EXERCISE 16 Flashcards
Assessment of gross colony characteristics is usually performed by visually inspecting [?] on the surface of agar plates
growth
Inspection of cultures is carried out by [?] and observing the surface of the agar for the presence of bacterial growth.
holding the plate in one hand
is a mass or cluster of bacteria forming on a solid culture medium as a result of repeated divisions of one or few organisms.
Colony
is consisting of only one species of microorganism
Pure culture
Importance of colonial morphology as a diagnostic tool
- Provide a [?] to the physician.
- Enhance the [?] through rapid reporting of results and by increasing the cost-effectiveness of laboratory testing.
- Play a [?] especially of automated procedures and other commercially available identification systems.
- presumptive identification
- quality of patient care
- significant role in quality control
Interpretation of Cultures
o generally observed after [?] hours of incubation where the bacteria are presumed in the logarithmic growth phase.
18 to 24 hrs
the media where organism grow is a
preliminary indicator
- Type of media supporting bacterial growth
- consider:
▪ generally, all bacteria grow on [?] because it is an enriched medium
▪ [?] as a selective culture media supports gram-negative organism but inhibits gram-positive organisms and fastidious gram-negative
▪ Growth on BAM but not on MAC is indicative of [?] or [?]
- Blood agar medium (BAM)
- MAC
- gram-positive isolate;
- fastidious gram-negative bacilli or cocci
Information derived from the type of culture media supporting bacteria growth must be correlated with the result of the [?].
initial Gram-staining
the [?] is a criterion (along with direct smear result, organisms’ virulence, site) for establishing clinical significance
predominance of the bacterial isolate
Number of Colonies Visible in each Quadrant
growth on #1
1+
Number of Colonies Visible in each Quadrant
growth on #1, #2
2+
Number of Colonies Visible in each Quadrant
growth on #1, #2, #3
3+
Number of Colonies Visible in each Quadrant
growth on #1, #2, #3, #4
4+
measured in millimeter or described in relative terms such as pinpoint, small, medium, large
Colony size
