Examination 4: Part I: Prions, Clinicopathologic Correlation, Anaerobes Flashcards
MadCow, Kuru, and CWD are all examples of transmissible spongiform encephalopathies (TSEs) or _____ disease. The protein involved has two forms _____ and _____.
Prion
PRP-c PRP-Sc (Coded for by the PRNP gene)
The exact physiological role of _____ is not known but it may aid in the formation of _____.
Creutzfeldt-Jakob Disease (CJD) has three forms. They are _____, _____, and _____.
PRPc, Synapses
Sporadic, Hereditary, Acquired
Effective or partially effective heat inactivation of CJD can be done by _____, _____, or _____, because boiling, alcohol, ammonia, formaldehyde, HCl, H2O2, and UV/microwave radiation is _____.
Incineration (1000C)
Autoclaving (134C for 20 min)
Autoclaving (121C for an hour)
Not effective
_____ is linked to cannibalism in indigenous people in the highlands of Papua New Guinea.
Is this transmissible from human to human?
How long is the incubation period of Kuru?
Kuru
Yes
Anywhere from 10-13 years to 50
On average, how many people are infected with CJD per year? How many cases are there per year in the US?
How are TSEs usually transmitted? Are spouses of CJD patients at any increased risk?
1 in 1 million per year (300/year in United States)
Through dural implants, contaminated pituitary growth hormone, cornea transplants. No.
What are a couple of differences between CJD and vCJD?
vCJD predominantly affects younger people
Delayed onset of neurological abnormalities.
Genetic defect in _____ gene coding for PrPc also causes Fatal Familial Insomnia, which is _____. The inheritance pattern of this disease is _____.
PRNP.
Prion disease interfering with sleep that causes severe mental deterioration.
Autosomal dominant
What is the primary difference between Fatal Familial Insomnia and other prion diseases?
When does Fatal Familial Insomnia typically start?
How long is a Fatal Familial Insomnia patient expected to survive following symptom onset?
FFI primarily affects the thalamus which controls sleep.
In someone’s 30’s
7 to 73 months
What are some symptoms of FFI?
How can FFI typically be diagnosed (instrument)?
Sleep disturbances, muscle spasms, stiffness
Metal deterioration
PET scan
What is Gerstmann-Straussler-Scheinker?
What is the expected longevity of a GSS patient?
This disease typically affects people in their _____.
Prion disease exhibiting loss of coordination. Clumsiness. Deterioration of cerebellum responsible for muscle tone and coordination, balance. Followed by slow mental dysfunction.
5 years
40s (35-50 years of age)
The inheritance pattern of Gerstmann-Straussler-Scheinker is _____ but _____.
How is GSS typically diagnosed (one of four answers)?
Autosomal dominant.
Some cases can arise spontaneously.
Genetic testing for mutated gene, family hx, amyloid plaques radiographically (PET scans), H&P
CWD, first identified in the 1960s in Colorado, only affects _____ and _____ and is therefore _____.
There is growing concern over _____.
Deer and Elk. Not found to be transmitted to humans like Madcow with vCJD.
the transmission of CWD from deer to livestock such as cattle and sheep.
Scrapies
Prion disease infecting sheep and goats, seen worldwide. First recognized as a disease 250 years ago.
Is CWD transmissable to humans?
Why is CWD a growing concern?
There are no documented CWD transmission to humans.
Under experimental conditions the disease can be transmitted to Squirrel Monkeys. Possible long-term incubation may be occurring without our awareness.
Anaerobic organisms lack what two enzymes?
Microaerophiles grow under _____ % oxygen, whereas aerotolerant organisms grow under _____ % oxygen.
Superoxide dismutase, catalase
5-10%, 5%
Capnophiles “prefer” _____ % CO2 and _____ % O2
Where are anaerobes most abundant in the body? In this location, what is the most abundant species?
1-10% CO2 15% O2
GI tract, Bacterioides
- Microaerophilic
- Gram-positive (thin) rods with spiral forms
- Catalase negative
- Normal flora of female genital tract
Colony morphology is pinpoint with alpha hemolysis
Lactobacillus
Proprionibacterium and Lactobacillus can both be normal flora of the ____.
Skin
Normal skin flora
Often associated with acne (inflammation serous/ purulent)
Can cause endocarditis, CNS infections, osteomyelitis, and arthritis
Most common anaerobic contaminant of BLOOD cultures
Proprionibacterium
C difficile is _____ to antibiotics such as _____, _____, and _____.
These antibiotics may lead to a condition called _____.
Resistant
Amoxicillin
Ampicillin
Clindamycin
Pseudomembranous colitis
An opening in the colon is a _____.
Anastomosis
Colostomy
Cross-connection between two channels (e.g., in the alimentary canal). Treatment that bypasses toxic megacolon of C. difficile
Complications of C difficile treatment may include _____, _____, or _____.
Perforated colon
Toxic megacolon
Pseudomembranous colitis.
C perfringens is found in _____ contaminated with feces. Some strains are part of _____. Some strains can also be found on _____ (fomite).
Soil and water
Normal flora
Kitchen counters
C perfringens can lead to soft tissue infections such as _____. (4)
Cellulitis
Myonecrosis (Gas gangreen, high mortality rate)
Food poisoning (Meat products)
Enteritis necroticans
Myonecrosis
Pseudomembranous colitis
Gas gangrene (high mortality rate)
Deposition of a pseudomembrane on mucosal surface composed of:
- fibrin
- neutrophils
- dead bacterial cells
A non-antibiotic treatment for clostridium perfingens would be…?
Enteritis necroticans is…?
Debridement of diseased tissue and air exposure
Inflammation (necrosis) of the jejunum and ileum
Often segmental in nature, perforation is possible
Enteritis necroticans from Cp
3 at risk groups for Enteritis Necroticans
People undergoing protein deprivation
People with poor hygiene/food handling habits
People from African/Asian countries
C botulinum spores are _____ and resemble a _____.
Subterminal
Tennis racket
C botulinum consists of _____ distinct genotypic groups. Humans are affected by _____. Animals are affected by _____. _____ is not usually known to cause disease.
C botulinum toxin can (primarily) cause _____.
I and II
III
IV
Flaccid paralysis
There are _____ types of Cb toxin. _____ cause human disease.
7 (A - G)
A B E F
Botulinum toxin enters body though _____ or _____.
Ingestion into the GI tract
Mucous membranes of eyes or respiratory tract
Cb toxin enters the bloodstream or lymphatics and makes its way to _____ which _____ causing _____.
Neuromuscular junctions
Blocks neurotransmitter release
Creates symptoms of botulism (flaccid paralysis)
Symptoms of botulinum toxin
Limb/Cranial muscle paralysis
Double vision/dilated pupils
Slurred speech/Dry mouth/Dysphagia
Respiratory dysfunction
Anaerobes are microorganisms that _____. Some anaerobes are also _____.
usually fail to grow in the presence of oxygen thus carry out fermentation
aerotolerant
Obligate aerobes grow best with _____
21% O2, 0.3% CO2 (Cannot grow anaerobically). Typically produces superoxide dismutase.
Obligate anaerobes grow _____.
Microaerophiles only grow under _____.
Facultative anaerobe can grow under _____.
only in or near 0% O2 levels
(also 5-10% hydrogen and CO2 & 80-90% N)
reduced O2 levels (5-10% O2), CO2 (8-10%).
under aerobic or anaerobic conditions thus some can be normal skin flora potentially
Facultative anaerobes respire until _____ and then _____.
Capnophiles prefer _____.
oxygen is depleted
ferment
increased CO2 (5-10%) and 15% 02. Candle jars achieve about 3-5% CO2 and 8-10%O2
_____ are the most abundant microorganisms in the gastrointestinal tract.
Many spp. of _____ are part of normal flora.
Anaerobes (Bacterioides (normal flora) most abundant spp.) These bacteria are important in the breakdown of food products into forms our bodies can absorb. They also break down dietary carcinogens.
Clostridium
Three normal-flora anaerobes of skin and/or upper respiratory tract are _____, _____, and _____.
Propionibacterium, Prevotella, Fusobacterium
Lactobacillus
Lactobacillus
Microaerophilic, catalase-negative
Gram positive thin rods with spiral forms
(Figure 18-1 Tille p. 291)
Normal flora of the female genital tract (contaminant of Urine, rarely pathogenic)
Colony morphology on SBAP can be pinpoint, alpha-hemolytic resembling streptococci.
An endogenous infection is an _____.
opportunistic infections where pathogens gain access to sterile sites (e.g., trauma)
Exogenous sources of anaerobe infections include _____.
Anaerobes can also be _____
rusty nails, skin puncture
Ingested (botulism in canned foods)
C difficile can be spread from _____ to _____.
Human to human
Some possible anaerobe infection sites
- Brain/lung/liver/intra-abdominal abscess
- Chronic otitis media
- Dental infections (abscess formation)
Are anaerobes found in urine?
Very rarely urine, only 1% of isolates isolated from urines are anaerobes.
T / F Voided or catheterized urine is acceptable to use for studying anaerobic organisms
False. Suprapubic bladder aspirate is acceptable.
_____ can lead to…
- Aspirate pneumonia
- Peritonitis
- Appendicitis
- Cellultis
Anaerobic infection
_____ can lead to…
Trauma/surgical wounds
Post-abortion sepsis (gynecological infections)
Myonecrosis
Anaerobic infection
Preferred specimens for specimen collection of anaerobic are _____ because they _____.
Aspirates, tissue, blood
Limit the amount of normal flora contamination
Small amounts drying
Normal flora contamination often taken from skin or mucosal surfaces
Toxic exposure to air
Disadvantages of swab collection
Blood specimens should always be collected utilizing both _____ bottles.
aerobic and anaerobic blood culture
Steps of blood culture
Sanitize the collection site (skin) with iodine or clorhexidine gluconate in combo with 70% isopropyl alcohol
What is pseudomembranous colitis and which organism is it associated with?
Mucosal inflammation with deposition of a pseudomembrane on the mucosal surface. This is composed of fibrin, neutrophils, and dead bacterial cells.
Clostridium difficile
C perfringens is found in _____ and _____ (environmental locations) contaminated with _____. This sp is capable of producing up to _____ toxins.
Soil, water, feces
12
C pefringens can lead to soft tissue infections such as _____ or _____.
Cellulitis
Myonecrosis
Most abundant bacteria (normal flora) in the human colon
Bacterioides
Proprionibacterium, Prevotella, and Fusobacterium
Normal flora anaerobes of the skin and/or upper respiratory tract
Swabs should only be used when _____.
Aspirated material is not possible or tissue is unavailable
Artificial conditions mimicking warm, humid, moist environments are important for anaerobes is important because
This is where they came from
Tissue needs to be placed in anaerobic transport tubes or vials containing PRAS, which stands for
Pre-reduced Anaerobically sterilized (PRAS)
GasPaks contain 2 tablets, What is in these tablets?
One tablet has citric acid and sodium bicarbonate.
One tablet has sodium borohydride.
Also uses a palladium catalyst.
PEA, KVLB, KVBA, BEE, and Thioglycollate are
PRAS media
All primary isolation media should be supplemented with _____, _____, and _____ due to specific nutritional requirements of anaerobes. _____ may be another required nutrient.
Hemin
Blood
Vitamin K
Cysteine
What does anaerobic PEA do? (3)
Inhibits Proteus swarming
Inhibits facultative enterobacteriacea
Allow growth of G+ bacteria
Kanamycin-vancomycin laked blood/blood agar is selective for, and is the preferred media for _____.
Gram negative obligate anaerobes
Vancomycin inhibits the growth of _____.
Kanamycin inhibits the growth of _____.
All G+ organisms
G- FA Bacilli
Mutations of PRNP lead to conformation changes that cause _____, or protein, in the CNS to build up.
In the mutated form, Sc is an abbreviation for _____.
Amyloid proteins
Scrapie
In CJD, prions show resistance to _____ fixation and _____ embedding.
CJD typically manifests in people _____ years of age (or older) and causes death within _____.
Formalin, Paraffin
60’s, 6 months
Vancomycin inhibits the growth of _____.
Kanamycin inhibits the growth of _____ _____ bacilli.
Gram positive organisms (G+ and G-)
Gram-negative facultative anaerobic
What is a laked-blood media? What is its purpose?
Refers to freezing and thawing of blood in agar. Improves pigment production in Prevotella melaninogenica – black pigment production
BBE agar
- Bacteroides-Bile Esculin agar
- Provides presumptive ID of Bacteroides fragilis
Detects organisms that can grow in 20% bile and hydrolyze esculin
BBE agar
Gentamicin inhibits _____. What are two other antibiotics worth noting?
- facultative anaerobes
- most G- anaerobic bacteria
Presumptive ID of Bacteroides fragilis can be detected by the growth of _____ on BBE agar.
- brown-black colonies
- blackening of media.
Thioglycollate broth supplements _____. Thioglycollate broth has a small amount of agar which _____.
plating media
prevents widespread diffusion of oxygen allowing anaerobes to grow.
Thioglycollate broth supports the growth of _____ in clinical specimens. It provides a backup for _____.
most anaerobes
slow-growing anaerobes or failing anaerobic system.
It is important to _____ anaerobic work to see if the infection is _____.
Gram staining can also reveal the presence of _____ or _____ at the site of infection.
Gram-stain
Polymicrobic
Leukocytes, SECs
Gram-staining serves as a QC measure because _____.
The gold standard for identification of anaerobes which analyzes metabolic products is _____.
Organisms observed from a Gram-stain and not isolated may indicate a problem with your anaerobic work-up protocol
Gas chromatography
