Micro Ii Exam I

Front 1

Tuberculosis basics

Back 1

Aerobic G+, slightly curved or straight bacteria, in beaded chains that may branch. Non-motile, Urease +

Cell wall is made of Mycolic Acid and Waxes, hard to satin and requires acid fast.

Grows at 35-37c over 6-8 weeks in 5% CO2, also loves fatty acids (egg yolks), some may require iron or Hemian

Front 2

Tuberculosis Specimen collection

Back 2

Take early morning sputum for three consecutive days. Two positive smears, are diagnostic for some form of Tuberculosis.

A gastric aspirate is often performed on children.

Samples are invalid after 1 hour unless kept at 4c

Plate onto Middlebrook Agar 7H11 to enhance M. bovis, 7H10 contains Hemin for M. haemophilum

Or plate on Egg based medium (Loewenstein-Jensen agar

Dose not require transport medium.

Front 3

Tuberculosis General Pathology

Back 3

Patients with HIV/AIDS or are otherwise immunocompromised are at the greatest risk in the U.S.

Upon inhalation MTB enters macrophages and multiplies. From there it spreads to the LN, and begins damaging epithelial tissue and macrophages by forming granulomata and multinucleated Langerhans cells.

Granulomata fills the tissue with holes leading to cavitation. This damage is healed by forming fibrous tissue and calcifying the area.

Front 4

Tuberculosis Treatment

Back 4

1st: Isoniazid (INH) & Rifampin (RIF)

2nd: Pyraziamide (Z) & Ethambutol (E)

Treat with 4 drugs for 2 months, or 2 drugs for 4-7 months.

LTBI can be treated with a singular drug (INH) over 9 months.

Front 5

Tuberculosis Infection Paths

Back 5

Only found in humans and spread by aresoles (coughing and sneezing)

Front 6

Tuberculosis Drug Resistance

Back 6

Multidrug Resistance MDR TB: Resistant to Isoniazid and Rifampin

Extensivly Resistant: Resistant to Isoniazid, Rifampin, and one 2nd line drug.

Front 7

Tuberculosis Diagnosis

Back 7

Chest X-rays reveal damage.

Tuberculin Skin Test (TST) AKA: Mantoux test or Purified Protein Derivative (PPD); 5 units of tuberculin are injected intradermally and the skins raising in response is measured.

IFN-gamma release test: Heperinized blood

-Quantiferon Gold: stimulation with ESAT-6 and CFP-10, quantifies IFN-gama released by T-cells

-T-Spot TB (elispot): Counts number of T-cells releasing IFN-gama

Blood tests are overall more accurate, but harder to perform.

Front 8

Ziehl Neelsen & other stains

Back 8

Ziehl Neeslen is an Acid-Fast Stain: It is made of Carbo Fuschin and heat fixed at 65c over 2 hours and then counter stained with Methyl-Blue. Smear positive patients are highly infectious and more likely to die. Look for Cording of the bacteria.

Kinjoun stain: Fix with Phenol instead of heat

Auramine Rhodamine: view under 20x or 40x

Modified AF stain: 1% sulfuric acid

Front 9

M. Tuberculosis Testing

Back 9

Look for Dry, pale, crumbly colonies

12-25 days to grow.

Visible cording microscopicly

Niacin accumulation (yellow color)

Nitrate reduction

Pyrazinamidase +

Weakly catalase + up to 68c

Front 10

M. Bovis Testing

Back 10

Niacin-

Nitrate -

Pyrazinamidase -

Front 11

BCG Vaccine

Back 11

Bacille Calmette-Guérin

Dose not prevent infection, but limits it's ability to spread by 20-80%

Front 12

Tuberculosis Symptoms

Back 12

90% of infections are aysymptomatic

Pulmonary is most common with: Cough, Hemoptysis (Bloody Sputum), fever, malasia, night sweats and weight loss.

TB can extra pulmonary and occur nearly anywhere in the body. The most common is Cervical Lymphadentitis (Scrofula) 25% of cases.

Front 13

Sputum Protocol

Back 13

Add 4% NaOH for 20 minutes or NALC+2%NaoH

For CF use 5% Oxalic acid

Spin 20 seconds at 3000g

Discard most SN, and resuspend pellet in about 2-5mL

Contamination should be no more than 3-5%

Stop decontamination with 2x PBS

Heat fix to slide and kill TB with a bleach solution and then stain

Front 14

M. tb-AST

Back 14

Bactec460: Routine liquid radiometric ¤ 7H12 medium + radiolabeled (C14 O2) palmitic acid ¤ Scintillation counter – gives growth index ¤ >10 equals growth

Agar Proportion method ¤ >1% growth compared to control => resistance ¤ >6-10% growth compared to control => drug adds nothing

MGIT: Mycobacteria Growth Indicator Tube

Direct microscopic observation (sens. >90% and fast turnaround – less than 10 days)

Molecular Tests – Lineprobe Assay

Front 15

M. leprae Infection Paths

Back 15

9-banded armodillo is the carrier.

Front 16

M. Leprae Pathology

Back 16

Causes chronic granulomatous and Anesthic skin lesions and peripheral neuropathy.

Front 17

M. Leprae Specimen Collection

Back 17

Can not be cultered

Front 18

What are NTM?

Back 18

Non-Tuberculoid Mycobacterium.

Divided into rapid growers (less than 7 days), and slow growers (More than 7 days)

Front 19

NTM basics

Back 19

Aerobic, Non-motile, Thick Walls, Many are acid fast, can not spread between people

Often spread by tap water.

Pulmonary infections are the most common at 75% of all cases (MAC, kansasii, absecessus, xenopi)

Front 20

Photo- Vs Scotochromogens

Back 20

Photo = Produces yellow pigment only when exposed to light.

Scoto = Produces yellow pigment in the light or dark.

Non-chromogens do not produce pigment.

Front 21

Runyon Classification of NTM

Back 21

Group I = Photochromogens

Group II = Scotochomogens

Group III = Nonchromogens

Goup IV = Rapid-Growers

Front 22

NTM species in each group

Back 22

I = Kansasii (Yellow) & Marinum

II = Gordonae (yellow), Szulgai & Scrofulaceum

III = MAC, Haemophilum (28-30c), Ulcerans & Xenopi (42c)

IV = Fortuitum, Chelonae, Abscessus, Mucogenicum (No pigment), Smegmatis (Non or Late pigment)

Front 23

Microscopic Xenopi

Back 23

Long, Thing, and Floaty

Front 24

Group Microscopy

Back 24

I = Chaotic, long and fat Acid-fast

II = Beaded with pointed ends and pallisade, also Acid fast

III = Very evenly dispersed (Tiles), pleomorphic or coccobacilli

IV = Poorly staining and Chaotic

Front 25

Catalase & Catalase at 68c

Back 25

>45mm = positive (high)

~45 mm = Positive

<45mm = Negative

At 68c

No bubbles = negative

+ = Scant bubbling

++ = Bubbles on the whole buffer surface

+++= 1cm of bubbles

++++ = 5+cm of bubbles

Front 26

Pyrazinamidase test

Back 26

M. marinum produces a bright red band in the viles center. Other wise the test is a straw yellow.

Front 27

Tween 80 Hydrolysis

Back 27

Positive = Pink/Red color within 10 days

Negative = Maintains yellow color

Control/Weak Positive = Orange color

Front 28

Iron Uptake Test

Back 28

Positive = Colonies turn a rust color and discolor the medium.

Negative = Normal colored colonies on a blue medium

Front 29

General Anarobe infection Signs

Back 29

Crepitance - Gas in tissues

Necrotic flesh and a putrid smell

Mucosal Abscess

Front 30

Anarobe specimine

Back 30

Transport stability is less than 2 hours

Regect samples taken from the throat, ETT, Urine from a catheter, or cervical swabs, and swabs in general.

Front 31

Anarobe Culture

Back 31

Cultur medium should be PRAS; Pre-Reduced Anaerobicly Stabalized

Can be kept at 36c for 5 days, but do not open for 48 hours

An anaerobic enviroment is 80% N2 / 10%CO2 / 10% H2

Anaerobic conditions can be checked with a methylene blue test.

2-3 weeks of growth to identify

Front 32

Clostridium tertium Pathology

Back 32

Commensel: Found of the skin, GI tract and enviroment

Enterotoxin A: Diarhea

Cytoxin B: Colitis

Front 33

Clostridium tertium Testing

Back 33

Cat -, Spore forming, Gram variable, Short or long coccoids, Ox -, Butyric Acid +

Yellow, ground-glass colonies that glow

Neurotoxin B can be detected with EIA or NAAT, this is diagnostic

Front 34

Propionibacterium spp Pathology

Back 34

Spread by animal bites, surgery, being immunocompromised, and infects the skin, eye, bones and joints

Front 35

Propionibacterium spp Testing

Back 35

No spores, Air-tolerant, Cat+

Colonies are tiny and opaque with a gold tinge

Bacteria are slightly curved and Pleomorphic

Aerotolerant, Cat +

Front 36

A. viscosus/neuii Testing

Back 36

No Spores, Air Tolerant, Cat +

Front 37

Actinomyces Pathology

Back 37

Causes a granulomatous infection leading to swollen abscesses in the mouth, lungs and GI tract.

Front 38

Actinomyces Treatment

Back 38

Penicillin susceptible, but Metronidazole resistant.

Front 39

Actinomyces Testing

Back 39

No Spore, Air tolerant, Cat -

Front 40

Bifidobacterium Testing

Back 40

No Spore, Air tolerant, Cat -

Front 41

Lactobacillus Testing

Back 41

No Spore, Air tolerant, Cat -

Front 42

Clostridium perfringens Pathology

Back 42

Exoenzymes: Lecithinase (alpha-toxin), lyses mammal cells, includes collagenase and hyalurodinase

Causes Myonecrosis (gas gangrene)

Front 43

Clostridium perfringens Testing

Back 43

Long rectangular bacteria, spores are rare.

Produces a distinct double zone hemolysis

Reverse CAMP+, Lecithinase + on egg yolk agar (EYA)

Grows at 42c and is an obligate anareobe

Front 44

C. botulinum Neurotoxin

Back 44

Bind the presynamptic of the motor neurons in the peripheral nervous system where they inhibit the release of acetylcholine.

Causes flacid paralysis, associated with floppy baby syndrome, contracted by giving honey to babies.

Front 45

C. tetani Neurotoxin

Back 45

Tetanus toxin: Bind the receptors of the presynaptic motor neuron, but migrates to the spinal cord where it binds inhibitory neurons

Inhibits the release of GABA/glycine, causing uncontrollable contraction (spastic paralysis) and lock jaw.

may cause cardiac falure

Front 46

Actinomyces israeli Testing

Back 46

Variable colony morphology, but develops a Molar tooth like appearance after a few weeks.

Clubshaped (diphtheroid), may or not be branched, but always beaded

Not stained by acid fast

Cat -, Urease -, Nitrate +, Esculin +

Produces "sulfur granules" (yellow clumps) and is aero-tolerant

Digests sucinate

Front 47

A. odontolyticus

Back 47

Red pigment on BHI plate after a few days

Front 48

Propionibacterium propionicum

Back 48

Branched, beaded cocci, with a dry colony

Cat -/ Indol - / Nitrate +

Obligate anaerobe

FA test needed to see if propionic or succinic

Causes: Actinomycosis, Endocarditis, Osteomyelitis, Arthritis

Front 49

Propionibacterium acnes

Back 49

Most common anaerobic G+ and is normal flora of the skin, nose, mouth and GI

Coryneform (Bird wings)

Pleiomorphic, Cat +, Indol +

Causes Endocarditis, CNS shunt infections, and Acne

Front 50

What medications treat anaerobes

Back 50

Beta-lactams (penicillin S)

Metronidazole S except Actinomyces, Propionibacterium, Lactobacillus, Bifidobacterium

Front 51

Peptostreptococcus

Back 51

SPS susceptible / Indol -

Identified based on fatty acids it can digest, but this is not needed, just report as G+C

Anaerobic

Front 52

Veillonella

Back 52

Infects the mouth, URT, intestines and GU

Causes endocarditis, and bacteremia

Vanco R, produces propionic acid, some have red glow

Front 53

Bacteroides fragilis

Back 53

Very common isolate

A pleomorphic G-

Causes intrabdominal abscesses and bacteremia

ID: Mucoid/Shiny, Cat+, BBE+, Kr, Cr, Vr, succicn and isobutyic

Front 54

Bacteroides urealyticum

Back 54

Pitting, and dose not grow on BBE, Urase +, Ks, Cs, Vr

Front 55

Prevotella spp

Back 55

Anaerobic G-

Black colonies that glow red

Found in human oral cavities

Saccharolytic

Cat- / Kr / Cs / Vr

Causes: Periodontitis, Root canal infections, appendicitis, pneumonia

Front 56

Porphyromonas

Back 56

Anaerobic G-

Black colonies with a red glow

Human oral cavity

Cat- / Kr / Cr/ Vs

Causes root canal infections and appendicits

Front 57

Fusobacterium

Back 57

Thin, long to large pleomorphic G-

Dry, crummy colonies, hemolyis and blood greening

Cat -/ Nit - / Major butyric acid

Front 58

Fusobacterium mortiferum

Back 58

Large G- with a rounded shape

Lip - / SPI -

Glows

Front 59

Fusobacterium necrophorum

Back 59

Rounded ends, but less rounded over all

Lip + / SPI +

Glows

Causes Lemierre syndrome: postangial sepsis

Front 60

Fusobacterium nucleatum

Back 60

Thin with tapered ends

Lip- / SPI +

Glows yellow