Culture Characteristics:
- Growth at 22-25oC and at 35oC
- Organism prefers 25oC, so the colonies will grow faster at this temperature
- Growth occurs on most routine media, including sheep blood agar (SBA), chocolate agar (CHOC), MacConkey (MAC) agar, and routine blood culture media
- Non-lactose fermenter on MAC agar
- Growth is slower than other Enterobacteriaceae
Colony Morphology on SBA at 35oC:
- At 24 hours, colonies are pinpoint and translucent with a gray-white color
- Colonies take on a yellow tint as they age, after 48-72 hours, referred to as a "hammered copper" appearance
- An irregular or "fried egg" appearance, shown in the lower image, can also be seen at 48-72 hours
Characteristic Features:
- Growth at 22-25oC is a hallmark feature of this organism
7. CDC/Dr. Brodsky. Image #3361. "This image depicts a front view of a Petri dish culture plate, which had contained a growth medium of blood agar, that had been inoculated with Yersinia pestis bacteria, and is seen here after a 48-hour inoculation period." PHIL, 1966 public domain. Accessed May 25, 2022. https://phil.cdc.gov/Details.aspx?pid=33618. CDC/L Stauffer. Image #1921. "This petri dish culture plate contained a growth medium of sheep blood agar (SBA), which had been inoculated with
Yersinia pestis and incubated for a 72-hour period. Note the classic fried egg colonial morphology produced by
Y. pestis." PHIL, 2002, public domain. Accessed May 25, 2022.
https://phil.cdc.gov/Details.aspx?pid=1921
