Otilia Ferrer
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Otilia Ferrer has a total of 26 co-authors. Here are the top co-authors by number of shared publications:
- Antonio Ruiz
Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35416 Arucas, Spain
6 shared publications - José Manuel Molina
Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35416 Arucas, Spain
6 shared publications - Francisco Rodriguez
Department of Anatomy and Compared Anatomy Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35413 Gran Canaria, Spain
4 shared publications - Magnolia María Conde-Felipe
Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35413 Gran Canaria, Spain
4 shared publications - José Adrián Molina
Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35413 Gran Canaria, Spain
3 shared publications - Jessica Quesada
Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35413 Arucas, Spain
2 shared publications
Latest Publications
- Open Access
Field Studies on Immunization of Goat Kids Against Coccidiosis Using X-Radiation-Attenuated Oocysts of Different Eimeria Species
Background/Objectives: Caprine coccidiosis caused by Eimeria spp. is an important parasitic disease affecting goat health and production, with current control strategies relying mainly on anticoccidial drugs. The emergence of drug resistance and the need for sustainable alternatives highlight the importance of developing effective immunoprophylactic approaches. This study aimed to evaluate the immunoprotective effect of X-ray-attenuated Eimeria oocysts against caprine coccidiosis under field conditions and to determine the influence of vaccination on parasite burden, clinical outcomes, and productive performance. Methods: A field study was conducted using attenuated oocysts obtained from naturally infected goats from the same farm. The main Eimeria species identified were E. christenseni, E. arloingi, and E. ninakohlyakimovae. Three sequential trials were performed to optimize vaccination protocols. Goat kids aged 1–6 weeks received different immunization treatments consisting of doses ranging from 5 × 103 to 6 × 104 sporulated oocysts attenuated by X-ray irradiation at 10–30 kRad (100–300 Gy). Animals were monitored weekly through the evaluation of body weight, faecal consistency, health status, faecal oocyst shedding, and Eimeria species composition. Results: Vaccination with radiation-attenuated oocysts reduced parasite replication and faecal oocyst shedding, particularly affecting highly pathogenic species such as E. ninakohlyakimovae, while maintaining overall Eimeria species diversity. Clinical protection was mainly reflected in reduced parasite pressure rather than the complete prevention of mild diarrhoea. Productive parameters were not markedly improved, suggesting that the main benefit of vaccination was improved parasite control and reduced environmental contamination. Conclusions: Early administration of X-ray-attenuated Eimeria oocysts represents a promising strategy for controlling caprine coccidiosis. Vaccine efficacy depends on appropriate timing and optimization of attenuation conditions. Further studies investigating immune mechanisms, species-specific protection, and performance under commercial farming conditions are required to support the development of sustainable vaccines for goat production.
Open AccessField Studies on Immunization of Goat Kids Against Coccidiosis Using X-Radiation-Attenuated Oocysts of Different Eimeria Species
Background/Objectives: Caprine coccidiosis caused by Eimeria spp. is an important parasitic disease affecting goat health and production, with current control strategies relying mainly on anticoccidial drugs. The emergence of drug resistance and the need for sustainable alternatives highlight the importance of developing effective immunoprophylactic approaches. This study aimed to evaluate the immunoprotective effect of X-ray-attenuated Eimeria oocysts against caprine coccidiosis under field conditions and to determine the influence of vaccination on parasite burden, clinical outcomes, and productive performance. Methods: A field study was conducted using attenuated oocysts obtained from naturally infected goats from the same farm. The main Eimeria species identified were E. christenseni, E. arloingi, and E. ninakohlyakimovae. Three sequential trials were performed to optimize vaccination protocols. Goat kids aged 1–6 weeks received different immunization treatments consisting of doses ranging from 5 × 103 to 6 × 104 sporulated oocysts attenuated by X-ray irradiation at 10–30 kRad (100–300 Gy). Animals were monitored weekly through the evaluation of body weight, faecal consistency, health status, faecal oocyst shedding, and Eimeria species composition. Results: Vaccination with radiation-attenuated oocysts reduced parasite replication and faecal oocyst shedding, particularly affecting highly pathogenic species such as E. ninakohlyakimovae, while maintaining overall Eimeria species diversity. Clinical protection was mainly reflected in reduced parasite pressure rather than the complete prevention of mild diarrhoea. Productive parameters were not markedly improved, suggesting that the main benefit of vaccination was improved parasite control and reduced environmental contamination. Conclusions: Early administration of X-ray-attenuated Eimeria oocysts represents a promising strategy for controlling caprine coccidiosis. Vaccine efficacy depends on appropriate timing and optimization of attenuation conditions. Further studies investigating immune mechanisms, species-specific protection, and performance under commercial farming conditions are required to support the development of sustainable vaccines for goat production.
- Open Access
Comparative Study of Two Immunisation Protocols in Goats Using Thiol-Sepharose Chromatography-Enriched Extracts from Adult Haemonchus contortus Worms
Background: A comparative analysis was conducted between two immunisation protocols using different amounts of protein extracts from adult Haemonchus contortus worms, purified by thiol-Sepharose chromatography (625 μg/animal vs. 200 μg/animal). These protocols involved either five or two inoculations of the immunogen, respectively. Methods: To evaluate the level of immunoprotection, animals were challenged with L3 of H. contortus two weeks after the last inoculation of the immunogen and humanely sacrificed at 8 weeks post-infection. Parasitological, biopathological, and serological parameters were monitored through the experiment. Parasite burden, abomasal-specific antibody responses, and histopathological changes were determined at the end of the trial. Results: The immunisation protocols resulted in similar reductions in cumulative faecal egg counts (60.5–64.9%) and the total worm burden (47.5–50%) compared to non-immunized (control) animals. Overall, these parasitological data showed an early recovery of the haematocrit (PCV) after challenge in the immunised groups relative to control. Similarly, levels of H. contortus-specific IgG and IgA antibodies increased in both the serum and gastric mucus of immunised groups. Conclusions: These findings represent a further step towards the potential application of this type of immunogen under field conditions, as protective responses (associated with a reduction in faecal egg output) were achieved using a simplified protocol, with lower immunogen doses and fewer inoculations required to induce immunoprotection, thereby mitigating the pathological effects of the parasite and reducing its ability to spread and infect susceptible hosts.
Open AccessComparative Study of Two Immunisation Protocols in Goats Using Thiol-Sepharose Chromatography-Enriched Extracts from Adult Haemonchus contortus Worms
Background: A comparative analysis was conducted between two immunisation protocols using different amounts of protein extracts from adult Haemonchus contortus worms, purified by thiol-Sepharose chromatography (625 μg/animal vs. 200 μg/animal). These protocols involved either five or two inoculations of the immunogen, respectively. Methods: To evaluate the level of immunoprotection, animals were challenged with L3 of H. contortus two weeks after the last inoculation of the immunogen and humanely sacrificed at 8 weeks post-infection. Parasitological, biopathological, and serological parameters were monitored through the experiment. Parasite burden, abomasal-specific antibody responses, and histopathological changes were determined at the end of the trial. Results: The immunisation protocols resulted in similar reductions in cumulative faecal egg counts (60.5–64.9%) and the total worm burden (47.5–50%) compared to non-immunized (control) animals. Overall, these parasitological data showed an early recovery of the haematocrit (PCV) after challenge in the immunised groups relative to control. Similarly, levels of H. contortus-specific IgG and IgA antibodies increased in both the serum and gastric mucus of immunised groups. Conclusions: These findings represent a further step towards the potential application of this type of immunogen under field conditions, as protective responses (associated with a reduction in faecal egg output) were achieved using a simplified protocol, with lower immunogen doses and fewer inoculations required to induce immunoprotection, thereby mitigating the pathological effects of the parasite and reducing its ability to spread and infect susceptible hosts.
- Open Access
Electrochemotherapy Intralesional Treatment in a Captive Peregrine Falcon (Falco peregrinus) with Dermal Squamous Cell Carcinoma
Captive birds of prey often exceed their wild counterparts’ lifespan, as seen in bald eagles (Haliaeetus leucocephalus, ~20 years wild vs. ~40 years captive), golden eagles (Aquila chrysaetos, ~32 years wild vs. ~46 years captive), and Andean condors (Vultur gryphus, ~50 years wild vs. ~79 years captive), highlighting the impact of controlled environments on longevity. However, recent evidence suggests a rising incidence of neoplastic processes in these species. While previous studies have indicated a higher-than-expected prevalence of neoplasia in raptors, comprehensive research on this topic remains scarce. Squamous cell carcinoma (SCC), a frequently reported neoplasm in pet birds, has been documented in birds of prey, though the literature on its prevalence and management is limited. Retrospective studies have identified SCC cases in peregrine falcons (Falco peregrinus), primarily affecting the flank or thigh, with locally invasive behavior and rare distant metastasis. Complete surgical excision is the preferred treatment for SCCs, yet its feasibility is often constrained by tumor invasiveness and anatomical limitations. Electrochemotherapy (ECT) has emerged as a promising alternative, utilizing electroporation to enhance intracellular drug uptake while minimizing systemic toxicity. Bleomycin and cisplatin have been successfully used in avian intralesional chemotherapy, offering a potentially safer and effective treatment approach. ECT has demonstrated efficacy in various exotic species, yet its application in raptors remains largely unexplored. This case report describes the use of electrochemotherapy with bleomycin in a peregrine falcon diagnosed with SCC, contributing to the growing body of evidence supporting its clinical utility in avian oncology.
Open AccessElectrochemotherapy Intralesional Treatment in a Captive Peregrine Falcon (Falco peregrinus) with Dermal Squamous Cell Carcinoma
Captive birds of prey often exceed their wild counterparts’ lifespan, as seen in bald eagles (Haliaeetus leucocephalus, ~20 years wild vs. ~40 years captive), golden eagles (Aquila chrysaetos, ~32 years wild vs. ~46 years captive), and Andean condors (Vultur gryphus, ~50 years wild vs. ~79 years captive), highlighting the impact of controlled environments on longevity. However, recent evidence suggests a rising incidence of neoplastic processes in these species. While previous studies have indicated a higher-than-expected prevalence of neoplasia in raptors, comprehensive research on this topic remains scarce. Squamous cell carcinoma (SCC), a frequently reported neoplasm in pet birds, has been documented in birds of prey, though the literature on its prevalence and management is limited. Retrospective studies have identified SCC cases in peregrine falcons (Falco peregrinus), primarily affecting the flank or thigh, with locally invasive behavior and rare distant metastasis. Complete surgical excision is the preferred treatment for SCCs, yet its feasibility is often constrained by tumor invasiveness and anatomical limitations. Electrochemotherapy (ECT) has emerged as a promising alternative, utilizing electroporation to enhance intracellular drug uptake while minimizing systemic toxicity. Bleomycin and cisplatin have been successfully used in avian intralesional chemotherapy, offering a potentially safer and effective treatment approach. ECT has demonstrated efficacy in various exotic species, yet its application in raptors remains largely unexplored. This case report describes the use of electrochemotherapy with bleomycin in a peregrine falcon diagnosed with SCC, contributing to the growing body of evidence supporting its clinical utility in avian oncology.
- Open Access
- 12 March 2025
- Published by MDPI AG in Microorganisms
- Vol. 13 (3) , 644
Molecular Epidemiology of Cryptosporidiosis on Lamb and Goat Kid Farms in Gran Canaria, Canary Islands (Spain)
The aim of this study was to analyse and characterise Cryptosporidium spp. in sheep and goats in Gran Canaria (Spain) and to identify the risks and economic factors related to the disease. During sampling, a semi-structured survey was conducted with farmers, and faecal samples were collected from lambs, goat kids, sheep, and adult goats from a total of 30 farms. Adult samples were examined microscopically for the presence of Cryptosporidium spp. oocysts, with only three positive samples being found in sheep and one in goats. The PCR of the SSU rRNA gene was performed on all juvenile and adult samples, and positive samples from lambs (8.3%), sheep (6.9%), goat kids (23.3%), and goats (2.5%) were subjected to sequencing, detecting three of the most important species in small ruminants: C. parvum, C. xiaoi, and C. ubiquitum. By sequencing the GP60 PCR products, two subtypes of C. parvum belonging to the IId family were identified, IIdA16G1 and IIdA23G1, with the latter being the most frequent. Although the prevalence of the disease was not very high, the zoonotic potential of C. parvum and the limited awareness of the parasite among farmers make surveillance and health education focused on the control of this member of Apicomplexa necessary.
- 12 March 2025
- Published by MDPI AG in Microorganisms
- Vol. 13 (3) , 644
Open AccessMolecular Epidemiology of Cryptosporidiosis on Lamb and Goat Kid Farms in Gran Canaria, Canary Islands (Spain)
The aim of this study was to analyse and characterise Cryptosporidium spp. in sheep and goats in Gran Canaria (Spain) and to identify the risks and economic factors related to the disease. During sampling, a semi-structured survey was conducted with farmers, and faecal samples were collected from lambs, goat kids, sheep, and adult goats from a total of 30 farms. Adult samples were examined microscopically for the presence of Cryptosporidium spp. oocysts, with only three positive samples being found in sheep and one in goats. The PCR of the SSU rRNA gene was performed on all juvenile and adult samples, and positive samples from lambs (8.3%), sheep (6.9%), goat kids (23.3%), and goats (2.5%) were subjected to sequencing, detecting three of the most important species in small ruminants: C. parvum, C. xiaoi, and C. ubiquitum. By sequencing the GP60 PCR products, two subtypes of C. parvum belonging to the IId family were identified, IIdA16G1 and IIdA23G1, with the latter being the most frequent. Although the prevalence of the disease was not very high, the zoonotic potential of C. parvum and the limited awareness of the parasite among farmers make surveillance and health education focused on the control of this member of Apicomplexa necessary.
- Open Access
Analysis of Protection and Immune Response against Teladorsagia circumcincta in Goats Immunised with Thiol-Binding Proteins from Adult Worms
In view of the increasing occurrence of anthelmintic-resistant strains of gastrointestinal nematodes in ruminants, various alternative control strategies have been investigated, such as those based on the induction of protective immune responses by immunisation with parasite antigens. In this study, the protective activity of somatic antigens from adult worms of Teladorsagia circumcincta purified by affinity chromatography on thiol-sepharose was analysed in goats. After challenge, the enriched products induced a slight reduction in the cumulative faecal egg counts (21%) and in the number of worms (23.3%), with a greater effect on female worms, which also showed a reduction in parameters related to their fertility. These parasitological findings were associated with a Th2 immune response, with a prominent local humoral response and an eosinophilic infiltrate in the gastric mucosa (negatively associated with the fertility of female worms and the number of worms, respectively), as well as an infiltration of MCHII+, CD4+, IgG+ and IgA+ cells. However, several analyses showed an increase in CD8+ cells in the mucosa, as well as IL-2 expression in the gastric lymph nodes, which may have been associated with inhibition of protective responses or with the development of mixed Th1/Th2 responses, a finding that should be analysed in future studies.
Open AccessAnalysis of Protection and Immune Response against Teladorsagia circumcincta in Goats Immunised with Thiol-Binding Proteins from Adult Worms
In view of the increasing occurrence of anthelmintic-resistant strains of gastrointestinal nematodes in ruminants, various alternative control strategies have been investigated, such as those based on the induction of protective immune responses by immunisation with parasite antigens. In this study, the protective activity of somatic antigens from adult worms of Teladorsagia circumcincta purified by affinity chromatography on thiol-sepharose was analysed in goats. After challenge, the enriched products induced a slight reduction in the cumulative faecal egg counts (21%) and in the number of worms (23.3%), with a greater effect on female worms, which also showed a reduction in parameters related to their fertility. These parasitological findings were associated with a Th2 immune response, with a prominent local humoral response and an eosinophilic infiltrate in the gastric mucosa (negatively associated with the fertility of female worms and the number of worms, respectively), as well as an infiltration of MCHII+, CD4+, IgG+ and IgA+ cells. However, several analyses showed an increase in CD8+ cells in the mucosa, as well as IL-2 expression in the gastric lymph nodes, which may have been associated with inhibition of protective responses or with the development of mixed Th1/Th2 responses, a finding that should be analysed in future studies.
- Open Access
- 23 March 2023
- Published by Elsevier in Experimental Parasitology
- Vol. 248, 108512
Immunization with thiol-binding proteins from Haemonchus contortus adult worms partially protects goats against infection during prepatency
- 23 March 2023
- Published by Elsevier in Experimental Parasitology
- Vol. 248, 108512
Open AccessImmunization with thiol-binding proteins from Haemonchus contortus adult worms partially protects goats against infection during prepatency
- Open Access
- 15 January 2022
- Published by Springer Nature in Parasites & Vectors
- Vol. 15 (1) , 1-10
Local immune response of Canarian Majorera goats infected with Teladorsagia circumcincta
Background: Due to increased anthelmintic resistance, alternative methods to drugs are necessary to control gastrointestinal nematodes (GINs). Some of the most promising alternatives are based on the immune response of the host, such as the selection of genetically resistant breeds or the use of vaccines against these parasites. Given the limited information available on the immune response against GINs in goats, this study investigated the local immune response of goat kids of an indigenous Canary Islands breed (Majorera breed) experimentally infected withTeladorsagia circumcincta, one of the most pathogenic and prevalent GIN species.Methods: For this purpose, the relationship between different parasitological (number of mature and immature worms, worm length, and number of intrauterine eggs) and immunological parameters at the local level (related to both the humoral and cellular immune response) was analyzed at early (1 week post-infection [wpi]) and late (8 wpi) stages of infection.Results: Primary infection of goat kids withT. circumcinctainfective larvae (L3) generated a complex immune response that could be defined as Th2 type, characterized by increased infiltration in abomasal tissues of several effector cells as well as a progressive presence of specific antibodies against parasitic antigens in the gastric mucus. Cellular responses were evidenced from 1 wpi onward, showing an increase in antigen-presenting cells and various lymphocyte subsets in the gastric mucosa.Conclusions: The complexity of the host response was evidenced by statistically significant changes in the number of all these subpopulations (MHCII+, CD4+, CD8+, γδ+, CD45R+, IgA+, and IgG+), as well as in the evolution of the relative cytokine gene expression. From a functional point of view, negative associations were observed between the number of most of the immune cells (CD4, IgA, IgG, and CD45R cells) and parameters that could be related to the fecundity of worms, a phenomenon that was especially evident when the number of IgG and CD45R cells or the specific IgA levels of the gastric mucus were compared with parasitological parameters such as the female worm length or fecal egg counts at 8 wpi.Graphical
- 15 January 2022
- Published by Springer Nature in Parasites & Vectors
- Vol. 15 (1) , 1-10
Open AccessLocal immune response of Canarian Majorera goats infected with Teladorsagia circumcincta
Background: Due to increased anthelmintic resistance, alternative methods to drugs are necessary to control gastrointestinal nematodes (GINs). Some of the most promising alternatives are based on the immune response of the host, such as the selection of genetically resistant breeds or the use of vaccines against these parasites. Given the limited information available on the immune response against GINs in goats, this study investigated the local immune response of goat kids of an indigenous Canary Islands breed (Majorera breed) experimentally infected withTeladorsagia circumcincta, one of the most pathogenic and prevalent GIN species.Methods: For this purpose, the relationship between different parasitological (number of mature and immature worms, worm length, and number of intrauterine eggs) and immunological parameters at the local level (related to both the humoral and cellular immune response) was analyzed at early (1 week post-infection [wpi]) and late (8 wpi) stages of infection.Results: Primary infection of goat kids withT. circumcinctainfective larvae (L3) generated a complex immune response that could be defined as Th2 type, characterized by increased infiltration in abomasal tissues of several effector cells as well as a progressive presence of specific antibodies against parasitic antigens in the gastric mucus. Cellular responses were evidenced from 1 wpi onward, showing an increase in antigen-presenting cells and various lymphocyte subsets in the gastric mucosa.Conclusions: The complexity of the host response was evidenced by statistically significant changes in the number of all these subpopulations (MHCII+, CD4+, CD8+, γδ+, CD45R+, IgA+, and IgG+), as well as in the evolution of the relative cytokine gene expression. From a functional point of view, negative associations were observed between the number of most of the immune cells (CD4, IgA, IgG, and CD45R cells) and parameters that could be related to the fecundity of worms, a phenomenon that was especially evident when the number of IgG and CD45R cells or the specific IgA levels of the gastric mucus were compared with parasitological parameters such as the female worm length or fecal egg counts at 8 wpi.Graphical