B3 Flashcards
What follow up test is performed on certain strands of Haemophilus influenzae?
The Cefinase disk test.
(Moisten disk and inoculate with isolated colonies of Haemophilus influenzae.
Disk area inoculated turns pink/red if beta lactamase enzyme produced. (POSITIVE
No color change is produced if beta lactamase absent. (NEGATIVE)
The Cefinase test is done on Haemophilus influenzae growing on chocolate agar.
The enzyme catalase is present in most aerobic, facultative anaerobic and some obligate anaerobic bacteria, with the major exception of what two species?
streptococci and enterococci
The enzyme catalase catalyzes dissociates what two elements from hydrogen peroxide.
oxygen and water, from Hydrogen peroxide.
What organism is…
- Gram positive
- beta hemolytic
- catalase positive
- coagulase positive
Staphylococcus aureus
What organism is:
- Gram positive
- catalase positive
- coagulase negative
- urease positive
- novobiocin sensitive
Staphylococcus epidermidis
The enzyme catalase does what?
Catalase dissociates oxygen and water from hydrogen peroxide.
The organism is Gram positive and catalase negative.
This means the organism is likely to be one of what two species?
streptococcus
or
Enterococci
This organism is:
- Gram positive
- beta hemolytic
- catalase positive
- coagulase negative
- urease positive
- Novobiosin sensitive
Staphylococcus lugdunensis
This organism is:
- Gram positive
- alpha hemolytic
- catalase negative
- optichin sensitive
Streptococcus pneumoniae
Under Gram stain, Gram positive, lancet shaped, diplococci
Zones of clearing around the P disk on respiratory plates reveals S. pneumonia is elsewhere on the plate.
What organism is:
- Gram positive
- beta hemolytic
- Bacitracin Resistant (B disk on choc)
- catalase negative
- PYR negative
- Hippurate positive (hydrolyzes hippurate into glycine and benzois acid)
Streptococcus agalactiae (Group B Strep.)
What organism is:
- Gram positive
- beta hemolytic
- catalase negative
- Basitracin sensitive (B disk on choc)
- PYR positive
Streptococcus Pyogenes (Group A Strep)
Think PYogenes is PYR positive
This Gram positive, beta hemolytic, catalase negative, organism is PYR positive.
Streptococcus Pyogenes (Group A Strep.)
This Gram positive, beta hemolytic, catalase negative, organism is PYR negative.
Streptococcus Agalactiae (Group B Strep.)
What organism is:
- Gram positive
- alpha hemolytic
- catalase negative
- Optichin resistant (P disk on blood)
Strep Viridans
- S. mitis
- S. oralis
others…
The classical differentiation of streptococci separates the group of beta-hemolytic streptococci from the group of non- beta-hemolytic streptococcal species. Beta-hemolytic streptococci, also referred to as pyogenic streptococci, include what human-pathogenic species?
S. pyogenes,
S. agalactiae,
S. dysgalactiae subsp. equisimilis,
