Common Cold Respiratory System Over 200 different viruses -PCR aids rapid identification Learning Objective -Rhinoviruses(30-50%) ·Thrive in temperatu lower than body temperature List the causative agents and treatments Coronaviruses(10-15%) for the common cold. -20%-30%unknown Sneezing,nasal secretion,congestion -Can lead to laryngitis and otitis medic -Not accompanied by fever First three days,nasal secretions contain high numbers of cold viruses Antibiotics are of no use Relief via cough suppressants and antihistamines
1/26/2016 4 Otitis Media • Infection of the middle ear – Formation of pus puts pressure on the eardrum • Causes – Streptococcus pneumoniae (35%) – Nonencapsulated Haemophilus influenzae (20–30%) – Moraxella catarrhalis (10–15%) – S. pyogenes (8–10%) – Staphylococcus aureus (1–2%) • Common in childhood due to smaller auditory tube • Treated with broad-spectrum penicillins (one-fourth of the antibiotic prescriptions) • 8 million cases each year in the US Acute otitis media, with bulging eardrum Bulg g in eardrum Viral Disease of the Upper Respiratory System Learning Objective List the causative agents and treatments for the common cold. The Common Cold • Over 200 different viruses – PCR aids rapid identification – Rhinoviruses (30–50%) • Th i i l h b d Thrive in temperatures lower than body temperature – Coronaviruses (10–15%) – 20% - 30% unknown • Sneezing, nasal secretion, congestion – Can lead to laryngitis and otitis media – Not accompanied by fever • First three days, nasal secretions contain high numbers of cold viruses • Antibiotics are of no use – Relief via cough suppressants and antihistamines
1/26/2016 Microbial Diseases of the Lower Structures of the lower respiratory system Respiratory System Bronchiole Branch from Caused by many of the same bacteria () Brinch from the and viruses as the upper respiratory (vpice box Left lung system Trache As the bronchi become involved -Bronchitis -Bronchiolitis -Pneumonia Pulmonary alveoli are involved Bacterial Diseases of the Lower Pertussis(Whooping Cough) Respiratory System Caused by Bordetella pertussis Learning Objectives -Gram-negative coccobacillus List the causative agent,symptoms. ·Produces a capsule prevention,preferred treatment,and -Allows attachment to ciliated cells in the laboratory identification tests for trachea pertussis and tuberculosis. Destroys ciliated cells and shuts down the Compare and contrast the seven bacterial ciliary escalator pneumonias discussed in this chapter. Tracheal cytotoxin of cell wall damages List the etiology,method of transmission, ciliated cells;escalator does not work and symptoms of melioidosis. Pertussis toxin enters the bloodstream associated with systemic symptoms 5
1/26/2016 5 Microbial Diseases of the Lower Respiratory System • Caused by many of the same bacteria and i th i t d viruses as th e upper respira tory system • As the bronchi become involved – Bronchitis – Bronchiolitis – Pneumonia • Pulmonary alveoli are involved Structures of the lower respiratory system Pharynx (throat) Larynx ( b) Bronchiole Branch from the pulmonary vein Branch from the pulmonary artery Blood (voice box) Trachea (windpipe) Right lung Bronchus Bronchiole Pleura Left lung H t Blood capillaries Alveoli Pleura Diaphragm (breathing muscle) Heart Bacterial Diseases of the Lower Respiratory System Learning Objectives List the causative agent, symptoms, prevention, preferred treatment, and laboratory identification tests for pertussis and tuberculosis. Compare and contrast the seven bacterial pneumoni di d i hi h ias discussed i n thi s c hapter. List the etiology, method of transmission, and symptoms of melioidosis. Pertussis (Whooping Cough) • Caused by Bordetella pertussis – Gram-negative coccobacillus • Produces a capsule – Allows attachment to ciliated cells in the trachea • Destroys ciliated cells and shuts down the ciliary escalator • Tracheal cytotoxin of cell wall damages ciliated cells; escalator does not work • Pertussis toxin enters the bloodstream associated with systemic symptoms