Biology subjects

Gortazar, C.

Publications and source records attributed to Gortazar, C..

8 recordsLinked to original sources

bioRxiv2024

Using integrated wildlife monitoring for quantifying the impact of emerging Bagaza virus in red-legged partridges in Portugal, 2012-2024

Bagaza virus, a vector-borne flavivirus that causes significant mortality in wild bird species, emerged in Portugal in September 2021. This study used integrated wildlife monitoring to quantify its impact on a natural population of red-legged partridge (Alectoris rufa) in southern Portugal. We constructed a baseline model of population dynamics prior to the outbreak (2012-2021) and used this model to predict population size in subsequent years (2022-2024). This model, which included population abundance and demographic data of red-legged partridge, as well as climatic variables, showed a strong fit to the observed data, and the difference between the predicted and observed population size in 2022 suggests a Bagaza-induced mortality rate of at least 59% (95% CI 52-66%). In addition to enabling the adaptive management of populations, our results demonstrate that integrated wildlife monitoring offers epidemiological insights for risk assessment, highlighting its role in proactive wildlife disease surveillance within the One Health framework.

ecology↗

bioRxiv2023

High prevalence of Bovine Tuberculosis reported in Cattle and Buffalo of Eastern Nepal

Livestock farming, specifically of cattle and buffalo, is crucial to Nepals economy, with more than 66% of the population involved in agriculture and animal husbandry. Animal tuberculosis (TB) caused by Mycobacterium bovis is a chronic disease that affects these animals and results in economic losses due to reduced milk and meat productivity, fertility and mortality. M. bovis also 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, including M. 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 of M. bovis. Of the 400 samples collected, 74 animals (18.75%) tested positive for M. bovis, with the majority of positive samples coming from cattle (n=71, 17.75%) and only three from buffalo (<1%). Among the screened breeds of cattle and buffalo, Holstein Friesian cattle (HF) (n=43, 58%), Jersey-cross cattle (JX) (n=20, 27%), Local buffalo (n=8, 10.8%) and Murra breed buffalo (n=3, 4.1%) were found to carry M. bovis. The majority (50%) of infected animals were between 3-6 years old. Morang (n= 24 positive in cattle; n=1 positive in buffalo) and Jhapa (n= 22 positive in cattle; n=2 positive in buffalo) had the highest prevalence of M. bovis, while all the positive cases in Sunsari (n=19) and Udaypur (n=6) were in cattle. The fact that over 18% of the samples tested positive for M. bovis is of great concern. It is critical to thoroughly test animal products from these livestock prior to human consumption. To prevent and mitigate M. bovis-related infections in Nepal, a more comprehensive screening strategy coupled with more effective animal husbandry practices needs to be adapted.

microbiology↗

bioRxiv2023

Heat-inactivated mycobacteria activate the Toll-like receptor 2 and 4 pathways in the zebrafish model of tuberculosis

Based on previous evidence demonstrating the efficacy of inactivated mycobacteria for the control of fish mycobacteriosis, we explored the protective efficacy of two inactivated Mycobacterium bovis administered via parenteral and mucosal routes against Mycobacterium marinum infection mimicking natural conditions in the zebrafish model of tuberculosis. Although we did not observe a clear effect of any of the immunostimulants on mycobacterial burden, the results showed a significant increase in TLR2 and TLR4 gene expression levels in fishes parenterally immunized with inactivated Bacillus Calmette-Guerin (BCG). Our findings demonstrated that the TLR2 and the TLR4 signaling pathways are involved in the immune response elicited by inactivated mycobacteria in the zebrafish model of tuberculosis and support the use of inactivated mycobacteria in vaccine formulations for the control of mycobacteriosis.

immunology↗

bioRxiv2022

Identification and Characterization of Probiotics Isolates from Indigenous Chicken (Gallus domesticus) of Nepal

BackgroundExcessive and irrational use of antibiotics as growth promoters in poultry has been one of key factors contributing to increased emergence of antibiotics resistant bacteria. Drug resistant infections are becoming major concerns in poultry production impacting both human and poultry health. Several alternatives for antibiotic growth promoters are being sought, and the search for effective probiotics to be used as feed additives is amongst the promising ones. Our study aimed to isolate and test potential probiotics bacteria from cloacal swabs of various indigenous chicken (Gallus domesticus) breeds from rural outskirts of the Kathmandu valley (Nepal). MethodsSelective isolation of probiotics was conducted by micro-aerophilic enrichment of sample in MRS Broth at 37{degrees}C, followed by culturing on MRS agar supplemented with 5 g/L of CaCO3. Isolated bacterial colonies producing transparent halo were selected as potential lactic acid bacteria (LAB), and tested for their antibacterial activity, phenotypic and biochemical characteristics, acidic yield, and tolerance to acid and bile. ResultsA total of 90 potential LAB were isolated from cloacal samples collected from 41 free-ranging chickens of indigenous breeds. Of these, 52 LAB isolates (57%) showed variable antibacterial activity to at least one bacterial pathogen. Of 52 LAB, 46 isolates fulfilled phenotypic and biochemical criteria of Lactobacillus spp. Of these, 37 isolates produced varying percentage yields of lactic acid, 27 isolates showed survival at pH 3.0, and 17 isolates showed survival tolerances in the presence of 0.3% and 0.5% bile salts for 24 hours. Phylogenetic analysis of 16SrDNA sequencing of LAB isolates fulfilling in vitro probiotics properties showed that 3 isolates had genetic identity of 99.38% with Lactobacillus plantarum, while one isolate was genetically similar (99.85%) with the clade of L. reuteri, L. antri and L. panis. ConclusionsOur study identified four Lactobacillus spp. strains having potential probiotics properties. Further investigations are needed to evaluate these isolates to be used as poultry probiotics feed supplement.

microbiology↗

bioRxiv2021

Bagaza virus in wild birds, Portugal, 2021

Bagaza virus (BAGV) emerged in Spain, in 2010. Since then, BAGV was not reported in other European countries until September 2021, when BAGV was diagnosed by molecular methods in one corn bunting and several red-legged partridges, after abnormal mortality in Southern Portugal. Sequencing revealed high similarity with strains reported previously.

pathology↗

bioRxiv2021

Natural SARS-CoV-2 infection in kept ferrets, Spain

We found SARS-CoV-2 RNA in 6 of 71 ferrets (8.4%) and isolated the virus from one rectal swab. Natural SARS-CoV-2 infection does occur in kept ferrets, at least under circumstances of high viral circulation in the human population. However, small ferret collections are probably unable to maintain prolonged virus circulation.

microbiology↗

bioRxiv2020

The antibody response to the glycan α-Gal correlates with COVID-19 disease symptoms

The coronavirus disease 19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide. The characterization of the immunological mechanisms involved in disease symptomatology and protective response is important to advance in disease control and prevention. Humans evolved by losing the capacity to synthesize the glycan Gal1-3Gal{beta}1-(3)4GlcNAc-R (-Gal), which resulted in the development of a protective response against pathogenic viruses and other microorganisms containing this modification on membrane proteins mediated by anti--Gal IgM/IgG antibodies produced in response to bacterial microbiota. In addition to anti--Gal antibody-mediated pathogen opsonization, this glycan induces various immune mechanisms that have shown protection in animal models against infectious diseases without inflammatory responses. In this study, we hypothesized that the immune response to -Gal may contribute to the control of COVID-19. To address this hypothesis, we characterized the antibody response to -Gal in patients at different stages of COVID-19 and in comparison with healthy control individuals. The results showed that while the inflammatory response and the anti-SARS-CoV-2 (Spike) IgG antibody titers increased, reduction in anti--Gal IgE, IgM and IgG antibody titers and alteration of anti--Gal antibody isotype composition correlated with COVID-19 severity. The results suggested that the inhibition of the -Gal-induced immune response may translate into more aggressive viremia and severe disease inflammatory symptoms. These results support the proposal of developing interventions such as probiotics based on commensal bacteria with -Gal epitopes to modify the microbiota and increase the -Gal-induced protective immune response and reduce the severity of COVID-19.

immunology↗

bioRxiv2019

Genetic characterization of a recombinant myxoma virus leap into the Iberian hare (Lepus granatensis)

Myxomatosis is a lethal disease of wild European and domestic rabbits (Oryctolagus cuniculus) caused by a Myxoma virus (MYXV) infection, a leporipoxvirus that is found naturally in some Sylvilagus rabbit species in South America and California. The introduction of MYXV in the early 1950s into feral European rabbit populations in Australia and Europe demonstrate the best documented field example of host-virus coevolution following a cross-species transmission. Recently, a new cross-species jump of MYXV has been suggested in both Great Britain and Spain, where European brown hares (Lepus europaeus) and Iberian hares (Lepus granatensis) were found dead with lesions consistent with those observed in myxomatosis. To investigate the possibility of a new cross-species transmission event by MYXV, tissue samples collected from a wild Iberian hare found dead in Spain (Toledo region) were analyzed and deep sequenced. Our results report a new MYXV strain (MYXV Toledo) in the tissues of this species. The genome of this new strain encodes three disrupted genes (M009L, M036L and M152R) and a novel 2.8 KB recombinant region that resulted from an insertion of four novel poxviral genes towards the 5 end of its genome. From the open reading frames inserted into the MYXV Toledo strain, a new orthologue of a poxvirus host range gene family member was identified which is related to the MYXV gene M064R. Overall, we confirmed the identity of a new MYXV strain in Iberian hares that we hypothesize was able to more effectively counteract the host defenses in hares and start an infectious process in this new host.

microbiology↗