Details Title: 08.Medical Microbio - TB Description: Finished Total Flash Cards: 32 Created: 12/15/2008 13:44:47		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Biology Flashcards
Cards in this set: Term Tuberculosis Global Incidence Definition kills about 1.7 million people per year   about 1/3 of the world is infected w/ TB   People w/ HIV are at much higher risk Term multi-drug resistance TB Definition TB that fails to respond to standard first line drubs Term Extensively drug resistant TB Definition occurs when there is resistance to first AND second line drugs Term TB in Canada Definition highest in Nunavut Lowest on the East coast Term Mycobacteria Definition aerobic, non-motile bacilli Are Acid fast   include:   Mycobacterium tuberculosis and mycobacterium leprae Term MOTTS Definition Mycobacterium Other Than Tuberculosis   -resp. for opportunistic infections, esp. w/ AIDS patients Term Acid Fast Stain Definition Used to determine the presence of TB   dye w/ red stain carbolfushin put HCl and alchohol over   *If red remains, then it is acid fast b/c mycobacterium cell walls to not dissolve w/ acid alcohol.     Term What makes mycobacterium acid fast? Definition due to thick layer of mycolate (mycolic acid) on the outside     mycolic acid is an important virulence factor Term cording Definition When grown on agar, colonies of virulent strains attache to each other by rope like cords Term Sulfatides Definition myscosides w/ sulphates attached inhibit phagasomes (which protects M. tuberculosis) Term Wax D Definition complicated mycoside that activates the cellular immune system Term Transmission of TB Definition -occurs via the inhalation of droplet nuclei (released by coughing/sneezing)   -infected patients can have as many as 105 - 107 bacilli/mL Term Body's fight against TB Definition macrophages - kill mycobacterium                       -However, can provide niche for th                        bacteria to multiply w/i   denditic cells - engulfs bacteria   T-cells -  release cytokines w/ enhance macrophages Term Primary progressive disease Definition aka. Primary Tuberculosis   If t-cell response in insufficient in controlling TB, clinical symptoms will develop w/i a year.   Usually occurs amoung young children and immuno-comprimised persons. Term Latent TB Infection Definition -occurs in most individuals   -T-cell response is mounted, and no clinical symptoms occur   However, there is the risk of secondary TB because the bacteria can persist w/i granulomas Term Vaccine to help establish T-cell numbers Definition live Bacille Calmette - Guerin Term Definition Term Secondary Tuberculosis Definition Dormant bacilli become reactivated after years Term Stage I of pulmonary tubercuosis Definition -inhalation of bacilli, which are ingested by macrophages   -90% of bacilli are destroyed by macrophages, however, remaining 10% evade the host's defense by hiding in the macrophages Term Stage II of tuberculosis Definition -Bacilli w/i macrophages multiply and are released upon macrophage death   -bacilli attract monocytes and macrophages and forms and tubercle    -bacilli multiply within the cytoplasm of unactivated macrophages   -both bacilli and macrophages are increasing, and neither is being destroyed during this phase=symbiosis Term stage III of TB Definition -2-3 weeks after infection get delayed    hypersensitivity and cellular immunity   -delayed hypersensitivity halts the logarithmic growth by killing bacilli-laden macrophages   -results in caseous necrotic center of dead and live bacilli in the tubercle   -bacteria w/i necrotic center cannot multiply     Term Stage IV of TB Definition two options:   Weak cell mediated immunity     -caseous center enlarges, lung tissue destroyed,      bacteria is released and ingested by unactivated      macrophages.   Strong cell mediated immunity     -bacilli released from caseous center, ingested by      activated macrophages with little tissue      destruction.  Occurs in 90% of cases. Term Stage V of TB Definition -liquefaction of the solid caseous focus   -bacilli multiply extracellularly, extensive tissue damage   -Spread of bacilli via the bronchial tree to other parts of the lungs often leads to tuberculous pneumonia. Term PPD Test Definition Purified Protein Derivative Test   -PPD injected intradermally   -macrophages in skin take it up   -induration of >10mm after 2 days suggests TB expo. -induration of >5mm in AIDS patients suggests TB  exposure. Term Symptoms of TB Definition -weight loss -low grade fever -productive cough -night sweats -calcified tubercles in middle-lower lung region Term Extra pulmonary tuberculosis Definition -affect lymph nodes, pleua, gentiourinary tract, etc   -pretty much any organ system can be affected Term TB rule of '5' Definition -droplet nuclei are 5 micrometers (and contain 5 bacilli)   -Patients w/ TB have a 5% risk of reactivation w/i first 2 years, and 5% risk life long   -HIV patients have a 5+5% change of reactivation each year. Term Mycobacterium Avium Definition -usually infects birds -found in over 50% of AIDS patients   -Infects when helper T-cell levels are virtually nil Term TB Diagnosis Definition -PPD test -Chest xray (for calcified tuburcles) -acid fast test on sputum -Culture Term First line of Anti-TB drugs Definition Insert clever mnemonic here.....     Isoniazid Rifampin Pyrazinamide Ethambutol Streptomycin I Read Poetry Every Sunday Term Important principles of TB treatment Definition -administer multiple drugs at a time -in cases of failure, add at least 2 new drugs   Term Length of TB Treatment Definition 6-9 months with drug combo