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68 Cards in this Set
- Front
- Back
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Two major sources of biological hazards in micro lab |
Patient specimens Actively growing cultures |
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How to avoid aerosolized specimen |
Dont flame wet slides Dont cool hot loops on media plates |
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Decontamination how to |
10% bleach on surfaces Autoclave media, tools, supplies |
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Standard precautions include |
Hand washing Gloves Mask/shield Coats Sharps disposal Env. Control ie cleaning surfaces |
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Engineering controls |
Controls or tools that isolate hazards in the workplace ie safety needles, eyewash, negative pressure rooms, emergency showers |
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Work practice controls |
Ways in which tasks are performed to reduce exposure Disinfecting work space, no eat/drink Careful transport of specimen Handwashing, appr. Needle disposal |
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High risk specimens |
Brucella/Francisella, salmonella typhi, Ecoli O157, shigella, neisseria meningitis, hepatitis B,C, HIV, coccidiodes immitis |
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Biosafety cabinet |
Form of engineering control Protects worker from aerosolized transmission Move in and out slow and infrequent Limit clutter |
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Class 1 BSC |
Moves air inward thru front and thru filter then exit Not common |
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Class II BSC |
Circular air pattern Prevents air from entering or exiting |
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Class III BSC |
Self contained Need glove system to enter |
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Proper use of BSC |
Let run for 15 to 30 min prior/ after Minimize clutter Slow movements |
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Biosafety level 1 |
Not known to cause disease in healthy Use standard precaution Can do work on bench top |
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Examples of BSL 1 organisms |
Bacillus spp., coag neg staph, normal flora, E coli. |
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BSL 2 |
Moderate potential hazard to employees, should use a BSC II |
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BSL II organisms |
Salmonella, hepatitis B, HIV |
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BSL III |
Have potential for aerosol production, serious or lethal, must be handled in negative pressure BSL II lab using BSL III precautions is allowed |
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BSL III organisms |
TB, coxiella, Brucella |
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BSL 4 |
Dangerous and exotic agents CDC Maximum protection of people Ante room, change clothes |
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BSL 4 organisms |
Ebola, hemorrhagic fever, smallpox, marburg virus |
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Performance improvement or quality assurance |
Steps taken to insire overall quality care for patients Useful in all stages mostly pre & post |
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Temperatures |
Daily record on temp Sens equipt. Thermometer in glycerol keeps a more constant temp |
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Media QC |
Rules determined by CLSI Manufacturers do QC, must keep |
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Collection of sample should be done during |
acute phase |
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Swab samples |
URI, external ear, eye, genital, wound Collected from leading edge of lesion Cleaned before swab, reduce nflora Dacron, rayon May contain media to mimic body conditions |
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Aspirate samples |
Fluid from a site that should b sterile Cleanse skin before puncture Fluid should not be placed on a swab Submit in container |
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Tissues |
Collected by doctor in surgical procedure Placed in sterile container |
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Foley cath sample |
DO NOT COLLECT FROM BAG CLAMP OFF AND GET FRESH SAMPLE |
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Sputum |
Least relevant most ordered First morning Transport ASAP |
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Specimen transport |
Maintain specimen in state closest to original state as possible Does not increase or decrease #s Within 30 min <2hours |
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Boric acid |
Preserve urine if refrigeration isn't possible (24hr) |
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Sps anticoagulant |
Used in blood culture bottles Keeps organisms from getting stuck in clots |
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Components of transport media |
Sodium thioglycollate-reducing agen Agar- solidifies media Phosphate buffer-maintain neut ph Charcoal- absorbs toxins in specimen |
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Shipping specimens |
Dedicated bio vehicle Trained staff Ups, FedEx need training and certification from govt |
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Nonselective media |
Supports growth of most non fastidious organisms Sheep BAP |
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Selective media |
Supports growth of specific type or group of organism Incorporates substances that inhibit some bacteria |
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Selective media examples |
MacConkey CNA PEA |
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Differential media |
Allows for grouping of bacteria based on what it shows when it grows on media Nonselective or selective BAP, MAC, mannitol salt agar |
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Enriched media |
Contains substances to enhance growth of fastidious organisms Ex chocolate agar |
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Enrichment broth |
Liquid media designed to encourage growth of small # of organism while inhibiting normal flora |
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Broth media |
Liquid media that may be used to supplement agar plates to detect small numbers of organisms in a specimen |
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Growth correlation to number of organism |
1st quad is small 2nd is small mod 3rd moderate 4th large numbers |
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Plating urine |
Use calibrated loop Single streak down center Lawning Use quantitative isolation technique |
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Incubation |
35 C Co2 rich or poor depending on spec Media side of petri up prevent contamination |
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Purpose of gram stain |
Determine quality of specimen Infection likely? Yes if many pmns Preliminary indication of organism Correlation to culture growth should you work up or not |
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Swab gram stain |
Roll swab back and forth across slide Do not rub as it may destroy cell morphology |
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Thick fluid/ semi solid gram stain |
ie stool Use swab |
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Thick granular mucoid slide |
Use crush prep method |
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Thin fluid gram stain |
If turbid use crush prep method If clear mark a circle with a marker Place drop and allow to dry |
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Cytocentrifugation method |
Used for thin fluids Cell elements confined to single area of slide Excess fluid and protein absorbed by filter paper Cxs specimen |
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When is gram stain not help |
Specimens with lots of normal flora (stool or throats) Samples for screening cultures ie group a/b strep, gc culture, MRSA Useful in sputum bc pneum bacteria look diff than normal flora |
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PMNs |
Can be helpful in identifying infection BUT May not see many if infection response is low or pt has low WBC ct Squamous cells with PMNs may be contaminate |
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KOH prep |
Breaks down chitin in hair and nails Looking for fungal elements |
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India ink |
Wet mount of CSF looking for Cryptococcus neoformans |
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Dark field exam |
Looks for spirichetes ie treponema pallidum (syphilis) |
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Acid fast stain |
Used to stain bacteria with high lipid content cell walls ie TB Won't gram stain because cell wall has lots of lipid |
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Lactophenol cotton blue |
Used to stain fungal organisms |
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Fluorescent stains |
Small number of organisms Brucella Lots of pmns no organisms in gram |
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Gram stain steps |
CV stain Mordant (iodine) Decolonization (acetone/ alcohol) Counter stain (safranin) |
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Look gram neg but not |
Over decolorized Gram pos organisms is too old |
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Colony morphology |
Provides prelim id Observe at 18-24 hrs old |
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Characteristics of colonies |
Hemolysis Size Margin Elevation Density Color Consistency Pigment Odor |
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BAP agar |
Enriched and differential Readly grows most except haemoph Hemolytic reactions |
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Columbia (CNA) agar |
Enriched selective Grows gram pos Colistin and nalidixic acid inhibit gram neg growth |
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PEA agar |
Selective Grows gram pos Phenylethyl alcohol inhibits gram neg so only small growth Will not grow gram neg bacillus anthracis at all Dont interpret hemolytic rxns |
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MacConkey agar |
Selective and differential Grows gran neg rods Bile salts and CV inhibit gram pos Diff lactose ferment Pink =ferment clear = nonferment |
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Eosin methylene blue agar |
Selective and differential Gram neg enteric bacteria Eosin Y and meth blue inhibit pos Diff lactose ferment |
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Chocolate agar |
Enrichment Grows fastidious, haemophilus Cells have been used to release hgb |
