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Ou B, Jiang B, Jin D, Yang Y, Zhang M, Zhang D, Zhao H, Xu M, Song H, Wu W, Chen M, Lu T, Huang J, Seo H, Garcia C, Zheng W, Guo W, Lu Y, Jiang Y, Yang S, Kaushik RS, Li X, Zhang W, Zhu G. Engineered Recombinant Escherichia coli Probiotic Strains Integrated with F4 and F18 Fimbriae Cluster Genes in the Chromosome and Their Assessment of Immunogenic Efficacy in Vivo. ACS Synth Biol 2020; 9:412-426. [PMID: 31944664 DOI: 10.1021/acssynbio.9b00430] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
F4 (K88) and F18 fimbriaed enterotoxigenic Escherichia coli (ETEC) are the predominant causes of porcine postweaning diarrhea (PWD), and vaccines are considered the most effective preventive approach against PWD. Since heterologous DNA integrated into bacterial chromosomes could be effectively expressed with stable inheritance, we chose probiotic EcNc (E. coli Nissle 1917 prototype cured of cryptic plasmids) as a delivery vector to express the heterologous F4 or both F4 and F18 fimbriae and sequentially assessed their immune efficacy of anti-F4 and F18 fimbriae in both murine and piglet models. Employing the CRISPR-cas9 technology, yjcS, pcadA, lacZ, yieN/trkD, maeB, and nth/tppB sites in the chromosome of an EcNc strain were targeted as integration sites to integrate F4 or F18 fimbriae cluster genes under the Ptet promotor to construct two recombinant integration probiotic strains (RIPSs), i.e., nth integration strain (EcNcΔnth/tppB::PtetF4) and multiple integration strain (EcNc::PtetF18x4::PtetF4x2). Expression of F4, both F4 and F18 fimbriae on the surfaces of two RIPSs, was verified with combined methods of agglutination assay, Western blot, and immunofluorescence microscopy. The recombinant strains have improved adherence to porcine intestinal epithelial cell lines. Mice and piglets immunized with the nth integration strain and multiple integration strain through gavage developed anti-F4 and both anti-F4 and anti-F18 IgG immune responses. Moreover, the serum antibodies from the immunized mice and piglets significantly inhibited the adherence of F4+ or both F4+ and F18+ ETEC wild-type strains to porcine intestinal cell lines in vitro, indicating the potential of RIPSs as promising probiotic strains plus vaccine candidates against F4+/F18+ ETEC infection.
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Affiliation(s)
- Bingming Ou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- College of Life Science, Zhaoqing University, Zhaoqing 526061, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Boyu Jiang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Duo Jin
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Ying Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Minyu Zhang
- College of Life Science, Zhaoqing University, Zhaoqing 526061, China
| | - Dong Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Haizhou Zhao
- College of Life Science, Zhaoqing University, Zhaoqing 526061, China
| | - Mengxian Xu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Haoliang Song
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Wenwen Wu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Mingliang Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
| | - Ti Lu
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Jiachen Huang
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Hyesuk Seo
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
- Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61802, United States
| | - Carolina Garcia
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Wanglong Zheng
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Weiyi Guo
- College of Life Science, Zhaoqing University, Zhaoqing 526061, China
| | - Yinhua Lu
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yu Jiang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Radhey S. Kaushik
- Biology and Microbiology Department, South Dakota State University, Brookings, South Dakota 57007, United States
| | - Xinchang Li
- College of Life Science, Zhaoqing University, Zhaoqing 526061, China
| | - Weiping Zhang
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
- Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61802, United States
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou 225009, China
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Lu T, Seo H, Moxley RA, Zhang W. Mapping the neutralizing epitopes of F18 fimbrial adhesin subunit FedF of enterotoxigenic Escherichia coli (ETEC). Vet Microbiol 2019; 230:171-177. [PMID: 30827385 PMCID: PMC7173344 DOI: 10.1016/j.vetmic.2019.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/05/2019] [Indexed: 11/27/2022]
Abstract
K88 and F18 fimbrial enterotoxigenic Escherichia coli (ETEC) are the major causes of post-weaning diarrhea (PWD) in pigs. A vaccine that induces broad immunity to prevent K88 and F18 fimbrial ETEC bacterial attachment and colonization in pig small intestines and to neutralize enterotoxin enterotoxicity would be effective for PWD. Structure-based multiepitope-fusion-antigen (MEFA) technology using a backbone immunogen to present neutralizing epitopes of representing virulence factors capacitates development of broadly protective ETEC vaccines. Neutralizing epitopes have been identified from K88 fimbrial adhesin (FaeG) and enterotoxins but not F18 fimbrial adhesin. In this study, we in silico identified immunodominant epitopes from F18ac fimbrial subunit FedF which plays a critical role in F18 fimbrial adherence, genetically fused each epitope to a carrier, examined immunogenicity of each epitope fusion, and determined epitope-derived antibodies neutralizing activities against F18 fimbrial adherence. Data showed that seven immune-dominant epitopes were identified from FedF subunit. Fused to heterologous human ETEC adhesin subunit CfaB, epitope fusions induced anti-F18 antibodies in subcutaneously immunized mice. Moreover, antibodies derived from each fusion significantly blocked adherence of a F18-fimbrial E. coli bacteria to pig intestinal cell line IPEC-J2. While all seven epitopes exhibited neutralizing activity, results from this study identified FedF epitopes #3 (IPSSSGTLTCQAGT) and #7 (QPDATGSWYD) the most effective for antibodies against F18 fimbrial adherence, and suggested their future application in PWD vaccine development.
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Affiliation(s)
- Ti Lu
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
| | - Hyesuk Seo
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
| | - Rodney A Moxley
- Department of Veterinary Basic Sciences, University of Nebraska-Lincoln, School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE, USA
| | - Weiping Zhang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA.
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Won G, John Hwa L. Potent immune responses induced by a Salmonella ghost delivery system that expresses the recombinant Stx2eB, FedF, and FedA proteins of the Escherichia coli-producing F18 and Shiga toxin in a murine model and evaluation of its protective effect as a porcine vaccine candidate. Vet Q 2017; 37:81-90. [DOI: 10.1080/01652176.2017.1308040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Gayeon Won
- College of Veterinary Medicine, Chonbuk National University, Iksan, Republic of Korea
| | - Lee John Hwa
- College of Veterinary Medicine, Chonbuk National University, Iksan, Republic of Korea
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Won G, Lee JH. Effectiveness of F18 + Fimbrial Antigens Released by a Novel Autolyzed Salmonella Expression System as a Vaccine Candidate against Lethal F18 + STEC Infection. Front Microbiol 2016; 7:1835. [PMID: 27920758 PMCID: PMC5118419 DOI: 10.3389/fmicb.2016.01835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/01/2016] [Indexed: 12/04/2022] Open
Abstract
Porcine edema disease (ED) caused by Shiga toxin 2e producing Escherichia coli expressing F18ab+ fimbriae (F18ab+STEC) frequently occurs in post-weaned piglets, resulting in a significant economic loss in swine industries worldwide. In the present study, we proposed an efficient prevention scheme against ED in which the attenuated Salmonella Typhimurium inactivated by the E-mediated cell lysis to deliver target antigens, FedF and FedA, which function in fimbrial-mediated adhesion and as a major subunit of F18ab+fimbriae, respectively. The co-expression of FedA and FedF protein with outer membrane protein A signal peptide was confirmed in the resultant strains JOL1460 and JOL1464 by immunoblot analysis. Immunization with the candidate strains in mice led to the significant generation of immunoglobulin (Ig) G, specific to both antigens and secretory IgA specific to FedF (P < 0.05). The titers of IgG isotypes, IgG1 and IgG2a, used as markers for T-helpers (Th)-2 and Th-1lymphocytes, respectively, also significantly increased in the immunized group (P < 0.05). The increase in CD3+CD4+ T lymphocyte subpopulation and in vitro proliferative activity was observed in in vivo stimulated splenocytes, which indicated the immunostimulatory effect of the candidate strains. Moreover, the immunized mice were completely protected from a lethal challenge against wild-type F18+STEC whereas 28% of mice died in the non-immunized group. This study demonstrated that the inactivated Salmonella system could efficiently release FedF and FedA and induce robust immune responses specific to the target antigens, which is sufficient to protect the mice from the lethal challenge.
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Affiliation(s)
- Gayeon Won
- College of Veterinary Medicine, Chonbuk National University Iksan, South Korea
| | - John H Lee
- College of Veterinary Medicine, Chonbuk National University Iksan, South Korea
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Dubreuil JD, Isaacson RE, Schifferli DM. Animal Enterotoxigenic Escherichia coli. EcoSal Plus 2016; 7:10.1128/ecosalplus.ESP-0006-2016. [PMID: 27735786 PMCID: PMC5123703 DOI: 10.1128/ecosalplus.esp-0006-2016] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 12/13/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors: adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17, and F18 fimbriae. Once established in the animal small intestine, ETEC produce enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes: heat-labile toxins that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This review describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics, and the identification of potential new targets by genomics are presented in the context of animal ETEC.
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Affiliation(s)
- J Daniel Dubreuil
- Faculté de Médecine Vétérinaire, Université de Montréal, Québec J2S 7C6, Canada
| | - Richard E Isaacson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
| | - Dieter M Schifferli
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
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Abstract
The first described adhesive antigen of Escherichia coli strains isolated from animals was the K88 antigen, expressed by strains from diarrheic pigs. The K88 antigen was visible by electron microscopy as a surface-exposed filament that was thin and flexible and had hemagglutinating properties. Many different fimbriae have been identified in animal enterotoxigenic E. coli (ETEC) and have been discussed in this article. The role of these fimbriae in the pathogenesis of ETEC has been best studied with K88, K99, 987P, and F41. Each fimbrial type carries at least one adhesive moiety that is specific for a certain host receptor, determining host species, age, and tissue specificities. ETEC are the most frequently diagnosed pathogens among neonatal and post-weaning piglets that die of diarrhea. Immune electron microscopy of animal ETEC fimbriae usually shows that the minor subunits are located at the fimbrial tips and at discrete sites along the fimbrial threads. Since fimbriae most frequently act like lectins by binding to the carbohydrate moieties of glycoproteins or glycolipids, fimbrial receptors have frequently been studied with red blood cells of various animal species. Identification and characterization of the binding moieties of ETEC fimbrial adhesins should be useful for the design of new prophylactic or therapeutic strategies. Some studies describing potential receptor or adhesin analogues that interfere with fimbria-mediated colonization have been described in the article.
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Meng Q, Bai X, Zhao A, Lan R, Du H, Wang T, Shi C, Yuan X, Bai X, Ji S, Jin D, Yu B, Wang Y, Sun H, Liu K, Xu J, Xiong Y. Characterization of Shiga toxin-producing Escherichia coli isolated from healthy pigs in China. BMC Microbiol 2014; 14:5. [PMID: 24393167 PMCID: PMC3893481 DOI: 10.1186/1471-2180-14-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 01/02/2014] [Indexed: 01/21/2023] Open
Abstract
Background Shiga toxin-producing Escherichia coli (STEC) is recognized as an important human diarrheal pathogen. Swine plays an important role as a carrier of this pathogen. In this study we determined the prevalence and characteristics of STEC from healthy swine collected between May 2011 and August 2012 from 3 cities/provinces in China. Results A total of 1003 samples, including 326 fecal, 351 small intestinal contents and 326 colon contents samples, was analyzed. Two hundred and fifty five samples were stx-positive by PCR and 93 STEC isolates were recovered from 62 stx-positive samples. Twelve O serogroups and 19 O:H serotypes including 6 serotypes (O100:H20/[H20], O143:H38/[H38], O87:H10, O172:H30/[H30], O159:H16, O9:H30/[H30]) rarely found in swine and ruminants were identified. All 93 STEC isolates harbored stx2 only, all of which were stx2e subtype including 1 isolate being a new variant of stx2e. 53.76%, 15.05% and 2.15% STEC isolates carried astA, hlyA and ehxA respectively. Four STEC isolates harbored the high-pathogenicity island. Of the 15 adherence-associated genes tested, 13 (eae, efa1, iha, lpfAO113, lpfAO157/OI-154, lpfAO157/OI-141, toxB, saa, F4, F5, F6, F17 or F41) were all absent while 2 (paa and F18) were present in 7 and 4 STEC isolates respectively. The majority of the isolates were resistant to tetracycline (79.57%), nalidixic acid (78.49%), trimethoprim-sulfamethoxazole (73.12%) and kanamycin (55.91%). The STEC isolates were divided into 63 pulsed-field gel electrophoresis patterns and 21 sequence types (STs). Isolates of the same STs generally showed the same or similar drug resistance patterns. A higher proportion of STEC isolates from Chongqing showed multidrug resistance with one ST (ST3628) resistant to 14 antimicrobials. Conclusions Our results indicate that swine is a significant reservoir of STEC strains in China. Based on comparison by serotypes and sequence types with human strains and presence of virulence genes, the swine STEC may have a low potential to cause human disease.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Yanwen Xiong
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China.
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Bellot P, Tiels P, Melkebeek V, Devriendt B, Goddeeris B, Cox E. Maltose-binding protein is a potential carrier for oral immunizations. Vet Immunol Immunopathol 2013; 152:101-8. [DOI: 10.1016/j.vetimm.2012.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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DNA vaccine encoding the major virulence factors of Shiga toxin type 2e (Stx2e)-expressing Escherichia coli induces protection in mice. Vaccine 2013; 31:367-72. [DOI: 10.1016/j.vaccine.2012.10.107] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/26/2012] [Accepted: 10/30/2012] [Indexed: 01/22/2023]
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Development of a novel live vaccine delivering enterotoxigenic Escherichia coli fimbrial antigens to prevent post-weaning diarrhea in piglets. Vet Immunol Immunopathol 2012; 146:283-8. [DOI: 10.1016/j.vetimm.2012.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 01/06/2012] [Accepted: 02/05/2012] [Indexed: 11/19/2022]
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Barth S, Schwanitz A, Bauerfeind R. Polymerase chain reaction-based method for the typing of F18 fimbriae and distribution of F18 fimbrial subtypes among porcine Shiga toxin-encoding Escherichia coli in Germany. J Vet Diagn Invest 2012; 23:454-64. [PMID: 21908273 DOI: 10.1177/1040638711403417] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Edema disease is an enterotoxemic disorder of weaned piglets that represents a significant threat to pig husbandry worldwide. The causative Escherichia coli strains are highly adapted to the porcine host and characterized by the production of Shiga toxin type 2e (Stx2e) and adhesive F18 fimbria. The current study assessed the occurrence of F18 fimbrial subtypes in 241 porcine stx2e(+) fedA(+) E. coli strains in Germany, including 116 Shiga toxin-encoding E. coli (STEC) and 125 Shiga toxin E. coli/enterotoxigenic E. coli (STEC/ETEC) isolates. In addition, a novel multiplex polymerase chain reaction (PCR) was developed in order to improve the typing system in terms of costs, time, and discriminative power. Utilizing the novel F18 typing PCR, 93 E. coli strains (38.5%) tested positive for the F18ab fimbrial subtype and 147 strains (61.0%) for the F18ac fimbrial subtype, while 1 strain remained nontypeable. Six strains were classified as F18ac using the F18 typing PCR, but were classified as F18ab using the F18-restriction fragment length polymorphism assay. Nucleotide sequencing of the FedA gene revealed that 5 of these strains encoded F18ac fimbriae, while the FedA of 1 strain did not cluster with F18ab or with F18ac amino acid sequences. The F18 fimbrial subtype was significantly associated with the pathovar of the E. coli strains, as 73.2% of the STEC isolates harbored F18ab genes whereas 93.6% of the STEC/ETEC isolates proved F18ac positive. In conclusion, the novel F18 typing PCR allows a specific identification of the F18 fimbrial subtype. The genetic and phenotypic heterogeneity of F18 fimbriae in porcine E. coli strains should be considered in the development of new vaccines and diagnostic tools.
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Affiliation(s)
- Stefanie Barth
- Institute for Hygiene and Infectious Diseases of Animals, Justus-Liebig University Giessen, Frankfurter Strasse 85-89, D-35392 Giessen, Germany.
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A tripartite fusion, FaeG-FedF-LT(192)A2:B, of enterotoxigenic Escherichia coli (ETEC) elicits antibodies that neutralize cholera toxin, inhibit adherence of K88 (F4) and F18 fimbriae, and protect pigs against K88ac/heat-labile toxin infection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:1593-9. [PMID: 21813665 DOI: 10.1128/cvi.05120-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT(192)) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT(192)A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT(192)A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT(192)A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrial E. coli strains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea.
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Tiels P, Verdonck F, Coddens A, Goddeeris B, Cox E. The excretion of F18+ E. coli is reduced after oral immunisation of pigs with a FedF and F4 fimbriae conjugate. Vaccine 2008; 26:2154-63. [PMID: 18543416 DOI: 10.1016/j.vaccine.2008.01.054] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Currently, no vaccines are available for edema disease and post-weaning diarrhoea (PWD) in pigs. In the present study, a subunit vaccine containing the F18 fimbrial adhesin FedF was studied. Hereto, recombinant FedF was produced as a fusion protein with maltose-binding protein. Even though the produced MBPFedF was shown to attach in vitro to enterocytes, almost no FedF-specific immune response could be detected after oral administration to piglets. The delivery of FedF to the intestinal mucosa was improved by conjugating the MBPFedF to F4 fimbriae. Indeed, this conjugation induced a systemic and local FedF-specific immune response and led to a reduction in excretion after infection with F18+ E. coli. Although complete protection was not observed, the conjugation between FedF and F4 fimbriae can be considered as a first step towards the development of a combined vaccine against F4+ and F18+ E. coli infections.
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Affiliation(s)
- P Tiels
- Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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14
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Mucosal immunization of piglets with purified F18 fimbriae does not protect against F18+ Escherichia coli infection. Vet Immunol Immunopathol 2007; 120:69-79. [PMID: 17686530 DOI: 10.1016/j.vetimm.2007.06.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 06/01/2007] [Accepted: 06/13/2007] [Indexed: 10/23/2022]
Abstract
Post-weaning diarrhoea and oedema disease in weaned piglets are caused by infection with F4+ or F18+ Escherichia coli strains. There is no commercial vaccine available, but it is shown that oral immunization of weaned piglets with purified F4 fimbriae induces a protective mucosal immune response. In the present study, piglets were orally and nasally immunized with purified F18 fimbriae in the presence of the mucosal adjuvant LT(R192G) or CTA1-DD, respectively. This immunization could not lead to protection against F18+ E. coli infection. The induced F18-specific immune response was directed towards the major subunit FedA and weakly towards the adhesive subunit FedF. The results of these experiments demonstrate that it is difficult to induce protective immunity against F18+ E. coli using the whole fimbriae due to the low response against the adhesin.
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Tiels P, Verdonck F, Coddens A, Ameloot P, Goddeeris B, Cox E. Monoclonal antibodies reveal a weak interaction between the F18 fimbrial adhesin FedF and the major subunit FedA. Vet Microbiol 2007; 119:115-20. [PMID: 17084564 DOI: 10.1016/j.vetmic.2006.08.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 08/28/2006] [Accepted: 08/31/2006] [Indexed: 10/24/2022]
Abstract
F18+ Escherichia coli can cause post-weaning diarrhoea and oedema disease in pigs. These diseases are responsible for substantial economic losses, but a vaccine is not available. A good knowledge of the characteristic of the fimbriae is useful for the development of a vaccine composed of the fimbrial virulence factor. F18 fimbriae are composed of the major subunit FedA and the minor subunits FedE and the adhesin FedF. In the present study monoclonal antibodies (mAbs) against FedA and FedF were produced. In addition to their diagnostic value, these mAbs revealed a weaker interaction between FedA and FedF compared to the subunit-subunit interactions in other fimbriae, like type 1 and P pili. Further experiments are needed to investigate if this weak interaction could be one of the reasons for the slow colonisation of the small intestinal mucosa by F18+ E. coli.
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Affiliation(s)
- P Tiels
- Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Zhang W, Berberov EM, Freeling J, He D, Moxley RA, Francis DH. Significance of heat-stable and heat-labile enterotoxins in porcine colibacillosis in an additive model for pathogenicity studies. Infect Immun 2006; 74:3107-14. [PMID: 16714538 PMCID: PMC1479275 DOI: 10.1128/iai.01338-05] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Although heat-stable (ST) and heat-labile (LT) enterotoxins produced by enterotoxigenic Escherichia coli (ETEC) have been documented as important factors associated with diarrheal diseases, investigations assessing the contributions of individual enterotoxins to the pathogenesis of E. coli infection have been limited. To address the individual roles of enterotoxins in the diarrheal disease caused by K88-positive ETEC in young pigs, enterotoxin-positive and -negative isogenic E. coli strains were constructed by using pBR322 to clone and express LT and STb. Four strains, K88+ astA, K88+ astA/pBR322, K88+ astA STb+, and K88+ astA LT+, were constructed and subsequently included in gnotobiotic piglet challenge studies, and their pathogenesis was assessed. The results indicated that all K88+ isogenic strains were able to colonize the small intestines of piglets exhibiting the K88 receptor. However, only LT- and STb-positive strains caused appreciable diarrhea. Piglets inoculated with the K88+ astA LT+ strain became dehydrated within 18 h, while those inoculated with the K88+ astA STb+ strain did not, although diarrhea developed in several piglets. The changes in the blood packed-cell volume and plasma total protein of gnotobiotic piglets inoculated with the LT-positive strains were significantly greater than those of pigs inoculated with the K88 astA/pBR322 strain (P = 0.012, P = 0.002). Immunochemistry image analysis also suggested that LT enhanced bacterial colonization in a gnotobiotic piglet model. This investigation suggested that LT is a major contributor to the virulence of K88+ ETEC and that isogenic constructs are a useful tool for studying the pathogenesis of ETEC infection.
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Affiliation(s)
- Weiping Zhang
- Veterinary Science Department, Box 2157, South Dakota State University, Brookings, SD 57006, USA
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Fairbrother JM, Nadeau E, Gyles CL. Escherichia coli in postweaning diarrhea in pigs: an update on bacterial types, pathogenesis, and prevention strategies. Anim Health Res Rev 2005; 6:17-39. [PMID: 16164007 DOI: 10.1079/ahr2005105] [Citation(s) in RCA: 590] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Escherichia coli is one of the most important causes of postweaning diarrhea in pigs. This diarrhea is responsible for economic losses due to mortality, morbidity, decreased growth rate, and cost of medication. The E. coli causing postweaning diarrhea mostly carry the F4 (K88) or the F18 adhesin. Recently, an increase in incidence of outbreaks of severe E. coli-associated diarrhea has been observed worldwide. The factors contributing to the increased number of outbreaks of this more severe form of E. coli-associated diarrhea are not yet fully understood. These could include the emergence of more virulent E. coli clones, such as the 0149:LT:STa:STb:EAST1:F4ac, or recent changes in the management of pigs. Development of multiple bacterial resistance to a wide range of commonly used antibiotics and a recent increase in the prevalence and severity of the postweaning syndromes will necessitate the use of alternative measures for their control. New vaccination strategies include the oral immunization of piglets with live avirulent E. coli strains carrying the fimbrial adhesins or oral administration of purified F4 (K88) fimbriae. Other approaches to control this disease include supplementation of the feed with egg yolk antibodies from chickens immunized with F4 or F18 adhesins, breeding of F18- and F4-resistant animals, supplementation with zinc and/ or spray-dried plasma, dietary acidification, phage therapy, or the use of probiotics. To date, not a single strategy has proved to be totally effective and it is probable that the most successful approach on a particular farm will involve a combination of diet modification and other preventive measures.
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Affiliation(s)
- John M Fairbrother
- The Escherichia coli Laboratory, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, QC, Canada J2S 2M2.
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Lindholm A, Smeds A, Palva A. Receptor binding domain of Escherichia coli F18 fimbrial adhesin FedF can be both efficiently secreted and surface displayed in a functional form in Lactococcus lactis. Appl Environ Microbiol 2004; 70:2061-71. [PMID: 15066797 PMCID: PMC383157 DOI: 10.1128/aem.70.4.2061-2071.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adherence of F18 fimbrial Escherichia coli to porcine intestinal epithelial cells is mediated by the adhesin (FedF) of F18 fimbriae. In a previous study, we demonstrated the specificity of the amino acid residues between 60 and 109 as the receptor binding domain of FedF. In this study, different expression, secretion, and anchoring systems for the receptor binding domain of the FedF adhesin in Lactococcus lactis were evaluated. Two partially overlapping receptor binding domains (42 and 62 amino acid residues) were expressed as fusions with L. lactis subsp. cremoris protein PrtP for evaluation of secretion efficiency. To evaluate the cell surface display of these FedF-PrtP fusions, they were further combined with different lengths of PrtP spacers fused with either the L. lactis AcmA anchor or the PrtP cell wall binding domain. An HtrA-defective L. lactis NZ9000 mutant was constructed to determine its effect on the level of secreted or anchored fusion proteins. Recombinant L. lactis clones secreting the receptor binding domain of F18 fimbriae as a fusion with the H domains of L. lactis protein PrtP were first constructed by using two different signal peptides. FedF-PrtP fusions, directed by the signal sequence of L. brevis SlpA, were throughout found to be secreted at significantly higher quantities than corresponding fusions with the signal peptide of L. lactis Usp45. In the surface display systems tested, the L. lactis AcmA anchor performed significantly better, particularly in the L. lactis NZ9000DeltahtrA strain, compared to the L. lactis PrtP anchor region. Of the cell surface display constructs with the AcmA anchor, only those with the longest PrtP spacer regions resulted in efficient binding of recombinant L. lactis cells to porcine intestinal epithelial cells. These results confirmed that it is possible to efficiently produce the receptor binding domain of the F18 adhesin in a functionally active form in L. lactis.
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Affiliation(s)
- Agneta Lindholm
- Division of Microbiology, Department of Basic Veterinary Sciences, University of Helsinki, Helsinki, Finland
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Verdonck F, Cox E, Schepers E, Imberechts H, Joensuu J, Goddeeris BM. Conserved regions in the sequence of the F4 (K88) fimbrial adhesin FaeG suggest a donor strand mechanism in F4 assembly. Vet Microbiol 2004; 102:215-25. [PMID: 15327796 DOI: 10.1016/j.vetmic.2004.06.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 06/07/2004] [Accepted: 06/14/2004] [Indexed: 10/26/2022]
Abstract
Oral immunization of newly weaned piglets with recombinant F4 (K88) fimbrial adhesin FaeG induces a F4-specific immune response, significantly reducing F4+ Escherichia coli excretion following challenge. In order to use FaeG subunits in an oral vaccine against F4+ enterotoxigenic E. coli, it is necessary to determine the conservation of the adhesin subunit. Hereto, the faeG sequence was determined of 21 F4ac+ E. coli field isolates from piglets with diarrhoea and subsequently compared with these of the reference strain GIS26 and previously reported FaeG sequences from F4ab, F4ac and F4ad antigenic variant strains. The FaeG amino acid sequence was 96-100% homologous within each F4 serotype, but only 92 and 88% when the F4ab and F4ad antigenic variants were compared with the F4ac antigenic variant. Furthermore, the conserved regions of the adhesin suggest a donor strand mechanism in F4 fimbriae assembly as reported for type 1 and P pili. In conclusion, the results of the reported experiments support the usefulness FaeG in an oral subunit vaccine against F4+ E. coli infections or as a mucosal carrier since the adhesin is conserved among F4+ E. coli field isolates.
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Affiliation(s)
- F Verdonck
- Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
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