A multivalent vaccine and single platform diagnostic for bacterial respiratory diseases of pigs

Lead Research Organisation: University of Cambridge
Department Name: Veterinary Medicine

Abstract

Pigs can get many diseases but amongst the most serious are those caused by bacteria that can live in their throats, airways or tonsils but can also cause severe lung (or brain) infections. Large numbers of animals may die quickly (acute infection) or fail to grow normally (chronic infection). Such infections cost the world's pig industry huge sums of money each year. A major problem is that such infections are difficult to diagnose. Some strains of a particular bacterium cause disease and others do not and there is no reliable method to distinguish them. Most experts agree that the best way to control the spread of bacteria is to use a vaccine. However, current vaccines are poor. They do not prevent the spread of bacteria from animal to animal and only work against a few strains. We plan to target four of the most common bacteria that cause infections in pigs: Actinobacillus pleuropneumoniae, Haemophilus parasuis, Mycoplasma hyopneumoniae and Streptococcus suis. The last of these can also cause serious disease in humans such as blood poisoning (septicaemia) and brain infection (meningitis) especially in people who work with pigs. Our aim is to develop (1) tests that can tell which strains can cause disease or not and (2) a single vaccine that protects against more than one of the pig pathogens. We will isolate bacteria from UK pigs and, using genetic techniques, find out how many different sorts of each bacterium are present. The results will be used to develop a diagnostic test and also help in choosing appropriate vaccine candidates. The work will be done in collaboration with partners in the Veterinary Laboratories Agency, Scottish Agricultural College, Agri-Food and Biosciences Institute and Huazhong Agricultural University (Wuhan, China). A successful conclusion to the project (diagnostics and vaccines) will prevent animal suffering (through reduction in infections via vaccination, early diagnosis and treatment, prevention of unnecessary treatment) and save the pig industry substantial amounts of money contributing to the prosperity of the UK.

Technical Summary

The worldwide economic/welfare burden resulting from bacterial respiratory diseases of pigs is enormous. Control of infection is hampered by the lack of efficacious vaccines and diagnostic tools. Problems include differentiating low/non-virulent/pathogenic strains and the incomplete correlation of phenotype to pathogenic potential. Traditional vaccines (bacterins) typically only protect against homologous strains and do not prevent colonisation. This research program concerns 4 major bacterial respiratory pathogens of pigs: A. pleuropneumoniae, H. parasuis, M. hyopneumoniae and S. suis. All cause substantial mortality and morbidity in pigs worldwide. Additionally S. suis causes severe outbreaks of human infection. There is an international imperative for improved diagnostics and vaccines for all these pathogens. Now is the opportunity to exploit genome data and technical innovations, many of which have been pioneered by the applicants. A multi-centre integrated approach will be used to develop a multivalent vaccine and single platform diagnostic for the 4 bacteria. The largest known collection of disease/non-disease associated UK isolates will be assembled and subjected to MLST and comparative phylogenetics (genomotyping). The data will be used to develop a genotypic based diagnostic. Genetic tools will be developed that allow mutagenesis and/or heterologous antigen expression. Functional genomic screens and follow up studies will identify live attenuated vaccine (LAVs) candidates and conserved immunogenic proteins. The latter will be used as the basis for protein array-based diagnostics and be heterologously expressed either in LAVs or vaccines based on protein glycan coupling technology. The multivalent vaccine and single platform diagnostics will be evaluated in experimental and field trials in collaboration with UK /Chinese veterinarians. The major deliverable will be to reduce animal suffering and the economic and welfare burden of disease in the pig industry.

Publications


10 25 50
 
Description This work has produced vastly improved diagnostic methods for detecting important respiratory pathogens, such as Streptococcus suis and Haemophilus parasuis in pigs, by understanding the genome (complete DNA) sequences of a large collection of bacteria isolated over a period of time from the UK, Vietnam and several other countries. We have also shown which genes are required for these bacteria to colonize pig tissue from the upper respiratory tract (nasal tissue and trachea).
Exploitation Route Development of diagnostics and vaccines.
Sectors Agriculture, Food and Drink,Healthcare,Pharmaceuticals and Medical Biotechnology
 
Description Our findings have been or are about to be published in scientific journals. Some of our findings will be patented and possibly taken further by our industrial collaborator, Zoetis. Our diagnostic outputs may be used by commercial companies.
First Year Of Impact 2013
Sector Other
Impact Types Economic
 
Description Characterisation of the putative virulence factors of S. suis
Amount £100,000 (GBP)
Organisation Cambridge Commonwealth Trust 
Sector Charity/Non Profit
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 01/2010 
End 01/2013
 
Description Models of mixed respiratory infections in pigs - functional genomics, vaccines and diagnostic development
Amount £23,500 (GBP)
Funding ID BB/J020664/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 03/2012 
End 02/2014
 
Description Molecular tools for detection and control of Streptococcus suis.
Amount £160,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 10/2013 
End 10/2017
 
Description New approaches to diagnosis and management of H. parasuis related disease
Amount £63,000 (GBP)
Organisation British Pig Executive BPEX 
Sector Charity/Non Profit
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 10/2011 
End 09/2014
 
Description New approaches to diagnosis and management of H. parasuis related disease
Amount £63,000 (GBP)
Organisation British Pig Executive BPEX 
Sector Charity/Non Profit
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 10/2011 
End 10/2014
 
Description Project funded under China-UK cooperation program in global priorities.
Amount £196,363 (GBP)
Funding ID BB/L003902/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 04/2013 
End 04/2015
 
Description Streptococcus suis subunit vaccine protection study
Amount £130,000 (GBP)
Organisation Zoetis 
Sector Private
Country United States of America
Start 12/2015 
End 11/2016
 
Title Development of a Multiplex PCR Assay for Molecular Serotyping of Haemophilus parasuis. 
Description A multiplex PCR system which is based on variation within the capsule loci of the 15 serovars of H. parasuis for rapid molecular serotyping. The multiplex PCR (mPCR) distinguishes between all previously described serovars except 5 and 12, both of which can be detected by one pair of primers. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact This is an improvement on currently available serotyping methods. 
URL http://www.ncbi.nlm.nih.gov/pubmed/26424843
 
Title Multiplex PCR assay for unequivocal differentiation of Actinobacillus pleuropneumoniae serovars 1 to 3, 5 to 8, 10, and 12. 
Description An improved multiplex PCR, using redesigned primers targeting the serovar 3 capsule locus, which differentiates serovars 3, 6, and 8 Actinobacillus pleuropneumoniae isolates. The new primers eliminate an aberrant serovar 3-indicative amplicon found in some serovar 6 clinical isolates. Furthermore, we have developed a new multiplex PCR for the detection of serovars 1 to 3, 5 to 8, 10, and 12 along with apxIV, thus extending the utility of this diagnostic PCR to cover a broader range of isolates. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact This is an improvement on currently available diagnostic techniques for APP. 
URL http://www.ncbi.nlm.nih.gov/pubmed/24759717
 
Title Tn5 Transposon library of the pig respiratory pathogen, Haemophilus parasuis 
Description A Tn5 transposon library of Haemophilus parasuis which has been analyzed by TraDIS to identify the transposon integration sites. this can be used for screening pools of mutants in a selective system to investigate gene function. 
Type Of Material Biological samples 
Year Produced 2014 
Provided To Others? Yes  
Impact Identification of live attenuated vaccine strains. 
URL http://www.ncbi.nlm.nih.gov/pubmed/23928120
 
Title Tn917 Transposon library of the pig respiratory pathogen, Streptococcus suis 
Description A Tn917 transposon library of Streptococcus suis which has been analyzed by TraDIS to identify the transposon integration sites and which has been used to infect an in vitro organ culture model of porcine respiratory tissue. The transposon libary can be used for screening pools of mutants in a selective system to investigate gene function. 
Type Of Material Biological samples 
Year Produced 2014 
Provided To Others? Yes  
Impact Identification of genes encoding proteins likely to be required for colonization of the pig upper respiratory tract. The proteins are being investigated to assess their efficacy as vaccines against infection with S. suis. 
 
Title Meta-data of clinical details of pigs submitted for post-mortem in England and Wales 2011-2015 
Description Clinical details of pigs submitted for post-mortem in England and Wales 2011-2015. Stains of Streptococcus suis, Haemophilus parasuis and Actinobacillus pleuropneumoniae were isolated and genome sequenced. Genome sequence data was analyzed to gain an understanding of pathogenicity of the organisms. 
Type Of Material Database/Collection of data 
Year Produced 2015 
Provided To Others? Yes  
Impact An understanding of the difference between bacteria which cause disease and those that are carried asymptomatically. 
 
Title Streptococcus suis TraDIS data from in vitro organ culture experiments 
Description This database can be analyzed to identify transposon mutants screened in pools which are relatively less fit than others and hence may be attenuated in fitness or ability to colonize respiratory tissue in organ culture. 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact An understanding of the difference between bacteria which cause disease and those that are attenuated and have potential to be used as live-attenuated vaccines or that are missing a key component of their cell surface which renders them unable to colonize, invade and cause disease. 
 
Description Centre de Recerca en Sanitat Animal (CReSA) Collaboration 
Organisation Cresa
Country United States of America 
Sector Private 
PI Contribution New collaboration regarding Haemophilus parasuis
Start Year 2011
 
Description Clinical Research Unit - Ho Chi Minh 
Organisation Hospital for Tropical Diseases HCM
Department Oxford University Clinical Research Unit in Viet Nam (OUCRU)
Country Vietnam, Socialist Republic of 
Sector Academic/University 
PI Contribution Work on Strep. suis
Start Year 2011
 
Description Danish Technical University 
Organisation Technical University of Denmark
Country Denmark, Kingdom of 
Sector Academic/University 
PI Contribution Collaboration on Haemophilus parasuis
Start Year 2011
 
Description In vivo studies of candidate vaccines against bacterial respiratory pathogens of pigs 
Organisation USDA Agricultural Research Service, National Animal Diseases Center
Country United States of America 
Sector Public 
PI Contribution A collaboration with USDA ARS in Ames, Iowa, USA enabling sharing of facilities and expertise for the preliminary evaluation of candidate vaccines using animal challenge models already established at USDA.
Start Year 2013
 
Description Ceva Animal Health Symposium on A. pleuropneumoniae 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Sparked discussion on the topic of diagnostic approaches for A. pleuropneumoniae

None specific
Year(s) Of Engagement Activity 2014
 
Description European Symposium on Pig Health Management 2013 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact This was an invited lecture to discuss the interaction between bacterial pathogens (Strep suis) environment and host susceptibility. Sparked questions and further invitations to speak at subsequent international meetings.

None specific
Year(s) Of Engagement Activity 2013
 
Description European Symposium on Pig Health Management 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We presented data on diagnostic approaches for Streptococcus suis and antimicrobial susceptibility data.
Year(s) Of Engagement Activity 2015
 
Description IPVS 2012, Korea 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Questions and discussion followed.

discussions on potential collaborations.
Year(s) Of Engagement Activity 2012
 
Description International Pig Veterinary Society 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Outcomes of the project will be presented in oral and poster presentations, confirmed as accepted for publication: including antibiotic susceptibility; prevalence and diversity of Strep suis carriage in UK and China and the impact of temperature.
Year(s) Of Engagement Activity 2016
 
Description Norfolk, Suffolk, Essex, Cambs Pig Discussion Groups 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presentation to vet practitioners on best practices for diagnosis, treatment and prevention of S. suis disease in laughter pig production systems.

Follow-up phone discussions, changes in vaccination strategies, and herd management methods.
Year(s) Of Engagement Activity 2014
 
Description Nottingham University Seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact A seminar on natural history of Streptococcus suis in the pig meat supply chain was given at Nottingham University The audience comprise academics and also members of policy making committees in government. There was active discussion and a subsequent meeting to plan future research collaborations.
Year(s) Of Engagement Activity 2015
 
Description PIC China Symposium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The PI (Tucker) gave a presentation at the PIC China Symposium on the management and prevention of infectious diseases of pigs, including Streptococcus suis.
Year(s) Of Engagement Activity 2015
URL http://www.wattagnet.com/articles/24751-pic-chinas-2015-symposium-highlights-value-components
 
Description Polish Swine Conference 2013 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Questions and discussion on the topic of management of pig respiratory health.

Follow-up discussions with Professor Pesjak, Head of Pulawy Inst.
Year(s) Of Engagement Activity 2013
 
Description Scottish pig producer group 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Talk stimulated reflection of effectiveness of respiratory disease control in group members' pig production units.

Further phone discussions.
Triggered change in diagnostics and vaccination programme.
Year(s) Of Engagement Activity 2014
 
Description Streptococcus suis Workshop 2016: The dynamics of Streptococcus suis carriage in recently weaned and slaughter-aged pigs in China and UK 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The workshop was attended by around 80 global specialist researchers, medics and veterinarians with interest in Streptococcus suis associated disease management.
Year(s) Of Engagement Activity 2016
 
Description UK Pig Vet Soc 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk sparked questions and discussion

Interest expressed in new diagnostic methodologies arising from our work.
Year(s) Of Engagement Activity 2014
 
Description Update on Streptococcus suis: epidemiology, diagnosis and control 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Research updates were provided to members of the UK Animal and Plant Health Agency's Pig Expert Group. Specifically progress on new vaccine development, diagnostic approaches and non-antimicrobial control strategies.
Year(s) Of Engagement Activity 2016
 
Description Vet Public Health Assoc conference 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lecture sparked questions and discussion.

Nothing major.
Year(s) Of Engagement Activity 2014
 
Description Wuhan Pig Veterinary Congress, 2013 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk sparked questions and discussion on diagnosis and management of Streptococcal diseases in pigs.

None specific
Year(s) Of Engagement Activity 2013