Monday, June 29, 2009

Updated Quick Microbe Meetup

Update to this original post:

Check it out so you can get the skinny on the question before you see the answer!

Result: Upon careful examination of the gram stain you will see Gram negative diplococci that are kidney bean shaped, strongly indicative of the organism Neisseria meningitidis. Neisseria meningitidis usually appears as Gram (-) diplococci that sometimes may display considerable size variation, resist decolorization, and a distinct pink halo around the cells. The physician should be notified immediately so the antibiotic care can be administered.
After 18 to 24 hours the culture should be ready and growth on chocolate agar shows colonies that are generally larger than other gonococcal species, usually attaining a diameter of 1mm or more. Colonies are also low and convex, with a smooth, moist entire edge and a glistening surface. Sheep’s blood may present some alpha hemolysis and are grey, heavily encapsulated strains appear mucoid and are oxidase positive. N.meningitidis can be identified by acid production tests or by chromogeneic enzyme substrate tests. It acidifies glucose and maltose, but not sucrose fructose, or lactose. Serotyping is generally done to obtain epidemiological data on the organism and is done through a simple slide agglutination, also PCR, PFGE, and DNA fingerprinting.
All in all, N.meningitidis is an extremely pathogenic organism that can cause rapid death so stat diagnosis is key.


Post a Comment