PBL: Case 1 Part 1 Flashcards
Presence of bacteria in the blood
bacteremia
Bacteria passing through (dental, colonoscopy)
transient bacteremia
bacteria seeding from the infected site to another area intermittently (seeding blood) (same organism off and on)
intermittent bacteremia
- Bacteria coming from an intravascular source all of the time (Endocarditis)
continous bacteremia
sepsis goin on inside a site such as an iv catheter, endocarditis
primary sepsis
sepsis going on in an external site such as strep from lungs, UTI, dental surgery, tooth accesses.
secondary sepsis
a contaminant in the blood
pseudobacteremia
bacteremia with organisms multiplying in blood and symptoms showing
septicemia
molds and yeast in the blood
fungemia
viruses in the blood
viremia
*Systemic inflammatory response syndrome (things must fall in a category?)
SIRS
inflammation of the cardiac lining
endocarditis
Sepsis with hypotension
septic shock
when the proteins that control blood clotting become over active and you get massive bleeding out
disseminated Intravascular coagulation (DIC)
blood culture system where the instrument checks for positive cultures 24-7
continuous monitoring blood culture systems
bacteria secreting _______ are notorious for septic shock
endotoxins
common symptoms and abnormal lab tests that would be associated with possible sepsis
- fever (i or d)
- shaking
- chills
- tachypnea
- prostration (laying down)
- blood pressure (i or d)
- DIC
- WBC count (i or d)
- lactic acidosis
- C-RP (i)
- procalcitonin (indicator of inflammation on high levels indicative of septicemia)
Proper method of collecting a blood specimen for bacteriologic culture (5 steps)
- alcohol
- iodine based
- make circles going out
- draw opposite arm that has iv
- draw below iv if have to draw from arm with iv
correlate the number, timing and volume of specimens with optimal recovery of organisms for meaningful clinical use
Number: one set = one aerobic bottle and one anaerobic bottle; no more then 3 sets in 24 hours
Volume: 8-10 for adults and 1-3 for babies;
Timing: take blood before antibiotics or any therapy and right before a fever
blood to medium ratio when collecting a blood
1:5- 1:10
IV catheter related
Skin flora:
- alpha/gama strep
- CoNS
- Propionibacterium ances
- staphylococcus sacchrolyticus
- Corynebacterium spp.
UTI
- E. coli (coming from GI)
Subacute endocarditis
- CoNS
- Veridans strep
- (s. aureus)
acute endocarditis
- staph aureus
- enterococcus
- strep pneumo
Gunshot to the abdomen
GI flora:
- E. coli
- Other enterobacteriaceae
- Enterococcus
- anaerobes (B. frag, Clostridium, Bifidobacterium, anaerobic coccci, Fusobacterium)
Oral surgery
Mouth Flora:
- alpha and gamma streptococci
- Corynebacterium
- CoNS
- non-pathogenic Neisseria app.
- Prevotella melaninogenica
- Porphyromonas spp.
- Prevotella spp.
Most common contaminants found in the blood
Skin flora:
- alpha/gama strep
- CoNS
- Propionibacterium ances
- staphylococcus sacchrolyticus
- Corynebacterium spp.
Immunocomporomised
anything really; fungi
Preexisting pneumonia is the most common cause of septicemia. This pneumonia is caused by….
S. pneumo
Klebs. pneumo
BACTEC system
measuring CO2 by fluorescences
BacT/Allert system
measuring CO2 by pH change
SeptiCheck
agar paddle and you inoculate it
Lysis Centrifugation
(saphonin lysis white blood cells) this is for: intracellular pathogens and fungi, yeasts and molds
What is the purpose of sodium polyanetholsulfonate (SPS)
anticoagulant
What is the purpose of resins (ARD antimicrobial removal devices) in blood culture systems
neutralizes antibiotics
Blood culture procedure for possible brucellosis
Castanata bottle/biphasic bottle: used when takes a long time to grow brucellosis (4 weeks)
What approaches could be used to determine whether an isolate is a skin contaminant or a pathogen
Collect multiple specimens (3 sets a day max); Skin contaminant: 1 out of all the bottles positive Pathogen: all positive more likely to be a pathogen
What one gram POSITIVE organism may be observed on a gram stained smear from a blood culture bottle but would NOT grow on SBA and, with some organisms, not on CHCO
- Anaerobes
- Streptococcus abiotrophia (nutrient varient)
What one gram NEGATIVE organism may be observed on a gram stained smear from a blood culture bottle but would NOT grow on SBA and, with some organisms, not on CHCO
- Haemophilus (only grows on chocolate)
- Campylobacter (charcoal containing media, not blood OR chocolate)
- anaerobes
What media should be set up on a positive blood culture, based on results of a positive smear
- blood
- choc
- anaerobe blood
- do preliminatry susceptibilites, - - GLC for anaerobes
What test should you set up if you think you have a strep?
- of these which can you set up directly from the blood?
- Catalase
- NaCl
- PYR
- Bile Esculin
- CAMP
- Optochin (bile solubility)
- Bacitracin
Set up from blood: Bile Esculin and optochin
If you have a gram positive cocci what should you do first?
Gram stain, plate it out, and do optochin right away!
What would you do if your gram stain was clumped (staph)
Do a coag right away (in 4 hours) FROM BLOOD
What would you do if your gram stain was a GNR
Vitek or KIA FROM BLOOD
We keep blood bottles for how many days?
5 days
What is the significance if positive on the first day v.s. the fifth day?
First day: more likely to be significant
Fifth day: more likely to be a contaminant
What is the best way to do a gram stain on a blood?
Methanol Fixation because it preserves red cells the best
