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Hinrichs JB, Kreitlow A, Plötz M, Schotte U, Becher P, Gremmel N, Stephan R, Kemper N, Abdulmawjood A. Development of a Sensitive and Specific Quantitative RT-qPCR Method for the Detection of Hepatitis E Virus Genotype 3 in Porcine Liver and Foodstuff. Foods 2024; 13:467. [PMID: 38338602 PMCID: PMC10855453 DOI: 10.3390/foods13030467] [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: 01/10/2024] [Revised: 01/25/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
As an international and zoonotic cause of hepatitis, hepatitis E virus (HEV) poses a significant risk to public health. However, the frequency of occurrence and the degree of contamination of food of animal origin require further research. The aim of this study was to develop and validate a highly sensitive quantitative RT-qPCR assay for the detection and quantification of HEV contamination in porcine liver and food. The focus was on genotype 3, which is most common as a food contaminant in developed countries and Europe. The selected assay has its target sequence in the open reading frame 1 (ORF1) of the HEV genome and showed good results in inclusivity testing, especially for HEV genotype 3. The developed assay seems to show high efficiency and a low intercept when compared to other assays, while having a comparable limit of detection (LOD). In addition, a standard curve was generated using artificially spiked liver to provide more accurate quantitative results for contamination assessment and tracking in this matrix. Application of the assay to test 67 pig livers from different origins resulted in a positivity rate of 7.5%, which is consistent with the results of numerous other prevalence studies. Quantitative detection of the viral genome in the food chain, particularly in pig livers, is essential for understanding the presence and evolution of HEV contamination and thus ensures consumer safety.
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Affiliation(s)
- Jan Bernd Hinrichs
- Institute of Food Quality and Food Safety, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (J.B.H.); (A.K.); (M.P.)
| | - Antonia Kreitlow
- Institute of Food Quality and Food Safety, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (J.B.H.); (A.K.); (M.P.)
| | - Madeleine Plötz
- Institute of Food Quality and Food Safety, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (J.B.H.); (A.K.); (M.P.)
| | - Ulrich Schotte
- Department C Animal Health and Zoonoses, Central Institute of the Bundeswehr Medical Service Kiel, 24119 Kronshagen, Germany;
| | - Paul Becher
- Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (P.B.); (N.G.)
| | - Nele Gremmel
- Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (P.B.); (N.G.)
| | - Roger Stephan
- Vetsuisse Faculty, Institute for Food Safety and Hygiene, University of Zurich, 8057 Zurich, Switzerland;
| | - Nicole Kemper
- Institute for Animal Hygiene, Animal Welfare and Farm Animal Behaviors, University of Veterinary Medicine Hannover, 30173 Hannover, Germany;
| | - Amir Abdulmawjood
- Institute of Food Quality and Food Safety, University of Veterinary Medicine Hannover, 30173 Hannover, Germany; (J.B.H.); (A.K.); (M.P.)
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Locus T, Lambrecht E, Lamoral S, Willems S, Van Gucht S, Vanwolleghem T, Peeters M. A Multifaceted Approach for Evaluating Hepatitis E Virus Infectivity In Vitro: Cell Culture and Innovative Molecular Methods for Integrity Assessment. Vet Sci 2023; 10:676. [PMID: 38133227 PMCID: PMC10748075 DOI: 10.3390/vetsci10120676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Hepatitis E virus is a prominent cause of viral hepatitis worldwide. In Western countries, most infections are asymptomatic. However, acute self-limiting hepatitis and chronic cases in immunocompromised individuals can occur. Studying HEV is challenging due to its difficulty to grow in cell culture. Consequently, the detection of the virus mainly relies on RT-qPCR, which cannot differentiate between infectious and non-infectious particles. To overcome this problem, methods assessing viral integrity offer a possible solution to differentiate between intact and damaged viruses. This study aims at optimizing existing HEV cell culture models and RT-qPCR-based assays for selectively detecting intact virions to establish a reliable model for assessing HEV infectivity. In conclusion, these newly developed methods hold promise for enhancing food safety by identifying approaches for inactivating HEV in food processing, thereby increasing food safety measures.
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Affiliation(s)
- Tatjana Locus
- Fisheries and Food, Technology and Food Unit, Flemish Research Institute for Agriculture (ILVO), Brusselsesteenweg 370, 9090 Melle, Belgium or (T.L.); (E.L.)
- Sciensano, Infectious Diseases in Humans, Viral Diseases, Engelandstraat 642, 1180 Ukkel, Belgium
- Laboratory of Experimental Medicine and Pediatrics, Viral Hepatitis Research Group, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - Ellen Lambrecht
- Fisheries and Food, Technology and Food Unit, Flemish Research Institute for Agriculture (ILVO), Brusselsesteenweg 370, 9090 Melle, Belgium or (T.L.); (E.L.)
| | - Sophie Lamoral
- Sciensano, Infectious Diseases in Humans, Viral Diseases, Engelandstraat 642, 1180 Ukkel, Belgium
| | - Sjarlotte Willems
- Fisheries and Food, Technology and Food Unit, Flemish Research Institute for Agriculture (ILVO), Brusselsesteenweg 370, 9090 Melle, Belgium or (T.L.); (E.L.)
| | - Steven Van Gucht
- Sciensano, Infectious Diseases in Humans, Viral Diseases, Engelandstraat 642, 1180 Ukkel, Belgium
| | - Thomas Vanwolleghem
- Laboratory of Experimental Medicine and Pediatrics, Viral Hepatitis Research Group, University of Antwerp, Drie Eikenstraat 655, 2650 Edegem, Belgium
| | - Michael Peeters
- Sciensano, Infectious Diseases in Humans, Viral Diseases, Engelandstraat 642, 1180 Ukkel, Belgium
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Gremmel N, Keuling O, Eiden M, Groschup MH, Johne R, Becher P, Baechlein C. Hepatitis E virus neutralization by porcine serum antibodies. J Clin Microbiol 2023; 61:e0037323. [PMID: 37823649 PMCID: PMC10662371 DOI: 10.1128/jcm.00373-23] [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] [Received: 03/24/2023] [Accepted: 08/26/2023] [Indexed: 10/13/2023] Open
Abstract
The consumption of raw or undercooked meat products poses a serious risk for human hepatitis E virus (HEV) infections. In many high-income countries, domestic pigs and wild boars represent the main animal reservoirs for HEV and are usually identified by reverse transcription-PCR and antibody enzyme-linked immunosorbent assay (ELISA). In order to characterize the humoral immune response in more detail, a cell culture-based serum neutralization assay using a culture-adapted HEV strain was established here. Measurement of neutralizing antibodies was only possible after removing the viral quasi-envelope by detergent treatment. Serum samples of 343 wild boars from Northern Germany were first analyzed for anti-HEV IgG using an in-house ELISA, resulting in 19% positive samples. Subsequently, a subset of 41 representative samples was tested with the neutralization assay, and the results correlated well with those obtained by ELISA. Not only the human HEV strain 47832c but also two porcine HEV strains were shown to be neutralized by porcine serum antibodies. Neutralizing activity was also found in samples containing both HEV-specific antibodies and HEV RNA. Testing of serum samples derived from two experimentally infected domestic pigs showed a steep increase in neutralizing activity at 24 or 51 days post infection, dependent on the used infectious dose. The developed assay can be useful for characterization of the humoral immune response after HEV infection and for assessing the efficiency of HEV vaccine candidates.
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Affiliation(s)
- Nele Gremmel
- Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine, Hannover, Germany
| | - Oliver Keuling
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine, Hannover, Germany
| | - Martin Eiden
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Insel Riems, Germany
| | - Martin H. Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Insel Riems, Germany
| | - Reimar Johne
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Paul Becher
- Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine, Hannover, Germany
| | - Christine Baechlein
- Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine, Hannover, Germany
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In Vitro Replication of Swine Hepatitis E Virus (HEV): Production of Cell-Adapted Strains. Animals (Basel) 2023; 13:ani13020276. [PMID: 36670816 PMCID: PMC9854997 DOI: 10.3390/ani13020276] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
The hepatitis E caused by the virus HEV of genotypes HEV-3 and HEV-4 is a zoonotic foodborne disease spread worldwide. HEV is currently classified into eight different genotypes (HEV-1-8). Genotypes HEV-3 and HEV-4 are zoonotic and are further divided into subtypes. Most of the information on HEV replication remains unknown due to the lack of an efficient cell cultivation system. Over the last couple of years, several protocols for HEV cultivation have been developed on different cell lines; even if they were troublesome, long, and scarcely reproducible, they offered the opportunity to study the replicative cycle of the virus. In the present study, we aimed to obtain a protocol ready to use viral stock in serum free medium that can be used with reduced time of growth and without any purification steps. The employed method allowed isolation and cell adaptation of four swine HEV-3 strains, belonging to three different subtypes. Phylogenetic analyses conducted on partial genome sequences of in vitro isolated strains did not reveal any insertion in the hypervariable region (HVR) of the genomes. A limited number of mutations was acquired in the genome during the virus growth in the partial sequences of Methyltransferase (Met) and ORF2 coding genes.
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Hansen S, Menandro ML, Franzo G, Krabben L, Marino SF, Kaufer B, Denner J. Presence of porcine cytomegalovirus, a porcine roseolovirus, in wild boars in Italy and Germany. Arch Virol 2023; 168:55. [PMID: 36609605 PMCID: PMC9825524 DOI: 10.1007/s00705-022-05690-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/27/2022] [Indexed: 01/09/2023]
Abstract
Porcine cytomegalovirus (PCMV), a porcine roseolovirus (PRV) that is closely related to human herpesviruses 6 and 7, is commonly found in commercial pigs. PCMV/PRV is important in xenotransplantation, because in preclinical trials in which pig organs were transplanted into non-human primates, transmission of PCMV/PRV was shown to be associated with significantly reduced survival of the xenotransplants. PCMV/PRV was also transmitted in the first transplantation of a pig heart into a human patient worldwide and apparently contributed to the death of the patient. The prevalence of PCMV/PRV in wild boars is largely unknown. In this study, we screened wild boars from several areas of northern Italy and Germany to test for the presence of PCMV/PRV using PCR-based and Western blot assays. By Western blot analysis, 54% and 82% of Italian and German wild boars, respectively, were found to be PCMV/PRV positive, while 36% and 60%, respectively, tested positive by real-time polymerase chain reaction (PCR). These data indicate that the virus is common in German and Italian wild boars and that the Western blot assay detected a PCMV/PRV infection more often than did real-time PCR. The data also indicate that pigs raised for xenotransplantation should be protected from contact with materials from wild boars and commercial pigs.
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Affiliation(s)
- Sabrina Hansen
- Institute of Virology, Free University Berlin, 14163, Berlin, Germany
| | - Maria Luisa Menandro
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, 35020, Legnaro, Italy
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, 35020, Legnaro, Italy
| | - Ludwig Krabben
- Institute of Virology, Free University Berlin, 14163, Berlin, Germany
| | - Stephen F Marino
- Parasites in Foodstuffs, Department of Biological Safety, Unit Diagnostics, German Federal Institute for Risk Assessment, 10589, Berlin, Germany
| | - Benedikt Kaufer
- Institute of Virology, Free University Berlin, 14163, Berlin, Germany
| | - Joachim Denner
- Institute of Virology, Free University Berlin, 14163, Berlin, Germany.
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