Alba Pablos-Tanarro

Injuries and bone fractures are the most frequent causes of admission at wildlife rescue centers. Wild birds are more susceptible to open fractures due to their anatomical structure, which can lead to osteomyelitis and necrosis. Antibiotic therapy in these cases is indispensable, but the increase of antimicrobial-resistant isolates in wildlife has become a significant concern in recent years. In this context, the likelihood of antibiotic failure and death of animals with infectious issues is high. This study aimed to isolate, identify, and assess the antimicrobial resistance pattern of bacteria in wounds and open fractures in wild birds. To this end, injured birds admitted to a wildlife rescue center were sampled, and bacterial isolation and identification were performed. Then, antimicrobial susceptibility testing was assessed according to the disk diffusion method. In total, 36 isolates were obtained from 26 different birds. The genera detected were Staphylococcus spp. (63.8%), Escherichia (13.9%), Bacillus (11.1%), Streptococcus (8.3%), and Micrococcus (2.8%). Among Staphylococcus isolates, S. lentus and S. aureus were the most frequent species. Antimicrobial resistance was detected in 82.6% of the isolates, among which clindamycin resistance stood out, and 31.6% of resistant isolates were considered multidrug-resistant. Results from this study highlight the escalating scope of antimicrobial resistance in wildlife. This level of resistance poses a dual concern for wildlife: firstly, the risk of therapeutic failure in species of significant environmental value, and, secondly, the circulation of resistant bacteria in ecosystems.

The malaria parasite Plasmodium falciparum readily develops resistance to dihydroorotate dehydrogenase inhibitors in vitro and in a mouse model of infection.

Scope: Egg is the second most frequent source of allergic reactions in children. Egg yolk (EY) amounts to one‐third in weight of a fresh whole egg, but its contribution to egg allergy has not been investigated in depth. This study assesses whether EY influences the capacity of egg white (EW) to sensitize and trigger allergic responses.Methods and results: BALB/c mice were exposed to EW, EY, and their mixture, using models of orally (with and without adjuvant) and adjuvant‐free intraperitoneally induced allergy. In vitro assays were also conducted to examine epithelial and dendritic cell (DC) functions. Results showed that EY played a role during the sensitizing phase of allergy. EY exerted local Th2‐biasing effects through the upregulation of intestinal IL‐33 expression and it also favored Th2 polarization directly during DC presentation of allergens to T cells.Conclusion: The results obtained reveal that EY provides Th2‐adjuvant stimuli to the immune system that may increase the susceptibility to develop egg allergy. The joint administration of EW and EY may be a trigger for initiation or maintenance of egg allergy with implications in prevention strategies regarding egg introduction in the diet of susceptible children.

The objective of the present study was to investigate the seroprevalence of Toxoplasma gondii infection in Iberian sows reared in extensive and intensive management conditions and to compare two serologic techniques used for diagnosis. In addition, some possible risk factors associated with the presence of serum antibodies to T. gondii were also studied. Serum samples were collected from 2492 Iberian sows on 14 pig farms. Three types of management systems were included, traditional extensive outdoor farms (five farms), intensive farms with outdoor access (n = 4), and conventional intensive indoor farms (n = 5). The presence of serum antibodies to T. gondii was evaluated by two commercially available tests: an indirect enzyme-linked immunosorbent assay (ELISA) and a direct agglutination test (DAT). Serum antibodies against T. gondii were detected in 237 sows (9.5%) by at least one of the techniques used. The mean seroprevalence of toxoplasmosis in Iberian sows was 5.8% by ELISA and 8.9% by DAT. An agreement kappa-value of 0.68 (95%, CI = 0.63–0.74) was found between both tests. The results from this study suggest that the prevalence of T. gondii antibodies among Iberian sows seems to be moderate-low. The presence of serum antibodies against T. gondii in Iberian sows was associated to an extensive management system and low-level facilities of the farm, sow number (> 1000 animals), presence of cats, absence of rodent control and bird-proof nets in windows, well-water source, feed sources and storage (from the same farm and not stored in silo), absence of fences, and low farm worker qualification.

This work aimed to assess the contribution of the major egg white proteins, ovalbumin, ovomucoid and lysozyme, to the induction and elicitation of allergenic responses. For this purpose, BALB/c mice were orally administered either the individual egg allergens or a mixture of the three proteins in the same proportion, in order to evaluate their relative allergenicity avoiding their different abundance in egg white. Cholera toxin was used as a Th2-polarizing adjuvant. Ovomucoid and lysozyme triggered the most severe anaphylaxis reactions upon oral challenge. As compared with ovalbumin and ovomucoid, lysozyme was a more active promotor of early IgE and IgG1 production and it stimulated stronger Th2-biased responses from both mesenteric lymph node and spleen cells. These results indicate that lysozyme is highly immunogenic and should be considered as a major allergen whose clinical usefulness in the diagnosis, prognosis and therapeutic approaches of egg allergy deserves further consideration.

Cow’s milk allergy (CMA) prevails in infants and brings increased risk of developing other allergic diseases. Oral administration of specific β-lactoglobulin (BLG)-derived peptides (PepMix) and a specific blend of short- and long-chain fructo-oligosaccharides and Bifidobacterium breve M-16V (FF/Bb) was found to partially prevent CMA development in mice. In this study, we aimed to expand the knowledge on the preventive potential and the underlying mechanisms of this approach. Three-week-old female C3H/HeOuJ mice were orally exposed to PepMix ± FF/Bb prior to a 5-week oral sensitization with whole whey and cholera toxin as an adjuvant. The acute allergic skin response was determined after an intradermal challenge with whole whey protein. Following an oral challenge with whey, regulatory T cells (Tregs) in the small intestine lamina propria (SI-LP) and mRNA expression of immune markers in the Peyer’s patches (PP) were investigated. The early impact of PepMix and FF/Bb interventions on the immune system during the oral tolerance (OT) induction phase was investigated after the last OT administration. Pre-exposing mice to PepMix+FF/Bb partially prevented the acute allergic skin response compared to PBS and increased Tregs and activated T cells in the SI-LP compared to sham-sensitized mice. It also increased the mRNA expression of Tbet over GATA3 in the PP of whey-sensitized mice. Directly upon the 6-day OT phase, FF/Bb intervention enhanced caecal content levels of propionic and butyric acid in PepMix-fed mice and the former was positively correlated with Foxp3+ cell numbers in the colon. In the PP of PepMix+FF/Bb-exposed mice, IL-22 mRNA expression increased and IL-10 followed the same tendency, while the Foxp3 expression was increased over GATA3 and RorγΤ. In the colon, the Tbet mRNA expression increased over GATA3, while IL-22 decreased. In addition, the Foxp3+/GATA3+ and regulatory/effector T cell ratios in the MLN and the CD11b+/CD11b- conventional DC ratio in the SI-LP were increased. In conclusion, the FF/Bb diet facilitates the capacity of the specific BLG-peptides to partially prevent the allergic response after sensitization to whole whey protein, possibly by creating a tolerance-prone environment during the OT phase. Such a dietary intervention might contribute to tailoring successful strategies for CMA prevention.

Summary: Background: The application of specific immunotherapy to stimulate oral tolerance towards food allergens is hampered by the high frequency of adverse side‐effects and the excessive duration of the treatments.Objective: In this work, a hydrolysate of ovalbumin with pepsin (OP), selected for its low IgE reactivity and Th2‐stimulating capacity, was assayed for its ability to prevent and treat allergy to egg white (EW).Methods: As a first step, the safety of OP, in terms of the absence of sensitizing and eliciting potential, was evaluated in BALB/c mice. Then, its suitability for prophylactic and therapeutic applications was compared with that of the intact allergen, paying attention to the molecular and cellular mechanisms involved in the control of the allergic process. To this aim, IgE, IgG1, IgG2a and IgA levels, allergic reactions, expression of genes related to Th1, Th2, Th17 and Treg responses, dendritic and T cell populations were assessed in intestinal tissues and spleens of EW‐allergic mice, either untreated or treated with intact ovalbumin (OVA) or OP.Results: The hydrolysate of OVA with pepsin was hypoallergenic, lacked sensitizing potential and offered preventive and therapeutic protection against allergy to EW through the induction of Treg cells and the up‐regulation of TGF‐β, IL‐10, IL‐17, Foxp3 and RORγt in intestinal tissues. This restrained the expression of GATA3 and the differentiation of Th2 cells, leading to low cytokine responses following ex vivo spleen cell stimulation. As compared with intact OVA, OP was more effective against sensitization. In addition, in the therapeutic setting, OP provided quicker desensitization that lasted for at least 3 weeks after discontinuation of the therapy.Conclusions and Clinical Relevance: This study provides evidence for the superior role of hydrolysed, as compared to intact allergens, in the prevention of allergy development and in the promotion of long‐term desensitization, as well as of intermolecular tolerance.

This study assesses to what extent technological processes that lead to different degrees of denaturation of egg white proteins affect their allergenicity. We focused on heat (80 °C, 10 min) and high-pressure (400 MPa and 37 °C, 10 min) treatments and used a BALB/c mouse model of food allergy. Oral sensitization to egg white using cholera toxin as adjuvant induced the production of IgE and IgG1 isotypes and led to severe clinical signs following challenge with the allergen. Extensive protein denaturation caused by heat treatment increased its ability to induce Th1 responses and reduced both its sensitizing and eliciting capacity. Heated egg white stimulated the production of IgE over IgG1 antibodies directed, at least in part, toward new epitopes exposed as a result of heat treatment. Conversely, partial denaturation caused by high-pressure treatment increased the ability of egg white to stimulate Th2 responses and its allergenic potential.