Vasileios Ntafis
Agricultural University of Athens
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Publication
Featured researches published by Vasileios Ntafis.
Journal of Clinical Microbiology | 2010
Vasileios Ntafis; Eftychia Xylouri; Arianna Radogna; Canio Buonavoglia; Vito Martella
ABSTRACT An outbreak of norovirus (NoV) infection was identified in a kennel. Sequence analysis of a short fragment in the polymerase complex indicated the clonal origin of the strains, which were similar to the prototype canine NoV strain GIV.2/Bari/170/07-4/ITA (94.7% nucleotide identity). The findings demonstrate that canine NoV circulates in dogs in Greece and that it can spread easily across a group of animals.
Veterinary Microbiology | 2010
Vasileios Ntafis; Eir. Fragkiadaki; Eftychia Xylouri; A. Omirou; A. Lavazza; V. Martella
Severe outbreaks of diarrhoeic syndrome occurred in young foals at the same stud farm during two consecutive breeding periods namely spring 2006 and 2007. Rotavirus-like particles were detected by electron microscopy in the faeces of the affected foals and group A rotavirus infection was confirmed by Reverse-Transcription (RT)-PCR with selected sets of rotavirus-specific primers. Sequence analysis of the genes encoding the outer capsid rotavirus proteins VP7 and VP4 enabled classification of the viruses as G3AP[12] and revealed that the viruses were highly similar to recently reported equine rotavirus strains circulating in Europe. All Greek equine rotavirus isolates were genetically identical, suggesting persistence of the same viral strain in the stud farm, over the two consecutive foaling periods.
Archives of Virology | 2012
Vasileios Ntafis; Eftychia Xylouri; Viviana Mari; Maria Papanastassopoulou; N. Papaioannou; Angelos Thomas; Canio Buonavoglia; Nicola Decaro
In the present study, the detection of a pantropic canine coronavirus (CCoV) strain in a dog with lethal diarrhoea is reported. RT-PCR and real-time RT-PCR assays were used for the detection, characterization and quantitation of CCoV. Sequence and phylogenetic analysis of the CCoV NA/09 revealed a high degree of sequence identity with the pantropic strain CB/05, indicating the presence of CB/05-like pantropic strains in Greece. The absence of the 38-nucleotide deletion in ORF3b, which is characteristic of CB/05, indicates the need to identify new genetic markers for pantropic variants of CCoV, probably in the spike-protein gene region.
Veterinary Microbiology | 2011
Vasileios Ntafis; Viviana Mari; Nicola Decaro; Maria Papanastassopoulou; N. Papaioannou; R. Mpatziou; Canio Buonavoglia; Eftychia Xylouri
Abstract Canine coronavirus (CCoV) is an enveloped RNA virus, responsible for gastrointestinal infection in dogs. To date, two different CCoV genotypes have been recognized, CCoV type I and CCoV type II. Recently, CCoV type II strains of potential recombinant origin with transmissible gastroenteritis virus (TGEV) were detected and characterized as a new subtype (CCoV-IIb) of canine coronavirus, in order to be differentiated from the “classical” CCoV type II strains (CCoV-IIa). In the present study, two CCoV-IIb strains were detected in the faeces and internal organs of two puppies, which died after presenting gastrointestinal symptoms. Mixed infection of both subtypes (CCoV-IIa/IIb) was detected in the faeces, while only CCoV-IIb was detected in the organs. Puppies were also infected by canine parvovirus type 2 (CPV-2). Both CCoV-IIb strains were isolated on cell cultures and subjected to sequence analysis and phylogeny. By means of RT-PCR and real time RT-PCR assays, tissue distribution and quantitation of viral loads took place. These cases represent the first description of tissue distribution and quantitation of CCoV-IIb strains, detected in the organs. The detection of CCoV-IIa strains, which is restricted to the faeces, suggests that CCoV-IIb strains may have an advantage in disseminating throughout a dog with CPV-2 coinfection, in contrast to common enteric CCoV-IIa strains.
Journal of Veterinary Diagnostic Investigation | 2010
Vasileios Ntafis; Eftychia Xylouri; Iris Kalli; Costantina Desario; Viviana Mari; Nicola Decaro; Canio Buonavoglia
The aim of the present study was to characterize Canine parvovirus 2 (CPV-2) variants currently circulating in Greece. Between March 2008 and March 2009, 167 fecal samples were collected from diarrheic dogs from different regions of Greece. Canine parvovirus 2 was detected by standard polymerase chain reaction, whereas minor groove binder probe assays were used to distinguish genetic variants and discriminate between vaccine and field strains. Of 84 CPV-2–positive samples, 81 CPV-2a, 1 CPV-2b, and 2 CPV-2c were detected. Vaccine strains were not detected in any sample. Sequence analysis of the VP2 gene of the 2 CPV-2c viruses revealed up to 100% amino acid identity with the CPV-2c strains previously detected in Europe. The results indicated that, unlike other European countries, CPV-2a remains the most common variant in Greece, and that the CPV-2c variant found in Europe is also present in Greece.
Infection, Genetics and Evolution | 2013
Vasileios Ntafis; Viviana Mari; Nicola Decaro; Maria Papanastassopoulou; Dimitra Pardali; Timoleon S. Rallis; Theophanis Kanellos; Canio Buonavoglia; Eftychia Xylouri
Abstract Canine coronavirus (CCoV) is an etiologic agent of diarrhea in dogs and is known to have spread worldwide. Mild disease or asymptomatic carriage are probably in many cases common outcomes of infection. To date, two different genotypes of CCoV are known, CCoV type I (CCoV-I) and CCoV type II (CCoV-II). CCoV type II is divided in two subtypes, CCoV-IIa (classical strains) and CCoV-IIb, with CCoV-IIb emerging as a result of a putative recombination between CCoV-IIa and transmissible gastroenteritis virus (TGEV). The aim of the present study was to investigate the presence of CCoV in Greece and to genetically analyze the circulating strains. Between December 2007 and December 2009, 206 fecal samples were collected from dogs with diarrhea from kennels, pet shops and veterinary clinics of different country regions. RT-PCR and real time RT-PCR assays were used for CCoV detection and characterization. CCoV was identified in 65.1% of the dogs presenting diarrhea, being more frequently detected in animals younger than 3months old and in animals housed in groups. In 47% of the positive samples more than one CCoV genotype/subtype were detected, with triple CCoV-I/CCoV-IIa/CCoV-IIb infections being identified for the first time. Molecular and phylogenetic analysis revealed that CCoV-I Greek strains share low genetic relatedness to each other and to the prototype CCoV-I strains in the 5’ end of the S gene. Moreover, a divergent CCoV-IIa strain was identified. The circulation of highly variable CCoV-I and CCoV-IIb emerging strains, as well as the detection of the divergent strain, raise concerns on the importance of these new strains as primary pathogens of diarrhoeic syndromes diagnosed in dogs.
Journal of Veterinary Diagnostic Investigation | 2010
Vasileios Ntafis; Viviana Mari; Stefania Danika; Eftychia Fragkiadaki; Canio Buonavoglia
Canine coronavirus (CCoV) is usually the cause of mild gastroenteritis in dogs and is known to have spread worldwide. However, to date, no CCoV cases have been confirmed in Greece. In the present work, the authors investigated an outbreak of enteritis in puppies from a Greek kennel for the presence of CCoV. Dogs were presented with clinical signs of diarrhea, anorexia, weakness, depression, dehydration, and 1 death. Canine coronavirus type II was detected by reverse transcription nested polymerase chain reaction in all 11 puppies, whereas 1 puppy presented dual infection with CCoV type II and canine parvovirus 2. Surprisingly, sequence analysis of the samples revealed higher similarity to the pantropic CCoV II strain CB/05 than to other reference strains, in the most variable region of the S gene.
Computers and Electronics in Agriculture | 2010
Athanasios Voulodimos; Charalampos Z. Patrikakis; Alexander B. Sideridis; Vasileios Ntafis; Eftychia Xylouri
Food Analytical Methods | 2016
Martin D’Agostino; Susana Robles; Flemming Hansen; Vasileios Ntafis; John Ikonomopoulos; Petros Kokkinos; Avelino Alvarez-Ordóñez; Kieran Jordan; Elisabetta Delibato; Elżbieta Kukier; Zbigniew Sieradzki; Krzysztof Kwiatek; Dubravka Milanov; Tamas Petrovic; Patricia González-García; David Rodríguez Lázaro; Emily E. Jackson; Stephen J. Forsythe; Lorna O’Brien; Nigel Cook
Virology Journal | 2011
Maria Bountouri; Eirini Fragkiadaki; Vasileios Ntafis; Theo Kanellos; Eftychia Xylouri