Saturday, March 17, 2018

Not so smooth strawberry smoothie







Several day old strawberry smoothie - N. Carlson
Beware of the several day old strawberry smoothie. This one was was a fuzzy gray when it arrived at the kitchen sink.  I took a tease tape, transferred to a slide with some mounting fluid and examined it under a microscope. The organism has characteristics of both Rhizomucor spp. and Rhizopus spp.  With Rhizopus spp. the sporangiophores start at the same location as the rhizoids (root like structure) individual Rhizopus spp. are connected with a non septate stolon perpendicular to the rhizoids. This is similar to the runners that strawberry plants employ.  With Rhizomucor spp. the sporangiophores branch some distance away from the rhizoids. The branching on this sample is some distance from the rhizoids.

The Rhizomucor spp. sporangiospores are usually under 6 microns in diameter with round to slightly oval spores although some are irregularly shaped.  The sporangiospores in this sample are greater than 6 microns and have the characteristic walnut shell shape of a Rhizopus spp. spore. Both of these organisms can cause strawberries to rot.

Rhizopus spp. line drawing - N. Carlson

Rhizopus spp. or Rhizomucor spp.  - 400x - N. Carlson

The branching at the end is more typical of Rhizomucor spp. - 100x

Close-up of sporangiospores  that are more typical of Rhizopus spp. 


Clinical signs for zygomycete exposure (Mucor spp., Rhizopus spp., or Rhizomucor spp.) infection - 4 min.





Friday, March 9, 2018

Tickborne diseases in Minnesota


MDH  tickborne disease stats from 2007 to 2017

The official start of spring in the northern hemisphere is approaching. With the warmer weather families plan outdoor adventures. This past year I gave a talk on tick borne diseases in Minnesota and the surrounding areas. After reviewing the information, it reinforced my conviction to be careful.

Most of the emphasis has been on Lyme disease transmitted by small black legged ticks. There are other diseases. Fortunately, one of the really nasty tick borne diseases  Powassan Virus (CDC) is rare. Unfortunately the effects of this rare illness are really nasty. It can cause swelling of the brain, crushing headaches, and death.  Doctors can only offer palliative care as there is no effective treatment.

There has been controversy surrounding the treatment for chronic Lyme disease.  A reference below lists some of the side effects from these treatments. As a tick may carry more than one disease this may in part explain ongoing symptoms. Continuing to use the antibiotics for Lyme disease would be ineffectual and make the patient susceptible to more side effects.

On a personal note: I was misdiagnosed with Lyme disease in the 1980s when the blood tests were not as accurate.  I ended up going through the course of antibiotics and met my share of marginally competent phlebotomists.  The experience was not pleasant and it was also ineffectual.

Please review the interesting article below on how the decline in the fox population is associated with an increase in Lyme disease.  Other habitat changes that allow deer mice populations to explode also increase the risk for tick disease transmission.

These are a few of the many tips from MDH tick prevention:
  • Apply DEET on skin and use Permethrin on clothing (not skin). 
  • Walk in the center of a trail
  • Tuck light colored pants inside socks.
  • Inspect and remove ticks within 24 hours. 
  • Avoid walking in woody or brushy areas during times of the year where the risk of tick borne disease is high.



Applying DEET and Permethrin MDH - Approximately 3 minutes.


Tick removal - MDH Approximately 1 minute. 

Tickborne disease references:




University of Manitoba - tick removal - 2 min.