Unit 4 Exam Review Flashcards
1
Q
Bacteremia that occurs when chewing food or brushing teeth
A
Transient
2
Q
Bacteremia that is released into the bloodstream at a fairly consistent rate. Ex. Septic shock, endocarditis, early stages of typhoid fever, brucellosis, leptospirosis
A
Continuous
3
Q
Bacteremia that infections demonstrate bacteria at variable times. This occurs in patients with un-drained abscesses. Bacteria may be released about 45 minutes before a febrile episode
A
Intermittent
4
Q
Bloodstream infection that originates within the cardiovascular system
A
Intravascular
5
Q
Bloodstream infection that enters the circulation through the lymphatics from another site of infection. Common portals of entry include the Genitourinary tract, respiratory tract, abscesses, surgical wound infections, and the biliary tract
A
Extravascular
6
Q
Bacteria in the blood or the toxins produced by the bacteria causes harm to the host. Bacteria multiply more rapidly than immune system can work
A
Septicemia
7
Q
Basic symptoms of septicemia
A
Fever or hypothermia, chills, hyperventilation, skin lesions, change in mental status, diarrhea
8
Q
Serious symptoms of septicemia
A
shock or hypotension, disseminated intravascular coagulation (DIC), major organ failure, septic shock
9
Q
What is used to clean the area for blood culture?
A
70% alcohol and another antiseptic (iodine)
10
Q
How long should antiseptic stay on the skin when collecting a blood culture?
A
Follow manufacturer’s suggestions for recommended length of time
11
Q
What type of broth is used in blood cultures?
A
Enrichment broth
12
Q
How much bacterium is a blood culture designed to enhance?
A
Designed to enhance the growth of even one bacterium
13
Q
What type of blood culture system do most labs use?
A
A dual system with an aerobic and anaerobic bottle.
14
Q
What is the amount of blood needed for an adult blood culture? What is the minimum?
A
10-20 mL with a 10mL minimum
15
Q
Why is so much blood needed for an adult blood culture?
A
Typically fewer bacteria per mL in adults in children
16
Q
What is the amount of blood needed for a child’s blood culture?
A
1-5mL
17
Q
Why is so little blood needed for a child’s blood culture?
A
More bacteria per mL may be adequate. Not safe to take large volumes of blood from children.
18
Q
How many bottles are needed for a blood culture sample?
A
2 or 3 sets are sufficient. More may be necessary if patient is on antibiotics
19
Q
How often are blood culture samples supposed to be collected?
A
spaced 1 to 2 hours apart.
20
Q
Which is more important. The number of cultures or time interval they are collected?
A
Number of cultures
21
Q
Which type of blood culture sample is more important to collect? The aerobic or anaerobic?
A
Aerobic. Recovery of anaerobic bacteria in blood is much more infrequent than recovery of aerobic bacteria
22
Q
What needs to be done to blood culture bottles?
A
Provide proper incubation temp, constant agitation and continuous monitoring
23
Q
What do blood culture bottles contain?
A
Nutrient broth, resins or charcoal and SPS
24
Q
What system measures the production of CO2 produced by the metabolizing organisms by using fluorescence.
A
BACTEC
25
How do you know if bacteria is growing in a blood culture bottle?
Sensors on the bottom of each bottle increase in fluorescence as bacteria grows
26
What system measures CO2 and pH changes by a colormetric sensor located on the bottom of each bottle?
BacT/ALERT
27
How does a BacT/ALERT sensor work?
Sensor is separated from the broth by a membrane which is permeable to CO2. As the organism produces CO2, the sensor changes color
28
What do WBC give off in a blood culture?
CO2
29
What must be done to a positive blood culture?
A sample of the culture broth must be gram stained. A sample should also be plated onto conventional media which supports aerobic and anaerobic growth
30
Contaminate or Pathogen?
Growth of Bacillus, multiple organisms from several cultures, clinical presentation inconsistent with sepsis, infection at primary site of infection
Contaminant
31
Contaminant or Pathogen?
Growth of the same organism in repeat cultures, growth of certain organisms from endocarditis, growth of organisms such as enterbacteriaceae, growth of commensal organisms from immune-compromised patients
Pathogen
32
Possible pathogens with special requirements
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HACEK
Fungi
Mycobacteria
Brucella
Mycoplasma
Campylobacter
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33
Inflammation of the tracheobronchial tree
Acute Bronchitis
34
Symptoms of acute bronchitis
cough, variable fever, and sputum production
35
What causes acute bronchitis
Viral agents and may be part of or proceeded by an URI (flu or common cold)
36
What can be a complication of acute bronchitis in infants and preschool aged children?
Bordetella pertussis should be considered
37
Excessive mucus production which leads to coughing up sputum on most days at least 3 months to two years.
Chronic bronchitis
38
What causes chronic bronchitis?
Bacteria may be the cause of acute flare-ups, but viruses are the more frequent cause
39
Inflammation of the lower respiratory tract involving the lung's airways and supporting structures
Pneumonia
40
Associated pathogens are age-dependent
| Ex. S. pneumonia, H. influenza, M. catarrhalis, M. pneumonia, C. pneumonia, Legionella
Community acquired bronchitis
41
Pathogens will include MRSA, P. aeruginosa, K. pneumonia, E. coli
Health care associated pneumonias (HCAP)
42
Infection caused by an organism infecting the lung and then gaining access to the pleural space via an abnormal passage
Pleural infections
43
Primary type of sample. Will be contaminated with upper respiratory secretions. Specimen should be the result of a deep cough
Expectorated Sputum
44
A respiratory therapist may need to assist patients and use postural drainage or thoracic percussion to stimulate production.
Induced Sputum
45
What type of reagent is used to induce sputum?
Aerosol induction. Breathe a 15% sodium chloride - 10% glycerin mix for 10 minutes
46
Invasive procedure which allows the physician to obtain bronchial washings or broncheoalveolar lavage samples; may also do bronchial brushings
Bronchoscopy
47
What might be performed if there is pleural fluid present in a Bronchoscopy?
Thoracentisis
| Secondary Endotrachael and Transtracheal aspirates
48
What is the most common direct exam?
Gram stain
49
What is easy to recognize in a gram stain?
Bacteria and yeast
50
What are the requirements of a good sputum smear?
Fewer than 10 squamous epithelial cells per low power field.
51
What implies and excellent sputum specimen?
The presence of 25 or more WBC and a few epithelial cells
| Presence of WBC is not necessary for acceptance of a specimen.
52
What can be examined for the presence of parasites and fungi
Wet prep
53
What can be used to identify acid-fast bacilli
Acid-fast stains
54
What may be used to detect Legionella?
Direct fluorescent antibody
55
What plates are used for differentiation of gram negative bacilli
Sheep blood and MacConkey
56
What plate is used for differentiation of Haemophilus and Neisseria?
Chocolate
57
What agar should be used if legionnaires disease is suspected?
BYCE Buffered charcoal yeast extract
58
What type of media is not used in specimens thought to contain contaminating oral flora
Enrichment media
59
What type of bacteria may require special procedures for detection?
Mycobacteria, Chlamydia, Nocardia, B. pertussis, Legionella, and Mycoplasma pneumonia
60
What type of URT Infection is usually caused by viruses?
Laryngitis
61
What type of URT Infection is caused by a virus which usually occurs in children under 3
Croup (Laryngotracheobronchitis)
62
Usually caused by H. influenza type b; Most common in children between 2 and 6; can be very dangerous because airway may be blocked
Epiglottitis
63
May accompany several viral infections. most bacterial infections are cause by S. pyogenes;
Pharyngitis
64
Usually caused by viruses; C. diphtheria may be isolated from patients with sore throat; massive immunization has reduced infection with Bordetella pertussis, but outbreaks still occur
Rhinitis
65
Inflammation of the mucous membranes of the oral cavity - caused by HSV
Stomatitis
66
Caused by Candida spp. usually occurs in young infants or immunocompromised patients
Thrush
67
What type of swabs are suitable for collecting most upper respiratory microorganisms
Cotton, Dacron or calcium alginated tipped swabs
68
What are transport requirements of swabs?
Remains moist - cultured within 4 hours.
| Longer use a transport media
69
What types of swabs are better for recovering viruses, Neisseria and B. pertussis
Nasopharyngeal swabs
70
What organism are most throat cultures screened for?
S. pyogenes (group A)
71
What media is used to screen most throat cultures?
5% sheep blood agar
72
What may be placed on the inoculation of bacteria for presumptive ID
0.04 unit differential bacitracin disk
73
What plates should be plated if Corynebacterium is suspected?
Sheep blood, streptococcal selective, Loeffler's and cysteine-tellurite agar plate
74
What types of plate is cultured for Bordetella pertussis?
Bordet-Gengou agar in past.
| Today the more common choice is Regan-Lowe or charcoal horse blood agar
75
What types of plate is cultured for Neisseria?
Thayer-Martin or Martin-Lewis agar
76
What plates should be cultured from epiglottitis?
Sheep blood and chocolate
77
How many products are there to test for Rapid Group A strep?
40
78
What type of technologies are used for rapid strep test?
Latex agglutination, enzyme immunoassay, gene probe technology
79
How long does a rapid strep test take?
10 minutes or less
80
What are other methods are used for direct detection of influenza viruses
EIA, PCR, DFA
81
How long do different methods for rapid viral testing take to process?
EIA - 10-30 minutes
PCR - 2 hours
DFA - 2 hours
82
What are UTI's associated with?
Sexual intercourse, hormonal changes, diabetes, renal disease, renal transplantation, structural and neurologic abnormalities that interfere with urine flow
83
How are UTI's associated with hospitalization?
catheterization
84
What is the most common source of UTI?
E. coli other than catheterization
85
What are other agents of infection for UTI?
Klebsiella, other Enterbacteriaceae, and S. Saprophyticus
86
In recurrent infections what organisms are more common?
Proteus, Pseudomonas, Klebsiella and Enterobacter spp.
87
Infection of the urethra is common. C. trachomatis, N. gonorrhoeae and T. vaginalis are common causes and are discussed further under genital infections
Urethiritis
88
Infection of the bladder. Symptoms include dysuria, frequency and urgency. Often there is pain over the area over the area of the bladder
Cystitis
89
Symptoms are similar to systitis but there are fewer bacteria (less than 10^5 CFU/mL). It may be caused by STDs but is often caused by the same bacteria which cause cystitis
Acute urethral syndrome
90
Inflammation of the kidney parenchyma, calices and pelvis
Pyelonephritis
91
What UTI infection may be significant in pregnancy
Asymptomatic Bacteriuria
92
UTI sample collection: Involves cleansing prior to urination. Sample collection does not begin until the urine starts to flow and collection should end before the flow stops
Clean catch (midstream)
93
UTI sample collection: A catheter is inserted into the urethra. Contamination may occur from introducing organisms from the urethra
Straight catheterization
94
UTI sample collection: Urine is withdrawn directly from the bladder into a syringe through a percutaneously inserted needle
Suprapubic bladder aspiration
95
UTI sample collection: Patients with "permanent" catheters often develop bacteriuria. Urine may be aspirated from catheter tubing using aseptic technique
Indwelling catheter
96
What should be done with urine samples?
Transported to the lab as soon as possible, refrigerated, or preserved
97
What tests are done before a urine culture?
Urinalysis, leukocyte esterase, nitrate, possible gram stain
98
What is the threshold for a low colony count so screening tests are not necessary?
10^2-10^3
99
What are the two sizes of calibrate loops that are used?
0.01 or 0.001 mL
100
What is the colony count for a 0.001 loop?
1000 CFU/mL
101
What plates are inoculated and what are the culture requirements for urine specimens?
5% sheep blood and MacConkey @35C for 24 hrs.
102
Describe the special technique for streaking a plate for a urine culture.
A line is made with the calibrated, inoculated loop pulling downward. The loop is then drawn across the line in a zigzag manner. The loop is not flamed during this step.
103
How do urine colony counts help a laboratorian?
They can determine if the growth is a contaminant or pathogen.
104
What are the collection requirements for sterile body fluids?
Collect by aspiration with syringe, transport in sterile container, no refrigeration, concentrate by centrifugation, decant supernatant and process specimen for culture and direct gram stain
105
1 organism/oil field is equal to _____?
10^5 org/mL
106
What plates should be inoculated for sterile fluids? How long to incubate? What has special requests?
BA, Choc, Mac, broth incubate 3-7 days
| Special requirements for AFB, Mycology, Anaerobes, rapid test
107
What is normally found in GI tract infections?
A variety of flora
108
What percentage of feces is bacteria? What kind?
80%, mostly anaerobes
109
How fresh should a stool specimen be?
Received within 30 minutes in a clean container
110
A delay in transport of a fecal specimen requires what transport media?
Cary-Blair for bacterial culture
111
What type of selective agars should fecal specimens be plated on?
XLD
CCDA
Selenite broth
Molecular and antigen detection methods are also used
112
What type of organisms normally colonize the Genital tract?
Commensal
113
How are infections that may be caused by the patient's endogenous flora transmitted?
Sexually
114
What type of specimens are used for Genital tract infections?
Urethral, cervical/vaginal
115
Who must monitor and control incidence of hospital acquired infections?
Infection Control
116
What areas have the highest rates of hospital acquired infections?
Surgical and medical services
117
What are the three factors for infection control?
Susceptibility, virulence, exposure
118
What is the purpose of Infection Control?
Detect and monitor nosocomial infections and prevent their spread; investigate the source of an outbreak
119
What includes the attending physician, IC nurse, microbiologist, epidemiologist and pharmacist?
The IC Committee
120
Name 3 disadvantages to hospital acquired infections?
Adds to healthcare costs, contributes to mortality and morbidity, puts healthcare workers at risk
121
What is the most effective infection control procedure?
Handwashing or sanitizing
122
The majority of nosocomial infections involves the patient's own _____?
Endogenous flora
123
What can surpress an immune system?
Steroids, chemo, and antimicrobials
124
Natural barriers of infection control are broken by _____?
Urinary and IV catheters
125
Name 5 predisposing factors?
age, therapies, skin integrity, surgical procedures, nutrition and obesity
126
What is the most common cause of nosocomial UTIs?
gram neg rods
127
What is the most common cause of nosocomial respiratory infections?
Pneumonias from gram neg rods, S. aureus, H. influenza
128
What is the most common cause of nosocomial surgical infections?
Gram pos rods, gram neg rods and yeast (50% occur after discharge)
129
What is the most common cause of nosocomial bloodstream infections?
CNS, Enterococcus, S. aureus, yeast and gram neg rods
130
What is the most common cause of nosocomial GI infections?
C. difficile
131
Modes of spread:
| Direct contact
food, IV
132
Modes of spread:
| Indirect contact
patient to patient
| ex. MRSA
133
Modes of spread:
| Droplet
B. pertussis, N. menin, Mumps
134
Modes of spread:
| Airborne
TB measles
135
Modes of spread:
| Vectors
mosquitoes, mites
136
What are 1970s CDC guidelines for infection control prevention?
Hand washing, segregation of infected patients, appropriate PPE, bagging contaminated items, cleaning rooms between patients, door signage
137
What two infections have a BOLO?
CRE and VRSA
138
This network include labs at CDC, USDA, FDA and other facilities run by federal agencies
Federal
139
This network include labs run by state and local departments of health. In addition to being able to test for Category A biological agents, a few LRN public health labs are able to measure human exposure to toxic chemicals through tests on clinical specimens
State and local public health
140
This network includes labs operated by the Department of Defense located both within the United States and abroad
Military
141
The LRN includes FDA and USDA labs, and others that are responsible for ensuring the safety of the food supply.
Food testing
142
Includes labs that are capable of testing water and other environmental samples
Environmental
143
Some LRN labs, such as those run by USDA, are responsible for animal testing. Some diseases can be shared by humans and animals, and animals often provide the first sign of disease outbreak
Veterinary
144
The LRN has labs located in Canada, the United Kingdom, Australia, Mexico and South Korea
International
145
This lab has the unique resources to handle highly infectious agents and the ability to identify specific agent strains
National labs
146
This lab can perform tests to detect and confirm the presence of a threat. These labs ensure a timely local response in the event of a threat incident. Rather than having to rely on confirmation from labs at CDC, these labs are capable of producing conclusive results. This allows local authorities to respond quickly to emergencies
Reference labs
147
These labs represent the thousands of hospital-based labs that are on the front lines. These labs have direct contact with patients. These labs could be the first facility to spot a suspicious specimen. This labs responsibility is to refer a suspicious sample to the right lab.
Sentinel labs
148
These labs work with hospitals and other first responders within their jurisdiction to maintain competency in clinical specimen collection, storage, and shipment
Level 3 Labs
149
Chemists in these labs are trained to detect exposure to a number of toxic chemical agents. Analysis of cyanide, nerve agents, and toxic metals in human samples are examples of this labs activities
Level 2 Labs
150
These labs, which serve as surge-capacity labs for CDC, are able to detect toxic chemical agents and exposure to an expanded number of chemicals, including mustard agents, nerve agents, and other toxic industrial chemicals. Using unique high-throughput analysis capabilities, they expand CDC's ability to analyze large number of patient samples when responding to large-scale exposure incidents
Level 1 Labs
151
What is a VITEK instrument?
Automated system for ID and antimicrobial susceptibilities of bacteria and yeast
152
While providing more safety what does a VITEK instrument eliminate?
Repetitive manual operations
153
What are some features for a VITEK instrument?
Bi-directional interface
Epidemiology report module
Expert software for on-line result validation
Several models available
154
How big is a VITEK Test Card?
The size of a playing card made up of 30 or 45 micro wells
155
How is the VITEK card transported?
sealed container, no aerosol or splattering, spills or personal contamination
156
What is DataTrac?
information management system that oversees the test data generated by the VITEK
157
How does DataTrac work?
Information gathers and formatted into reports and exported for analysis in other PC based programs
158
What type of interface does DataTrac have?
bidirectional
159
What type of system does the VITEK2 have?
unique, closed system with 64 well test cards
160
AST
Antimicrobic Susceptibility Testing
161
What is AST aimed at?
High Quality MIC with extended ranges
162
What does the AST workflow provide?
Improve processes with Security & Productivity
163
What does the AST Therapy provide?
Fast results on High-efficacy, low cost therapy
164
What does the AST Economics provide?
Lab investment leading to hospital savings
165
What does the AST Outcome provide?
Rapid information for Efficiency and Cost Containment
166
What is the purpose of BacT/ALERT?
Instrument designed to process numerous blood cultures automatically. Cultures are incubated, positives are detected and technologist is alerted
167
What are some advantages of BacT/ALERT?
saves time, facilitates cross training and helps prevent errors
168
What is the technology used for BacT/ALERT?
Colorimetric
169
How does BacT/ALERT work?
sensor and detection method finds microorganisms by tracking CO2 production
170
What color does the sensor turn when microorganisms multiply in the media, generating CO2
yellow
171
The BacT/ALERT monitors and detects color changes in the sensor after measuring _____?
reflected light
172
What analyzes the data to determine positivity and identifies the lab with visual and audible alarms?
Algorithms
173
What are benefits of alternate methods in microbiology?
rapid, larger volume, higher sensitivity and specificity, more cost effective
174
Technique in which single stranded NA is allowed to interact so that complexes called hybrids are formed by molecules with similar, complementary sequences
Nucleic acid hybridization
175
What are the 4 steps of nucleic acid hybridization
1. production of probe
2. prep of target
3. mix target and probe
4. detect hybridization
176
What are advantages of nucleic acid hybridization?
detects both non-viable organisms and ones that can't be readily be grown in culture, detects slower growing organisms, can quantitate infectious agents, may ID organism already growing in culture
177
What do serologic methods detect?
rise in titer of a specific antibody in the patient
178
What are different types of serologic procedures?
IFA, FTA-ABS, Western Blot, ELISA, Hemagglutination
