Preventive Veterinary Microbiology - the Miki Bojesen group
Our aim is to design novel approaches for disease prevention through development of vaccines and alternative antimicrobial treatments. Our main focus is to identify and understand factors involved in disease initiation and progression in animals to improve welfare and productivity. Infectious diseases in poultry, pigs, fish and horses are the main focus of our research.
Salpingitis caused by E. coli is a major cause of reduced productivity, increased mortality and risk for vertical transmission of E. coli in egg-laying hens.
Chronic salpingitis – what are the consequenses?
The fate of infection is dependant on both the hen itself and the strain of E. coli casing the infection. Hens that survive the acute infection may either cure the infection, cure the infection but stop laying eggs, develop a chronic salpingitis but continue egg production or develop a chronic infection but stop laying eggs.
The aim of the project is to investigate how many hens that develop a chronic infection after being acutely infected using an ascending infection model. Furthermore the impact on the egg production will be investigated.
The project will be carried out during 2017 and is funded by "Fjerkræafgiftsfonden" (”Æggelederbughindebetændelses betydning for pro-duktivitet”)
Effect of vaccination against E. coli in layers
The use of commercially available vaccines against respiratory E. coli infections are becoming more and more popular in the prevention of E. coli salpingitis in layers despite very little documentation on the efficacy for this indication of use.
The aim of the project is to investigate the effect of these vaccines in high producing layers using ascending infections.
The project will be carried out during 2017 and is funded by "Fjerkræafgiftsfonden" (”Effekt af Poulvac Vaccination i konsumægs-produktion”)
Effect of vaccination against E. coli in broiler breeders
The use of commercially available vaccines against respiratory E. coli infections together with autogenous vaccines has become a widely used practice in broiler breeders to ensure both a high quality offspring but also to reduce the occurrence of salpingitis in the broiler breeders.
The aim of the project is to optimize the vaccination strategies for broiler parents and broilers. The project will be carried out during 2017 and is funded by "Fjerkræafgiftsfonden" (”Optimeret E. coli vaccination af slagtekyllingeforældre”)
Rising demand for animal products, an increasing global population as well as global competition have increased level and intensification of animal production. This trend comes at a price: production diseases compromise health and welfare, generating inefficiencies which negatively impact on profitability, environmental footprint, and product quality. They may also increase the need to treat the affected animals with antibiotics. Production diseases can be defined as 'Diseases which tend to persist in animal production systems and, typically, become more prevalent or severe, in proportion to the potential productivity of the system'. These disease conditions have a great impact both in the EU and worldwide: compromised health and welfare for the animals themselves, and consequently tremendous financial losses. The PROHEALTH project aims to develop an understanding of the multi-factorial dimension of animal pathologies linked to the intensification of production and to use this new knowledge to develop, evaluate and disseminate effective management and control strategies. Our Group is responsible for most of the poultry aspects of the project, including:
- Investigations of the vertical transmission pattern of E. coli and Enteroccocus faecalis, two major causes of first week mortality within the poultry industry and to determine the optimal egg disinfection strategy to minimize this post hatch mortality an ability to cope with environmental challenges in chickens
- Susceptibility to leg disorders in poultry and pigs will be evaluated, respectively. High-productive broiler breeders selected for different productive traits will be exposed to experimental infections (Gr+ bacteria) using spiked footbaths to investigate whether foot pads serve as entry sites for infections. In addition, observational studies of broiler breeder flocks will investigate the correlation between the prevalence of foot pad dermatitis and egg production, hatchability, first week mortality and broiler performance.
- Physical activity and associated strategies for preserving bone quality. In collaboration with IPH, the nature and validity of the relationship between leg health, automatic measurements of activity of the flock and foot pad dermatitis in broiler chickens will be assessed. The optimal age and level of activity in broiler chickens has recently been determined; the novelty of the project involves determining the optimal strategy for reaching this activity level in a commercial setting, via changes in the lighting environment, and assessing the consequences for the overall leg health and production output. To determine the interactive effects of activity, age and housing conditions on bone quality and resulting welfare issues, bone quality will be compared between different common housing systems for laying hens in the EU (Enriched cages vs non-cage systems), highlighting the link between production, health and welfare in laying hens, and providing an animal based measure to support this link.
For further information please contact Jens Peter Christensen (firstname.lastname@example.org) and on the webpage http://www.fp7-prohealth.eu
Host-pathogen interaction in relation to salpingitis and peritonitis in poultry
Bacterial peritonitis and salpingitis are common infections found in egg-laying hens. The result of such infections are lowered animal welfare and loss of production. The main goal of our research is to investigate how these infections establish in the avian reproductive tract.
Gallibacterium anatis and Escherichia coli
Gallibacterium anatis and Escherichia coli are the main organisms investigated. Both bacteria are opportunistic pathogens and possess a high degree of genetic diversity.
A large part of the work is done by experimental infections of hens. From the infected birds, numerous samples are obtained and broad range of methods are used for analysis. Including evaluation of the lesions at different time points, counts of bacterial cells in tissue, histopathology, in situ hybridization, flow-cytometry and immunohistochemistry.
Pors SE, Olsen RH, Christensen JP. Variations in virulence of avian pathogenic Escherichia coli demonstrated by the use of a new in vivo infection model. Veterinary Microbiology 2014 Jun 4;170(3-4):368-74.
Identification of novel vaccine targets against G. anatis and A. pleuropneumoniae
The aim of our vaccine projects is to develop vaccine prototypes that offer protection in a serotype-independent manner.
G. anatis is an opportunistic pathogen that cause salpingitis and peritonitis in egg-laying chickens. Antimicrobial resistance and high antigenic diversity make prevention and control by traditional treatments ineffective.
Actinobacillus pleuropneumoniae (App) is a gram negative bacteria which infects pigs as its sole host and reservoir, causing severe economic losses to the livestock industry worldwide.
App is a widespread pathogen currently classified in 15 serotypes and 2 biovars, with a geographic serotype prevalence which varies greatly over time. The infection App provokes is a necrotizing bronchopneumoniae with a mortality rate ranging from 20% to 80 %, mainly depending on the serotype involved (Ser 1,5,9,10,11 most virulent). Currently available vaccines either confer a limited protection against just some of the App serotypes or are far too expensive to be adopted as a vast scale prophylaxis procedure.
The approach is based on the concept of reverse vaccinology were bioinformatics tools and immunogenic screening are used to identify novel antigen. Two alternative vaccine strategies are currently used; one based on antigen delivery by adenoviral vectors or by antigen-enriched outer membrane vesicles naturally produced by both pathogens.
Bager, RJ, Kudirkiene, E, da Piedade, I, Seemann, T, Nielsen, TK, Pors, SE, Mattsson, AH, Boyce, JD, Adler, B & Bojesen, AM 2014, 'In silico prediction of Gallibacterium anatis pan-immunogens' Veterinary Research, vol 45, 80., 10.1186/s13567-014-0080-0
Kudirkiene, E, Bager, RJ, Johnson, TJ & Bojesen, AM 2014, 'Chaperone-usher fimbriae in a diverse selection of Gallibacterium genomes' B M C Genomics, vol 15, 1093.,10.1186/1471-2164-15-1093
Bager R.J., Persson G., Nesta B., Soriani M., Serino L., Jeppsson M., Nielsen T.K., Bojesen A.M. (2013): Outer membrane vesicles reflect environmental cues in Gallibacterium anatis. Vet Microbiol.167(3-4):565-72
Bager, R.J., Nesta, B., Pors, S.E., Soriani, M., Serino, L., Boyce, J.D., Adler, B., Bojesen, A.M. (2013): The fimbrial protein FlfA from Gallibacterium anatis is a virulence factor and vaccine candidate. Infect Immun. 81(6):1964-73
Co-evolution of selected Pasteurellaceae species and their hosts
Pasteurellaceae bacteria are opportunistic pathogens that appear to have evolved in close association with a broad range of vertebrate hosts. Extended knowledge about co-evolution of host and parasites will improve the understanding of fundamental evolutionary aspects of bacteria-host association and allow identification of specific mechanisms involved in pathogen evolution, immune evasion and antibiotic resistance.
The main aim of this research is to investigate co-evolution between Pasteurellaceae bacteria and their hosts, and to extend the knowledge on occurrence, diversity and host adaption of Pasteurellaceae bacteria.
We are currently investigating non-domestic host species representing a broader array of the tree of life, especially within the groups of birds, marine mammals, Paenungulata, marsupials and monotremes to further explore co-evolution.
Hansen, M J (2013). Co-evolution of selected Pasteurellaceae species and their hosts. PhD Thesis. SL Grafik: Faculty of Health and Medical Sciences.
Hansen MJ, MF Bertelsen, M Delaney, VA Fravel, F Gulland, AM Bojesen (2013). Otariodibacter oris and Bisgaardia genomospecies 1 isolated from infections in pinnipeds. Journal of Wildlife Diseases. 49 (3), 661-5.
Hansen MJ, MF Bertelsen, H Christensen, M Bisgaard, AM Bojesen (2012). Otariodibacter oris gen. nov., sp. nov., a new member of the family Pasteurellaceae isolated from the oral cavity of pinnipeds. International Journal of Systematic and Evolutionary Microbiology. 62 (11), 2572-2578.
Hansen MJ, MF Bertelsen, H Christensen, M Bisgaard, AM Bojesen (2012). Occurrence of Pasteurellaceae bacteria in the oral cavity of selected marine mammal species. Journal of Zoo and Wildife Medicine. 43, 828-835.
Wojcik J (2012), Animals and bacteria evolve together. ScienceNordic.com. http://sciencenordic.com/animals-and-bacteria-evolve-together
The role of Streptococcus zooepidemicus persister cells during endometritis in the natural equine host
Streptoccocus equi subspecies zooepidemicus (S. zooepidemicus) is an opportunistic pathogen colonizing the mucus membranes of various animal species, yet it has also remained the most frequent cause of endometritis and lowered breading efficacy in mares for decades.
Recently, S. zooepidemicus was found to cause persister-like infections deep within the endometrium of mares despite antimicrobial treatment and a fully functional endometrial immune system.
In this project, we are investigating the formation and regulation of S. zooepidemicus persisters. In general, bacterial persister cells are thought to enter a slow-growing or dormant state, making them tolerant to antibiotic treatment and other environmental stress factors. In this project, we aim to isolate persistent S. zooepidemicus cells in vitro and characterize the mechanisms involved in the formation and re-activation of those persisters. Moreover, we investigate and verify the mechanism of persistence in vivo through experimental inoculation of mares.
The role of Streptococcus zooepidemicus persister cells during endometritis in the natural equine host: Kudirkiene, E, Welker, M, Knudsen, NR & Bojesen, AM 2015, 'Rapid and accurate identification of Streptococcus equi subspecies by MALDI-TOF MS' Systematic and Applied Microbiology., doi: 10.1016/j.syapm.2015.02.010
Petersen, M.R., K. Lu, M. Christoffersen, J. M. Nielsen, M. H. Troedsson, A. M. Bojesen. Impact of activation and subsequent antimicrobial treatment of dormant endometrial streptococci in the Thoroughbred problem mare – a descriptive field study. Proceeding from the annual meeting in The Society for Theriogenology, 7th-10th August. 2013, Louisville, Kentucky, USA.
Da Piedade, I., B. Skive, H. Christensen, A. M. Bojesen. Draft genome sequence for Streptococcus equi subspecies zooepidemicus, strain S31A1 isolated from equine infectious endometritis. Genome Announcements. Genome Announc. 2013, 1(5):e00683-13. doi:10.1128/genomeA.00683-13.
Rasmussen, C. B., M. M. Haugaard, M. R. Petersen, J. M. Nielsen, H. G. Pedersen, A. M. Bojesen. Streptococcus equi subsp. zooepidemicus isolates from equine infectious endometritis belong to a distinct genetic group. Veterinary Research. 2013, 44, 26.
Skive, B., M. R. Petersen, A. M. Bojesen. Real-Time PCR’s anvendelse til diagnostik af endometritis hos hopper. Dansk Veterinær Tidsskrift. 2012, 1, 20-25.
Bisgaard, M., A. M. Bojesen, M. R. Petersen, H. Christensen. A major outbreak of Streptococcus equi subsp. zooepidemicus infections in free-range chickens is linked to horses. Avian Diseases. 2012, 56, 561-566.
Christoffersen, M., E. M. Woodward, A. M. Bojesen, M. R. Petersen, E. L. Squires, H. Lehn-Jensen, M. H. Troedsson. Effect of immunomodulatory therapy on the endometrial inflammatory response to induced infectious endometritis in susceptible mares. Theriogenology. 2012, 78, 991-1004.
Christoffersen, M., E. M. Woodward, A. M. Bojesen, S. Jacobsen, M. R. Petersen, M. Troedsson, H. Lehn-Jensen. Inflammatory responses to infectious endometritis in mares resistant or susceptible to persistent endometritis. BMC Veterinary Research. 2012, 8, 41.
Christoffersen, M., C.D. Baagoe, S. Jacobsen, A.M. Bojesen, M. R. Petersen, H. Lehn-Jensen. Evaluation of the systemic acute phase response and endometrial gene expression of serum amyloid A and pro- and anti-inflammatory cytokines in mares with experimentally induced endometritis. Veterinary Immunology and Immunopathology. 2010, 138, 95-105.
Nielsen, J. M.,W. Zent, M. M. Petersen, A. M. Bojesen, H. Lehn-Jensen, M. Troedsson. Diagnosis of endometritis in the mare based on bacteriological and cytological examinations of the endometrium. Comparison of results obtained by swabs and biopsies. Journal of Equine Veterinary Science. 2010, 30, 27-30.
Petersen, M. R., J. M. Nielsen, H. Lehn-Jensen, A. M. Bojesen. Streptococcus equi subspecies zooepidemicus resides deep in the chronically infected endometrium of mares. Clinical Theriogenology. 2009, 393-409.
|Aagaard, Katrine||Laboratory technician||+45 353-32766|
|Allahghadry, Toloe||Research assistant||+45 353-31168|
|Bertelsen, Mads Frost||Affiliate Professor|
|Bojesen, Anders Miki||Professor||+45 353-32671|
|Buthler, Thomas Frees||Affiliate (guest researcher)|
|Kragelund Strøm, Helene||+45 353-36762|
|Magnowska, Zofia||+45 353-31939|
|Poulsen, Louise Ladefoged||Assistant professor||+45 353-21295|
|Roshanak, Sahar||Visiting PhD fellow|
|Silveira Silva, Rodrigo Otavio||Guest researcher|
|Villumsen, Kasper Rømer||Assistant professor||+45 353-36763|
|Zhu, Zhuang||Enrolled PhD Student||+45 353-32123|