I'm curious about AFB as a disease phenomenon, ie, "where does it come from".  The stock answer of course, is "the bees spread it".  But infected bees as the primary vector is a very unsatisfying, and seemingly incomplete answer.  

 I recently reviewed the article below of a study comparing the microbiomes of bees (1) in infected hives (2) asymptomatic hives in the infected apiary and (3) control hives outside of the infection zone.  Of particular interest was the fact that very low levels of AFB spores were present in the control group outside the infection area. Since Paenibacillus, the genus of bacteria which includes AFB appears to be ubiquitous in the environment (as suggested by the Wikipedia article), I wondered about what environmental conditions promote the proliferation of AFB spores to begin with.   In other words, if you were a beekeeper in a totally isolated area, could your hives come down with it?   A local incident of AFB that I have some personal knowledge of involved an apiary which appears to be poorly sited, particularly for winter conditions - in a cold sink,  receiving little to no sun in the winter, and probably no more than 5 hrs/day in the summer.  These factors may be purely coincidental, but perhaps not. Surprisingly, the study found that varroa infection was not an AFB susceptibility factor.  Any thoughts?

Erban, Tomas et al.  Honeybee (Apis mellifera)-associated bacterial community affected by American foulbrood: detection of Paenibacillus larvae via microbiome analysis.  Scientific Reports 7, Article number: 5084 (2017).

https://www.nature.com/articles/s41598-017-05076-8






Knowing that the PSBA hives caught it, and knowing that the environment for those hives was awful (too cold & damp) I wondered if the bacteria is latently present everywhere, and just needs the right conditions to explode.  That's what this study seems to be saying, since even the control group was found to have a small % of the AFB spore in the hives outside of the infection area. 


The Wikipedia article on the genus of the bacteria that AFB belongs to also suggests that "it's everywhere". 

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html