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Luo T, Patel JG, Zhang X, McBride JW. Antibody reactive immunomes of Ehrlichia chaffeensis and E. canis are diverse and defined by conformational antigenic determinants. Front Cell Infect Microbiol 2024; 13:1321291. [PMID: 38264730 PMCID: PMC10803646 DOI: 10.3389/fcimb.2023.1321291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/19/2023] [Indexed: 01/25/2024] Open
Abstract
For decades, the defined antibody reactive proteins of Ehrlichia chaffeensis and E. canis were limited to a small group with linear antibody epitopes. Recently, our laboratory has utilized an immunomics-based approach to rapidly screen and identify undefined Ehrlichia chaffeensis and E. canis antigenic proteins and antibody epitopes. In this study, we analyzed the remaining portion (~50%) of the E. chaffeensis and E. canis proteomes (n = 444 and n = 405 proteins, respectively), that were not examined in previous studies, to define the complete immunomes of these important pathogens. Almost half of the E. chaffeensis proteins screened (196/444) reacted with antibodies in convalescent HME patient sera, while only 43 E. canis proteins reacted with CME dog sera. New major immunoreactive proteins were identified in E. chaffeensis (n = 7) and E. canis (n = 1), increasing the total number of E. chaffeensis (n = 14) and E. canis proteins (n = 18) that exhibited antibody reactivity comparable to well-defined major antigenic proteins (TRP120 and TRP19). All of the E. chaffeensis but only some E. canis major immunoreactive proteins contained major conformation-dependent antibody epitopes. The E. chaffeensis immunoreactive proteins were generally small (< 250 amino acids; ~27kDa) and the E. canis proteins were slightly larger (> 320 amino acids; ~35 kDa). The majority of these new Ehrlichia major immunoreactive proteins were predicted to be type I secreted effectors, some of which contained transmembrane domains. Characterization of the immunomes of E. chaffeensis and E. canis and understanding the host specific Ehrlichia immune responses will facilitate identification of protective antigens and define the biophysical epitope characteristics vital to effective vaccine development for the ehrlichioses.
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Affiliation(s)
- Tian Luo
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jignesh G. Patel
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Xiaofeng Zhang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jere W. McBride
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
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Stoakes E, Turner K, Baker DJ, Suau Sans M, Yasir M, Kalmar L, Costigan R, Lott M, Grant AJ. Application of TraDIS to define the core essential genome of Campylobacter jejuni and Campylobacter coli. BMC Microbiol 2023; 23:97. [PMID: 37024800 PMCID: PMC10077673 DOI: 10.1186/s12866-023-02835-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
Campylobacter species are the major cause of bacterial gastroenteritis. As there is no effective vaccine, combined with the rapid increase in antimicrobial resistant strains, there is a need to identify new targets for intervention. Essential genes are those that are necessary for growth and/or survival, making these attractive targets. In this study, comprehensive transposon mutant libraries were created in six C. jejuni strains, four C. coli strains and one C. lari and C. hyointestinalis strain, allowing for those genes that cannot tolerate a transposon insertion being called as essential. Comparison of essential gene lists using core genome analysis can highlight those genes which are common across multiple strains and/or species. Comparison of C. jejuni and C. coli, the two species that cause the most disease, identified 316 essential genes. Genes of interest highlighted members of the purine pathway being essential for C. jejuni whilst also finding that a functional potassium uptake system is essential. Protein-protein interaction networks using these essential gene lists also highlighted proteins in the purine pathway being major 'hub' proteins which have a large number of interactors across the network. When adding in two more species (C. lari and C. hyointestinalis) the essential gene list reduces to 261. Within these 261 essential genes, there are many genes that have been found to be essential in other bacteria. These include htrB and PEB4, which have previously been found as core virulence genes across Campylobacter species in other studies. There were 21 genes which have no known function with eight of these being associated with the membrane. These surface-associated essential genes may provide attractive targets. The essential gene lists presented will help to prioritise targets for the development of novel therapeutic and preventative interventions.
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Affiliation(s)
- Emily Stoakes
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Keith Turner
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Dave J Baker
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Maria Suau Sans
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Muhammad Yasir
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Lajos Kalmar
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Ruby Costigan
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Martin Lott
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Andrew J Grant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
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Elbehiry A, Abalkhail A, Marzouk E, Elmanssury AE, Almuzaini AM, Alfheeaid H, Alshahrani MT, Huraysh N, Ibrahem M, Alzaben F, Alanazi F, Alzaben M, Anagreyyah SA, Bayameen AM, Draz A, Abu-Okail A. An Overview of the Public Health Challenges in Diagnosing and Controlling Human Foodborne Pathogens. Vaccines (Basel) 2023; 11:vaccines11040725. [PMID: 37112637 PMCID: PMC10143666 DOI: 10.3390/vaccines11040725] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/19/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
Pathogens found in food are believed to be the leading cause of foodborne illnesses; and they are considered a serious problem with global ramifications. During the last few decades, a lot of attention has been paid to determining the microorganisms that cause foodborne illnesses and developing new methods to identify them. Foodborne pathogen identification technologies have evolved rapidly over the last few decades, with the newer technologies focusing on immunoassays, genome-wide approaches, biosensors, and mass spectrometry as the primary methods of identification. Bacteriophages (phages), probiotics and prebiotics were known to have the ability to combat bacterial diseases since the turn of the 20th century. A primary focus of phage use was the development of medical therapies; however, its use quickly expanded to other applications in biotechnology and industry. A similar argument can be made with regards to the food safety industry, as diseases directly endanger the health of customers. Recently, a lot of attention has been paid to bacteriophages, probiotics and prebiotics most likely due to the exhaustion of traditional antibiotics. Reviewing a variety of current quick identification techniques is the purpose of this study. Using these techniques, we are able to quickly identify foodborne pathogenic bacteria, which forms the basis for future research advances. A review of recent studies on the use of phages, probiotics and prebiotics as a means of combating significant foodborne diseases is also presented. Furthermore, we discussed the advantages of using phages as well as the challenges they face, especially given their prevalent application in food safety.
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Affiliation(s)
- Ayman Elbehiry
- Department of Public Health, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah 52741, Saudi Arabia (E.M.)
- Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City 32511, Egypt
- Correspondence:
| | - Adil Abalkhail
- Department of Public Health, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah 52741, Saudi Arabia (E.M.)
| | - Eman Marzouk
- Department of Public Health, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah 52741, Saudi Arabia (E.M.)
| | - Ahmed Elnadif Elmanssury
- Department of Public Health, College of Public Health and Health Informatics, Qassim University, Al Bukayriyah 52741, Saudi Arabia (E.M.)
| | - Abdulaziz M. Almuzaini
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah 52571, Saudi Arabia
| | - Hani Alfheeaid
- Department of Food Science and Human Nutrition, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah 51452, Saudi Arabia
- Human Nutrition, School of Medicine, Nursing and Dentistry, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G31 2ER, UK
| | - Mohammed T. Alshahrani
- Department of Neurology, Prince Sultan Military Medical City, Riyadh 12233, Saudi Arabia
| | - Nasser Huraysh
- Department of Family Medicine, King Fahad Armed Hospital, Jeddah 23311, Saudi Arabia
| | - Mai Ibrahem
- Department of Public Health, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia;
- Department of Aquatic Animal Medicine and Management, Faculty of Veterinary Medicine, Cairo University, Cairo 12211, Egypt
| | - Feras Alzaben
- Department of Food Service, King Fahad Armed Hospital, Jeddah 23311, Saudi Arabia
| | - Farhan Alanazi
- Supply Administration, Armed Forces Hospital, King Abdul Aziz Naval Base in Jubail, Jubail 35517, Saudi Arabia
| | - Mohammed Alzaben
- Department of Food Factories Inspection, Operation Sector, Saudi Food and Drug Authority, Riyadh 13513, Saudi Arabia
| | | | | | - Abdelmaged Draz
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah 52571, Saudi Arabia
| | - Akram Abu-Okail
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah 52571, Saudi Arabia
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Zubair M, Wang J, Yu Y, Faisal M, Qi M, Shah AU, Feng Z, Shao G, Wang Y, Xiong Q. Proteomics approaches: A review regarding an importance of proteome analyses in understanding the pathogens and diseases. Front Vet Sci 2022; 9:1079359. [PMID: 36601329 PMCID: PMC9806867 DOI: 10.3389/fvets.2022.1079359] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Proteomics is playing an increasingly important role in identifying pathogens, emerging and re-emerging infectious agents, understanding pathogenesis, and diagnosis of diseases. Recently, more advanced and sophisticated proteomics technologies have transformed disease diagnostics and vaccines development. The detection of pathogens is made possible by more accurate and time-constrained technologies, resulting in an early diagnosis. More detailed and comprehensive information regarding the proteome of any noxious agent is made possible by combining mass spectrometry with various gel-based or short-gun proteomics approaches recently. MALDI-ToF has been proved quite useful in identifying and distinguishing bacterial pathogens. Other quantitative approaches are doing their best to investigate bacterial virulent factors, diagnostic markers and vaccine candidates. Proteomics is also helping in the identification of secreted proteins and their virulence-related functions. This review aims to highlight the role of cutting-edge proteomics approaches in better understanding the functional genomics of pathogens. This also underlines the limitations of proteomics in bacterial secretome research.
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Affiliation(s)
- Muhammad Zubair
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Jia Wang
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yanfei Yu
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China,School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China,College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Muhammad Faisal
- Division of Hematology, Department of Medicine, The Ohio State University College of Medicine, The Ohio State University Comprehensive Cancer Center, Columbus, OH, United States
| | - Mingpu Qi
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Abid Ullah Shah
- National Research Centre of Engineering and Technology for Veterinary Biologicals, Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Zhixin Feng
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Guoqing Shao
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China,School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Yu Wang
- China Pharmaceutical University, Nanjing, China,*Correspondence: Yu Wang
| | - Qiyan Xiong
- Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China,College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China,School of Life Sciences, Jiangsu University, Zhenjiang, China,Qiyan Xiong
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5
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Liu S, Zhao K, Huang M, Zeng M, Deng Y, Li S, Chen H, Li W, Chen Z. Research progress on detection techniques for point-of-care testing of foodborne pathogens. Front Bioeng Biotechnol 2022; 10:958134. [PMID: 36003541 PMCID: PMC9393618 DOI: 10.3389/fbioe.2022.958134] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/30/2022] [Indexed: 11/21/2022] Open
Abstract
The global burden of foodborne disease is enormous and foodborne pathogens are the leading cause of human illnesses. The detection of foodborne pathogenic bacteria has become a research hotspot in recent years. Rapid detection methods based on immunoassay, molecular biology, microfluidic chip, metabolism, biosensor, and mass spectrometry have developed rapidly and become the main methods for the detection of foodborne pathogens. This study reviewed a variety of rapid detection methods in recent years. The research advances are introduced based on the above technical methods for the rapid detection of foodborne pathogenic bacteria. The study also discusses the limitations of existing methods and their advantages and future development direction, to form an overall understanding of the detection methods, and for point-of-care testing (POCT) applications to accurately and rapidly diagnose and control diseases.
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Affiliation(s)
- Sha Liu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Kaixuan Zhao
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Meiyuan Huang
- Zhuzhou Hospital Affiliated to Xiangya School of Medicine, Department of Pathology, Central South University, Zhuzhou, China
| | - Meimei Zeng
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Yan Deng
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Song Li
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Hui Chen
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
| | - Wen Li
- College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha, China
| | - Zhu Chen
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou, China
- *Correspondence: Zhu Chen,
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Lou H, Li X, Sheng X, Fang S, Wan S, Sun A, Chen H. Development of a Trivalent Construct Omp18/AhpC/FlgH Multi Epitope Peptide Vaccine Against Campylobacter jejuni. Front Microbiol 2022; 12:773697. [PMID: 35095793 PMCID: PMC8793626 DOI: 10.3389/fmicb.2021.773697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/29/2021] [Indexed: 11/25/2022] Open
Abstract
Campylobacter jejuni (C. jejuni) is one of the major pathogens contributing to the enteritis in humans. Infection can lead to numerous complications, including but not limited to Guillain-Barre syndrome, reactive arthritis, and Reiter’s syndrome. Over the past two decades, joint efforts have been made toward developing a proper strategy of limiting the transmission of C. jejuni to humans. Nevertheless, except for biosecurity measures, no available vaccine has been developed so far. Judging from the research findings, Omp18, AhpC outer membrane protein, and FlgH flagellin subunits of C. jejuni could be adopted as surface protein antigens of C. jejuni for screening dominant epitope thanks to their strong antigenicity, expression of varying strains, and conservative sequence. In this study, bioinformatics technology was adopted to analyze the T-B antigenic epitopes of Omp18, AhpC, and FlgH in C. jejuni strain NCTC11168. Both ELISA and Western Blot methods were adopted to screen the dominant T-B combined epitope. GGS (GGCGGTAGC) sequence was adopted to connect the dominant T-B combined epitope peptides and to construct the prokaryotic expression system of tandem repeats of antigenic epitope peptides. The mouse infection model was adopted to assess the immunoprotective effect imposed by the trivalent T-B combined with antigen epitope peptide based on Omp18/AhpC/FlgH. In this study, a tandem epitope AhpC-2/Omp18-1/FlgH-1 was developed, which was composed of three epitopes and could effectively enhance the stability and antigenicity of the epitope while preserving its structure. The immunization of BALB/c mice with a tandem epitope could induce protective immunity accompanied by the generation of IgG2a antibody response through the in vitro synthesis of IFN-γ cytokines. Judging from the results of immune protection experiments, the colonization of C. jejuni declined to a significant extent, and it was expected that AhpC-2/Omp18-1/FlgH-1 could be adopted as a candidate antigen for genetic engineering vaccine of C. jejuni MAP.
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Affiliation(s)
- Hongqiang Lou
- Medical Molecular Biology Laboratory, School of Medicine, Jinhua Polytechnic, Jinhua, China
| | - Xusheng Li
- Medical Molecular Biology Laboratory, School of Medicine, Jinhua Polytechnic, Jinhua, China
| | - Xiusheng Sheng
- Medical Molecular Biology Laboratory, School of Medicine, Jinhua Polytechnic, Jinhua, China
| | - Shuiqin Fang
- Shanghai Prajna Biotech Co., Ltd., Shanghai, China
| | - Shaoye Wan
- Shanghai Prajna Biotech Co., Ltd., Shanghai, China
| | - Aihua Sun
- Department of Pathogen Biology and Immunology, School of Basic Medicine and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Haohao Chen
- Medical Molecular Biology Laboratory, School of Medicine, Jinhua Polytechnic, Jinhua, China
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Keddy KH, Saha S, Okeke IN, Kalule JB, Qamar FN, Kariuki S. Combating Childhood Infections in LMICs: evaluating the contribution of Big Data Big data, biomarkers and proteomics: informing childhood diarrhoeal disease management in Low- and Middle-Income Countries. EBioMedicine 2021; 73:103668. [PMID: 34742129 PMCID: PMC8579132 DOI: 10.1016/j.ebiom.2021.103668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 09/26/2021] [Accepted: 10/20/2021] [Indexed: 01/20/2023] Open
Abstract
Despite efforts to reduce the global burden of childhood diarrhoea, 50% of all cases globally occur in children under five years in Low–Income and Middle- Income Countries (LMICs) and knowledge gaps remain regarding the aetiological diagnosis, introduction of diarrhoeal vaccines, and the role of environmental enteric dysfunction and severe acute malnutrition. Biomarkers may assist in understanding disease processes, from diagnostics, to management of childhood diarrhoea and the sequelae to vaccine development. Proteomics has the potential to assist in the identification of new biomarkers to understand the processes in the development of childhood diarrhoea and to aid in developing new vaccines. Centralised repositories that enable mining of large data sets to better characterise risk factors, the proteome of both the patient and the different diarrhoeal pathogens, and the environment, could inform patient management and vaccine development, providing a systems biological approach to address the burden of childhood diarrhoea in LMICs.
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Affiliation(s)
- Karen H Keddy
- Tuberculosis Platform, South African Medical Research Council, 1 Soutpansberg Rd, Pretoria, 0001, South Africa.
| | - Senjuti Saha
- Child Health Research Foundation, 23/2 Khilji Road, Mohammadpur, Dhaka 1207, Bangladesh
| | - Iruka N Okeke
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Oyo State, Nigeria
| | - John Bosco Kalule
- Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Uganda
| | - Farah Naz Qamar
- Department of Pediatrics and Child Health. Aga Khan University, Stadoum road Karachi, Pakistan 74800
| | - Samuel Kariuki
- Centre for Microbiology Research, Kenya Medical Research Institute, Off Mbagathi Road, Nairobi, Kenya
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Immunoreactive Protein Repertoires of Ehrlichia chaffeensis and E. canis Reveal the Dominance of Hypothetical Proteins and Conformation-dependent Antibody Epitopes. Infect Immun 2021; 89:e0022421. [PMID: 34370510 DOI: 10.1128/iai.00224-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immunomes of Ehrlichia chaffeensis (E. ch.) and E. canis (E. ca.) have recently be revised to include immunodominant hypothetical proteins with conformational antibody epitopes. In this study, we examined 216 E. ch. and 190 E. ca. highly antigenic proteins according to ANTIGENpro and also performed a genome-wide hypothetical protein analysis (E. ch. n=104; E. ca. n=124) for immunoreactivity. Using cell-free protein expression and immunoanalysis, 118 E. ch. and 39 E. ca. proteins reacted with sera from naturally E. ch.-infected patients or E. ca.-infected dogs. Moreover, 22 E. ch. and 18 E. ca. proteins consistently and strongly reacted with a panel of patient or canine sera. A subset of E. ch. (n=18) and E. ca. (n=9) proteins were identified as immunodominant. Consistent with our previous study, most proteins were classified as hypothetical and the antibody epitopes exhibited complete or partial conformation-dependence. The majority (28/40; 70%) of E. ch. and E. ca. proteins contained transmembrane domains and 19 (48%) were predicted to be secreted effectors. The antigenic repertoires of E. ch. and E. ca. were mostly diverse and suggest that the immunomes of these closely related ehrlichiae are dominated by species-specific conformational antibody epitopes. This study reveals a significant group of previously undefined E. ch. and E. ca. antigens and reaffirms the importance of conformation-dependent epitopes as targets of anti-Ehrlichia immune responses. These findings substantially expand our understanding of host-Ehrlichia immune responses, advance efforts to define the molecular features of protective proteins and improve prospects for effective vaccines for the ehrlichioses.
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Ehrlichia chaffeensis and E. canis hypothetical protein immunoanalysis reveals small secreted immunodominant proteins and conformation-dependent antibody epitopes. NPJ Vaccines 2020; 5:85. [PMID: 32963815 PMCID: PMC7486380 DOI: 10.1038/s41541-020-00231-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/12/2020] [Indexed: 01/05/2023] Open
Abstract
Immunomolecular characterization of Ehrlichia chaffeensis (E. ch.) and E. canis (E. ca.) has defined protein orthologs, including tandem repeat proteins (TRPs) that have immunodominant linear antibody epitopes. In this study, we combined bioinformatic analysis and cell-free protein expression to identify undiscovered immunoreactive E. ch. and E. ca. hypothetical proteins. Antigenicity of the E. ch. and E. ca. ORFeomes (n = 1105 and n = 925, respectively) was analyzed by the sequence-based prediction model ANTIGENpro, and we identified ~250 ORFs in each respective ORFeome as highly antigenic. The hypothetical proteins (E. ch. n = 93 and E. ca. n = 98) present in the top 250 antigenic ORFs were further investigated in this study. By ELISA, 46 E. ch. and 30 E. ca. IVTT-expressed hypothetical proteins reacted with antibodies in sera from naturally E. ch.-infected patients or E. ca.-infected dogs. Moreover, 15 E. ch. and 16 E. ca. proteins consistently reacted with a panel of sera from patients or dogs, including many that revealed the immunoreactivity of “gold standard” TRPs. Antibody epitopes in most (>70%) of these proteins exhibited partial or complete conformation-dependence. The majority (23/31; 74%) of the major immunoreactive proteins identified were small (≤250 aa), and 20/31 (65%) were predicted to be secreted effectors. Unlike the strong linear antibody epitopes previously identified in TRP and OMP orthologs, there were contrasting differences in the E. ch. and E. ca. antigenic repertoires, epitopes and ortholog immunoreactivity. This study reveals numerous previously undefined immunodominant and subdominant antigens, and illustrates the breadth, complexity, and diversity of immunoreactive proteins/epitopes in Ehrlichia.
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Koutsoumanis K, Allende A, Alvarez‐Ordóñez A, Bolton D, Bover‐Cid S, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Alter T, Crotta M, Ellis‐Iversen J, Hempen M, Messens W, Chemaly M. Update and review of control options for Campylobacter in broilers at primary production. EFSA J 2020; 18:e06090. [PMID: 32874298 PMCID: PMC7448041 DOI: 10.2903/j.efsa.2020.6090] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The 2011 EFSA opinion on Campylobacter was updated using more recent scientific data. The relative risk reduction in EU human campylobacteriosis attributable to broiler meat was estimated for on-farm control options using Population Attributable Fractions (PAF) for interventions that reduce Campylobacter flock prevalence, updating the modelling approach for interventions that reduce caecal concentrations and reviewing scientific literature. According to the PAF analyses calculated for six control options, the mean relative risk reductions that could be achieved by adoption of each of these six control options individually are estimated to be substantial but the width of the confidence intervals of all control options indicates a high degree of uncertainty in the specific risk reduction potentials. The updated model resulted in lower estimates of impact than the model used in the previous opinion. A 3-log10 reduction in broiler caecal concentrations was estimated to reduce the relative EU risk of human campylobacteriosis attributable to broiler meat by 58% compared to an estimate larger than 90% in the previous opinion. Expert Knowledge Elicitation was used to rank control options, for weighting and integrating different evidence streams and assess uncertainties. Medians of the relative risk reductions of selected control options had largely overlapping probability intervals, so the rank order was uncertain: vaccination 27% (90% probability interval (PI) 4-74%); feed and water additives 24% (90% PI 4-60%); discontinued thinning 18% (90% PI 5-65%); employing few and well-trained staff 16% (90% PI 5-45%); avoiding drinkers that allow standing water 15% (90% PI 4-53%); addition of disinfectants to drinking water 14% (90% PI 3-36%); hygienic anterooms 12% (90% PI 3-50%); designated tools per broiler house 7% (90% PI 1-18%). It is not possible to quantify the effects of combined control activities because the evidence-derived estimates are inter-dependent and there is a high level of uncertainty associated with each.
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