ESAV - DZERV - Artigo em revista científica, indexada ao WoS/Scopus
URI permanente para esta coleção:
Navegar
Entradas recentes
- Mapping PRNP Polymorphisms in Portuguese Serra da Estrela Ovine Populations: Insights into Scrapie Susceptibility and Farm Animal ImprovementPublication . Rodrigues, Soraia; Moreira, Guilherme; Santos-Silva, Sérgio; Gomes-Gonçalves, Sara; Aires Pereira, Maria; Baptista, Alexandra; Cruz, Rita; Esteves, Fernando; Mesquita, João R.Scrapie (classical and atypical) susceptibility in sheep is strongly influenced by PRNP gene polymorphisms. In Portugal, limited data exist for native breeds such as Serra da Estrela, despite their relevance to animal conservation and food production. The full coding region of PRNP gene of 92 Serra da Estrela sheep was sequenced and SNP frequencies were analysed. The predicted functional impact of nonsynonymous SNPs was assessed using PolyPhen-2 and AMYCO. A total of 27 SNPs were identified, including 20 nonsynonymous variants. Thirteen major haplotypes were observed. The ARR allele, which provides resistance to classical scrapie, was present in 58.7% of the population, with 18.5% of animals being homozygous. Several previously unreported SNPs were identified, and their impact on prion protein aggregation propensity and structure was explored. The high frequency of the ARR allele without full ARR fixation suggests that no selective breeding for scrapie resistance has been applied. These results support the adoption of gradual selection strategies that preserve genetic variability and promote farmer compliance, while increasing classical and atypical scrapie resistance.
- Targeted-Amplicon NGS for Blastocystis sp. in Shepherd Dogs of Portugal Discriminates Co-Colonization with Multiple Zoonotic SubtypesPublication . Gomes-Gonçalves, Sara; Feiteiro, Maria João; Moreira, Guilherme; Cruz, Rita; Esteves, Fernando; Vala Correia, Helena Maria; Mesquita, João R.Research on endoparasites in pet dogs has been growing, but shepherd dogs have largely been overlooked. These dogs frequently share close proximity not only with sheep, which are reservoirs of zoonotic subtypes of Blastocystis, but also with their owners. This close contact increases the potential for shepherd dogs to act as intermediates in the transmission of Blastocystis. To clarify the role of these dogs as reservoirs for this parasite, this study investigated the presence of Blastocystis in shepherd dogs. Stool samples from Portuguese shepherd dogs were analyzed using SYBR-Green-based real-time PCR and melting curve analysis followed by targeted-amplicon NGS for mixed infections detection. Our results revealed a 60% occurrence of Blastocystis sp. in shepherd dog stools and frequent identification of zoonotic subtypes ST1–ST4 and ST14. Additionally, we observed mixed infections and subtype diversity within individual dogs, suggesting a potential role in cross-species transmission between livestock and humans.
- Molecular Screening of Sarcocystis spp. in Grazing Sheep (Ovis aries) and Shepherd Dogs (Canis lupus familiaris) from Central PortugalPublication . Gomes-Gonçalves, Sara; Figueiredo, Ricardo J.; Rodrigues, Soraia; Bento, Jaqueline T.; Santos-Silva, Sérgio; Almeida, Daniela; Cruz, Rita; Esteve, Fernando; Esteves, Fernando; Baptista, Alexandra Lameira; Pereira, Maria Aires; Cardoso, Luís; Mesquita, João R.Sarcocystis spp. are cyst-forming protozoan parasites with a global distribution that infect a wide range of domestic and wild animals, impacting both animal health and livestock productivity. In sheep, infections can cause clinical disease, reproductive losses, and economic damage, articularly when pathogenic species such as Sarcocystis tenella are involved. Grazing sheep, including breeds such as the Serra da Estrela from central Portugal, are at increased risk due to frequent contact with shepherd dogs, which serve as definitive hosts. Despite their significance, data on the occurrence and distribution of Sarcocystis spp. in Portuguese sheep remain limited. This study analyzed 179 samples collected in central Portugal during 2024, including 41 brain tissues and 88 blood samples from sheep, and 50 stool samples from shepherd dogs, using conventional PCR and bidirectional Sanger sequencing. Sarcocystis sp. closely related to S. tenella was detected exclusively in sheep brain tissue, with a prevalence of 4.9% (2/41; 95% CI: 0.60–16.53), while no parasite DNA was found in blood or dog samples. These results provide the first molecular confirmation of Sarcocystis spp. closely related to S. tenella in Portuguese sheep raised for human consumption and establish baseline data for future epidemiological surveillance and control strategies.
- Toxoplasma Gondii In Shepherds and Cheesemakers – A Case-Control Study on Sheep-Associated Occupational Exposure in Central PortugalPublication . Moreira, Guilherme; Almeida, Daniela; Cruz, Rita; Nóbrega, Carmen; Arede dos Santos, Carla Sofia; Coelho, Catarina; Mega, Cristina; Pereira, Maria; Esteves, Fernando; Vala Correia, Helena Maria; Cardoso, Luís; Lopes, Ana P.; Coelho, Ana C.; Mesquita, João R.Objectives: The primary objective of this study was to determine if workers occupationally exposed (WOE) to sheep, specifically shepherds and cheesemakers in central Portugal, are more likely to be seropositive for anti-Toxoplasma gondii IgG compared to the general population. Additionally, the study aimed to explore potential differences in seropositivity between shepherds and cheesemakers, while evaluating age, gender, and activity as possible risk factors for T. gondii infection. Methods: A total of 96 WOE, including 21 shepherds and 75 cheesemakers, were tested for anti-T. gondii IgG using a commercial enzyme-linked immunosorbent assay (ELISA). The control group consisted of 192 sera samples from blood donors matched by age, gender, and residence. Chi-square tests with Yates correction were used to compare seroprevalence between WOE and the general population, and between shepherds and cheesemakers. Univariate and multivariable logistic regression analyses were performed to evaluate potential associations between T. gondii seropositivity and factors such as activity, gender, and age. Results: The overall seroprevalence was 63.5% in the WOE and 52.6% in the general population, with no statistically significant difference (p = .101). Among WOE, 52.4% of shepherds and 66.7% of cheesemakers were seropositive, with no significant difference between the two groups (p = .344). Univariate and multivariable analyses indicated neither activity, age, nor gender were significant risk factors for seropositivity in the case population. Conclusion: The study did not find a significant increased risk of T. gondii seropositivity among shepherds and cheesemakers compared to the general population. While high seroprevalence was observed in both groups, other factors unrelated to occupational exposure may be influencing the risk of T. gondii infection. More research is needed, particularly focusing on cheesemakers, to further explore potential occupational health risks related to T. gondii.
- Hepatocellular Early Apoptosis Associated with HES 130/0.4 Administration for Volume Replacement in Pigs After Severe BleedingPublication . Vala, Helena; Faustino-Rocha, Ana I.; Cruz, Rita; Venâncio, Carlos; Silva, Aura; Mesquita, João R.; Ortiz, Ana Liza; Ferreira, David A.Hydroxyethyl starch (HES) 130/0.4 is commonly used for volume replacement, yet its hepatic effects in the context of acute haemorrhage remain unclear. This study aimed to evaluate hepatic histopathological changes related to HES 130/0.4 administration when compared to Ringer’s lactate (RL) in healthy pigs subjected to acute bleeding under general anaesthesia. Eighteen pigs were randomised into three groups: RL (n = 6), HES 130/0.4 (n = 6), and a non-bleeding control (n = 6). Liver tissue was collected postmortem and analysed using haematoxylin–eosin staining, cytochrome c immunohistochemistry, the TUNEL assay, and M30 immunofluorescence. No statistically significant differences were observed in general histopathological changes, TUNEL, or cytochrome c expression (p > 0.050). However, the pigs that received HES 130/0.4 for volume replacement showed significantly higher intensity of the liver M30 immunostaining in the Q-score (p < 0.010), H-score (p < 0.010), and c indexc index (p < 0.050) when compared to animals that received Ringer’s lactate solution or animals in the control group. These findings suggest that HES 130/0.4 induces increased early hepatocellular apoptosis when compared to RL in this model, raising concerns about its hepatic safety profile under haemorrhagic conditions.
- Assessing Q Fever Exposure in Veterinary Professionals: A Study on Seroprevalence and Awareness in Portugal, 2024Publication . Guilherme Moreira; Mário Ribeiro; Miguel Martins; José Maria Cardoso; Esteves, Fernando; Sofia Anastácio; Sofia Duarte; Vala Correia, Helena Maria; Cruz, Rita; Mesquita, João R.Due to their frequent contact with animals, veterinarians may be at preferential risk of Coxiella burnetii exposure due to occupational contact with livestock. This study assesses the seroprevalence and risk factors associated with C. burnetii seropositivity in Portuguese veterinarians. A cross-sectional study compared IgG anti-C. burnetii in veterinarians’ sera to a demographically matched control group. Univariate and multivariate logistic regression analyses evaluated associations between the demographic, occupational, and biosecurity factors and seropositivity. Seroprevalence among veterinarians was 33.7%, significantly higher (p = 0.0023) than in the controls (17.39%). Univariate analysis identified higher seropositivity in the northern region (p = 0.03), though this association was not significant after adjustment (p = 0.07). Protective measures, including isolating aborting animals from the rest of the herd (adjusted OR [aOR]: 0.35, p = 0.03) and wearing gloves during sample collection (OR: 0.28, p = 0.009), were significantly associated with lower infection risk. Veterinarians face increased C. burnetii exposure, but specific biosecurity practices reduce risk. Strengthening preventive measures, including personal protective equipment (PPE) use and biosecurity training, is essential to mitigate occupational and public health risks. Further research should explore vaccination strategies and molecular epidemiology to improve risk reduction efforts.
- Integrated Soil Management: Food Supply, Environmental Impacts, and Socioeconomic FunctionsPublication . Pereira, José Luís da Silva; Pereira Domingues Martinho, Vítor JoãoThis Editorial refers to the Special Issue “Integrated Soil Management: Food Supply, Environmental Impacts, and Socioeconomic Functions”. The Special Issue highlights bringing a broader perspective on soil management, namely in its relationship with food supply, environmental dimensions, and socioeconomic activities. From a total of twenty-six manuscripts submitted for consideration and peer review, fourteen were accepted for publication and inclusion in this Special Issue (two reviews and twelve articles). The published contributions are listed below followed by a description review to encourage the reader to explore them.
- Targeted-Amplicon NGS for Blastocystis sp. in Shepherd Dogs of Portugal Discriminates Co-Colonization with Multiple Zoonotic SubtypesPublication . Sara Gomes-Gonçalves; Maria João Feiteiro; Guilherme Moreira; Rita Cruz; Fernando Esteves; Helena Vala; João R. Mesquita; Cruz, Rita; Esteves, Fernando; Vala Correia, Helena Maria
- Greenhouse Gas Emissions and Ryegrass Yield after Application of Solid-Liquid Pig Slurry and Biochar to an Agricultural SoilPublication . Pereira, José Luís da Silva; Perdigão, Adelaide; Bonifácio, Gabriel; Figueiredo, Vitor; Marques, Francisco; Trindade, Henrique; Ferreira Wessel, DulcineiaBackground: The application of animal slurry to the soil improves its quality, as manure contains many nutrients for plants. However, this could negatively impact the environment. Objective: This field study investigated the effects of the addition of biochar after the mechanical separation of Whole pig Slurry (WS) into Solid (SF) and Liquid Fractions (LF) on Greenhouse Gases (GHG) emissions (N2O, CO2, and CH4) and ryegrass (Lolium multiflorum Lam. cv magnum) yield. Methods: Biochar (1.0 kg m-2) was applied in plots alone or together with each of the three slurries (80 kg N ha-1) in a total of eight treatments with three replications, including just soil with and without biochar as controls. Soil properties, Greenhouse Gas (GHG) fluxes, and yield were measured during theautumn/winter growing season. Results: The results showed that the addition of biochar to these three slurries significantly increased the soil pH and showed no impact on the other physicochemical properties. The GHG emissions were not significantly different between treatments with and without biochar. The N use efficiency increased significantly in SF > WS > LF, whereas no differences were observed among these three slurries with and without biochar. Conclusion: It can be concluded that the addition of biochar combined with WS or SF/LF to sandy-loam soil appears to have no impact on GHG emissions and ryegrass yield during the autumn/winter season. Overall, this finding suggests that amounts higher than 1.0 kg m-2 of biochar combined with SF may need to be applied to soil to reduce GHG emissions and nitrate leaching and increase N use efficiency and crop yield
- Production and characterization of powder from drone brood of honeybees (Apis mellifera)Publication . Goncalves, J. C.; Vouga, Beatriz; Costa, Cristina Amaro Da; Gonçalves, Fernando Jorge; Coelho, Catarina; Guiné, Raquel; Correia, PaulaDrone bee brood are a natural source of food with potential for human nutrition. This work aims to investigate the production and extraction of the drone bee brood (larvae and pupae), as well as the production of powder from this insect for food applications. To produce the drone brood (DB), in some hives of the colony appropriate empty frames were placed. Some measurements were done in the hive to monitor the global wellbeing of the colony, namely, temperature, relative humidity, and weight. After approximately one month, the frames were removed from the hives and frozen. The yield of DB by frame was 38%. For the extraction of the drone brood, different methods were tested, being the best ones the cold room extraction (∼ 6.5 °C), on a cold surface extraction (∼ 11 °C), and in boiling water extraction (100 °C). The results show that the extraction efficiencies were 74.3% (336.3 s), 62.5% (246.8 s) and 84.9% (332.0 s), for extraction in a cold room, on a cold surface, and in boiling water, respectively. After extraction, two drying processes were tested: evaporation and freeze-drying, being the last one the recommended, preserving in a better way the appearance and composition of the DB. DB powders presented different colour characteristics according to the extraction method used. The powder obtained by boiling extraction was darker than the one produced with cold extraction. Powders are rich in protein, fat and carbohydrates, being the fat content quite high for DB powders produced by boiling extraction method.