Microbial diseases of respiratory Flashcards
Strept throat
sore throat. may progress to scarlet fever or rheumatic fever. S pyogenes gram positive facultative anaerobic pairs or chains, beta hemolytic. Occurs when normal microbiota are depleted. Penicillin effecive treatment, S. pyogenes beta hemolytic diagnostic because other Streps are normal microbiota.
Diptheria.
Sore throat oozes, pseudomembrane acorss airways. Cornyeobacterium. High GC pleomorphic non endospore forming Diptheria toxin, prevents peptide synthesis. Causes cell death. Resp droplets. Skin contact. Immunocompromised. treat antitoxin.
Sinusitis and Otitus media.
S. pneumoneia. S pyogenes. H influenza. Moraxella. Bacteria in throat spread to sinuses. Cranium changes in adult so less common than in kids. Bacteria in pharynx spread to ear /sinus.
Cold and flu
No fever in cold last about a week.
Common cold
200 different types. Enteroviruses rhino viruses most common. Attach to ICAM 1 on nasal membrane surface. Infected cells lose cilliary action and slough off. Localized inflammation blocks nasal cavities. Highly infective. grows best 33C neutral pH. Mucus and snezing from immune response.
bacterial pneumonia
fluid in lungs.
lobar pneumonia
strep
mycoplasma pneumonia (primary atypical)
mycoplasma
nosocomial pnuemonia
klebsiella
pneumococcal pneumonia
neutrophils in sputum. S. pneumonia gram positive cocci. Rarely reaches lungs. Adhesin capsule pneumolysin prevents phagocytosis. Lining is damaged llowing fluid to fill. Then leukocytes attack more damage. Diagnose sputum smears, treat penicillin.
Mycooplasma pnueomnia
no cell wall. Low GC gram positive obligate aerobe. Adhesion protein. Nasal secretion. Treat with tetracycline
Legionaires disease
typical pneumonia symptoms. Death 50% if untreated. Legionella pneumophila. Gram negative pleiomorphic. Intracellular of freshwater protozoa or macrophages. Elderly or smokers at risk. Rind by serological test. Quinolones and macrolides.
Tuberculosis
rever cough, chest pain, coughing up blood. mycobacterium tuberculosis. High GC gram positive non endospore forming. Mhycooic acid slow growth resistant to antimicrobial drugs. Viable long time in respiratory droplets.
3 types tuberculosis
primary : tubercles
secondary reactivation
systemic
reactivated tuberculosis
tubercule surrounded bymacrophages bursts and allows them to gain access to system
tuberculin skin test
small amount of cell wall put underneath skin, reaction means exposure to TB.
Tuberculosis treatment
combination of drugs, 6 months. Bacterium takes long to grow. Drug resistant strains have emerged.
Pertussis whooping cough
Bordtella pertussis is gram negative aerobic coccobacillus. Pertussis toxin increases mucous production and decreasesleukocyte killing. Life threatening for children. Prevent with DATP vaccine.
inhalational anthrax
initially flu or cold. lethargy sever coughlater. Gram + spore forming rod aerobic. Anthrax toxin kills human cells, capsule prevents phagocytosis. Acquired by contact with endospores not person to person.
influenza
sudden fever pharyngitis. Similar to cold but with fever. Types A and B. -ssRNA enveloped sudded with HA or NA.Mutations in hemaglutinin and neuramidase produce new strains. Symptoms produced by immune reponse. Inhalation of virus.
SARS
High fever difficulty breathing. Later bad cough pneumonia. Mortality 10%. Caused by coronavirus. +ssRNA with helical capsid.
Hantavirus pulmonary syndrome
symptoms progress to cough, shock, 50% mortality. Widespread shock. segmented -ssRNA virus. transmitted mice excrement. Inflamation causes vessles to leak fluid. Prevention requires conrol of rodents.
3 fungal respiratory diseases
coccidiomycosis, blastomycosis, histoplasmosis
coccidiomycosi
resmbles tuberculosis or penumonia. Can become systemic in immunocompromised. Coccidiodes. Dimorphic soil Ascomyocota. In soil grows as filaments, converts to yeast in blood. Spherules diagnostgic. Treat with amphotericin B.
histoplasmosis
Most common in humans yet 95% asymptomatic. Infection causes coughing with bloody sputum. Histoplasma spatulum. dimorphic soil ascomycete. Intracellulr of macrophages, inhaled. Find fungus in samples.
