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?
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
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).
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.
Cyclospora cayetanensis
ReplyDeleteOne 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.
ReplyDeleteFlorida Fan
Cyclospora cayetanensis
ReplyDelete( Sir Galahad)
Cyclospora spp
ReplyDeleteCyclospora species
ReplyDeleteCyclospora 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).
ReplyDeleteOoops… 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.
ReplyDeleteI love this!!
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