Browsing by Author "Melo, Pedro"
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- Implementation of Mini-FLOTAC in routine diagnosis of Coccidia and Helminth infections in domestic and exotic birdsPublication . Lozano, João; Almeida, Cristina; Victório, Ana Cláudia; Melo, Pedro; Rodrigues, João Paulo; Rinaldi, Laura; Cringoli, Giuseppe; Gomes, Lídia; Oliveira, Manuela; Paz-Silva, Adolfo; Madeira de Carvalho, LuísMini-FLOTAC (MF) has recently been proposed for the fecal quantification of gastrointestinal (GI) parasites in birds due to its higher sensitivity and precision in comparison with the McMaster method. The current research aimed to test the use of MF in routine diagnosis of coccidia and helminth infections in several domestic and exotic bird collections in Portugal. Between July 2020 and April 2021, a total of 142 fecal samples from organic layers, peacocks and ratites were collected in four Portuguese bird collections and processed using MF and fecal cultures to identify and calculate GI parasite shedding and prevalence. The McMaster method was also used to compare the shedding levels obtained for both quantitative techniques. MF’s relative sensitivity and specificity were also assessed, using McMaster as the reference technique. The implementation of MF resulted in an average Eimeria spp. shedding higher in peacocks from bird collection 2 (502 OPG), followed by peacocks from collection 1 (107 OPG) and organic layers (24 OPG) and peacocks from collection 3 (9 OPG). Peacocks were also positive for Capillaria spp., Trichostrongylus tenuis and Strongyloides pavonis, whereas ostriches and emus were infected by L. douglassii. The MF protocol for exotic animals and the McMaster method did not differ significantly for each parasitic agent and bird species, and MF achieved relative sensitivities and specificities higher than 70% for Galliform Eimeria spp., peacock helminths and ratites’ L. douglassii infections. Higher L. douglassii EPG values were identified using the MF protocol for exotic species (2 g of feces/38 mL of sucrose solution), followed by McMaster 2/28, MF 5/45 and MF 2/18. The use of MF allowed for obtaining different intestinal parasitic populations in several bird species and locations, and MF 2/38 is globally proposed as the most suitable protocol for bird fecal samples as an alternative to the McMaster method in the diagnosis of avian intestinal parasitic infections.
- Isolation of saprophytic filamentous fungi from avian fecal samples and assessment of its predatory activity on coccidian oocystsPublication . Lozano, João; Louro, Mariana; Almeida, Cristina; Victório, Ana Cláudia; Melo, Pedro; Rodrigues, João Paulo; Oliveira, Manuela; Paz-Silva, Adolfo; Madeira de Carvalho, LuísFungal strains used in the biocontrol of animal gastrointestinal parasites have been mainly isolated from pasture soil, decaying organic matter, and feces from herbivores and carnivores. However, their isolation from birds and assessment of predatory activity against avian GI parasites has been scarce thus far. This research aimed to isolate flamentous fungi from avian fecal samples and evaluate their predatory activity against coccidia. A pool of 58 fecal samples from chickens, laying hens, and peacocks, previously collected between July 2020-April 2021, were used for isolation of flamentous fungi and assessment of their in vitro predatory activity against coccidian oocysts, using Water-Agar medium and coprocultures. The Willis-fotation technique was also performed to obtain concentrated suspensions of oocysts. A total of seven Mucor isolates was obtained, being the only fungal taxa identifed, and all presented lytic activity against coccidia. Isolates FR3, QP2 and SJ1 had signifcant coccidiostatic efcacies (inhibition of sporulation) higher than 70%, while isolates FR1, QP2 and QP1 had coccidicidal efcacies (destruction of the oocysts) of 22%, 14% and 8%, respectively, after 14 days of incubation, being a gradual and time-dependent process. To our knowledge, this is the frst report regarding the isolation of native predatory fungi from avian feces and demonstration of their lytic activity against coccidia
- Macular OCT-angiography parameters to predict the clinical stage of nonproliferative diabetic retinopathy: an exploratory analysisPublication . Rodrigues, Tiago M.; Marques, João P.; Soares, Mário; Simão, Sílvia; Melo, Pedro; Martins, Amélia; Figueira, João; Murta, Joaquim N.; Silva, RufinoBackground: To test whether a single or a composite set of macular vascular density parameters, evaluated with optical coherence tomography angiography (OCTA), are able to predict nonproliferative diabetic retinopathy (NPDR) staging according to the gold-standard ETDRS-grading scheme. Methods: Prospectively defined, cross-sectional study in which macular structural and vascular parameters of diabetic eyes with nonproliferative DR (up to ETDRS Level 53) were evaluated with OCTA (Avanti RTVue-XR 100, Optovue Inc, Fremont, CA). Seven-field photographs of the fundus were taken for DR staging according to the ETDRS-grading scheme. The vessel density in the superficial and deep capillary plexus (SCP and DCP, respectively), as well as in the choriocapillaris (CC), were calculated using automated software. Univariate and multivariate ordered logistic regression models were used in the analysis. P < 0.05 was considered statistically significant. Results: We included 101 eyes from 56 subjects (mean (SD) age 62.64 (11.74) years; 57.4% were male). On univariate analysis, several OCTA parameters were found to be associated with higher ETDRS level (parafoveal SCP density: OR = 0.87 (95% CI 0.76-0.99), p = 0.039; parafoveal DCP density: OR = 0.79 (95% CI 0.72-0.87), p < 0.001; CC density: OR = 0.89 (95% CI 0.80-0.99)), p = 0.036). In the final model, while also adjusting for relevant clinical features, only parafoveal vessel density in the DCP remained as a significant predictor of NPDR ETDRS level (OR = 0.54 (95% CI 0.32-0.92), p = 0.024). Conclusion: Our results suggest that parafoveal vessel density in the DCP is the parameter most robustly associated with ETDRS level. OCTA analysis may provide objective imaging biomarkers to monitor NPDR clinical progression.
- Peripapillary neurovascular coupling in the early stages of diabetic retinopathyPublication . Rodrigues, Tiago M.; Marques, João P.; Soares, Mário; Dolan, Michael-John; Melo, Pedro; Simão, Sílvia; Teles, João; Figueira, João; Murta, Joaquim N.; Silva, RufinoPurpose: To study radial peripapillary capillary (RPC) density in the early stages of diabetic retinopathy (DR), using optical coherence tomography angiography. Methods: A cross-sectional evaluation of RPCs was performed using optical coherence tomography angiography (Avanti RTVue-XR 100, Optovue Inc, Fremont, CA). Annular RPC density was the primary outcome. Global density and retinal nerve fiber layer thickness were secondary outcomes. Diabetic eyes were divided into three groups: no DR, mild nonproliferative DR (mild NPDR), and moderate NPDR. Multilevel mixed-effects univariate and multivariate linear regression models were used. Results: We included 155 eyes (n = 42 control; n = 27 no DR; n = 28 mild NPDR; and n = 58 moderate NPDR) from 86 subjects (mean [SD] age 63.39 [10.70] years; 46.45% male). When compared with controls, a significant decrease in annular RPC density was found in all groups of diabetic eyes on multivariate analysis (no DR: β = -2.95, P < 0.001; mild NPDR: β = -1.76, P = 0.017; and moderate NPDR: β = -2.82, P < 0.001). We also detected a significant decrease in retinal nerve fiber layer thickness in diabetic eyes (even in the no DR group). Furthermore, in diabetic eyes, annular RPC density and retinal nerve fiber layer thickness correlated significantly (R = 0.4874, P < 0.001). Conclusion: Peripapillary neurovascular changes occur early in the course of DR. Their significance in the progression of DR warrants further research.
- Trade of live bait in Portugal and risks of introduction of non-indigenous species associated to importationPublication . Sá, Erica; Fidalgo E Costa, Pedro; Cancela Da Fonseca, Luís; Alves, Ana; Castro, Nuno; Cabral, Sara; Chainho, Paula; Canning Clode, João; Melo, Pedro; Pombo, Ana; Costa, José LinoDifferent invertebrate groups are often exploited on sediment shores and mudflats, including polychaetes, sipunculids, bivalves and crustaceans. The commercial importance of polychaetes and sipunculids, that has increased in the early 2000's because of its use as a food source for the aquaculture sector and a growing demand of worms for use as sea angling bait, seems to be declining nowadays. In Portugal bait harvesting from natural populations became insufficient to meet market demands and as a result, polychaetes and sipunculids have been imported in recent years. Due to this it was important to know the ways of the live bait import to Portugal, and to assess the risk of introduction of non-indigenous species associated to that live bait trade. The origin and quantities of imported live bait were determined by examining the landing's records at Lisbon airport, from two periods: 2002-2003 and 2012-2015. Live worms imported to Portugal arrived almost exclusively from China, USA and Vietnam. Monthly import data and bait registers at fish auction landings were significantly correlated, showing that bait captures and imports are directly related to higher bait demand. In addition, the risk of live bait's importation as an introduction vector for non-indigenous species was evaluated by examining the bait boxes content. Five worm species were identified in bait boxes with foreign species: Glycera dibranchiata, Namalycastis rhodochorde, Perinereis cultrifera, Perinereis linea, and Sipunculus (Sipunculus) nudus. The examination of bait boxes in Portugal suggested that there is a low risk of associated hitchhiker species introduction and dissemination, mostly because of packaging procedures, which should be advised. The same is not true to the non-indigenous live bait species.