Publications by authors named "Athanasios Gelasakis"

Haemosporidians, a group of vector-borne parasites that parasitize the blood cells and internal organs of various animal species, are reported to cause severe pathology in raptors. Species belonging to the genera Plasmodium, Haemoproteus and Leucocytozoon are the ones of greatest wildlife importance. The common buzzard (Buteo buteo) and the Eurasian sparrowhawk (Accipiter nisus) are the most numerous raptor species in Europe.

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Vaccine adjuvants are crucial for reinforcing the immunogenicity of vaccines. Therefore, they are widely used in the aquaculture sector as vaccine components, facilitating the efficient prevention of infectious diseases and promoting sustainable teleost fish growth. Despite their benefits, there has been a growing concern about the potential adverse effects of vaccine adjuvants in teleost fish, connoting a valid impact on their overall health and welfare.

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Among the health issues of major concern in dairy ruminants, mastitis stands out as being associated with considerable losses in productivity and compromised animal health and welfare. Currently, the available methods for the early detection of mastitis are either inaccurate, requiring further validation, or expensive and labor intensive. Moreover, most of them cannot be applied at the point of care.

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Toxoplasmosis, caused by the protozoan , is a zoonotic disease that affects various animal species, including dogs, that can serve as sentinels for indirectly estimating the environmental contamination. The current study aimed to determine the seroprevalence of IgG and IgM antibodies in dogs across different regions of Greece and assess their living area as a potential risk factor. In total, 1282 blood samples were collected from dogs in urban and rural areas of Greece, including Attica and Thessaloniki.

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Aquaculture has rapidly emerged as one of the fastest growing industries, expanding both on global and on national fronts. With the ever-increasing demand for proteins with a high biological value, the aquaculture industry has established itself as one of the most efficient forms of animal production, proving to be a vital component of global food production by supplying nearly half of aquatic food products intended for human consumption. As in classic animal production, the prevention of diseases constitutes an enduring challenge associated with severe economic and environmental repercussions.

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Although in dogs is considered enzootic in northern Greece, the available data on the occurrence of infection in southern parts of the country demonstrate its scarcity. The aim of this study was to update the current knowledge on infection in dogs in areas of Greece previously considered non-enzootic (Central Greece, Attica, Peloponnese, North Aegean, South Aegean, Crete and the Ionian islands). In total, 1528 dog blood samples were collected from the aforementioned areas and examined by Dirochek ELISA (Synbiotics).

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Article Synopsis
  • The study focuses on the genetic diversity of small ruminant lentiviruses (SRLV) in sheep, which is important for disease control and diagnostics in Greece.
  • Researchers analyzed SRLV strains from 12 infected sheep from two breeds (Chios and Lacaune) and found distinct strain types linked to each breed.
  • The study revealed that while most parts of the capsid protein were similar within each strain type, some mutations could affect the virus's evolution, highlighting the need for more extensive research on SRLV genetic variation.
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, the poultry red mite (PRM), is the most prevalent and harmful ectoparasite of laying hens globally. Although prevalence and risk factor studies can help veterinarians make decisions regarding farm treatments, relevant data are scarce. The present study investigated the prevalence and infestation severity of PRM in poultry farms across Greece and examined potential risk factors.

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Article Synopsis
  • Genetic selection for higher productivity in dairy sheep has increased their vulnerability to diseases and environmental stress, affecting their health and efficiency.
  • A study analyzed the genomic heritability and identified SNPs related to resilience traits (milk somatic cell count, lactation persistency, body condition score) using data from 317 Chios and 346 Frizarta ewes.
  • The research found high heritability estimates and associated several novel SNPs with the traits, suggesting that resilience can be improved through genetic selection without hindering productivity.
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The objective of this study was to assess the capability of predicting carcass traits and meat cuts weights, in fattening lambs of indigenous Greek dairy sheep breeds, using ultrasound measurements and live body weight measurements pre-slaughter. A total of 187 lambs of Chios and Serres breeds were involved in the study. Body condition score, live body weight (LBW), and ultrasound measurements of Longissimus lumborum muscle depth (LMD) and subcutaneous fat thickness (SFT) at the lumbar region were recorded pre-slaughter.

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A two-year longitudinal cohort study was conducted on a total of 407 purebred Chios and Lacaune ewes from four intensive dairy sheep farms to assess potential risk factors for small ruminant lentiviruses (SRLVs) seropositivity. Ewes were serologically tested semiannually at pre-mating and pre-lambing, and their age, breed, and body condition score (BCS) were recorded. Εwes were categorized as constantly seronegative, constantly seropositive, seroconverted, seroreverted, or animals with an intermittent presence of antibodies.

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is a zoonotic protozoon with a complex life cycle and the second most important foodborne pathogen in Europe. Surveillance of toxoplasmosis is based on national considerations since there are no mandatory controls along the food chain in the European Union, and underreporting of meat is still a problem in many countries like Greece. The current review provides an overview of prevalence, associated risk factors, and surveillance in animals in Greece, focusing on the transmission role of meat and highlighting the control measures that should be adopted by consumers.

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The objective of this study is to prospectively evaluate the seroepidemiology of maedi-visna (MV) infections in intensively reared dairy sheep. A total of 407 purebred Chios and Lacaune ewes from four farms were surveyed for two consecutive years and were serologically tested semiannually with an indirect ELISA at pre-mating and pre-lambing. The farms' structure and management practices were similar and animal traits (age, breed, and production stage) were recorded.

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Leishmaniosis caused by the protozoon that is transmitted through the bites of infected phlebotomine sandflies is of major veterinary concern in Greece. The country is endemic with particularly favourable environmental conditions for the spread of this infection. Moreover, Greece remains a popular touristic destination, and the continuous travel of pets raises concern regarding the possible dissemination of infection from endemic to non-endemic areas.

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The incidence of small ruminant pestivirus infections in Greece remains unknown as they have not been diagnosed in the country since 1974 when the most recent Border Disease Virus (BDV) outbreak was reported. The objective of our study was to explore the possible occurrence of pestiviral infections among sheep and goat farms in Greece and to further determine the variants of major concern. Thus, serum samples were collected from 470 randomly selected animals belonging to 28 different flocks/herds.

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Article Synopsis
  • PRM (Poultry Red Mite) is a common parasite affecting laying hens, showing resistance to many traditional treatments, making it a significant issue in poultry farming.
  • A study explored the acaricidal (mite-killing) effects of silver nanoparticles (AgNPs) on PRM, demonstrating that higher concentrations of AgNPs resulted in increased mortality rates of the mites.
  • Scanning electron microscopy revealed that AgNPs caused physical damage to the mites’ exoskeleton, suggesting a possible mechanism of action, while future research is recommended to ensure safety regarding AgNPs residues in chicken tissues.
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Toxoplasma gondii is a ubiquitous zoonotic parasite, with felines being the only definitive hosts. Cats shed oocysts with their faeces, and seroprevalence studies can be used to indirectly assess the environmental contamination. The current study aimed to evaluate T.

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The effects of nematodes and bacteria on intestinal health are of primary importance in modern swine production. The aim of the present study was to assess the seropositivity status of Ascaris suum infection in fatteners in intensive swine farms in Greece and address possible risk factors, including Lawsonia intracellularis as a predisposing factor to swine ascariosis. In total, 360 blood serum samples from pigs in the late fattening period, from 24 Greek swine farrow-to-finish farms (15 samples/farm) were collected and tested with Svanovir® A.

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Zoonoses and animal diseases threaten human health and livestock biosecurity and productivity. Currently, laboratory confirmation of animal disease outbreaks requires centralized laboratories and trained personnel; it is expensive and time-consuming, and it often does not coincide with the onset or progress of diseases. Point-of-care (POC) diagnostics are rapid, simple, and cost-effective devices and tests, that can be directly applied on field for the detection of animal pathogens.

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The objectives of the study were to estimate the repeatability of health and welfare traits and investigate their association with performance in three breeds of dairy goats reared under low-input farming systems in Greece. A total of 1210 goats of Eghoria (n = 418), Skopelos (n = 429), and Damascus (n = 363) breeds were assessed. Udder health, parasitic resistance, welfare, milk yield and quality, and body condition score were recorded monthly for two milking periods.

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Article Synopsis
  • - Swine viral diseases threaten the sustainability of the pig farming industry by impacting animal health and productivity, highlighting the need for effective diagnosis methods due to the absence of antiviral medications and reliable vaccines.
  • - A new point-of-care (POC) diagnostic device has been developed that uses photonic integrated circuits (PICs) and microfluidics to detect two significant viruses in pigs: porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza A (SIV).
  • - The device showed promising diagnostic performance, with sensitivity and specificity percentages for PRRSV at 83.5% and 77.8%, and for SIV at 81.8% and 82.2%, indicating its potential for improving
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Extensively reared ruminants are seasonally exposed to ticks. Tick-related production losses and health issues have been well documented in cows and sheep but not in goats where relevant literature is scarce. The objective here was to investigate the association of hard tick infestation with milk production and udder health of dairy goats reared extensively.

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The replacement of soybean meal (SBM) from intensively reared dairy sheep diets has emerged as a significant challenge for sustainable production. However, the effects of this replacement on milk production have not been sufficiently elucidated. The objective of this study was to prospectively assess the effects of replacing SBM with a mixture of alternative protein sources on the milk yield (MY) and the milk quality traits (MQT) in intensively reared dairy sheep.

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Fly infestation remains a universal problem for dairy cattle herds, affecting the animals' health and welfare status. Pre-weaned dairy calves are significantly challenged by the direct and indirect consequences of severe fly infestation, heat-stress and their interaction, which contribute to a stressful and fatiguing environment. Among several physiological, behavioral, clinical and biochemical traits, serum cortisol (SC) and creatine kinase (CK) levels, as well as feed consumption can be used as valid indicators of potential stressful and fatiguing conditions and, therefore, can be efficiently used for stress analysis studies.

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Viral diseases challenge the health and welfare of pigs and undermine the sustainability of swine farms. Their efficient control requires early and reliable diagnosis, highlighting the importance of Point of Care (POC) diagnostics in veterinary practice. The objective of this study was to validate a novel POC system that utilizes Photonic Integrated Circuits (PICs) and microfluidics to detect swine viral pathogens using oral fluids and Porcine Parvovirus (PPV) and Porcine Circovirus 2 (PCV-2) as proofs of concept.

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