Anaerobes study questions Flashcards
What is added to Columbia sheep blood agar that makes it suitable for growing anaerobic bacteria?
It contains growth factors, peptides, vitamin K, yeast, hemin
What organisms grow on Columbia sheep blood agar
It grows obligate and facultative anaerobes
(gram - and +)
-Enterobacteriaceae, pseudomonas, nonfermenting gram-rods, strep, staph, candida
What criteria determine if a specimen is acceptable for anaerobic growth?
-if the specimen was collected properly like eswab, syringes
What ingredients are in the leaked KV agar?
KV agar has kanamycin and vancomycin and selects for gram-bacilli like prevotella, bacterioles
-porphyormonas will not grow
List sites that are unacceptable for anaerobic culture
-area with indigenous flora
-throat, mouth, rectum, urine unless suprapubic, tap, sputum, BAL, vaginal, cervical, placenta, catheter tips, Implements except for shunts and spinal/brain types
Holding Jar purpose in anaerobic culturing
-can be used to hold reduced media, or help to keep organisms alive while you work them up
Gas pack gas generating system purpose in anaerobic bacteria culturing
-a packet that when torn open generates H2. In the presence of a catalyst, the H2 combines with O2 to form H2O
Anaerobic glove box chamber in anaerobic culturing
-uses a lot of nitrogen gas to replace oxygen but incubates and everything you need is in the box
What is the aerotolerance test?
-in this test, you subculture the organism onto two chocolate plates and place one into ambient air and CO2. This shows oxygen required for organisms
What is BBE agar?
-Bacteroides Bile esculin agar and contains 20% bile esculin salt. We use this to identify B fragilis
-B frag will grow on the agar and turn black from hydrolyzing the bile salts
How long are anaerobic cultures incubated?
-they are incubated at 35-37 degrees for a minimum of 4 days but up to 14 days depending on the source. Anaeroboes take a longer time to grow
-joints are held longer to rule out cunitebacterium actines
How long are aerobic cultures incubated?
- held for 48 hours (2 days) for nonsterile, sterile sources get held up to
What antibiotics are used to treat anaerobic infections?
-antibiotic treatments are based on empirical treatment which would be ampicillin, penicillin, clindamycin, cefoxitin, carbapenems, metronidazole, beta-lactam combos, imipenem (the others too)
Who would order a susceptibilities test on anaerobic infections?
-The doctor in charge and the infectious disease
-only do this on a true sterile source
What method would be used for the susceptibility test of anaerobic infections?
-MIC, tube dilutions
