1. Investigación

Oestrus ovis is an obligate parasite that causes myiasis in domestic ruminants, being commonly found in the Mediterranean area. From 2009 to 2019 a total of 3476 heads of culling sheep and goats from the Mediterranean coast of Spain were examined for the presence of O. ovis. The total prevalence was 56.3%, significantly higher in sheep than in goats (61.2% and 43%, respectively). Differences were found in the mean annual prevalence, with the highest value being registered in 2018 (61.7%) and the lowest in 2012 (50.3%). Autumn, for sheep, and winter, for goats, were the seasons with the highest number of infested specimens. Temperature, but not rainfall, was found to be associated with prevalence (p < 0.05). Most L1 were found in the anatomic region I (septum, meatus, and ventral conchae), while L2 and L3 were mainly located in regions II (nasopharynx, ethmoid labyrinth, and dorsal conchae), and III (sinuses). The overall intensity was 12.8 larvae per head, significantly higher in sheep (13.3) than in goats (3.5). Our results confirm the high prevalence of O. ovis in sheep and goats in this geographic area over the last decade, with the trend increasing in recent years in association with higher mean temperatures.

Fasciolosis is caused by F. hepatica and F. gigantica. It is of economic and zoonotic importance. Several strategies for control of fasciolosis are being used; these include vaccination of animals that are at risk and control of the snails that carry the parasite. Several types of vaccines, such as recombinant cathepsin, mixed recombinant vaccine, fatty-acid-binding proteins, a cocktail of recombinant and fatty-acid-binding vaccines, nucleic acid-based vaccines and gene-silencing methods have been reported to show efficacy ranges of 32-75%, 52-79%, 8-36%, 43-68%, 74-100% and 90% respectively. These are currently undergoing experimental testing against fasciolosis. The study described in this paper was carried out to discover the comparative efficacy of these vaccines in the enhancement of the immune response in order to find the most effective method so that future research could focus on the development of that type of vaccine. Besides immunization, control of the intermediate host of the parasite (snail) is also an effective way to control fasciolosis. Snails are controlled through the use of physical, chemical and biological methods. The most effective of these is biological control using Sphaerodema urinator as a predator of snails.

Bonelli’s eagle (Aquila fasciata) is an endangered raptor species in Europe, and trichomonosis is one of the menaces affecting chicks at nest. In this paper, we attempt to describe the oral microbiome of Bonelli’s eagle nestlings and evaluate the influence of several factors, such as captivity breeding, Trichomonas gallinae infection, and the presence of lesions at the oropharynx. The core oral microbiome of Bonelli’s eagle is composed of Firmicutes, Bacteroidota, Fusobacteria and Proteobacteria as the most abundant phyla, and Megamonas and Bacteroides as the most abundant genera. None of the factors analysed showed a significant influence on alfa diversity, but beta diversity was affected for some of them. Captivity breeding exerted a high influence on the composition of the oral microbiome, with significant differences in the four most abundant phyla, with a relative increase of Proteobacteria and a decrease of the other three phyla in comparison with chicks bred at nest. Some genera were more abundant in captivity bred chicks, such as Escherichia-Shigella, Enterococcus, Lactobacillus, Corynebacterium, Clostridium and Staphylococcus, while Bacteroides, Oceanivirga, Peptostreptococcus, Gemella, Veillonella, Mycoplasma, Suttonella, Alloscardovia, Varibaculum and Campylobacter were more abundant in nest raised chicks. T. gallinae infection slightly influenced the composition of the microbiome, but chicks displaying trichomonosis lesions had a higher relative abundance of Bacteroides and Gemella, being the last one an opportunistic pathogen of abscess complications in humans. Raptor’s microbiomes are scarcely studied. This is the first study on the factors that influence the oral microbiome of Bonelli’s eagle.

Toxocara spp. is one of the most common zoonotic geohelminths in the world. Its infections are associated with the accidental ingestion of contaminated soil and affecting, especially children. In this study, feces, and soil samples from 14 public parks in the city of Valencia were analyzed. The Telemann method and a modified version of a sieving technique were used to process feces and soil, respectively. None of the fecal samples and 10.9% of soil samples from five parks (35.7%) tested positive for the presence of Toxocara eggs. The most contaminated areas were the canine sanitary parks (30.8% of the samples), followed by socialization areas for dogs (9.7%); no positive samples were found at children’s playgrounds. Our results suggest that most pets in Valencia are periodically dewormed, although additional preventive measures should be applied, since the risk of infection exists probably due to the presence of stray dogs and feral cats.

Honeybee populations have locally and temporally declined in the last few years because of both biotic and abiotic factors. Among the latter, one of the most important reasons is infection by the microsporidia Nosema ceranae, which is the etiological agent of type C nosemosis. This species was first described in Asian honeybees (Apis cerana). Nowadays, domestic honeybees (Apis mellifera) worldwide are also becoming infected due to globalization. Type C nosemosis can be asymptomatic or can cause important damage to bees, such as changes in temporal polyethism, energy and oxidative stress, immunity loss, and decreased average life expectancy. It causes drastic reductions in workers, numbers of broods, and honey production, finally leading to colony loss. Common treatment is based on fumagillin, an antibiotic with side effects and relatively poor efficiency, which is banned in the European Union. Natural products, probiotics, food supplements, nutraceuticals, and other veterinary drugs are currently under study and might represent alternative treatments. Prophylaxis and management of affected colonies are essential to control the disease. While N. ceranae is one potential cause of bee losses in a colony, other factors must also be considered, especially synergies between microsporidia and the use of insecticides.

Lungworms can exert a negative impact on wild ruminant fitness, for this reason, the diagnosis of the associated diseases is an important prevention measure. The Baerman-Wetzel technique is the most usual method for the diagnosis of bronchopulmonary nematodes and is based on the active migration and movement of their first-stage larvae (L1). Pulmonary tissue samples are frequently used for the diagnosis of these parasites, but this kind of sample is not always available and easy to obtain. Faecal samples represent a more accessible choice for parasite monitoring. This work aimed to evaluate the agreement between the results obtained by the Baermann–Wetzel technique when samples of lung parenchyma or faeces from wild ruminants are used. A good level of agreement as well as a similar sensitivity between the two types of sample were observed, validating the use of faecal samples as a less invasive and cost-effective alternative for the monitoring of lungworm in wild ruminant populations.

Avian trichomonosis is a parasitic disease that affects wild birds, The objective of this work was to determine the importance of avian trichomonosis in Bonelli's eagles to improve conservation measures in this population. One hundred and eighty-eight birds were studied: 181 chicks,, two juveniles, one subadult and four adults. The birds were externally examined and gross lesions at the oropharynx registered. Samples from the oropharyngeal cavity were obtained for Trichomonas spp. detection by culture and PCR, and positive samples were subjected to a multi-locus sequence typing approach, including the ITS1/5.8S/ITS2 region (ITS), ribosomal RNA small subunit (18S) and Fe-hydrogenase gene (FeHyd). Global prevalence for T. gallinae infection was 37.8% in total, 45.5% in nestlings. Thirty three percent of the birds developed lesions that ranged from mild (n=41) to moderate (n=14) or severe (n=7). MLST analysis showed five different MLS types, being ITS-A/18S-VI/FeHyd-A1 and ITS-D/18S-II/Fe-C4 the most frequent. An association between ITS-A/18S-VI/FeHyd-A1 and moderate or severe lesions was observed, but birds with type ITS-A/18S-VI/FeHyd-A2 also developed lesions. On the contrary, birds with MLS type ITS-D/18S-II/FeHyd-C4 displayed only a low proportion of mild lesions. Chicks raised in nests were at higher risk for T. gallinae infection and development of lesions than chicks raised in captivity. Disconrdances between samples cultured in TYM and samples subjected to PCR from oropharyngeal swabs were observed, being swab-ITS-PCR more sensitive.

The epidemiology behind multi-host/multi-parasite systems is particularly interesting to investigate for a better understanding of the complex dynamics naturally occurring in wildlife populations. We aimed to approach the naturally occurring polyparasitism of gastrointestinal nematodes in a sympatric wild ruminant scenario present in south-east Spain. To this end, the gastrointestinal tract of 252 wild ruminants of four different species (red deer, Cervus elaphus; mouflon, Ovis aries musimon; Iberian ibex, Capra pyrenaica and fallow deer, Dama dama) were studied in Cazorla, Segura y Las Villas Natural Park (Andalusia, Spain). Of the analysed animals, 81.52% were positive for parasite infection and a total of 29 nematode species were identified. Out of these, 25 species were detected in at least two host species and 11 parasitized all ruminant species surveyed. The multi-host interaction between these nematodes and the four host species is discussed under the perspective of host family-based differences.

Eighty-four Murciano–Granadina dairy goats slaughtered in the region of Murcia (South-East Spain) were necropsied to evaluate parasitic infections. The majority of the animals (94.0%) were parasitised and multiple infections were present. Twenty-one parasite species were found, including 18 nematode species (Muellerius capillaris, Dictyocaulus filaria, Neostrongylus linearis, Cystocaulus ocreatus, Teladorsagia circumcincta, T. occidentalis, T. trifurcata, Marshallagia marshalli, Camelostrongylus mentulatus, Trichostrongylus capricola, Nematodirus abnormalis, N. filicollis, N. spathiger, T. vitrinus, T. colubriformis, Trichuris spp., Chabertia ovina and Skrjabinema ovis); one trematode species (Dicrocoelium dendriticum); one arthropod species (Oestrus ovis); and one protozoa genus (Eimeria spp.). Additionally, 17.85% of the animals were Mycobacterium spp. positive. Therefore, comparison between parasite prevalence, intensity and abundance in tuberculosis-positive and -negative animals was performed. Statistically significant differences between the prevalence of lungworms and gastrointestinal nematodes in Mycobacterium spp. infected and free goats were found. The paper discusses this co-infection between Mycobacteriaceae and endoparasites.