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47 Cards in this Set
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tell me some general info about MAC (mycobacterium avium & intracellulare complex)
gram shape catalase/coagulase O2 where are they found |
acid fast
bacilli catalase + (same as nocardia) found in soil, water, saprophytes, humans and animals (no human transmission, no isolation tx) (contrast to nocardia that is found in soil only) Aerobic |
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what are 2 opprotunistic respiratory tract infections
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1. MAC (mycobacterium avium intracellulare complex)
Several Respiratory sx that are dif in men and women Lymph DMAC in HIV 2. Nocardia: respiratory, skin, CNS |
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how can we id staph vs strep?
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catalase
MAC is catalase + so is staph and nocardia |
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where might we pick up MAC from
what about nocardia |
NOT people, from decaying vegetation, soil, water
no person to person transmission!!! unlike MTB where its strictly person to person Nocardia: SOIL |
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what are 3 bugs with mycolic acid
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1. Mycobacterium
2. Nocardia 3. corynebacterium **all will be acid fast |
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where is MAC found
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everywhere!!!
water, birds, tobacco, farm animals, paper, dust |
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How are MAC, Nocardia and MTB simliar
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1. Slow grow
2. acit fast 3. bacillus 4. intracellular growth |
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what gives MAC its virulence
What about nocardia |
SAME FOR BOTH
intracellular growth elicits an immune response **disease is the result of host response to infection (MAC can be colonized and not have disease) ** MAC resitant to clorination, can persist in drinking water (same as legionella) **COntrast to MTB that had: LAM, WaxD, Cord Factor etc |
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who gets MAC infection and how
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it can colonize and not elicit disease in healthy person, in imminocomprimised we see disease
NO person to person contact **we see NEW infection, not latent as in MTB, after inhalation or ingestion **invade epithelium and infect macro **carried to lymph nodes **imminocompromised can spread via blood to liver, slpeen, BM |
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does mac grow fast?
if its in a smaple does it mean you have disease? how is MAC spred |
nope, neither does MTB or nocardia
nope, can be colonized w/o diesase not ppl to ppl, its inhaled OR INGESTED |
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what are the 3 forms of disease caused by MAC
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1. Pulmonary:
-fibrocavity: upper lobe in old male smokers -fibronodular: lady Windmereres (supress cough, junk stays in get lobe infiltrates and chronic dilated bronchioles) 2. Lymphadenitis: seen in kids 3. DMAC: disseminating, seen in HIV, CD4 <50, diarrhea |
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tell me about the fibronodulay pulm infection caused by MAC
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seen in upper lobe of old men who smoke
**get fibrous cavities, MAC easily detected in sputum |
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what is the fibronodular disease associated with pulm MAC infection
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Lady Windermeres Disease
**seen in old women who dont smoke but who supress their cough, the junk stays in and they get disease in MIDDLE lobe of lung and chronically dilates bronchioles **women also commonly have some throacic restircion- sccolioliosos, pectus excavatum |
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DMAC is seen in immunocomprimised pts. tell me about their granulomas
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not effective in containing MAC and so mac goes into blodo and infects other organs
*organs become large nad dysfunctional |
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what are 2 inportant immune mediators that are important in fighting MAC infections
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IFNg and TNFa
Get CMI rolling |
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typically in MAC if a person manifestes a disease we see pulm issues in old men who smoke and old women who dont cough (fibrocavitary and fibronodular), we can also see lymph involvement in kids and DMAC in HIV- what are some less common sx?
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IRS: immune reconstitution syndrome
**as the highly active antiviral tx (HAART) progresses we get a rise in CD4 and increased inflammatory response |
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is MTB reportable, what about MAC
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MTB you bet!!!
MAC not unless associated with AIDS |
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how is MAC dx
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1. exclusion of other causes
2. isolation of causitive agent -Sterile: your good -Non sterile: get another, can be colonization -LN: low counts, need to be cultivation **ID is same as MTB (turant flourscent stain, Lowenstein Jensen or Middlebrook media) 3. CXR: pulm leisions |
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what does it mean if we have MAC isolated from a sterile/non sterile site as far as Dx goes
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1. Sterile: its prbly significant. repetition not needed
2. Non sterile (from sputum): can jsut be colonization, needs a repeat |
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how can you ID a MAC
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1. analyze the cell wall lipids
2. PCR 3. Southern/Northern Blot |
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do MAC pts need to be in isolation for tx
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nope, no person to person spread
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what is the tx for MAC
how many AB how long is tx isolation? what about for HIV |
1. 3 AB
2. 12 mo min OR 1 year after - sputum sample 3. no isolation **may do surgery if needed to tale out affected LN or lung foci **previous protocol for HIV AND chemoprophylactic tx for HIV- clarithromycin or azithromycin |
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what types of infections are associated with nocardia
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1. Respiratory
2. Cutaneous 3. CNS |
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is nocardia associated with water?
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nope, but MAC and Legionella are
Nocardia is associated with SOIL |
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whats ruff buff and tuff?
whats pretty like fall |
MTB
nocardica |
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MAC is catalase +, is this a good way to distinguish it from nocardia
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nope, both are catalase +
also both are bacilli (so is MTB) and is aerobic just like the others, and grows slow...just like the others |
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what is the gram stain of nordicaria
shape |
gram + and weakly acid fast
bacillius that forms hyphae |
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what are some of the biochemical things that the branches hyphae nocardia do
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catalase +
liquify gelatin can grow on non selective media but can use selective to make it grow faster |
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what is the gram + weakly acid fast bug that is a branched hyphea
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nordicaria
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how do you ID nordicaria
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1. Acif fast/Gram +
2 branched hyphea 3. catalase + **16sRNA PCR andRestriction Fragment Length Polymorphish |
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what bugs dont have virulence factors but simply cause disease by living inside your cells and eliciting an immune repsonse
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MAC
Nocardia |
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who gets lots of nordicaria infections
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it grows in soil, then we inhale it and aspirate it and then we are infected
so ppl here in the yucky, dusty windy desert |
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we know MTB is spread....
how is MAC Nodocaria |
MTB: person to person
MAC: not person, can be in water Nodocaria: in the soil, inhale and then aspirate- these big branched hyphea need to be aspirated bf enter lungs |
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ok so nodocaris isnt trannmitted ppl to ppl or via hospital but through soil, what did that study find about who was infected commonly
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75% have underlying lung problem,
many were treated long term with corticosteroids (decreased immune system) and had underlying debilitating condition |
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we know mac commonly spreads as DMAC in HIV pts. does nodocaria spread also
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yep!
dissemination from lungs manifests as becteremia, empyema, brain abcess, pericarditis, synovitis |
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what are predisposing factors for nodocaria
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1. DM
2. Hematologic/other malignancy 3. AIDS 4. T cell deficit (leukemia, AIDS, immunosupressive therapy, corticosteroids) 5. Chronic Pulm Disease (bronchitis, emphysema, asthma,) BUT more than 10% had no predisposing or underlying factor **REMEBER IT IS OPPROTUNISTIC |
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when do bronchopulmonary infectins develop in nodocaria
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after colonization of oropharynx by INHALATION, then its aspirated into lower airway (remeber its that bid old branched hyphea thing)
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if I have chronic emphyseam and am on immunosuppresents for the heart transplant i had after it was removed bc of cancer what opprotunistic bug am i likey to get
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nodocaria
**its an acid fast/gram+ branched hyphea that is catalase + that is more common with risk factors including 1. DM 2 decreased T cells 3. chronic lung disease 4. cancer |
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what does the disease look like that is caused by nodocaria
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-pulm infection, hard to distinguish from other pyogenic organisms
-develops slow -cough, dyspnea, fever, -cavitation and spread to pleura -not common in ppl who are immunocompetent. - in HIV it will disseminate to the CNS and subcutaneous tissue |
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what bug should you consider in an HIV pt who...
has pneumonia with cavitation and spread to pleura, dissemination to CNS (brain abcess) or subcutaneous tissues |
nodocaris
**its uncommon in immunocompetent ppl |
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so in an HIV pt there is a typical presentation of nocardia (brain/subcutaneous abcess and cavitating pnemonia) but what about immuno competent
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ehh
cough, dyspnea, fever cavitation pnemonia and spread to pleura **dx is critical, grow on BCYE |
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whats hte deal with BYCE agar and Modified thayer martin medium for growin nocardia
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not really sure
To prevent obscurity, Nocardia should be isolated in: -the selective legionella medium BYCE (buffered charcoal yeast extract agar) -Modified Thayer martin (N gonorrhoae) **nocardia is a slow growe adn can be obscured by fast growers |
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how can you examine nocardia sample
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1. Gram +
2. WEAK acid fast, need modified Zeihl Neelson 3. culture on BYCE or Modified Thayer martin 4. If its found in a sterile site its likely its a causative agent |
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bc nocardia is pretty common in the environment (SOIL) what can be said about its presence in a pts sample
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could just be a contaminate but labs stay clean so its not likely it a contaminate
**if the sample is from a sterile area increases the likliehood that its etiologic agent |
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whats the tx protocol for nocardia
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DOC: TMP/SMX, IV tx for first 3-6 weeks then continue with oral (start with emperic while waiting for sensitivity)
**use 2-3 AB (MAC use 3, MTB use 4) |
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might you need surgery to tx MAC and nodocaria
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yep
MAC: can remove infected LN Nodocaria: remove any cerebral or skin abcess that developed or remove fluid |
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is nodocaria prone to relapse
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yep! treat really aggressive with several AB, (TMP/SMX IV then oral)
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