MLSCI340 Blood/ Fluids/ Anaerobes Flashcards
Normal flora in blood and CSF
NONE; sterile sites
List potential bacteria isolated in blood cultures
NOTE: may be a skin contaminant OR pathogen
- S. aureus
- S. pneumoniae (β strep)
- Haemophilus sp.
- Listeria monocytogenes
- Bacteroides sp. (anaerobes)
- Pseudomonas sp.
- Enterococcus sp.
- Campylobacter sp.
- Enterobacteriaceae
- Candida sp.
Define bacterial endocarditis
- disease resulting from bacterial invasion of heart valves
- widespread inflammation and destructive changes
- affects many organ systems
What causes ACUTE bacterial endocarditis ?
- develops within 2 months after implantation of prosthetic heart valve
- S. aureus, S. epidermis**
- S. pneumoniae, N. meningitidis, S. pyogenes, N. gonorrhoeae, P. aeruginosa, and Enterobacteriaceae sp.
What causes SUB-ACUTE bacterial endocarditis ?
- normally avirulent viridans group streptococci
- enter bloodstream during dental procedure
- colonize endothelial surfaces previously damaged by rheumatic disease or congenital cardiac malformation
Differentiate septicemia vs bacteremia
Septicemia: systemic disease due to persistence of pathogenic organisms OR toxins in blood
Bacteremia: simply presence of bacteria in blood
Define Pyrexia of Unknown Origin; “PUO”
investigation of cause for a fever
List potential bacteria isolated in CSF cultures
- N. meningiditis
- S. agalactiae
- S. aureus
- K. pneumoniae and S. pneumoniae
- Haemophilus influenzae
- Listeria monocytogenes
- Pseudomonas aeruginosa
- E. coli
- Cryptococcus neoformans
T or F: handling of all lumbar puncture specimens is ALWAYS considered STAT
TRUE; due to seriousness of infections in the nervous system, handling of all lumbar puncture specimens is ALWAYS considered STAT
Define meningitis
- inflammation of meninges membrane (covers brain and spinal cord)
- due to infections via bloodstream, direct invasion via fractures, or underlying cause (otitis media, mastoiditis, paranasal sinusitis)
Define aseptic meningitis. What causes it ?
- no bacteria can be isolated
- viruses (Coxsackie A/B, echoviruses, mumps) are responsible
- more common than bacterial pathogens
Define granulomatous meningitis
- Caused by Mycobacterium tuberculosis OR Cryptococcus neoformans
- subclinical course with definite remissions and relapses
- granuloma formation**
- spreads via bloodstream from infection in the lungs
Define viral encephalitis. What causes it ?
- localized or diffuse inflammatory processing involving the brain tissue = high mortality
- herpes virus and arboviruses
Define brain abscesses. What causes it ?
- may follow traumatic head injury
- brain becomes more susceptible to normal flora from middle ear, mastoids, nasal cavities…
- abscesses occur when other infections from body spreads to brain via bloodstream
- bacteroides sp. (anaerobes), CNS, S. pyogenes, Group D strep (S. bovis, enterococcus faecalis)
List other sterile body fluids
- amniotic fluid
- pericardial fluid
- peritoneal fluid
- pleural fluid
- synovial fluid
- vitreous fluid
Which pathogen is common in other sterile bodily fluids but NOT BLOOD OR CSF ?
N. gonorrhoeae
Define pericardial fluid
- The fibrous sac enclosing the heart, and the roots of the great vessels (pericardium)
- Viral cases are most common.
Define peritoneal fluid
Formed within the peritoneal cavity, which is bound by a serous membrane covering the abdominal cavity and organs.
Define pleural effusion
abnormal collection of pleural fluid (produced in small amounts to lubricate surfaces of the pleura, the thin membrane that lines the chest cavity and surrounds the lungs)
Define synovial fluid
- The synovial membrane is the inner membrane of tissue that lines a joint.
- Synovial fluid is secreted to lubricate the joint
Define vitreous fluid
transparent substance that fill the eyeball between the lens and the retina
Test Results to ID S. aureus
col morph= wop(h), gop(h)
%= gpc cl
cat= pos
slide/ tube coag= pos
DNAse= pos
TA= R
Which KB disk differentiates MSSA vs MRSA ?
Cefoxitin (FOX)
MSSA= S
MRSA= R
Test results for ID of S. pneumonia
col morph= (wet) alpha
%= gpc prs
TP= S
Bile Sol= pos
Test results for ID of N. gonorrhoeae
col morph= shygy
%= gndc
Ox= pos
CTA sugars:
Dextrose= pos
Maltose, Sucrose, Lactose= neg
Media for N. gonorrhoeae, N. meningitidis
Thayer Martin in CO2, New York City Agar in CO2
Test results for ID of N. meningitidis
col morph= shygy
%= gndc
Ox= pos
CTA sugars:
Dextrose, Maltose= pos
Sucrose, Lactose= neg
NOTE: M for Maltose and Meningitidis
Test results for N. lactamica
col morph= shygy
%= gndc
Ox= pos
CTA sugars:
Dextrose, Maltose, Lactose = pos
Sucrose= neg
NOTE: L for Lactose and Lactamica
List the CTA sugars
Cystine Tryptic Agar:
Base
Dextrose
Maltose
Sucrose
Lactose
How can M. catarrhalis be differentiated from Neisseria sp?
Butyrate esterase (catarrhalis disk)= pos
CTA sugars= neg for all (dextrose, maltose, sucrose, lactose)
Test results to ID S. agalactiae
col morph= small beta
%= gpc ch
cat= neg
PYR= neg
Latex= B
CAMP= pos
TA= R
NOTE: C for Camp and agalaCtiae
Test results to ID K. pneumoniae
MAC= pk
HE= yel
Orient= blu
TSI= A/Ag
Indole= neg
Lysine= pos
Test results to ID E. coli
%= gnb
MAC= pk
HE= gn
Orient= pk
TSI= A/Ag
Indole= pos
Lys= pos
What is propionibacterium ?
Contaminating anaerobic flora
Test results to ID H. influenzae
%= gncb
BAPss= sats
ALA= neg
Test results to ID L. monocytogenes
col morph= beta
%= gpb
cat= pos
BE= pos
TSI= A/A sick
RT Motility= tumbling
37°C Motility= neg
Semi-solid Motility= umbrella pattern
Test results for ID of Cryptococcus neoformans
India Ink= negative stain of capsule
Test results to ID Enterococcus
col morph= ent
%= gpc ch
cat= neg/ wk+
PYR= pos
BE= pos
6.5% NaCl= pos
Test results to ID P. aeruginosa
col morph= sheen
%= gnb
MAC= wh
TSI= K/K
Ox= pos
Nitrate= pos
Motility= pos
42°C =pos
UV= pos
Test results to ID Campylobacter jejuni
Col morph= clr, flt, spr, drop-like
%= gnb
Cat= pos
Ox= pos
Motility= cork-screw
What is the correct additional media OR test to the microscopic morphology: GPCCL
Tube coagulase
What is the correct additional media OR test to the microscopic morphology: GPCCH
Ethyl hydrocupreine hydrocholride
What is the correct additional media OR test to the microscopic morphology: GNDC
New York city agar
What is the correct additional media OR test to the microscopic morphology: Box-square GPB
Egg yolk agar
Which of the following statements is true about the collection of blood culture specimens?
a.
If coagulase negative Staphylococci isolated it is due to poor collection technique
b.
Should be collected after the fever has subsided and the patient is feeling better
c.
Should always collect 2 sets; one with two anaerobic vials and the second set with one aerobic vial
d.
Collection should occur from 2 separate sites in case skin contamination occurs from one of the sites
d.
Collection should occur from 2 separate sites in case skin contamination occurs from one of the sites
List the correct steps in viral replication:
- Synthesis
- Adsorption
- Release
- Maturation
- Penetration
Which of the following order of steps is correct?
2: Adsorption
5: Penetration
1: Synthesis
4: Maturation
3: Release
Which of the following organisms are susceptible to SPS?
a.
N. gonorrhoeae
b.
S. pneumoniae
c.
H. influenzae
d.
All of the above
a.
N. gonorrhoeae
Which of the following tests confirm Hepatitis C infection?
a.
PCR
b.
ELISA
c.
MALDI-TOF MS
d.
DFA
a.
PCR
Which of the following stains is used to examine for the presence of bacteria in a blood culture after the gram stain reveals no bacteria seen?
a.
Acridine Orange
b.
Auramine Rhodamine
c.
Ziehl-Neelsen
d.
Calcofluor White
a.
Acridine Orange
Which of the following methods is / are useful for direct viral examination?
Select all that apply:
a.
ELISA
b.
Western blot
c.
Polymerase chain reaction
d.
Electron microscopy
a.
ELISA
c.
Polymerase chain reaction
d.
Electron microscopy
Which of the following terms best describe an organism which prefers an environment with oxygen present but which functions well without oxygen?
a.
Aerobe
b.
Microaerophilic
c.
Aerotolerant
d.
Facultative anaerobe
d.
Facultative anaerobe
Which of the following organisms is associated with transient bacteremia?
a.
Coagulase negative staphylococci
b.
Diphtheroids
c.
Staphylococcus aureus
d.
Neisseria gonorrhoeae
a.
Coagulase negative staphylococci
Which of the following light sources is / are suitable for a fluorescence microscope?
a.
Xenon arc
b.
Mercury vapor
c.
Halogen quartz
d.
Tungsten filament
a.
Xenon arc
b.
Mercury vapor
c.
Halogen quartz
The following results are recorded for a tissue specimen:
Direct Smear Results:
4+ WBC
3+ RBC
3+ GPB
Culture Results:
BAPO2: no growth
BAP*: large translucent colony with two zones of hemolysis
MAC: no growth
Which of the following descriptors would best match the Gram stain result?
a.
Thin Gram positive bacilli with terminal spore
b.
Thick Gram positive bacilli with blunt ends and no spores
c.
Short Gram positive bacilli, almost coccoid in shape
d.
Short Gram positive bacilli, palisading
b.
Thick Gram positive bacilli with blunt ends and no spores
NOTE: C. perfringens
The following results are recorded for a tissue specimen:
Direct Smear Results:
4+ WBC
3+ RBC
3+ GPB
Culture Results:
BAPO2: no growth
BAP*: large translucent colony with two zones of hemolysis
MAC: no growth
Which of the following terms best describe the atmospheric requirements of the organism?
a.
Facultative anaerobe
b.
Capnophilic organism
c.
Microaerophilic organism
d.
Obligate anaerobe
d.
Obligate anaerobe
Which of the following organisms is resistant to kanamycin, vancomycin, and colistin?
a.
Peptostreptococcus sp
b.
Bacteroides fragilis
c.
Clostridium sp
d.
Veillonella sp
b.
Bacteroides fragilis
Which of the following results best match the CSF from a patient with bacterial meningitis?
a.
PMNs, elevated glucose, elevated protein
b.
Lymphocytes, normal glucose, elevated protein
c.
PMNs, low glucose, elevated protein
d.
Lymphocytes, low glucose, elevated protein
c.
PMNs, low glucose, elevated protein
A patient is diagnosed with peritonitis after bowel surgery. Which of the following organisms is most likely to be isolated in the peritoneal fluid?
a.
Campylobacter jejuni
b.
Shigella dysentariae
c.
Bacteroides fragilis
d.
Salmonella enterica Serovar typhi
c.
Bacteroides fragilis
The following results are recorded for a tissue specimen:
Direct Smear Results:
4+ WBC
3+ RBC
3+ GPB
Culture Results:
BAPO2: no growth
BAP*: large translucent colony with two zones of hemolysis
MAC: no growth
Which of the following tests will help identify the pathogen?
a.
KVC disks
b.
SPS disk
c.
Room temperature motility
d.
Reverse CAMP
d.
Reverse CAMP
NOTE: C. perfringens = pos
The following results are recorded for a tissue specimen:
Direct Smear Results:
4+ WBC
3+ RBC
3+ GPB
Culture Results:
BAPO2: no growth
BAP*: large translucent colony with two zones of hemolysis
MAC: no growth
Which of the following conditions is often associated with this pathogen?
a.
Gas gangrene
b.
Otitis media
c.
Spontaneous abortion
d.
Pseudomembranous colitis
a.
Gas gangrene
The following results are recorded for an isolate:
Gram stain: GPB large
Catalase: negative
Egg Yolk:
Lecithinase negative
Lipase positive
Reverse CAMP: negative
Which of the following organisms best fit the results?
a.
Clostridium sporogenes
b.
Actinomyces israelii
c.
Bacillus cereus
d.
Clostridium perfringens
a.
Clostridium sporogenes
NOTE: Lipase positive, Reverse CAMP negative
The following results
The following results are recorded for a CSF direct smear:
3+ WBC
1+RBC
4+ YST? (large round, yeast like organism? no budding or branching)
Which of the following organisms is the most likely pathogen?
a.
Cryptosporidium parvum
b.
Cryptococcus neoformans
c.
Echovirus
d.
Candida albicans
b.
Cryptococcus neoformans
Which of the following organisms is considered a Risk Group III organism?
a.
Francisella tularensis
b.
Pasteurella multocida
c.
Bordetella pertussis
d.
Neisseria meningitidis
a.
Francisella tularensis
Which of the following statements is / are true about eye wash stations?
Select all that apply:
a.
Weekly cleaning and maintenance is required
b.
Water should be cold to decrease risk of burns
c.
Eyes must be flushed for a minimum of 5 minutes
d.
Remove contacts before using
a.
Weekly cleaning and maintenance is required
Principle of Plate Bile Solubility. What is a positive result ?
Principle:
Presence of bile salts accelerate activity of autolytic enzyme
Positive: flattened/ dissolved colonies after 15 min
Bile Sol reagent
Sodium deoxycholate
Chemical name for TP
(Optochin)/ Ethyl hydrocupreine hydrochloride
Principle of PYR test. What is a positive result ?
Principle:
Detects PYRase= hydrolyzes L-pyrrolidonyl-beta-beta-naphthylamide (PYR)
Positive: pink color within 1 minute
PYR reagent
N,N-dimethyl-aminocinnamaldehyde
How to differentiate anaerobic GPB ?
L. monocytogenes = cat pos
Clostridium sp = cat neg
KVC results for Fusobacterium
Kanamycin = S
Vancomycin =R
Colistin = S
Test to differentiate Micrococcus from S. aureus
Bacitracin/ TA:
Micrococcus = S
S. aureus = R
T or F: Tube coagulase detects free coag, while slide coag detects bound coagulase
TRUE; Tube coagulase detects free coagulase
Which is known as “clumping factor:” free or bound coag?
bound coagulase in slide coag
List HACEK group. What are they known for ?
Haemophilus
Aggregatibacter
Cardiobacterium
Eiknella corrodens
Kingella
= ENDOCARDITIS
Ideal ratio of blood: media in BACTEC vials
1:5
