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Diagnostic Approach to Enteric Disorders in Pigs. Animals (Basel) 2023; 13:ani13030338. [PMID: 36766227 PMCID: PMC9913336 DOI: 10.3390/ani13030338] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/21/2023] Open
Abstract
The diagnosis of enteric disorders in pigs is extremely challenging, at any age. Outbreaks of enteric disease in pigs are frequently multifactorial and multiple microorganisms can co-exist and interact. Furthermore, several pathogens, such as Clostridium perfrigens type A, Rotavirus and Lawsonia intracellularis, may be present in the gut in the absence of clinical signs. Thus, diagnosis must be based on a differential approach in order to develop a tailored control strategy, considering that treatment and control programs for enteric diseases are pathogen-specific. Correct sampling for laboratory analyses is fundamental for the diagnostic work-up of enteric disease in pigs. For example, histology is the diagnostic gold standard for several enteric disorders, and sampling must ensure the collection of representative and optimal intestinal samples. The aim of this paper is to focus on the diagnostic approach, from sampling to the aetiological diagnosis, of enteric disorders in pigs due to different pathogens during the different phases of production.
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Li Y, Lin F, Sun L, Huang A, Chen J, Hao G, Yuan X, Zhang H, Su S. Detection of cyprinid herpesvirus 2 by loop-mediated isothermal amplification in combination with a lateral flow dipstick. Mol Cell Probes 2020; 50:101507. [PMID: 31911113 DOI: 10.1016/j.mcp.2020.101507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/17/2019] [Accepted: 01/01/2020] [Indexed: 01/23/2023]
Abstract
We developed a convenient technique to detect Herpesviral haematopoietic necrosis attributed to cyprinid herpes virus 2 (CyHV-2), a serious disease of Crucian carp and goldfish related to high mortality. In the present study, we employed a lateral flow dipstick (LAMP-LFD) to present a loop-mediated isothermal amplification assay. The specificity was ascertained via other six viruses, and the sensitivity was compared using PCR method, which are the reaction conditions changes for the method improved. The results revealed that CyHV-2 performance was observable at 64 °C in a separated tube within 60 min, when the samples hybridized using an FITC-labeled probe. As the LAMP-LFD method's specificity was high, with its sensitivity identical to that of traditional PCR, the overall DNA collected revealed the lowest detection limit of 0.18 pg/μl from goldfish diseased by CyHV-2. In summary, the development of LAMP-LFD's method does not require expensive instruments, and it can be regarded as a fast, simple, and reliable method for CyHV-2 detection.
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Affiliation(s)
- Yanli Li
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), College of Animal Science and Technology, Southwest University, Chongqing, 400715, PR China; Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China.
| | - Feng Lin
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China.
| | - Lihui Sun
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China
| | - Aixia Huang
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China
| | - Jianming Chen
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China
| | - Guijie Hao
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China
| | - Xuemei Yuan
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China
| | - Haiqi Zhang
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture, Zhejiang Institute of Freshwater Fisheries, Huzhou, 313001, China.
| | - Shengqi Su
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), College of Animal Science and Technology, Southwest University, Chongqing, 400715, PR China.
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Joachim A, Ruttkowski B, Sperling D. Detection of Cystoisospora suis in faeces of suckling piglets - when and how? A comparison of methods. Porcine Health Manag 2018; 4:20. [PMID: 30250747 PMCID: PMC6145109 DOI: 10.1186/s40813-018-0097-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 12/30/2022] Open
Abstract
Background Cystoisospora suis is the causative agent of porcine neonatal coccidiosis, a diarrheal disease which affects suckling piglets in the first weeks of life. Detection of oocysts in the faeces of infected animals is frequently hampered by the short individual excretion period and the high fat content of faecal samples. We analysed oocyst excretion patterns of infected piglets, evaluated different detection methods for their detection limit and reproducibility, and propose a sampling scheme to improve the diagnosis of C. suis in faecal samples from the field using a protocol for reliable parasite detection. Results Based on a hypothesized model of the course of infection on a farm, three samplings (days of life 7–14-21 or 10–15-20) should be conducted including individual samples of piglets from each sampled litter. Samples can be examined by a modified McMaster method (lower detection limit: 333 oocysts per gram of faeces, OpG), by examining faecal smears under autofluorescence (lower detection limit: 10 OpG) or after carbol-fuchsin staining (lower detection limit: 100 OpG). Reproducibility and inter-test correlations were high with (R2 > 0.8). A correlation of oocyst excretion with diarrhoea could not be established so samples with different faecal consistencies should be taken. Pooled samples (by litter) should be comprised of several individual samples from different animals. Conclusions Since oocyst excretion by C. suis-infected piglets is usually short the right timing and a sufficiently sensitive detection method are important for correct diagnosis. Oocyst detection in faecal smears of samples taken repeatedly is the method of choice to determine extent and intensity of infection on a farm, and autofluorescence microscopy provides by far the lowest detection limit. Other methods for oocyst detection in faeces are less sensitive and/or more labour- and cost intensive and their usefulness is restricted to specific applications.
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Affiliation(s)
- Anja Joachim
- 1Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria
| | - Bärbel Ruttkowski
- 1Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria
| | - Daniel Sperling
- CEVA Santé Animale, 10 avenue de la Ballastière, 33500 Libourne, France
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Wang H, Cong F, Zeng F, Lian Y, Liu X, Luo M, Guo P, Ma J. Development of a real time reverse transcription loop-mediated isothermal amplification method (RT-LAMP) for detection of a novel swine acute diarrhea syndrome coronavirus (SADS-CoV). J Virol Methods 2018; 260:45-48. [PMID: 29936095 PMCID: PMC7113678 DOI: 10.1016/j.jviromet.2018.06.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 06/21/2018] [Accepted: 06/21/2018] [Indexed: 12/20/2022]
Abstract
A novel swine acute diarrhea syndrome Coronavirus (SADS-CoV) that causes severe diarrhea in suckling piglets was identified in southern China in 2017. A simple and rapid detection test was developed for this virus using real-time RT-LAMP based on the conserved N gene of the virus. The method had a detection limit of 1.0 × 101 copies/μL with no cross-reactions with classical swine fever virus, porcine and respiratory syndrome virus NA, porcine and respiratory syndrome virus EU, transmissible gastroenteritis coronavirus, foot and mouth disease virus, porcine epidemic diarrhea virus (S-INDEL and non-S-INDEL), swine influenza virus subtype H1N1, porcine circovirus type 2, seneca valley virus, porcine parvovirus, porcine deltacoronavirus and rotavirus. This method was also reproducible. Twenty of 24 clinical samples were identified as SADS-CoV RNA-positive by the real-time RT-LAMP and the results were consistent with that of the real time RT-PCR method. This new method for detecting SADS-CoV is specific and sensitive for the detection of SADS-CoV.
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Affiliation(s)
- Huanan Wang
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Feng Cong
- Guangdong Laboratory Animals Monitoring Institute and Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou 510633, China; Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510640, China
| | - Fanwen Zeng
- Guangdong Laboratory Animals Monitoring Institute and Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou 510633, China; Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510640, China
| | - Yuexiao Lian
- Guangdong Laboratory Animals Monitoring Institute and Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou 510633, China; Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510640, China
| | - Xiangnan Liu
- Guangdong Laboratory Animals Monitoring Institute and Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou 510633, China; Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510640, China
| | - Manlin Luo
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510640, China.
| | - Pengju Guo
- Guangdong Laboratory Animals Monitoring Institute and Guangdong Provincial Key Laboratory of Laboratory Animals, Guangzhou 510633, China.
| | - Jingyun Ma
- College of Animal Science, South China Agricultural University, Wushan Road 483, Tianhe District, Guangzhou, 510642, China.
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Development and application of a recombinant protein-based indirect ELISA for the detection of serum antibodies against Cystoisospora suis in swine. Vet Parasitol 2018; 258:57-63. [PMID: 30105979 DOI: 10.1016/j.vetpar.2018.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 06/05/2018] [Accepted: 06/07/2018] [Indexed: 01/27/2023]
Abstract
The apicomplexan parasite Cystoisospora suis which causes neonatal porcine coccidiosis is one of the predominant parasite in suckling piglets. Currently, the immunofluorescence antibody test (IFAT) is the only available serological tool for detecting serum antibodies against C. suis which has several limitations, including bias from interpretation and low throughput. In the present study, an indirect enzyme-linked immunosorbent assay (ELISA) was developed using a previously characterized recombinant merozoite protein for the detection of specific immunoglobulin G (IgG) and IgA against C. suis. The recombinant protein was expressed in Escherichia coli as a N-terminal histidine fusion protein, and its specificity was confirmed in an immunoblot probed with highly positive anti-C. suis sera from experimentally infected piglets. Optimal dilutions of recombinant protein, sera and conjugate were determined by checkerboard titrations, and the serum dilution that gave the greatest ratio between the positive and the negative sera was selected for subsequent analyses. Agreement between the IFAT and the newly developed ELISA was assessed with kappa statistics. The receiver operating characteristic (ROC) curve analysis based on 185 serum samples with known C. suis exposure previously tested in the reference IFAT was used to determine the cut-off value, sensitivity and specificity of the ELISA. For IgG, the ELISA had an estimated cut-off value of 0.82 and sensitivity and specificity values of 94.7% and 98%, respectively, whereas for IgA the estimated cut-off value was 0.41 and sensitivity and specificity values were both100%. According to kappa coefficient, an excellent correlation (κ > 0.8) was found between IFAT and ELISA for both isotypes. The diagnostic accuracy of the test measured as the area under the ROC curve index scaled between 0.98 and 1.0, indicating high discriminatory capacity and its possible application as a serological tool for detecting antibody response in the host following C. suis exposure/immunization and large-scale surveillance studies.
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Mahittikorn A, Thammasonthijarern N, Roobthaisong A, Udonsom R, Popruk S, Siri S, Mori H, Sukthana Y. Development of a loop-mediated isothermal amplification technique and comparison with quantitative real-time PCR for the rapid visual detection of canine neosporosis. Parasit Vectors 2017; 10:394. [PMID: 28835287 PMCID: PMC5569544 DOI: 10.1186/s13071-017-2330-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 08/14/2017] [Indexed: 11/10/2022] Open
Abstract
Background Dogs are the definitive hosts of Neospora caninum and play an important role in the transmission of the parasite. Despite the high sensitivity of existing molecular tools such as quantitative real-time PCR (qPCR), these techniques are not suitable for use in many countries because of equipment costs and difficulties in implementing them for field diagnostics. Therefore, we developed a simplified technique, loop-mediated isothermal amplification (LAMP), for the rapid visual detection of N. caninum. Methods LAMP specificity was evaluated using a panel containing DNA from a range of different organisms. Sensitivity was evaluated by preparing 10-fold serial dilutions of N. caninum tachyzoites and comparing the results with those obtained using qPCR. Assessment of the LAMP results was determined by recognition of a colour change after amplification. The usefulness of the LAMP assay in the field was tested on 396 blood and 115 faecal samples from dogs, and one placenta from a heifer collected in Lopburi, Nakhon Pathom, Sa Kaeo, and Ratchaburi provinces, Thailand. Results Specificity of the LAMP technique was shown by its inability to amplify DNA from non-target pathogens or healthy dogs. The detection limit was the equivalent of one genome for both LAMP and qPCR. LAMP and qPCR detected positive N. caninum infection in 15 of 396 (3.8%) blood samples; LAMP detected 9/115 (7.8%) positive faecal samples, while qPCR detected 5/115 (4.3%) positive faecal samples. The placental tissue was shown to be positive by both techniques. Agreement between LAMP and qPCR was perfect in blood samples (kappa value, 1.00) and substantial in faecal samples (kappa value, 0.697). Conclusions This is the first known LAMP assay developed for the amplification of N. caninum. The technique effectively and rapidly detected the parasite with high sensitivity and specificity and was cost-effective. This assay could be used in the field to confirm the diagnosis of canine or bovine neosporosis. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2330-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nipa Thammasonthijarern
- Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Amonrattana Roobthaisong
- Section of Bacterial Infections, Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi, Thailand
| | - Ruenruetai Udonsom
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Supaluk Popruk
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sukhontha Siri
- Department of Epidemiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Hirotake Mori
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Yaowalark Sukthana
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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