Zenodo (CERN European Organization for Nuclear Research), Sep 3, 2020
Bovine paratuberculosis (PTB) is a chronic granulomatous enteritis, caused by Mycobacterium avium... more Bovine paratuberculosis (PTB) is a chronic granulomatous enteritis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), responsible for important economic losses in the dairy industry. Current diagnostic methods have low sensitivities for detection of latent forms of MAP infection, defined by focal granulomatous lesions and scarce humoral response or MAP presence. In contrast, patent infections correspond to multifocal and diffuse types of enteritis where there is increased antibody production, and substantial mycobacterial load. Our previous RNA-Seq analysis allowed the selection of five candidate biomarkers overexpressed in peripheral blood of MAP infected Holstein cows with focal (ABCA13 and MMP8) and diffuse (FAM84A, SPARC and DES) lesions vs. control animals with no detectable PTB-associated lesions in intestine and regional lymph nodes. The aim of the current study was to assess the PTB diagnostic potential of commercial ELISAs designed for the specific detection of these biomarkers. The ability of these ELISAs to identify animals with latent and/or patent forms of MAP infection was investigated using serum from naturally infected cattle (n = 88) and non-infected control animals (n = 67). ROC analysis revealed that the ABCA13-based ELISA showed the highest diagnostic accuracy for the detection of infected animals with focal lesions (AUC 0.837, sensitivity 79.25% and specificity 88.06%) and with any type of histological lesion (AUC 0.793, sensitivity 69.41% and specificity 86.57%) improving on the diagnostic performance of the popular IDEXX ELISA and other conventional diagnostic methods. SPARC and MMP8 showed the highest diagnostic accuracy for the detection of animals with multifocal (AUC 0.852) and diffuse lesions (AUC 0.831), respectively. In conclusion, our results suggest that quantification of ABCA13, SPARC and MMP8 by ELISA has the potential for implementation as a diagnostic tool to reliably identify MAP infection, greatly improving early detection of MAP latent infections
Introduction: Echinococcus equinus is a cestode with a two-host life cycle, with carnivores as de... more Introduction: Echinococcus equinus is a cestode with a two-host life cycle, with carnivores as definitive hosts, shedding eggs with the faeces, and equids as intermediate hosts, with hydatid cysts forming mainly in the liver and lung. Materials and Methods: A 17-year-old Connemara horse with an oromaxillary sinus fistula and chronic colitis was humanely destroyed with poor prognosis. The horse had a history of long-term corticosteroid therapy. Necropsy examination identified several well-demarcated, greyewhite cysts of up to 5 cm in diameter in the liver parenchyma, filled with clear, amber-coloured liquid containing particles of !1 mm in diameter ('hydatid sand'). These cysts were further investigated by histopathology and polymerase chain reaction (PCR). Results: At necropsy examination, additional smaller cysts of up to 1 cm in diameter were visible in the liver and also in the lung. Histopathology revealed a trilayered appearance of the cysts with an outer connective tissue capsule followed by a PAS-positive, hyaline acellular layer and an inner germinal membrane. The cysts contained few free protoscolices indicating the presence of Echinococcus spp. PCR product sequencing revealed complete identity with E. equinus 12S rRNA and cytochromoxidase 1. Conclusion: The present case indicates that although E. equinus infections are still considered rare, they have emerged to our previously unaffected latitude. They pose a potential risk to dogs being fed with raw horse meat or liver in terms of the BARF (Biologically Appropriate Raw Foods) diet, which has gained increasing popularity. These dogs may potentially become reservoirs for E. equinus, a risk that should be considered.
Spanish goat encephalitis virus (SGEV) is a member of the genus Flavivirus, family Flaviviridae, ... more Spanish goat encephalitis virus (SGEV) is a member of the genus Flavivirus, family Flaviviridae, and causes encephalomyelitis in goats. The aim of this study was to determine whether sheep are susceptible to experimental challenge with SGEV by two different routes. The results show that SGEV can infect sheep by both the subcutaneous and intravenous routes, resulting in neurological clinical disease with extensive and severe histological lesions in the central nervous system. Lambs challenged subcutaneously developed more severe lesions on the ipsilateral side of the brain, but the lesion morphology was similar irrespective of the route of challenge. The clinical presentation, pathogenesis, lesion morphology and distribution shows that SGEV is very similar to louping ill virus (LIV) and therefore any disease control plan must take into account any host species and SGEV vectors as potential reservoirs. Furthermore, discriminatory diagnostics need to be applied to any sheep or goat suspected of disease due to any flavivirus in areas where SGEV and LIV co-exist.
Introduction: Macrorhabdus (M.) ornithogaster is an ascomycetous yeast of the Saccharomycetales f... more Introduction: Macrorhabdus (M.) ornithogaster is an ascomycetous yeast of the Saccharomycetales family, which infects certain species of birds, particularly budgerigars. Experimental infections of mice indicated that M. ornithogaster is not capable of growth in mammals. Materials and Methods: Cytological smears were prepared from adherent gastric mucus of the cardiac gland region in two colobine monkeys: a Hanuman (Semnopithecus entellus) and a Javan langur (Trachypithecus auratus). They were stained by Gram stain and calcofluor white. Additionally, partial sequencing of the fungal 28S rRNAgene and histology (HE and Gram stains) were carried out. Results: Macrorhabdus-like ascomycetous yeasts were identified in gram-stained cytological smears from the stomach in both monkeys. These filamentous, branching organisms stained positive with Gram and calcofluor white, identical to M. ornithogaster, and were located in the gastric mucus layer. Based on the phylogenetic analysis of the obtained nucleotide sequences, they were most closely related to M. ornithogaster and unidentified yeasts from another colobine primate, a Northern douc langur (Pygathrix nemaeus nemaeus). Conclusions: The filamentous organisms found in the stomach of both monkeys were morphologically, and in their staining properties, identical to M. ornithogaster from avian cases. This is the first report of M. ornithogaster-like ascomycetous yeasts in mammalian hosts in Germany. The specialized anatomy and physiology of the stomach of colobine primates may have resulted in conditions similar to the microenvironment in the avian proventriculus and thus allowed closely related yeasts to grow in mammals. However, their relevance as pathogen must be investigated in further studies.
Animal Husbandry, Dairy and Veterinary Science, 2020
This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xa... more This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xalda sheep, indigenous to the province of Asturias in northern Spain. We found that productive and reproductive parameters of the flock were also severely affected. In order to diagnose the cause of mortality and illness in the sheep, we examined the animals and their living conditions. We found high concentrations of nitrate in animal serum, well water and the surrounding pastures. Based on these findings and the absence of a geological source for nitrogen in the paddock, we believe that inappropriate management of manure in neighboring dairy farms resulted in nitrate toxicity in the Xalda sheep. This study highlights the importance of good practices in manure management and the need to monitor nitrate toxicity in pastures. It also highlights the importance of anthropogenic factors on the conservation of animal genetic resources.
Resumen del trabajo presentado a la 12th Conference of the European Wildlife Disease Association ... more Resumen del trabajo presentado a la 12th Conference of the European Wildlife Disease Association (EWDA), celebrada en Berlin (Alemania) del 27 al 31 de agosto de 2016.
In wildlife disease management there are few diseases for which vaccination is a viable option. T... more In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.
Background: Serum antibody detection has potential as a complementary diagnostic tool in animal t... more Background: Serum antibody detection has potential as a complementary diagnostic tool in animal tuberculosis (TB) control, particularly in multi-host systems. The objective of the present study was to assess the specificity (Sp) of an enzyme-linked immunosorbent assay (ELISA) based on the new multiprotein complex P22 for the detection of specific antibodies against the Mycobacterium tuberculosis complex (MTC) in the four most relevant domestic animals acting as MTC hosts: cattle, goat, sheep and pig. We used sera from an officially TB-free (OTF) country, Norway, and from a non-OTF one, Spain. The samples included sera from goats that had been vaccinated against M. avium subsp. paratuberculosis (MAP) and sheep from a herd in which Corynebacterium pseudotuberculosis had been isolated. Results: In cattle, the Sp ranged from 92.5 (IC95% 90.7-94) to 99.4% (IC95% 98.3-99.8) depending on the cutoff used and the origin of the samples (Spain or Norway). Sp in cattle (cut-off point 100) was significantly higher (P < 0. 05) for Norwegian samples. By contrast, Sp in goats was consistently low at the 100 cutoff [30.9 (CI95%23.4-39.5)-78% (CI95% 68.9-85)]. A higher cutoff of 150 improved Sp in Norwegian goats [97% (CI95% 91.6-99)], but still yielded a poor Sp of 56.1% (CI95% 47.3-64.6) in Spanish goats. In Norway at the 100 cutoff the Sp was 58.3 (CI95% 42.2-72.9) and 90.6% (CI95% 81-95.6) in MAP vaccinated and non-vaccinated goats, respectively, indicating interference due to MAP vaccination. Sp in sheep was between 94.4 (CI95% 91.7-96.3) and 100% (CI95% 96.3-100) depending on the cutoff and country, and no diagnostic interference due to infection with C. pseudotuberculosis was recorded. Sp in pigs was 100%, regardless the cutoff point applied, and no significant differences were observed between pigs from Norway and from Spain. Conclusions: Due to its excellent Sp in pigs and acceptable Sp in cattle and sheep, this ELISA may constitute a suitable option for TB screening at herd level, particularly in OTF-countries.
Livestock farming, specifically of cattle and buffalo, is crucial to Nepal’s economy, with more t... more Livestock farming, specifically of cattle and buffalo, is crucial to Nepal’s economy, with more than 66% of the population involved in agriculture and animal husbandry. Animal tuberculosis (TB) caused byMycobacterium bovisis a chronic disease that affects these animals and results in economic losses due to reduced milk and meat productivity, fertility and mortality.M. bovisalso infects humans, non-human primates, goats and other mammals, and can afflict both cattle and buffalo.Our study is a part of routine surveillance of prevalent diseases, includingM. bovis, in cattle and buffalo. We collected blood samples (n=400, 100 samples from each district) from selected eastern districts of Nepal. We used a Rapid Bovine TB Test Kit to test these samples for presence ofM. bovis.Of the 400 samples collected, 74 animals (18.75%) tested positive forM. bovis, with the majority of positive samples coming from cattle (n=71, 17.75%) and only three from buffalo (<1%). Among the screened breeds o...
Tuberculosis (TB) is a contagious chronic disease due to infection with Mycobacterium tuberculosi... more Tuberculosis (TB) is a contagious chronic disease due to infection with Mycobacterium tuberculosis complex (MTC) bacteria. Monitoring of wildlife, especially potential reservoirs, is important for detecting changes in disease occurrence and assessing the impact of interventions. Here, we examined whether wild boar (Sus scrofa) may contribute to the re-emergence of TB in Asturias (10,604 km2), northern Spain. Although this province was declared free of TB in cattle in November 2021, MTC bacteria remain prevalent in several “hotspots,” with the European badger (Meles meles) suggested as a TB potential wild reservoir. Drawing on data from the Spanish National Bovine Tuberculosis Eradication Program and the Government of the Principality of Asturias covering the period 2014–2020, we analyzed the prevalence of TB in cattle and wild boar in this region. In hotspots (592 km2), we also investigated the ranging behavior and habitat use of five cows that belonged to farms with a history of TB...
Tuberculosis (TB) vaccination could be used as a key part of integrated strategies for the diseas... more Tuberculosis (TB) vaccination could be used as a key part of integrated strategies for the disease’s control if an effective and safe vaccine under field conditions is obtained. Recent studies in Spain have evaluated the protective efficacy of two oral vaccines against experimental challenge with live intra-bronchial Mycobacterium bovis in captive badgers: the live-attenuated M. bovis BCG vaccine (Danish strain) and a heat-inactivated M. bovis (HIMB) vaccine. With the objective of increasing the knowledge of the cellular development progress of infection and generating further tools to discriminate between mild and severe TB lesions between and within animals, the immunopathology of tuberculous lesions was studied to characterize the local immune response (cell type profile) within lung granulomas from control (non-vaccinated), BCG vaccinated and HIMB-vaccinated experimentally infected badgers with M. bovis. Four immunohistochemical protocols, for the specific detection of macrophag...
Tuberculosis (TB) is a zoonotic mycobacterial infection with great importance in human health, an... more Tuberculosis (TB) is a zoonotic mycobacterial infection with great importance in human health, animal production, and wildlife conservation. Although an ambitious eradication programme in cattle has been implemented for decades, TB-free status has not yet been achieved in most of Spain, where animal TB persists in a multi-host system of domestic and wild hosts, including the red deer (Cervus elaphus). However, information on long time series and trends of TB prevalence in wildlife is scarce. The diagnosis of TB in wild red deer is often based on gross pathology and bacteriological culture confirmation, although recently serological assays have been developed to detect anti- Mycobacterium tuberculosis Complex (MTC) antibodies. Particularly, protein complex P22 has demonstrated to yield good specificity and sensitivity in the serological diagnosis of MTC for red deer, as well as cattle, goats, sheep, pigs, wild boar, and European badger. Thus, the objective of the present study was to compare the performance of the P22-ELISA with TB-compatible lesion detection, as well as to assess the potential application of each technique for determining spatiotemporal trends and risk factors of MTC infection in wild red deer from low and high TB prevalence areas of Spain over the last two decades. We tested 5095 sera from 13 wild populations by indirect ELISA using P22 as antigen. Mean seroprevalence (13.22%, CI95: 12.32-14.18) was compared with the prevalence of macroscopic TB-compatible lesions (6.94%, CI95: 6.18-7.79). The results evidenced a poor agreement between both techniques (K < 0.3), although generalized TB-lesions and anti-P22 antibodies showed a positive association (χ² = 9.054, P = 0.004). Consequently, TB-lesion based prevalence and seroprevalence cannot be considered as equivalent for TB surveillance in red deer. Regarding the spatiotemporal trend of TB in red deer in Spain, we observed a North-South gradient of TB occurrence [North: 1.23% (CI95: 0.77-1.97) of TB-lesions and 12.55% (CI95: 10.91-14.41) of P22-ELISA; Centre: 7.10% (CI95: 6.04-8.33) and 8.74% (CI95: 7.57-10.08); South: 21.04% (CI95:17.81-24.69) and 23.09% (CI95: 19.73-26.84), respectively]. Overall, there was a stability over time, with higher prevalence in adults belonging to densely populated sites. We conclude that the P22-ELISA alone is not sufficiently reliable for TB surveillance in red deer at large spatiotemporal scales. Instead, we recommend combining gross pathology and P22-ELISA.
In wildlife disease management there are few diseases for which vaccination is a viable option. T... more In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.
Trabajo presentado al: 37th International Society for Animal Genetics Conference (ISAG). Abstract... more Trabajo presentado al: 37th International Society for Animal Genetics Conference (ISAG). Abstract book, P216, pp.121.Lleida, Spain, 7-12 Julio 2019.
The present work investigated the prevalence, spatial distribution, and temporal distribution of ... more The present work investigated the prevalence, spatial distribution, and temporal distribution of tuberculosis (TB) in free-ranging Eurasian badgers (Meles meles) and cattle in Asturias (Atlantic Spain) during a 13-year follow-up. The study objective was to assess the role of badgers as a TB reservoir for cattle and other sympatric wild species in the region. Between 2008 and 2020, 673 badgers (98 trapped and 575 killed in road traffic accidents) in Asturias were necropsied, and their tissue samples were cultured for the Mycobacterium tuberculosis complex (MTC) isolation. Serum samples were tested in an in-house indirect P22 ELISA to detect antibodies against the MTC. In parallel, data on MTC isolation and single intradermal tuberculin test results were extracted for cattle that were tested and culled as part of the Spanish National Program for the Eradication of Bovine TB. A total of 27/639 badgers (4.23%) were positive for MTC based on bacterial isolation, while 160/673 badgers (23...
Zenodo (CERN European Organization for Nuclear Research), Sep 3, 2020
Bovine paratuberculosis (PTB) is a chronic granulomatous enteritis, caused by Mycobacterium avium... more Bovine paratuberculosis (PTB) is a chronic granulomatous enteritis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), responsible for important economic losses in the dairy industry. Current diagnostic methods have low sensitivities for detection of latent forms of MAP infection, defined by focal granulomatous lesions and scarce humoral response or MAP presence. In contrast, patent infections correspond to multifocal and diffuse types of enteritis where there is increased antibody production, and substantial mycobacterial load. Our previous RNA-Seq analysis allowed the selection of five candidate biomarkers overexpressed in peripheral blood of MAP infected Holstein cows with focal (ABCA13 and MMP8) and diffuse (FAM84A, SPARC and DES) lesions vs. control animals with no detectable PTB-associated lesions in intestine and regional lymph nodes. The aim of the current study was to assess the PTB diagnostic potential of commercial ELISAs designed for the specific detection of these biomarkers. The ability of these ELISAs to identify animals with latent and/or patent forms of MAP infection was investigated using serum from naturally infected cattle (n = 88) and non-infected control animals (n = 67). ROC analysis revealed that the ABCA13-based ELISA showed the highest diagnostic accuracy for the detection of infected animals with focal lesions (AUC 0.837, sensitivity 79.25% and specificity 88.06%) and with any type of histological lesion (AUC 0.793, sensitivity 69.41% and specificity 86.57%) improving on the diagnostic performance of the popular IDEXX ELISA and other conventional diagnostic methods. SPARC and MMP8 showed the highest diagnostic accuracy for the detection of animals with multifocal (AUC 0.852) and diffuse lesions (AUC 0.831), respectively. In conclusion, our results suggest that quantification of ABCA13, SPARC and MMP8 by ELISA has the potential for implementation as a diagnostic tool to reliably identify MAP infection, greatly improving early detection of MAP latent infections
Introduction: Echinococcus equinus is a cestode with a two-host life cycle, with carnivores as de... more Introduction: Echinococcus equinus is a cestode with a two-host life cycle, with carnivores as definitive hosts, shedding eggs with the faeces, and equids as intermediate hosts, with hydatid cysts forming mainly in the liver and lung. Materials and Methods: A 17-year-old Connemara horse with an oromaxillary sinus fistula and chronic colitis was humanely destroyed with poor prognosis. The horse had a history of long-term corticosteroid therapy. Necropsy examination identified several well-demarcated, greyewhite cysts of up to 5 cm in diameter in the liver parenchyma, filled with clear, amber-coloured liquid containing particles of !1 mm in diameter ('hydatid sand'). These cysts were further investigated by histopathology and polymerase chain reaction (PCR). Results: At necropsy examination, additional smaller cysts of up to 1 cm in diameter were visible in the liver and also in the lung. Histopathology revealed a trilayered appearance of the cysts with an outer connective tissue capsule followed by a PAS-positive, hyaline acellular layer and an inner germinal membrane. The cysts contained few free protoscolices indicating the presence of Echinococcus spp. PCR product sequencing revealed complete identity with E. equinus 12S rRNA and cytochromoxidase 1. Conclusion: The present case indicates that although E. equinus infections are still considered rare, they have emerged to our previously unaffected latitude. They pose a potential risk to dogs being fed with raw horse meat or liver in terms of the BARF (Biologically Appropriate Raw Foods) diet, which has gained increasing popularity. These dogs may potentially become reservoirs for E. equinus, a risk that should be considered.
Spanish goat encephalitis virus (SGEV) is a member of the genus Flavivirus, family Flaviviridae, ... more Spanish goat encephalitis virus (SGEV) is a member of the genus Flavivirus, family Flaviviridae, and causes encephalomyelitis in goats. The aim of this study was to determine whether sheep are susceptible to experimental challenge with SGEV by two different routes. The results show that SGEV can infect sheep by both the subcutaneous and intravenous routes, resulting in neurological clinical disease with extensive and severe histological lesions in the central nervous system. Lambs challenged subcutaneously developed more severe lesions on the ipsilateral side of the brain, but the lesion morphology was similar irrespective of the route of challenge. The clinical presentation, pathogenesis, lesion morphology and distribution shows that SGEV is very similar to louping ill virus (LIV) and therefore any disease control plan must take into account any host species and SGEV vectors as potential reservoirs. Furthermore, discriminatory diagnostics need to be applied to any sheep or goat suspected of disease due to any flavivirus in areas where SGEV and LIV co-exist.
Introduction: Macrorhabdus (M.) ornithogaster is an ascomycetous yeast of the Saccharomycetales f... more Introduction: Macrorhabdus (M.) ornithogaster is an ascomycetous yeast of the Saccharomycetales family, which infects certain species of birds, particularly budgerigars. Experimental infections of mice indicated that M. ornithogaster is not capable of growth in mammals. Materials and Methods: Cytological smears were prepared from adherent gastric mucus of the cardiac gland region in two colobine monkeys: a Hanuman (Semnopithecus entellus) and a Javan langur (Trachypithecus auratus). They were stained by Gram stain and calcofluor white. Additionally, partial sequencing of the fungal 28S rRNAgene and histology (HE and Gram stains) were carried out. Results: Macrorhabdus-like ascomycetous yeasts were identified in gram-stained cytological smears from the stomach in both monkeys. These filamentous, branching organisms stained positive with Gram and calcofluor white, identical to M. ornithogaster, and were located in the gastric mucus layer. Based on the phylogenetic analysis of the obtained nucleotide sequences, they were most closely related to M. ornithogaster and unidentified yeasts from another colobine primate, a Northern douc langur (Pygathrix nemaeus nemaeus). Conclusions: The filamentous organisms found in the stomach of both monkeys were morphologically, and in their staining properties, identical to M. ornithogaster from avian cases. This is the first report of M. ornithogaster-like ascomycetous yeasts in mammalian hosts in Germany. The specialized anatomy and physiology of the stomach of colobine primates may have resulted in conditions similar to the microenvironment in the avian proventriculus and thus allowed closely related yeasts to grow in mammals. However, their relevance as pathogen must be investigated in further studies.
Animal Husbandry, Dairy and Veterinary Science, 2020
This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xa... more This study analyzed potential causes of a 40% mortality rate observed in a flock of endangered Xalda sheep, indigenous to the province of Asturias in northern Spain. We found that productive and reproductive parameters of the flock were also severely affected. In order to diagnose the cause of mortality and illness in the sheep, we examined the animals and their living conditions. We found high concentrations of nitrate in animal serum, well water and the surrounding pastures. Based on these findings and the absence of a geological source for nitrogen in the paddock, we believe that inappropriate management of manure in neighboring dairy farms resulted in nitrate toxicity in the Xalda sheep. This study highlights the importance of good practices in manure management and the need to monitor nitrate toxicity in pastures. It also highlights the importance of anthropogenic factors on the conservation of animal genetic resources.
Resumen del trabajo presentado a la 12th Conference of the European Wildlife Disease Association ... more Resumen del trabajo presentado a la 12th Conference of the European Wildlife Disease Association (EWDA), celebrada en Berlin (Alemania) del 27 al 31 de agosto de 2016.
In wildlife disease management there are few diseases for which vaccination is a viable option. T... more In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.
Background: Serum antibody detection has potential as a complementary diagnostic tool in animal t... more Background: Serum antibody detection has potential as a complementary diagnostic tool in animal tuberculosis (TB) control, particularly in multi-host systems. The objective of the present study was to assess the specificity (Sp) of an enzyme-linked immunosorbent assay (ELISA) based on the new multiprotein complex P22 for the detection of specific antibodies against the Mycobacterium tuberculosis complex (MTC) in the four most relevant domestic animals acting as MTC hosts: cattle, goat, sheep and pig. We used sera from an officially TB-free (OTF) country, Norway, and from a non-OTF one, Spain. The samples included sera from goats that had been vaccinated against M. avium subsp. paratuberculosis (MAP) and sheep from a herd in which Corynebacterium pseudotuberculosis had been isolated. Results: In cattle, the Sp ranged from 92.5 (IC95% 90.7-94) to 99.4% (IC95% 98.3-99.8) depending on the cutoff used and the origin of the samples (Spain or Norway). Sp in cattle (cut-off point 100) was significantly higher (P < 0. 05) for Norwegian samples. By contrast, Sp in goats was consistently low at the 100 cutoff [30.9 (CI95%23.4-39.5)-78% (CI95% 68.9-85)]. A higher cutoff of 150 improved Sp in Norwegian goats [97% (CI95% 91.6-99)], but still yielded a poor Sp of 56.1% (CI95% 47.3-64.6) in Spanish goats. In Norway at the 100 cutoff the Sp was 58.3 (CI95% 42.2-72.9) and 90.6% (CI95% 81-95.6) in MAP vaccinated and non-vaccinated goats, respectively, indicating interference due to MAP vaccination. Sp in sheep was between 94.4 (CI95% 91.7-96.3) and 100% (CI95% 96.3-100) depending on the cutoff and country, and no diagnostic interference due to infection with C. pseudotuberculosis was recorded. Sp in pigs was 100%, regardless the cutoff point applied, and no significant differences were observed between pigs from Norway and from Spain. Conclusions: Due to its excellent Sp in pigs and acceptable Sp in cattle and sheep, this ELISA may constitute a suitable option for TB screening at herd level, particularly in OTF-countries.
Livestock farming, specifically of cattle and buffalo, is crucial to Nepal’s economy, with more t... more Livestock farming, specifically of cattle and buffalo, is crucial to Nepal’s economy, with more than 66% of the population involved in agriculture and animal husbandry. Animal tuberculosis (TB) caused byMycobacterium bovisis a chronic disease that affects these animals and results in economic losses due to reduced milk and meat productivity, fertility and mortality.M. bovisalso infects humans, non-human primates, goats and other mammals, and can afflict both cattle and buffalo.Our study is a part of routine surveillance of prevalent diseases, includingM. bovis, in cattle and buffalo. We collected blood samples (n=400, 100 samples from each district) from selected eastern districts of Nepal. We used a Rapid Bovine TB Test Kit to test these samples for presence ofM. bovis.Of the 400 samples collected, 74 animals (18.75%) tested positive forM. bovis, with the majority of positive samples coming from cattle (n=71, 17.75%) and only three from buffalo (<1%). Among the screened breeds o...
Tuberculosis (TB) is a contagious chronic disease due to infection with Mycobacterium tuberculosi... more Tuberculosis (TB) is a contagious chronic disease due to infection with Mycobacterium tuberculosis complex (MTC) bacteria. Monitoring of wildlife, especially potential reservoirs, is important for detecting changes in disease occurrence and assessing the impact of interventions. Here, we examined whether wild boar (Sus scrofa) may contribute to the re-emergence of TB in Asturias (10,604 km2), northern Spain. Although this province was declared free of TB in cattle in November 2021, MTC bacteria remain prevalent in several “hotspots,” with the European badger (Meles meles) suggested as a TB potential wild reservoir. Drawing on data from the Spanish National Bovine Tuberculosis Eradication Program and the Government of the Principality of Asturias covering the period 2014–2020, we analyzed the prevalence of TB in cattle and wild boar in this region. In hotspots (592 km2), we also investigated the ranging behavior and habitat use of five cows that belonged to farms with a history of TB...
Tuberculosis (TB) vaccination could be used as a key part of integrated strategies for the diseas... more Tuberculosis (TB) vaccination could be used as a key part of integrated strategies for the disease’s control if an effective and safe vaccine under field conditions is obtained. Recent studies in Spain have evaluated the protective efficacy of two oral vaccines against experimental challenge with live intra-bronchial Mycobacterium bovis in captive badgers: the live-attenuated M. bovis BCG vaccine (Danish strain) and a heat-inactivated M. bovis (HIMB) vaccine. With the objective of increasing the knowledge of the cellular development progress of infection and generating further tools to discriminate between mild and severe TB lesions between and within animals, the immunopathology of tuberculous lesions was studied to characterize the local immune response (cell type profile) within lung granulomas from control (non-vaccinated), BCG vaccinated and HIMB-vaccinated experimentally infected badgers with M. bovis. Four immunohistochemical protocols, for the specific detection of macrophag...
Tuberculosis (TB) is a zoonotic mycobacterial infection with great importance in human health, an... more Tuberculosis (TB) is a zoonotic mycobacterial infection with great importance in human health, animal production, and wildlife conservation. Although an ambitious eradication programme in cattle has been implemented for decades, TB-free status has not yet been achieved in most of Spain, where animal TB persists in a multi-host system of domestic and wild hosts, including the red deer (Cervus elaphus). However, information on long time series and trends of TB prevalence in wildlife is scarce. The diagnosis of TB in wild red deer is often based on gross pathology and bacteriological culture confirmation, although recently serological assays have been developed to detect anti- Mycobacterium tuberculosis Complex (MTC) antibodies. Particularly, protein complex P22 has demonstrated to yield good specificity and sensitivity in the serological diagnosis of MTC for red deer, as well as cattle, goats, sheep, pigs, wild boar, and European badger. Thus, the objective of the present study was to compare the performance of the P22-ELISA with TB-compatible lesion detection, as well as to assess the potential application of each technique for determining spatiotemporal trends and risk factors of MTC infection in wild red deer from low and high TB prevalence areas of Spain over the last two decades. We tested 5095 sera from 13 wild populations by indirect ELISA using P22 as antigen. Mean seroprevalence (13.22%, CI95: 12.32-14.18) was compared with the prevalence of macroscopic TB-compatible lesions (6.94%, CI95: 6.18-7.79). The results evidenced a poor agreement between both techniques (K < 0.3), although generalized TB-lesions and anti-P22 antibodies showed a positive association (χ² = 9.054, P = 0.004). Consequently, TB-lesion based prevalence and seroprevalence cannot be considered as equivalent for TB surveillance in red deer. Regarding the spatiotemporal trend of TB in red deer in Spain, we observed a North-South gradient of TB occurrence [North: 1.23% (CI95: 0.77-1.97) of TB-lesions and 12.55% (CI95: 10.91-14.41) of P22-ELISA; Centre: 7.10% (CI95: 6.04-8.33) and 8.74% (CI95: 7.57-10.08); South: 21.04% (CI95:17.81-24.69) and 23.09% (CI95: 19.73-26.84), respectively]. Overall, there was a stability over time, with higher prevalence in adults belonging to densely populated sites. We conclude that the P22-ELISA alone is not sufficiently reliable for TB surveillance in red deer at large spatiotemporal scales. Instead, we recommend combining gross pathology and P22-ELISA.
In wildlife disease management there are few diseases for which vaccination is a viable option. T... more In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.
Trabajo presentado al: 37th International Society for Animal Genetics Conference (ISAG). Abstract... more Trabajo presentado al: 37th International Society for Animal Genetics Conference (ISAG). Abstract book, P216, pp.121.Lleida, Spain, 7-12 Julio 2019.
The present work investigated the prevalence, spatial distribution, and temporal distribution of ... more The present work investigated the prevalence, spatial distribution, and temporal distribution of tuberculosis (TB) in free-ranging Eurasian badgers (Meles meles) and cattle in Asturias (Atlantic Spain) during a 13-year follow-up. The study objective was to assess the role of badgers as a TB reservoir for cattle and other sympatric wild species in the region. Between 2008 and 2020, 673 badgers (98 trapped and 575 killed in road traffic accidents) in Asturias were necropsied, and their tissue samples were cultured for the Mycobacterium tuberculosis complex (MTC) isolation. Serum samples were tested in an in-house indirect P22 ELISA to detect antibodies against the MTC. In parallel, data on MTC isolation and single intradermal tuberculin test results were extracted for cattle that were tested and culled as part of the Spanish National Program for the Eradication of Bovine TB. A total of 27/639 badgers (4.23%) were positive for MTC based on bacterial isolation, while 160/673 badgers (23...
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Papers by Ana Balseiro