my cobacterium Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
| Question | Answer |
| What are the general characteristic of Mycobacteria? | -obligate anaerobes 5-10% CO2 -slow growing 2-6 weeks -non spore-forming, non motile -slender, slightly curved or straight rods *high lipid content on cell wall so they are acid fast |
| How are Mycobacteria identified? | based on growth rate, colony morphology, incubation temperature, and biochemical reaction |
| How should expectorated sputum be collected and handled? | Spontaneous expectorated sputum • 5-10 ml of specimen with little oral flora • Best done 3-5 consecutive days • Early morning specimen |
| How should aerosol induced sputum be collected and handled? | Aerosol induced sputum • NaCl mist-nebulizer. This is done by respiratory therapy • Early morning specimen is best • Advantages: 1. Fewer contaminates 2. Faster growing |
| How should gastric lavage be collected and handled? | 1. Done 1/2 hr. after aerosol-induced sputum - collected to obtain swallowed sputum 2. Overnight fast 3. gastric + induced sputum combo yield more positive cultures than alone 4. Disadvantage: frequently contaminated with commensal Mycobacteria |
| How should urine be collected and handled? | Urine 1. Early morning clean catch 2. 3-5 specimens 3. 24 hour collection is not recommended |
| How should stool be collected? | Stool 1. Naturally passed 2. 3-5 consecutive days |
| How should Blood be collected? | 1. Sterile technique for draw 2. Special blood culture bottles (BACTEC or BACT/Alert) – continuous monitoring 3. Isolator lysis-centrifugation system 4. Sodium heparin tubes collected and sent to Mayo within 48 hours |
| How should tissue specimen be collected and handled? | Tissue Specimen 1. Grind 2. Incubate cutaneous tissue cultures at 35oC and 30oC |
| How should sterile body fluid be collected and handled? | 1. Sterile container or capped syringe, preferred 2. Anticoagulant could be added to fluids that may clot (citrate or heparin) 3. Swab is Discouraged, unless E-swab |
| What is Digestion of non-sterile specimens? | Digestion: • breaks up mucous and cells in specimen to liberate A.F.B. |
| What is the purpose of timed decontamination process of non-sterile specimens? | • Kills normal flora and contaminating bacteria without harming A.F.B. • Use strong acidic or alkaline solutions - the lipid content of A.F.B. cell walls protects them from extremes of pH • Decontamination increases the chances of recovering A.F.B. |
| What is the procedure of the traditional method of Digesting and decontaminating specimen? | NaOH 4% is the "traditional“ method to digest and decontaminate • Time carefully; needs to stand for 15 minutes • Neutralize sediments (phenol red indicator • 5% Oxalic acid - useful to decontaminate specimen contaminated with Pseudomonas (CF patients) |
| What is the procedure of the gold standard method of Digesting and decontaminating specimen? | NALC-NaOH 2% "gold standard“ • N-acetyl-L-cysteine is the mucolytic agent • NaOH 2% is the decontaminant • Neutralize with phosphate buffer • If after using the NALC method a specimen is still viscous a small amount of crystalline NACL can be added |
| What are properties of A.F.B (acid fast bacteria)? | • Cell walls have high lipid content enabling A.F.B. to retain stain when decolorized with acid alcohol • Stain morphology - slender, curved, pointed and beaded |
| What is the procedure to stain AFB using carbolfuchsin | 1. Carbolfuchsin - Fuchsin with phenol a) Primary stain: Carbolfuchsin b) Decolorizer: acid alcohol c) Counter stain: methylene blue d) Two techniques: 1. Ziehl-Nielsen "hot stain“ 2. Kinyoun "cold stain“ e) A.F.B. stain red; other bacteria stain blue |
| What is the procedure to stain AFB using fluorochrome dye? | Fluorochrome dye a) Primary stains: 1. Auramine 2. Rhodamine b) Decolorizer: acid alcohol c) Counter stain: potassium permanganate d) Screen slides using fluorescent scope on 25 or 40 objective e) A.F.B. will stain yellow against black background |
| What are the advantages of using fluorochrome dye? | 1. More fields scanned in less time 2. Yield higher number of positive stains 3. Questionable smears can be overlaid using Carbolfuchsin method |
| What is the disadvantage of using fluorochrome dye? | Dead mycobacteria will stain with fluorochrome method |
| Why are Stain results important? | 1. Early detection means early treatment 2. Monitor response to drug therapy 3. Must be paired with culture • 10,000 AFB/ml = positive smear • Sensitivity of 22-80% |
| What are Non-selective mycobacteria media? | 1. Egg based media 2.Agar based media |
| What are broth media used for mycobacteria? | 1.Middlebrook 7H9 2.Blood culture systems to detect A.F. • BACTEC systems • BacT/Alert system • Septi-Chek bottles • Isolator Lysis-Centrifugation system 3. MGIT 960 system: Modified 7H9, non-radiometric microbial detection system |
| What is used to interpret cultures? | 1. Testing of bottles -Culture held six weeks - Bottles are continuously monitored and automatically flagged as positive when growth is detected 2. Primary L-J slants- checked weekly |
| Preliminary identification made based on what? | Colony morphology: smooth or rough ▪ Rate of growth: rapid grower (colonies in <5 days) ▪ Optimal temperature of growth ▪ Pigment production: buff vs. yellow ▪ Photoreactivity |
| Name some mycobacteria and their optimal growth temperatures | - most grow at 35° - 42°-M. xenopi, - 30-32°-M. marinum, M. ulcerans, M. haemophilum |
| What are the different type of photo reactivity? | ▪ Photochromogens: produce pigment when exposed to light ▪ Scotochromogens: produce pigment in light or dark ▪ Non-chromogens: No pigment formation |
| How is Niacin accumulation tested? (media used & interpretation) | ■ an LJ slant with >50 colonies that are 3 weeks old need to be tested for niacin. ■ If niacin is present a yellow color will develop. |
| What is the Nitrate reduction test? | Test if bacteria conduct nitrate reduction, if they have the gene for the nitrate reductase enzyme. Red is positive for nitrite. 1: nitrate reduction to nitrite 2: nitrate reduction to ammonia 3: no reduction of nitrate |
Created by:
lemon8
Popular Laboratory Science sets