M1: Specimen Collection I Flashcards
(157 cards)
0
Q
Specimen volume: should be ______. If not, _______ request.
A
Adequate. Prioritize
1
Q
Timing of Specimen Collection: Best time to collect is during _________ of illness and ______________ therapy.
A
Acute Phase. Before Antimicrobial.
2
Q
Specimen volume: __________ swab on a plastic shaft.
A
Polyester-tipped
3
Q
Avoid in Collecting Swab Specimens: if collecting for viral culture, could inactivate HSV.
A
Calcium Alginate
4
Q
Avoid in Collecting Swab Specimens: toxic to N. Gonorrhea
A
Cotton
5
Q
Avoid in Collecting Swab Specimens: toxic to C. Trachomatis
A
Wooden shaft (wood)
6
Q
Specimen Volume: Swabs are not optimal for detection of _______, _______ & ________.
A
Anaerobes, Mycobacteria & Fungi “AMF”
7
Q
Specimen Volume: _____________ is always superior than swab.
A
Actual tissue/Fluid aspirate
8
Q
Specimen Collection: site of _______ & _______ container.
A
Infection. Sterile.
9
Q
Specimen Collection: Include all the following(_______ the container). Name & ________ of patient. ________ of specimen. And _________ collected.
A
Label. Indentification number. Source. Date & Time.
10
Q
Specimen Transport: all specimen must be in a _________ bag. And transported ________.
A
Biohazard. ASAP.
11
Q
Specimen Transport: Delays. Refrigerate.
A
Urine, Stool & Sputum other respiratory specimen “USS”
12
Q
Specimen Transport: Delays. Do not Refrigerate. (Keep @ room temp)
A
CSF & body fluids, Specimens for recovery of N. Gonorrhea & Blood “CSB”
13
Q
For detection of C. Trachomatis & viruses.
A
Stool
14
Q
Specimens Rejected: Specimen/s in ________.
A
Formalin
15
Q
Specimens Rejected: ______ sputum.
A
24°
16
Q
Specimens Rejected: _______ samples.
A
Leaking
17
Q
Specimens Rejected: Specimen inoculated into agar that has ________ or ________.
A
Dried/Outdated
18
Q
Specimens Rejected: Contaminated by
A
Chemical dyes, Oily chemicals & Barium “COB”
19
Q
Specimens Rejected: Foley catheter _____.
A
Tips
20
Q
Specimens Rejected: _______ specimen received within 24° period.
A
Duplicate specimen
21
Q
Specimens Rejected: Blood catheter tip from patient without concominant ______________.
A
Positive blood culture
22
Q
Rejected for Anaerobic Culture: _______ washing.
A
Gastric
23
Q
Rejected for Anaerobic Culture: Urine other than __________.
A
Suprapubic aspirate
24
Rejected for Anaerobic Culture: Stool (except for recovery of __________)
C. Difficile
25
Rejected for Anaerobic Culture: Oropharyngeal specimen (except __________ specimen obtained during surgery)
Deep tissue
26
Rejected for Anaerobic Culture: ______ & swabs for ________.
Sputum. Ileostomy.
27
Rejected for Anaerobic Culture: ________ specimens.
Superficial
28
Universal Precaution: Ideally, all specimens, but at a minimum respiratory specimens and those submitted for detection of mycobacteria or fungi must be opened in a _____________.
Biological Safety Cabinet
29
Personal Protective Equipment
Gloves & Lab coat, Masks & Goggles and Gowns or Aprons
30
Referral Testing: All infectious shipping packages must be labelled, containing ________ & _______ as well as __________ of person responsible for the shipment.
Address. Contents. Name & Address.
31
Dangerous Goods Shipping Guidelines: no more than ______.
40mL
32
Dangerous Goods Shipping Guidelines: Cultures of bacteria & fungi placed on _________ in tubes.
Solid media
33
Dangerous Goods Shipping Guidelines: Capped & sealed with _________.
Waterproof tape
34
Dangerous Goods Shipping Guidelines: Placed in a ____________.
Secondary container
35
Dangerous Goods Shipping Guidelines: If several primary container, it must be ___________ or separated to prevent contamination between containers.
Individually wrapped
36
Secondary packaging/container, must be ________, capped and placed in a corrugated fireboard or hard plastic. Must be able to withstand _______ & _________ it will be subjected to.
Leakproof. Temp & air pressure.
37
Dangerous Goods Shipping Guidelines: Itemized list must be enclosed in between the ________ & __________.
Secondary & Outer packaging
38
Dangerous Goods Shipping Guidelines: _______ if needed, must be placed outside second container.
Dry ice
39
Most important function of microbiology laboratory
Detection of blood borne pathogens
40
Is essential for identifying bacteria responsible for bacteremia, sepsis, infections of native or prostatic valves, suppurative thrombophlebitis, mycotic aneurysm & infections of vascular grafts.
Culture of blood
41
Blood is important in the diagnosis of invasive or disseminated infections caused certain fungi especially
Candida spp, Cryptococcus neoformans, Histoplasma capsulatum & Fusarium spp "CCHF"
42
Are detected using peripheral blood smear
Parasites
43
Blood should be collected for culture ____________ when one or combination of the following are present: Fever(38 or higher), Hypothermia(36 or lower), Leukocytosis(esp. Left shift), Granulocytopenia & Hypotension.
Before antimicrobial therapy
44
Specimen Collection of Blood: Timely collection and accurate identification of organisms depend on
Appropriate collection, Transportation & Processing specimen "ATP"
45
Specimen Collection of Blood: To minimize contamination of normal flora. Venipuncture site should be prepared with a ____________. 70% of _________ alcohol, 1-2% of _______ solution and _______ or Chlorhexidine.
Bactericidal. Isopropyl/Ethyl. Iodine. Iodophor.
46
Specimen Collection of Blood: For maximum antisepsis, drying are for _______ before venipuncture.
1-2mins
47
Appropriate Timing for Detection of Bacteremia & Fungemia: Optimal time if just _______ a chill. (Not predictable) Collected after onset of ______ & ______.
Before. Fever & Chills.
48
Appropriate Timing for Detection of Bacteremia & Fungemia: Procedure. Blood- bottles of culture media- _______ several times to ensure mixing- transported to laboratory at ______ temperature.
Inverted. Room.
49
Specimen volume: Adults,_______ blood per culture set. Infants & Children, _______.
20-30mL. 1-5mL.
50
Recommended number of blood specimen to collect depend on ____________.
Nature of bacteremia
51
Associated with undrained abscess
Intermittent Bacteremia
52
Hallmark of intravascular infection. Occurs during first weeks typhoid fever and brucellosis.
Continuous Bacteremia
53
Manipulation of a focus of infection. Instrumentation of a contaminated mucosal surface. Surgical procedure in a contaminated site. Occurs early in course of many systemic & localized infections.
Transient Bacteremia
54
Patients with Endocarditis: two to three ____ blood samples drawn over ______ period and equally distributed into aerobic and anaerobic blood culture bottles.
20mL. 24hr.
55
Patients with Endocarditis: _____ blood cultures drawn within 24hrs with ________ interval for the first ____ sets, another one to two dets drawn over remaining 24hrs if __________ persists (inc yield of potential pathogens by 20%)
Four. 30-60mins. 2. Septicemia.
56
Patients with Endocarditis: If antimicrobial therapy initiation is urgent, it should be collected ______ therapy begun, from separate sites within few minutes.
Before
57
Host Factors that might impede recovery of MO
Complement, Antibodies & WBC(phagocytic) "CAW"
58
Mech to Counteract Host Factors: Diluting blood specimens. 1:10 ratio to neutralize serum bacterial activity.
Broth medium
59
Mech to Counteract Host Factors: inhibits coagulation, phagocytosis, complement activation and inactivates aminoglycosides.
Incorporate 0.02%-0.05% Sodium Polyethanol
60
Mech to Counteract Host Factors: Counteract microbial agents
Antibiotic-adsorbent resins & Lysis-centrifugation System
61
Biphasic system. For aerobic & facultative bacteria & yeast. Broth medium in a bottle with attached chamber containing agar media on a paddle. Procedure. Bottle is tipped- blood broth mixtures enter chamber and flow over agar and media- colonies from agar media- used for identification & susceptibility testing.
Antibiotic Adsorbent Resins
62
Inhibits coagulation and complement cascade. Lyse blood cells. Provide cushion for MO during centrifugation. Smaller tubes for low volume samples. Procedure. Blood- tube- inverted several times- transported asap- centrifuged for _____ @ _________- supernatant discarded- sediment mixed in vortex mixer- plated to agar.
Lysis-Centrifugation System. 30mins. 3000g.
63
Advantages of Lysis-Centrifugation System: Excellent for recovery of ________ some _______ and ______.
Staph A., Enterobacteriaceae & Fungi
64
Advantages of Lysis-Centrifugation System: Best for recovery of ________.
Histoplasma capsulatum
65
Advantages of Lysis-Centrifugation System: __________ of colonies for identification & susceptibility testing. Carry out _______ cultures.
Direct availability. Quantitative.
66
Disadvantages of Lysis-Centrifugation System: Labor _______.
Intensive
67
Disadvantages of Lysis-Centrifugation System: Less likely to recover _______, _______ or anaerobes.
Streptococcus pneumoniae & Haemophilus influenzae
68
Disadvantages of Lysis-Centrifugation System: Risk of ______ increased.
Contamination
69
Advantages of Lysis-Centrifugation System: _____, special media can be inoculated to recover organisms with specific growth requirements like _________ & __________.
Flexible. Legionella & Mycobacteria.
70
Based on detection of CO2 produced during microbial growth. Procedure. Inoculated bottles continuously rocked- if bacteria is present- production of CO2- released to broth- pH dec- sensor change color- green to yellow.
Calorimetric
71
Calorimetric: medium available. Routine _____ of blood. PediBacT
5-10mL. 4mL.
72
Enhances detection of fungi & bacteria from patient under antimicrobials
Fastidious Antibiotic Neutralization
73
CO2 sensor generates hydrogen ions- dec pH- inc fluorescence- change signal- computer generates growth curves- data analyzed bia growth algorithms.
Fluorescent technology
74
Medium Available in Fluorescent technology: Aerobic & anaerobic low volume. _______ blood.
5-7mL
75
Medium Available in Fluorescent technology: High volume
8-10mL of blood
76
Medium Available in Fluorescent technology: Peds plus
0.5-5mL blood
77
Medium Available in Fluorescent technology: recovery of fungi & mycobacteria
Myco F Lytic
78
Procedure. Inoculated vial fitted with disposable connector that contains recessed needle- penetrates bottle stopper and connects bottle headspace to sensor probe- sensor monitors consumption and or production of all gases- creates data points in computer. Medium available is aerobic & anaerobic media ______ broth + 0.1-10mL blood. EZ draw(direct draw) _____ broth + 0.1-5mL blood.
Measuring Gas Consumption. 80mL. 40mL.
79
Positive blood cultures with commonly isolated aerobic organisms are detected within _________ of incubation. The initial report is ______ only. Identification & susceptibility report within _______ after gram stain report.
12-36hrs. 24-48hrs.
80
Cultures containing _______ not detected for 48-72hrs. Identification is not available for _______ after that.
Anaerobes. 3-4 days.
81
Fastidious organisms, such as those found in the HACEK group may not be detected until 3-5days
Haemophilus, Actinobacillus, Cardiobacterium, Eikenella & Kingella
82
Blood specimens are most commonly collected to monitor response of infection to antiviral therapy by using ___________ to measure viral load of HIV, HCV, HBV & CMV.
Quantitative PCR
83
For HIV & HCV, Blood specimens may also be collected for
Genotyping
84
Used to confirm an initial positive HCV antibody result
PCR
85
Useful for monitoring for development of disease and for diagnosis of disease in specific functions
Viral load
86
Used to predict those at high risk for development of CMV disease and direct the initiation or pre emptive therapy in immunocompromised patients, transplant recipients & AIDS.
Determining the level of CMV DNA
87
Indicated in transplant recipients at high risk for EBV associated lymphoproliferative disease.
Epstein Barr virus DNA serum or plasma by quantitative PCR
88
Test of choice for diagnosing disease caused by parvovorus B19 in immunosupressed patients or in the fetus.
Quantitative PCR from whole or peripheral blood for diagnosing HHV 6 & HHV 7
89
Are useful for detection of malaria, babesiosis, trypanosomiasis & some filariasis.
Blood specimens
90
Detection of Parasites: Specimens should be collected in tubes with ________ & transported promptly to the laboratory.
Anticoagulant
91
Detection of Parasites: If smears must be sent to a reference laboratory, they should be fixed in _______ soon after they are made.
Absolute alcohol
92
Detection of Parasites: The simple technique for detecting parasites in a sample of blood is the _________, prepared by placing one drop of blood on a glass slide, covering it with a cover glass, and examining it immediately.
Direct mount
93
Detection of Parasites: Are excellent for diagnosis of trypanosomiasis or filariasis because trypomastigotes and the microfilariae easily can be seen moving often with low or medium power.
Direct mounts
94
Detection of Parasites: the definitive diagnosis is made by
Staining smears
95
Detection of Parasites: made as for hematologic work and stained in a similar manner, is the standard preparation for determining species of plasmodium, babesia, trypanosoma & microfilaria.
Thin smear
96
Detection of Parasites: thin smears for parasitologic work are fixed and then preferably stained manually with _________, but automated hematologic staining is adequate.
Giemsa stain
97
Detection of Parasites: are first scan with low power to detect microfilariae, which are large objects (between 100 & 200 um) and easily seen, usually at the lateral edges of the smear.
Smears
98
Detection of Parasites: after they are located, ________ should be studied under oil immersion for identification.
Microfilariae
99
Detection of Parasites: Following scanning with low power, the smear is examined with a high dry objective, searching for
Trypanosomes
100
Detection of Parasites: and finally under oil immersion, to find and identify
Plasmodium, Babesia & Trypanosoma "PBT"
101
Detection of Parasites: are useful for detecting all the parasites mentioned and are part of minimum laboratory work up for their diagnosis
Thick smears
102
Is collected to diagnose meningitis and less frequently viral encephalitis
CSF
103
A medical emergency requiring early therapy to prevent death or serious neurologic sequelae. Divided into acute, subacute & chronic clinical syndromes based on duration of symptoms
Infectious meningitis
104
Duration is 1-7days. Caused by enteroviruses & pyogenic bacteria.
Subacute
105
Persisting at least 4 weeks with many pathologic causes
Chronic
106
Less than 24 hours. Caused by pyogenic bacteria.
Acute
107
Are the agents most commonly responsible for meningitis and they should be considered first in the differential diagnosis of meningitis in a child or adolescent during the late summer and early fall.
Enteroviruses
108
Responsible for meningitis vary with the age of the affected individual
Pyogenic bacteria
109
CSF: usually obtained by
Lumbar puncture
110
CSF: sometimes it is aspirated from the _______ or collected from a ______.
Ventricles. Shunt.
111
CSF: tube for cell counts and differential stains
Tube 3
112
CSF: tube for preparation of smears to stain with the Gram's stain or other stains and for a culture
Tube 2
113
CSF: protein & glucose
Tube 1
114
CSF: tube only if indicated, special test such as the cryptococcal antigen, serologic test for syphilis & cytology.
Tube 4
115
CSF: normal WBC
5 (lymphocytes)
116
CSF: normal protein
14-45mg/dL
117
CSF: normal glucose
45-100mg/dL
118
CSF: CSF should be transported ______ to the laboratory & processed as ________ as possible.
Promptly. Rapidly.
119
CSF: If a brief delay in processing is unavoidable, the specimen should be heal at _________ unless viral culture is requested, in which case a portion may be refrigerated at a short time.
Room temp
120
Processing of CSF includes concentration if 1mL or more is received. Preparation of smear by __________. (Gram stain)
Centrifugation
121
Concentrate the fluid by centrifugation of ______g for ____mins
1500. 15.
122
Decanted into sterile tube
Supernatant
123
Leave 0.5mL of sediment and fluid- mixed on vortex mixer or ________.
Forceful aspiration
124
Requires a special request
Chronic bacterial meningitis
125
Routine bacterial culture. Media are incubated for 2-3 weeks.
Brucelossis
126
May be cultured during the first few weeks of illness
Leptospira interogans
127
Pleocytosis. Elevated protein concentration. Positive VDRL test.
Neurosyphilis
128
Involvement of CNS. Detection of IgM & IgG in antibodies in CSF & serum.
B. Burgdorferi (Lyme dse)
129
Only useful method for detecting antibodies to Treponema Pallidum in the CSF
VDRL test
130
Detected only if the findings in the CSF shows pleocytosis or decreased glucose or elevated protein values.
Mycobacteria
131
Nucleic acid amplification for direct detection
Mycobacterium tuberculosis
132
Media for processing CSF for detection of fungi
Brain-heart infusion or SABHI agar w/out antibiotics
133
Most useful in diagnosing partially treated meningitis and confirming a positive Gram-stained smear. May be performed with the use of the supernatant of a centrifuged specimen or the original fluid. For detection of antigens of streptococcus agalactiae & S pneumoniae. Disadvantage is compared to gram stain, its sensitivity is not significantly greater and more expensive.
Latex Agglutination test
134
Meningitis is primarily caused by
Cryptococcus Neoformans
135
Two test for diagnosis of meningitis
Latex agglutination & ELISA and Indian Ink Preparation
136
Allow the visualization of encapsulated yeast cells. Performed by mixing 1 drop of CSF sediment with 1 drop of india ink. Sensitivity is low, except in HIV-infected persons
Indian Ink Prep
137
Specific for capsular antigen. Highly specific and have sensitivities of more than 90%. Recommended for diagnosis. Supernatant can be used. Should be performed before culture or on separate sample to avoid problem.
ELISA & Agglutination test
138
False positive latex agglutination occur due to the presence of _________ or to the introduction of condensation form agar into the test fluid.
Trichosporon asabii
139
Are used most often for dx of viral infections in CSF.
Nucleic Acid Amplification Test (NAAT)
140
Primarily for detection of enteroviruses although PCR is preferred
Conventional cell culture
141
For viruses that cause encephalitis
Serologic test
142
Are prepared directly from the specimen and from the sediment by first shaking the tube gently and the centrifuging the specimen at 250g for 10mins.
Wet preparations
143
Preparations are examined under the microscope with the condenser in a low position to allow visualization of trophozoites or by
Phase contrast microscopy
144
This volume is adequate for isolating most bacteria
1-5mL
145
Is optimal for recovery of mycobacteria & fungi
10-15mL
146
To diagnose peritonitis associated with chronic ambulatory peritoneal dialysis, collection of at least _______ of fluid may improve recovery of the responsible pathogen.
50mL
147
Are among the most common cause of pericarditis
Coxsackie viruses A & B (enteroviruses)
148
Strongly recommended for virus isolation from persons with suspected enteroviral pericarditis
Collection of throat washing or stools
149
A smear of the sediment is prepared for staining with Gram stain or __________.
Calcoflour white
150
Are rarely collected for detection of parasites
Body fluids
151
May be found in the pericardial, pleural or peritoneal cavity. Result of rupture of an abscess of the liver into those cavities. Perforatiom of amoebic ulcers into the peritoneal cavity.
Entamoeba Histolytica
152
Are infrequently diagnosed by examination of body cavity fluid also due to rupture of a cyst into a viscus contiguous to the cavity in question. Contains hyatid sand but rarely is turbid because of superimposed bacterial infection.
Hydatid cysts (Echinococcus spp)
153
Examination of wet preparations of a body cavity of fluid may demonstrate the microfilariae
Filarial infection
154
Larvae may be detected in body cavity fluids
Strongyloides hyperinfection
155
Serves not only to differentiate between infection and malignancy but also to distinguish between a suppurative & granulomatous process
Histopathology of the lesion
156
Used to inoculate all of the necessary culture media and is the stored under refrigeration for atleast 2 weeks before being discarded.
Suspensions
