Honeybee-Specific Lactic Acid Bacterium Supplements Have No Effect on American Foulbrood-Infected Honeybee Colonies.

Appl Environ Microbiol 2019 Jul 17;85(13). Epub 2019 Jun 17.

Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.

, the causative agent of American foulbrood (AFB), is the primary bacterial pathogen affecting honeybees and beekeeping. The main methods for controlling AFB are incineration of diseased colonies or prophylactic antibiotic treatment (e.g., with tylosin), neither of which is fully satisfactory. The search for superior means for controlling AFB has led to an increased interest in the natural relationships between the honeybee-pathogenic and mutualistic microorganisms and, in particular, the antagonistic effects of honeybee-specific lactic acid bacteria (hbs-LAB) against These effects have been demonstrated only on individual larvae in controlled laboratory bioassays. Here we investigated whether supplemental administration of hbs-LAB had a similar beneficial effect on infection at colony level. We compared experimentally AFB-infected colonies treated with hbs-LAB supplements to untreated and tylosin-treated colonies and recorded AFB symptoms, bacterial spore levels, and two measures of colony health. To account for the complexity of a bee colony, we focused on (Bayesian) probabilities and magnitudes of effect sizes. Tylosin reduced AFB disease symptoms but also had a negative effect on colony strength. The tylosin treatment did not, however, affect spore levels and might therefore "mask" the potential for disease. hbs-LAB tended to reduce brood size in the short term but was unlikely to affect AFB symptoms or spores. These results do not contradict demonstrated antagonistic effects of hbs-LAB against at the individual bee level but rather suggest that supplementary administration of hbs-LAB may not be the most effective way to harness these beneficial effects at the colony level. The previously demonstrated antagonistic effects of honeybee-derived bacterial microbiota on the infectivity and pathogenicity of in laboratory bioassays have identified a possible new approach to AFB control. However, honeybee colonies are complex superorganisms where social immune defenses play a major role in resistance against disease at the colony level. Few studies have investigated the effect of beneficial microorganisms on bee diseases at the colony level. Effects observed at the individual bee level do not necessarily translate into similar effects at the colony level. This study partially fills this gap by showing that, unlike at the individual level, hbs-LAB supplements did not affect AFB symptoms at the colony level. The inference is that the mechanisms regulating the honeybee microbial dynamics within a colony are too strong to manipulate positively through supplemental feeding of live hbs-LAB and that new potential remedies identified through laboratory research have to be tested thoroughly , in colonies.

Download full-text PDF

Source
http://aem.asm.org/lookup/doi/10.1128/AEM.00606-19
Publisher Site
http://dx.doi.org/10.1128/AEM.00606-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6581185PMC

Still can't find the full text of the article?

We can help you send a request to the authors directly.
July 2019
8 Reads

Article Mentions


Provided by Crossref Event Data
twitter
Twitter:
April 25, 2019, 5:11 pm EST
twitter
Twitter:
April 25, 2019, 4:43 pm EST
twitter
Twitter:
April 23, 2019, 8:33 am EST
twitter
Twitter:
April 23, 2019, 8:31 am EST
twitter
Twitter:
April 21, 2019, 3:38 am EST

Publication Analysis

Top Keywords

colony level
24
antagonistic effects
12
afb symptoms
12
colony
10
level
9
bee level
8
affect afb
8
individual bee
8
administration hbs-lab
8
afb
8
hbs-lab
8
honeybee colonies
8
demonstrated antagonistic
8
effects colony
8
lactic acid
8
controlling afb
8
spore levels
8
honeybee-specific lactic
8
laboratory bioassays
8
hbs-lab supplements
8

Similar Publications