Mycology 1.2

Question 1

acid fast

Answer 1

mycobacteria, bacilli obligate aerobes. high lipid content in cell wall, MYCOLIC ACID. pink staining.binds carbol fuchsin

Question 2

Mycobacterium tuberculosis complex

Answer 2

MTB, M. africanum, M. bovis, M. bovis (bovine bacillus) bacille calmette-guerin (BCG)–> can be used to treat bladder cancer.

Question 3

NTM, MOTT or atypical mycobacteria

Answer 3

slow growers: m. kansasii, ,.avium-intracellulare complex, m. marinarium, m. scrofulaceum Rapid growers: m. chelonae-abcessus complex, m. fortuitum complecspecial growers: m. leprae

Question 4

primary infection

Answer 4

individual’s first exposure

Question 5

granulomatous inflamation

Answer 5

alveolar macrophages?

Question 6

Ghon complex

Answer 6

that is the characteristic gross appearance with primary tuberculosis, In most persons, the granulomatous disease will not progress.

Question 7

caseous necrosis

Answer 7

morphological changes indicative of cell death caused by progressive enzymatic degradation.

Question 8

latent TB

Answer 8

alive organisms still contained in the body

Question 9

reactivated infection

Answer 9

10% of people with latent can progress to active.more likely to occur early than laterimmunocompromised more likelysite of reactivation is in the upper apical posterior lobes, due to its obligate aerobe status

Question 10

what is the most common organ infected by tb

Answer 10

lung, cough is symptom. blood tinged sputum, sweaty

Question 11

Cavitary TB

Answer 11

infiltrate in upper lung with hollow center

Question 12

Milliary TB

Answer 12

looks like millet seeds, hematogenous spread indication. be able to see them on X-rays

Question 13

risk factors of TB

Answer 13

close contact, healthcare workers, congregate settings, intravenous drug users, HIV/AIDS, recent immigrants

Question 14

WHO global prevalance

Answer 14

most dense in subsaharan africa and southeast asia

Question 15

TST

Answer 15

mantoux tuberculin skin testtests for delayed hypersensitivity, mounts immune responseNOT antibody mediated, type 4 hypersensitivity

Question 16

type 4 hypersensitivity

Answer 16

CD4+ helper T cells recognize antigen in a complex with Class 2 major histocompatibility complex. The antigen-presenting cells in this case are macrophages that secrete IL-12, which stimulates the proliferation of further CD4+ T1 cells. CD4+ T cells secrete IL-2 and interferon gamma, further inducing the release of other Th1 cytokines, thus mediating the immune response. Activated CD8+ T cells destroy target cells on contact, whereas activated macrophages produce hydrolytic enzymes and, on presentation with certain intracellular pathogens, transform into multinucleated giant cells.

Question 17

what is the purpose of two step system ppd?

Answer 17

memory weaning, not much of a reaction. a couple weeks later antigen will create more of a response.

Question 18

what is a positive TST?

Answer 18

induration of 15 o more mm.induration of 5 or more means HIV or organ transplants.induration of 10 mm or more indicates that they are recent immigrants or drug users

Question 19

interferon release assay

Answer 19

whole blood tests that a diagnose M. tuberculosis. both latent and and active. but to really know if its active need to do further exams. blood will develop same type 4 reaction.

Question 20

what can give you a false positive tests?

Answer 20

other mycobacterium infections, BCG vaccination

Question 21

diagnosis of active infection

Answer 21

respiratory samples, early morning sputa. children-gastric aspirate.sterile tissue/ body fluidusine signs of in UT

Question 22

AFB stains

Answer 22

Ziehl-neelson and kinyounAuramine-Rhodamine- need fluorescent micro

Question 23

nucleic acid amplification tests

Answer 23

PCR, can detect as little as 10 bacilli per sample

Question 24

how is TB identified?

Answer 24

from a cultured isolate using nuclide acid hybridization based on the ability of complimentary nuclidc acid chains.

Question 25

liquid vs solid agar

Answer 25

faster on liquid, looks like parmesan on specific DNA probe

Question 26

Runyon classifications

Answer 26

current identification classes, 4 groups. rate of growth, pigment production, dark or light

Question 27

Runyon 1

Answer 27

photochromogens

Question 28

Runyon 2

Answer 28

Scotochromogens

Question 29

Runyon 3

Answer 29

Nonchromogenic

Question 30

Runyon 4

Answer 30

Rapid growersno pigment, colonies in 5 days.M. fortuitum, m. chelonae-abscessus. <- (foot baths)

Question 31

M. Kansasii

Answer 31

Runyon 1- photochromogen.chronic pulmonary disease, resembles TB but not a public health concern.more common in men

Question 32

M. Marinum

Answer 32

Runyon 1- Photochromogen. Sporotrichoid lesion. lymphocutaneous infection from aquarium. skin leasions can be caused by other things too.

Question 33

M. scrofulaceum

Answer 33

Runyon 2- scotochromogen, slow grower causes cervical LYMPHADENITIS, or scrofula.from swamp water.use MTB or MAC for differential diagnosis.

Question 34

MAI Complex (MAC)

Answer 34

Runyon 3- non chromogen. ppulmonary infection and opportunistic disseminated disease in AIDS

Question 35

Hansen’s disease

Answer 35

lepromatous leprosy- more severe and advanced presentation.tuberculoid leprosy- well-demarcated lesions with central hypo pigmentation and hypoesthesia.

Question 36

leprosy key facts

Answer 36

Leprosy is a chronic disease caused by a bacillus, Mycobacterium leprae.Symptoms can take as long as 20 years to appear.Leprosy is not highly infectious. It is transmitted via droplets, from the nose and mouth, during close and frequent contacts with untreated cases.Untreated, leprosy can cause progressive and permanent damage to the skin, nerves, limbs and eyes.Early diagnosis and treatment with multidrug therapy remain the key elements in eliminating the disease and sequela of infection