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Xiao J, Yu S, Jiang K, He X, Bi L, Zhao P, Wang T, Yang N, Guo D. Identification of linear B cell epitopes on the leukotoxin protein of Fusobacterium necrophorum. Anaerobe 2024:102884. [PMID: 39059623 DOI: 10.1016/j.anaerobe.2024.102884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 06/29/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024]
Abstract
OBJECTIVE Fusobacterium necrophorum can casuse Lemierre's syndrome in humans and a range of illnesses, including foot rot and liver abscesses, in animals. The main virulence factor released by F. necrophorum is leukotoxin, which has been shown to have a strong correlation with the severity of the disease. Leukotoxin is commonly employed as the key antigen in the formulation of subunit vaccines. Therefore, identification of the B-cell epitope of F. necrophorum leukotoxin is necessary. METHODS In this research, we utilized lymphocyte hybridoma technology to develop a monoclonal antibody (mAb), 3D7, targeting the F. necrophorum leukotoxin protein. Identification of B-cell epitopes recognized by 3D7 mAb through Western blot, ELISA and dot blot using leukotoxin-truncated recombinant proteins and peptides, and through SWISS-MODEL homology modeling and PyMOL visualization. RESULTS The 3D7 mAb was identified as belonging to the IgG1 subclass with a κ-chain light chain. It demonstrated reactivity with the natural leukotoxin. The results showed that the 3D7 mAb recognizes a B-cell epitope of the F. necrophorum leukotoxin protein, I2168SSFGVGV2175 (EP-3D7). Sequence comparison analysis showed that EP-3D7 was highly conserved in F. necrophorum strains, but less conserved in other bacteria, indicating the specificity of EP-3D7. EP-3D7 is present on the surface of leukotoxin proteins in a β-folded manner. CONCLUSIONS In summary, these results establish EP-3D7 as a conserved antigenic epitope of F. necrophorum leukotoxin. It could be valuable in the development of vaccines and diagnostic reagents for F. necrophorum epitopes.
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Affiliation(s)
- Jiawei Xiao
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Siwen Yu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Kai Jiang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Xianjing He
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Lan Bi
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Pengyu Zhao
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Tianshuo Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Ning Yang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China
| | - Donghua Guo
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China; Ministry of Agriculture and Rural Affairs Key Laboratory of Prevention and Control of Bovine Diseases, No. 5 Xinyang Road, Sartu District, Daqing 163319, Heilongjiang Province, China.
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Qureshi S, Wani SA, Farooq S, Kashoo Z, Bhat B, Isfaqul Hussain M, Habib A, Altaf Bhat M, Khan SM, Pandit AA, Malla JA, Dar BA. Genome sequence of Dichelobacter nodosus JKS-07B isolate from J&K, India associated with virulent footrot of sheep. Sci Prog 2021; 104:368504211057678. [PMID: 34904916 PMCID: PMC10358635 DOI: 10.1177/00368504211057678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Virulent footrot of sheep caused by Dichelobacter nodosus is associated with tremendous economic losses due to recurrent treatment costs and increased culling rates. This organism being a fastidious anaerobe is difficult to isolate on ordinary media that does not support its growth. The D. nodosus serogroup B isolate described in the present study has been used in the preparation of the whole-cell killed vaccine against footrot in India. D. nodosus serogroup B is the predominant serogroup involved in virulent footrot (lesion score 4) in India as well as in many sheep-rearing countries of the globe. METHODS Genomic DNA was extracted using wizard Genomic DNA purification kit. The whole genome of the D. nodosus strain B was sequenced using an Illumina HiSeq 2500 platform and annotated according to functional gene categories. Annotations were performed using in-house developed Perl scripts using Nr/Nt database, uniprot, Pfam, KEGG, Panther DB, and GO database. RESULT The assembled genome size is 1.311,533 Mb and GC content is 44.38. A total of 1215 protein-coding genes, 44tRNA and 7 rRNA were identified. The genome shows 98.63% sequence homology with the reference genome. However, 21 new genes have been identified in this genome. The information will provide insights into the various genes and regulators necessary for D. nodosus growth and survival. DISCUSSION The genome information of this serogroup B of D. nodosus isolate involved in 85-90% cases of virulent footrot of sheep in India provides further insights for improvement of the killed vaccine (B serogroup) developed recently in India. For the development of an efficacious vaccine against virulent footrot, it is essential to know the serological diversity as well as the virulent status of the strains of the D. nodosus. This serogroup isolate is a potential vaccine candidate to mitigate ovine footrot in India as the majority of virulent footrot cases belong to serogroup B of D. nodosus.
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Affiliation(s)
- Sabia Qureshi
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Shakil A Wani
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Shaheen Farooq
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Zahid Kashoo
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Basharat Bhat
- Division of Animal Genetics and Breeding, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Mohammad Isfaqul Hussain
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Aasim Habib
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Mohd Altaf Bhat
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Shafkat Majeed Khan
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Arif Ahmad Pandit
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Javeed A Malla
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
| | - Bilal Ahmad Dar
- Anaerobic Laboratory, Division of Veterinary Microbiology & Immunology, FVSc & A.H, Shuhama (Aulesteng) SKUAST-K, India
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Identification of Immunodominant Outer Membrane Proteins of Fusobacterium necrophorum from Severe Ovine Footrot By MALDI-TOF Mass Spectrometry. Curr Microbiol 2021; 78:1298-1304. [PMID: 33638672 PMCID: PMC7997824 DOI: 10.1007/s00284-021-02383-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/05/2021] [Indexed: 11/21/2022]
Abstract
The aim of this study was to identify the immunodominant outer membrane proteins (OMPs) of Fusobacterium necrophorum from sheep affected with severe foot-rot. The OMP profile of ovine strains of F. necrophorum has not been well studied. We analyzed the OMP profile of the most frequent lktA variant JKS-F3 of F. necrophorum associated with severe ovine foot-rot with lesion score 4 in order to identify its major immunodominant OMPs. Electrophoretic separations of extracted OMPs showed a number of spots in two-dimensional electrophoretic gels. Two immunoreactive proteins of size around 43 kDa were identified through western blotting using hyperimmune sera raised in rabbits. These two immunogenic OMPs were analyzed by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF/MS) which revealed that these two OMPs of lktA variant JKS-F3 of F. necrophorum showed 46 and 42 percent protein sequence coverage and scores of 125 and 114, respectively, with the reported 43 kDa outer membrane protein of F. necrophorum strain H05, a putative porin having properties similar to pore-forming proteins of anaerobic Gram-negative bacteria. These identified immunogenic OMPs will contribute to our understanding of the pathogenic role played by this organism in ovine foot-rot and could be exploited to devise an effective control strategy through development of an OMP-based recombinant vaccine to mitigate foot-rot in sheep and goats.
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Farooq S, Wani SA, Hassan MN, Aalamgeer S, Kashoo ZA, Magray SN, Bhat MA. The detection and prevalence of leukotoxin gene variant strains of Fusobacterium necrophorum in footrot lesions of sheep in Kashmir, India. Anaerobe 2018; 51:36-41. [PMID: 29596988 DOI: 10.1016/j.anaerobe.2018.03.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/13/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
Abstract
The objective of this study was to determine the prevalence and identification of leukotoxin gene, lktA, variant strains of Fusobacterium necrophorum in the footrot lesions of sheep. The detection of F. necrophorum was carried out by PCR targeting the lktA gene fragment and identification of lktA variant strains was done by PCR-single stranded conformational polymorphism (PCR-SSCP) and gene sequencing. Of the 450 swabs collected from footrot lesions of sheep, 117 were lktA-positive for F. necrophorum. Of the 50 swabs collected from apparently asymptomatic sheep, only one was lktA-positive for F. necrophorum. The overall prevalence of F. necrophorum in footrot affected sheep in Kashmir valley was 26%, and ranged from 20 to 34.8%, respectively. PCR-SSCP of lktA gene fragment analysis revealed three lktA variants, designated as JKS-F1/F2/F3, while two samples (1.7%) showed multiple lktA variant strains of F. necrophorum in a single footrot-affected sheep hoof. This appears to be the first report on the presence of more than one lktA variant of F. necrophorum in a footrot lesion of sheep. The JKS-F3 lktA variant was the most frequent (75.4%), followed by JKS-F2 (14.4%) and JKS-F1 (8.4%), respectively. Among the three lktA variants identified, JKS-F3 was detected in 74 (86.0%) samples from severe footrot affected sheep with a lesion score of 4. The data suggest that JKS-F3 is the predominant lktA variant of F. necrophorum and is associated with severe footrot in sheep. Hence, JKS-F3 may be a significant variant contributing to the severity and duration of the disease in sheep.
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Affiliation(s)
- S Farooq
- KVK-Kupwara, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Jammu and Kashmir, India.
| | - S A Wani
- Division of Veterinary Microbiology and Immunology, SKUAST-K, Shuhama (Alusteng), Srinagar, 190006, Jammu and Kashmir, India
| | - M N Hassan
- KVK-Nyoma, SKUAST-K, Jammu and Kashmir, India
| | - S Aalamgeer
- Division of Veterinary Microbiology and Immunology, SKUAST-K, Shuhama (Alusteng), Srinagar, 190006, Jammu and Kashmir, India
| | - Z A Kashoo
- Division of Veterinary Microbiology and Immunology, SKUAST-K, Shuhama (Alusteng), Srinagar, 190006, Jammu and Kashmir, India
| | - S N Magray
- Division of Veterinary Microbiology and Immunology, SKUAST-K, Shuhama (Alusteng), Srinagar, 190006, Jammu and Kashmir, India
| | - M A Bhat
- Division of Veterinary Microbiology and Immunology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu (SKUAST-J), R.S.Pura, Jammu and Kashmir, India
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