Tuesday, June 20, 2023

Case of the Week 719

This week's case is very timely! The following objects were seen on a modified safranin-stained stool specimen. They measure approximately 8 to 10 micrometers in diameter. Identification?

40x objective:

100x objective:




8 comments:

Anonymous said...

Cyclospora cayetanensis

Anonymous said...

One sure characteristic of coccidian oocysts is that they are variably acid fast, some may stain strongly while some may not stain at all. The third picture shows this fact perfectly. Using the relative size,we can see that this is a case of Cyclospora cayetanensis infection. Thank you Dr. Pritt for a very timely reminder.
Florida Fan

Anonymous said...

Cyclospora cayetanensis
( Sir Galahad)

Vinod said...

Cyclospora spp

Anonymous said...

Cyclospora species

Idzi P. said...

Cyclospora cayetanensis oocysts. As Florida Fan states: these stain very variably acid fast (shown perfectly in the third image). Very timely indeed as this organism is the cause of yearly outbreaks in the US due to (fecal) contamination of raw fruits and/or vegetables (like cilantro etc). In acid fast stains they can be differentiated from Cryptosporidium based on their size (Cryptosporidium oocysts are slightly smaller without overlapping Cyclospora’s size).

Idzi P. said...

Ooops… this was safranin staining. But Cyclospora also stains variably in safranin stainings. Heating (e.g. with a microwave oven) improves uniformity of safranin staining of these oocysts.

Anonymous said...

I love this!!