1. Investigación

European hedgehogs (Erinaceus europaeus) are nocturnal insectivores frequently found in urban areas. In the last decades, their population has declined in various European countries and human activities have emerged as significant contributors to this trend. While the literature has mainly focused on trauma as the major cause of mortality, few authors have considered pathological findings. The present study is based on the results of full post-mortem examinations performed on 162 European hedgehogs in Italy and 109 in Switzerland. Unlike in previous studies, the main cause of mortality was infectious diseases (60.5%), followed by traumatic insults (27.7%). The lungs were the main organ affected, showing mostly lymphoplasmacytic (45.9%), granulomatous (18.1%) or suppurative (8.2%) pneumonia. Nematodes were detected in 57.2% of all lungs and were significantly associated with pneumonia (p-value < 0.001). To our knowledge, this is the first study to report infectious diseases as the main cause of hedgehog death, emphasizing the need for wildlife rescue centers to adopt appropriate diagnostic and therapeutic measures. Further research is necessary to determine the broad range of infectious agents that affect this species and elucidate their interplay with the host. Finally, citizen sensitization should be implemented to promote responsible behaviors that could reduce human-related traumatic events.

The incidence of Listeria monocytogenes in refrigerated and frozen chicken parts was investigated, using the Mini-Vidas™ system (bioMérieux). Two hundred and eigthy chicken parts were tested: 40 skin samples from the breast and leg, 120 samples from refrigerated wings, breasts and legs and 120 samples from frozen wings, breasts and legs (40 of each). The 219 samples tested positive (78.21%). The parts with the highest incidence were frozen breasts (100%) and wings (95%). In frozen legs, the values were lower (60%). In refrigerated parts, the incidence was higher in breasts (85%) and in wings (80%). In legs samples, similarly to the frozen ones, the incidence was lower (50%). In the skin of the breasts and legs, the incidence was 77.50%. Statistical evaluation demonstrated that there are no differences between frozen breasts and wings but there are differences between similar refrigerated parts. The refrigerated and frozen legs are the only parts that are statistically equal. The percentages that were detected show the importance of requiring the absence of Listeria spp. in chickens.

The study was carried out under field conditions in a commercial farm, and 1,440 as-hatched Ross-308 broilers were included. Broilers were randomly distributed into 24 experimental 4-m2 pens (60 broilers/pen). Pens were randomized to the 3 treatment groups: a) tylvalosin 10 mg/kg of live BW during 2 d, b) positive control (tylosin during 2 d), and c) negative control (no treatment). The drugs were provided in the water supply. Mortality, individual BW, and feed intake were assessed. Clostridium presence was assessed in fecal and cecal samples, coccidian oocyst counts were assessed in fecal samples, and bacterial diversity was assessed in ileal content. Live BW at 42 d old was significantly better in the tylvalosin group than in tylosin and no-treatment groups, with tylvalosin-treated broilers reaching 80 to 100 g higher final live weight. Average daily gain results mirrored BW findings. The improvement of feed conversion rate with tylvalosin amounted to 0.13 and to 0.10 versus tylosin and no-treatment, respectively, with mortality being similar in all groups. Significantly reduced sulfite-reducing Clostridium and Clostridium perfringens counts in tylvalosin and tylosin groups versus the no-treatment group were observed in cecum content samples. In conclusion, according to the present study results, tylvalosin, at doses substantially lower than registered for poultry in Europe, has proven effective in controlling the colonization of the cecum by Clostridium ssp. in broilers, improving some productive performances.

Ovine pulmonary adenocarcinoma (OPA) is a contagious respiratory tumor of small ruminants, manifesting in chronic weight loss and respiratory failure. Infection with the betaretrovirus jaagsiekte sheep retrovirus (JSRV) is the cause of OPA. Here, we describe the gross and microscopic features of twenty-six sheep and one goat with naturally occurring JSRV-associated OPA. All the animals included in this study had pulmonary lesions morphologically consistent with OPA, but the majority of the observed lesions demonstrated features of both the classical and the atypical form of OPA, and were, therefore, classified grossly as mixed. The gross lesions were located mainly in the cranial pulmonary lobes, were multifocal to coalescing, variable in number and size, flat to slightly raised, firm, and white to grey. Histologically, the cases were classified according to the predominant architectural patterns as lepidic, papillary, acinar, or mixed; the mixed histological pattern was the most prevalent. The aim of this study was to describe the gross and microscopic spectrum of OPA in naturally infected small ruminants from Spain. The mixed form of OPA is less commonly reported, and can be confused with other concurrent pulmonary pathologies (such as BALT hyperplasia in SRLV-associated pneumonia or lungworm granulomas).

Listeria monocytogenes is a major human and animal foodborne patho-gen. However, data from environmental reservoirs remain scarce. Here, we usedwhole-genome sequencing to characterize Listeria species isolates recovered over 1year from wild animals in their natural habitats in Spain. Three different Listeria spp.(L. monocytogenes [n = 19], Listeria ivanovii subsp. londoniensis [n = 4], and Listeriainnocua [n = 3]) were detected in 23 animal tonsils (9 deer, 14 wild boars) and 2feeding troughs. No Listeria species was detected in feces. L. monocytogenes wasdetected in tonsils of 44.4% (8 out of 18) of deer and 40.7% (11 out of 27) of wildboars. L. monocytogenes isolates belonged to 3 different core genome multilocussequence typing (cgMLST) types (CTs) of 3 distinct sublineages (SL1, SL387, andSL155) from lineages I and II. While cgMLST type L1-SL1-ST1-CT5279 (IVb; clonalcomplex 1 [CC1]) occurred only in one animal, types L1-SL387-ST388-CT5239 (IVb;CC388) and L2-SL155-ST155-CT1170 (IIa; CC155) were retrieved from multiple ani-mals. In addition, L1-SL387-ST388-CT5239 (IVb; CC388) isolates were collected 1 yearapart, revealing their long-term occurrence within the animal population and/orenvironmental reservoir. The presence of identical L. monocytogenes strains in deerand wild boars suggests contamination from a common food or environmentalsource, although interhost transmission cannot be excluded. Pathogenicity islandsLIPI-1, LIPI-3, and LIPI-4 were present in 100%, 5%, and 79% of the L. monocytogenesisolates, respectively, and all L. monocytogenes lineage II isolates (n = 3) carried SSI-1stress islands. This study highlights the need for monitoring L. monocytogenes envi-ronmental contamination and the importance of tonsils as a possible L. monocyto-genes intrahost reservoir.

Background: Listeria monocytogenes is a foodborne bacterial pathogen that causes listeriosis, an infectious disease in animals and people, with pigs acting as asymptomatic reservoirs. In August 2019 an outbreak associated with the consumption of pork meat caused 222 human cases of listeriosis in Spain. Determining the diversity as well as the virulence potential of strains from pigs is important to public health. Methods: The behaviour of 23 L monocytogenes strains recovered from pig tonsils, meat and skin was compared by studying (1) internalin A, internalin B, listeriolysin O, actin assembly-inducing protein and PrfA expression levels, and (2) their invasion and intracellular growth in eukaryotic cells. Results: Marked differences were found in the expression of the selected virulence factors and the invasion and intracellular replication phenotypes of L monocytogenes strains. Strains obtained from meat samples and belonging to serotype 1/2a did not have internalin A anchored to the peptidoglycan. Some strains expressed higher levels of the studied virulence factors and invaded and replicated intracellularly more efficiently than an epidemic L monocytogenes reference strain (F2365). Conclusion: This study demonstrates the presence of virulent L monocytogenes strains with virulent potential in pigs, with valuable implications in veterinary medicine and food safety.

Listeriosis is a zoonotic disease caused by Listeria monocytogenes and Listeria ivanovii. The genus Listeria currently includes 27 recognized species and is found throughout the environment. The number of systematic studies on antimicrobial resistance in L. monocytogenes isolates from domestic farms using antimicrobial substances is limited. Importantly, dairy ruminant farms are reservoir of hypervirulent lineage I L. monocytogenes isolates, previously associated with human clinical cases. Considering that the classes of antibiotics used in food-producing domestic animals are frequently the same or closely related to those used in human medicine, studies about the impact of antibiotic use on the acquisition of antibiotic resistance in Listeria spp. in domestic animal farms are, therefore, of high importance. Here, susceptibility to 25 antibiotics was determined. Eighty-one animal-related, 35 food and 21 human pathogenic Listeria spp. isolates and 114 animal-related non-pathogenic Listeria spp. isolates were tested. Whole genome sequencing data was used for molecular characterization. Regarding L. monocytogenes, 2 strains from the clinical-associated linage I showed resistance to erythromycin, both related to dairy ruminants. Acquired resistance to one antibiotic was exhibited in 1.5% of L. monocytogenes isolates compared with 14% of non-pathogenic Listeria spp. isolates. Resistance to tetracycline (7.9%), doxycycline (7.9%), penicillin (4.4%), and ampicillin (4.4%) were the most frequently observed in non-pathogenic Listeria spp. While resistance to two or more antibiotics (5.6%) was most common in Listeria spp., isolates, resistance to one antibiotic was also observed (1.6%). The present results show that non-pathogenic Listeria spp. harbour antimicrobial resistance genes.

Leishmania is a genus of parasitic protozoa that causes a disease called leishmaniasis. Leishmaniasis is transmitted to humans through the bites of infected female sandflies. There are several different species of Leishmania that can cause various forms of the disease, and the symptoms can range from mild to severe, depending on species of Leishmania involved and the immune response of the host. Leishmania parasites have a variety of reservoirs, including humans, domestic animals, horses, rodents, wild animals, birds, and reptiles. Leishmaniasis is endemic of 90 countries, mainly in South American, East and West Africa, Mediterranean region, Indian subcontinent, and Central Asia. In recent years, cases have been detected in other countries, and it is already an infection present throughout the world. The increase in temperatures due to climate change makes it possible for sandflies to appear in countries with traditionally colder regions, and the easy movement of people and animals today, facilitate the appearance of Leishmania species in new countries. These data mean that leishmaniasis will probably become an emerging zoonosis and a public health problem in the coming years, which we must consider controlling it from a One Health point of view. This review summarizes the prevalence of Leishmania spp. around the world and the current knowledge regarding the animals that could be reservoirs of the parasite.

Leishmaniasis is a zoonotic parasitic disease, and the main reservoir of the parasite is the dog, although recent years have seen an increase in other mammalian species. In the Mediterranean region, where it is an endemic disease, it is caused by the species Leishmania infantum. The Ibizan hound, an autochthonous breed of this region, appears to have a genetic resistance to parasitic infection, whereas other canine breeds, such as the Boxer, are susceptible to infection. These differences are related to the differentiated activation of the immune response, with the Ibizan hound activating the Th1 immune response, whereas the Boxer breed triggers the Th2 immune response. Cytokine levels and genomic haplotypes of several genes involved in the immune response were analysed in twenty-eight Ibizan hound (resistant canine breed model) and twenty-four Boxer (susceptible canine breed) without clinical signs in the Mediterranean region. Cytokine levels were analysed by ELISA commercial kits and haplotypes were studied using CanineHD DNA Analysis BeadChip including 165,480 mapped positions. The results show 126 haplotypes associated with differential immune response in dogs. Specifically, haplotypes in IL12RB1, IL6R, CIITA, THEMIS, NOXA1, HEY2, RAB38, SLC35D2, SLC28A3, RASEF and DAPK1 genes are associated with serum levels of IFN-γ, IL-2, IL-8, and IL-18. These results suggest that the resistance or susceptibility to Leishmania infantum infection could be a consequence of haplotypes in several genes related to immune response. Future studies are needed to elucidate the relationship of these haplotypes with immune response and gene expression regulation.

Leishmaniosis is a zoonosis caused by Leishmania spp., an intracellular protozoan parasite. This parasite is transmitted by sandflies, and the disease is endemic in the Mediterranean basin. In recent years, the number of species which could be a reservoir of the parasite is increased. One of the most relevant species is the horse, due to their contact with humans and ability to control the disease, thus being a possible silent reservoir. In this study, we have analyzed the prevalence and factors related to L. infantum infection in healthy horses in the Mediterranean region. Epidemiological data and serum samples were obtained from 167 apparently healthy horses, and the presence of L. infantum was evaluated via the ELISA method and real-time PCR. The results show 27.5% of prevalence and that the main factors related to infection are equine breed, morphotype, outdoor living, use, and season. In conclusion, the prevalence of L. infantum infection in apparently healthy horses from eastern Spain (Mediterranean basin) is elevated. To control this zoonosis, it would be advisable to carry out more studies on this and other species that could be silent reservoirs of the parasite, as well as carry out measures such as the use of repellents on a regular basis.