The effect of honeybee-specific Lactic Acid Bacteria on American foulbrood disease of honeybees
(2018) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2018(76).- Abstract
- The honeybee, Apis mellifera, is one of the most economically important pollinators and highly valued for its honey and wax production. Managed honeybees occupy an increasingly critical role in agricultural productivity and food security. American foulbrood (AFB) is a highly contagious and destructive bacterial honeybee brood disease caused by Paenibacillus larvae that affects beekeeping worldwide. However, only a minority of bacteria associated with honeybees are harmful. Honeybee-specific Lactic Acid Bacteria (hbs-LAB), a defined group of beneficial bacteria inhabiting the honey crop, have strong antimicrobial properties important for honey production and honeybee health that could be exploited for combating diseases such as AFB.... (More)
- The honeybee, Apis mellifera, is one of the most economically important pollinators and highly valued for its honey and wax production. Managed honeybees occupy an increasingly critical role in agricultural productivity and food security. American foulbrood (AFB) is a highly contagious and destructive bacterial honeybee brood disease caused by Paenibacillus larvae that affects beekeeping worldwide. However, only a minority of bacteria associated with honeybees are harmful. Honeybee-specific Lactic Acid Bacteria (hbs-LAB), a defined group of beneficial bacteria inhabiting the honey crop, have strong antimicrobial properties important for honey production and honeybee health that could be exploited for combating diseases such as AFB.
The aim of this thesis was to investigate the effect of hbs-LAB on P. larvae and AFB, both in culture, in individual larval bioassays, and at colony level.
First we showed that the laboratory cultivation of the 13 distinct hbs-LAB was significantly improved by the addition of L-cysteine and fructose to the medium and optimized a culture-independent molecular technique for the detection and identification of the individual hbs-LAB species. Secondly the effect of the cell free supernatant, the secretome, from a culture mix of the 13 hbs-LAB species was investigated on P. larvae growth and associated larval mortality. The results showed that this secretome strongly inhibited the multiplication of P. larvae vegetative cells but that spore germination appeared to be unaffected, and that it decreased the mortality of P. larvae infected larvae. Finally it was shown that oral administration of hbs-LAB supplement to honeybee colonies had no influence on colony-level P. larvae spore levels or colony strength. Furthermore, the results showed that although the antibiotic tylosin decreased AFB symptoms in colonies, it had no effect on P. larvae spore levels.
In conclusion, the colony-level results do not contradict the antagonistic effects observed in individual larvae in laboratory studies, but rather suggest that supplementary administration of live bacteria may not be the most effective way to harness such effects in a useful application.
(Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/e941ae73-5dc9-447e-a2ae-ffab3858d793
- author
- Lamei, Sepideh LU
- opponent
-
- professor Vandamme, Peter, Gent Universitet, Belgium
- organization
- publishing date
- 2018
- type
- Thesis
- publication status
- published
- subject
- in
- Lund University, Faculty of Medicine Doctoral Dissertation Series
- volume
- 2018
- issue
- 76
- pages
- 58 pages
- publisher
- Lund University: Faculty of Medicine
- defense location
- Hörsal L, Undervisningshuset SLU, Ultuna
- defense date
- 2018-06-01 09:00:00
- ISSN
- 1652-8220
- language
- English
- LU publication?
- yes
- additional info
- ISSN: 1652-8220 Lund University, Faculty of Medicine Doctoral Dissertation Series 2018:76
- id
- e941ae73-5dc9-447e-a2ae-ffab3858d793
- date added to LUP
- 2018-05-08 14:27:02
- date last changed
- 2020-03-13 10:26:52
@phdthesis{e941ae73-5dc9-447e-a2ae-ffab3858d793,
abstract = {{The honeybee, Apis mellifera, is one of the most economically important pollinators and highly valued for its honey and wax production. Managed honeybees occupy an increasingly critical role in agricultural productivity and food security. American foulbrood (AFB) is a highly contagious and destructive bacterial honeybee brood disease caused by Paenibacillus larvae that affects beekeeping worldwide. However, only a minority of bacteria associated with honeybees are harmful. Honeybee-specific Lactic Acid Bacteria (hbs-LAB), a defined group of beneficial bacteria inhabiting the honey crop, have strong antimicrobial properties important for honey production and honeybee health that could be exploited for combating diseases such as AFB. <br/>The aim of this thesis was to investigate the effect of hbs-LAB on P. larvae and AFB, both in culture, in individual larval bioassays, and at colony level.<br/>First we showed that the laboratory cultivation of the 13 distinct hbs-LAB was significantly improved by the addition of L-cysteine and fructose to the medium and optimized a culture-independent molecular technique for the detection and identification of the individual hbs-LAB species. Secondly the effect of the cell free supernatant, the secretome, from a culture mix of the 13 hbs-LAB species was investigated on P. larvae growth and associated larval mortality. The results showed that this secretome strongly inhibited the multiplication of P. larvae vegetative cells but that spore germination appeared to be unaffected, and that it decreased the mortality of P. larvae infected larvae. Finally it was shown that oral administration of hbs-LAB supplement to honeybee colonies had no influence on colony-level P. larvae spore levels or colony strength. Furthermore, the results showed that although the antibiotic tylosin decreased AFB symptoms in colonies, it had no effect on P. larvae spore levels.<br/>In conclusion, the colony-level results do not contradict the antagonistic effects observed in individual larvae in laboratory studies, but rather suggest that supplementary administration of live bacteria may not be the most effective way to harness such effects in a useful application.<br/>}},
author = {{Lamei, Sepideh}},
issn = {{1652-8220}},
language = {{eng}},
number = {{76}},
publisher = {{Lund University: Faculty of Medicine}},
school = {{Lund University}},
series = {{Lund University, Faculty of Medicine Doctoral Dissertation Series}},
title = {{The effect of honeybee-specific Lactic Acid Bacteria on American foulbrood disease of honeybees}},
url = {{https://lup.lub.lu.se/search/files/43096682/Lamei_s_180905.pdf}},
volume = {{2018}},
year = {{2018}},
}