Bactericidal activity of avian complement: a contribution to understand avian-host tropism of Lyme borreliae

© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Complement has been considered as an important factor impacting the host-pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete's ecology. Birds are known to be important hosts for ticks and in the maintenance of borreliae. Recent field surveys and laboratory transmission studies indicated that certain avian species act as reservoir hosts for different Borrelia species. Nevertheless, our current understanding of the molecular mechanisms determining host tropism of Borrelia is still in its fledgling stage. Concerning the role of complement in avian-host tropism, only a few bird species and Borrelia species have been analysed so far. Here, we performed in vitro serum bactericidal assays with serum samples collected from four bird species including the European robin Erithacus rubecula, the great tit Parus major, the Eurasian blackbird Turdus merula, and the racing pigeon Columba livia, as well as four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi sensu stricto). From July to September 2019, juvenile wild birds were caught using mist nets in Portugal. Racing pigeons were sampled in a loft in October 2019. Independent of the bird species analysed, all Borrelia species displayed an intermediate serum-resistant or serum-resistant phenotype except for B. afzelii challenged with serum from blackbirds. This genospecies was efficiently killed by avian complement, suggesting that blackbirds served as dead-end hosts for B. afzelii. In summary, these findings suggest that complement contributes in the avian-spirochete-tick infection cycle and in Borrelia-host tropism.Open Access funding enabled and organized by Projekt DEAL. This study received financial support from Fundação para a Ciência e a Tecnologia by the strategic program of MARE (MARE—UID/MAR/04292/2020) and the transitory norm contract DL57/2016/CP1370/CT89 to ACN, and the Portuguese National Institute of Health (INSA).info:eu-repo/semantics/publishedVersio

Begging calls and mouth colouration as predictors of breeding success in blue tits

Nestlings normally exhibit a mix of traits that attract parental care, such as postural and vocal begging and carotenoid-based mouth colouration. These signals are hypothesised to be signs of nestling needs (vocal begging) and quality (mouth colouration). Therefore, we hypothesised that broods, where nestlings beg for less time and display more saturated carotenoid-based mouth colouration, would have lower nestling mortality. We tested these predictions in two wild blue tit (Cyanistes caeruleus) populations. The breeding success (here defined as the proportion of eggs that produced fledglings) was related to nestling mouth flanges’ carotenoid-based colour saturation. This means that blue tits that raised nestlings with more coloured flanges had a higher within-population breeding success. Time spent in vocal begging, by contrast, was not associated with breeding success. Hence, our findings reveal that some communication signals displayed by nestlings (carotenoid-based colouration) predict breeding success, in our study mostly reflecting the proportion of eggs that hatched, while begging intensity does not, probably because the former reflects a better maternal pre-laying condition and nestling physiological status in the mid-term.Project of the Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía (A-RNM-48-UGR20), "una manera de hacer Europa", and a project from the National Plan of the Spanish Ministry of Economy and Competition (CGL2017-84938-P), both cofinanced with FEDER funds from the European Union (EU), the Fundação para a Ciência e a Tecnologia (FCT) through the strategic MARE program (MARE-UID/MAR/04292/2020)Project granted to the Associate Laboratory ARNET (LA/P/0069/2020)AUIP mobility grant and a FPU Pre-doctoral contract (FPU18/03034) from the Spanish Ministry of EducationThe transitory norm contract DL57/2016/CP1370/CT89Funding for open access charge by Universidad de Granda/CBUA

Prevalence of asymptomatic Leishmania infection and knowledge, perceptions, and practices in blood donors in mainland Portugal

Funding Information: This paper has been sponsored by Elanco Animal Health in the framework of the CVBD®World Forum Symposium. The authors would like to acknowledge all the blood donors who agreed to participate in this study for contributing with their answers to the questionnaire and their blood samples. The authors would also like to acknowledge all the professionals of the following institutions that contributed to organization of physical equipment, presentation of the study to potential participants, obtaining of informed consent, separation and storage of samples and questionnaires: Instituto Português do Sangue e da Transplantação; Centro Hospitalar Universitário do Algarve; Hospital do Espírito Santo de Évora; Unidade Local de Sáude do Norte Alentejano; Unidade Local de Saúde do Baixo Alentejo and Unidade Local de Saúde do Litoral Alentejano. Lastly, the authors would like to acknowledge the researcher Regina Loesch for her contribution to filling in the electronic database with answers to the paper questionnaires, and the researcher Ana Rita Goes for her contributions to designing the questionnaire for this study. Funding Information: RR was supported by the Portuguese Ministry of Education and Science (via Fundação para a Ciência e a Tecnologia, I.P.—FCT) through a PhD grant (UI/BD/151067/2021). The authors would also like to acknowledge FCT for funding through contracts with GHTM (UID/Multi/04413/2020, UIDB/00006/2020 and UIDP/00006/2020) and LA-REAL (LA/P/0117/2020). This project was also funded by the Tropical Clinic Unit (Institute of Hygiene and Tropical Medicine [IHMT]). Publisher Copyright: © 2023, BioMed Central Ltd., part of Springer Nature.Background: Asymptomatic infection is the most common outcome of exposure to Leishmania parasites. In the Mediterranean region, where Leishmania infantum is endemic, studies on the prevalence of asymptomatic infection have often relied on serological testing in blood donors. In Spain, regional studies have shown seroprevalence in blood donors between 1 and 8%; in Portugal, values of 0 and 2% were suggested by two localized studies, in different populations. The purpose of this study was (i) to estimate the prevalence of asymptomatic Leishmania infection in blood donors in mainland Portugal, and (ii) to study the association between the detection of antibodies to Leishmania and sociodemographic factors, and also the knowledge, perceptions and practices (KPP) of the blood donors regarding leishmaniasis. Methods: A cross-sectional study targeted the population of people who donated blood in mainland Portugal. Participants, distributed proportionally by municipality and aged between 18 and 65 years, were selected randomly in 347 blood collection points between February and June 2022, and completed a sociodemographic and a KPP questionnaire. Detection of anti-Leishmania antibodies in serum was performed using an ELISA commercial kit. Individual KPP scores were calculated by adding grades defined for each question. Results: Globally, 201/3763 samples were positive. The estimated national true seroprevalence was 4.8% (95% CI 4.1–5.5%). The proportion of positive results was significantly different between NUTS (Nomenclature of Territorial Units for Statistics) regions. Models suggested that seropositivity was significantly higher in male sex, people older than 25 years, or residing in the Centro NUTS2 region, but not in dog owners nor people with lower KPP scores. Overall, 72.3% of participants had previously heard of leishmaniasis and, in multivariate analysis, a higher Knowledge score was associated with age 25–40 years, female sex, ownership of dogs, and higher education. Conclusions: Global estimated true seroprevalence (4.8%) was similar to previous regional studies in blood donors in neighboring Spain. Higher seroprevalence values in the NUTS2 Centro region were consistent with incidence data from humans and seroprevalence studies in dogs. On the other hand, the low values in the Alentejo and the high values in the northern subregions may be the result of geographical shifts in parasite circulation due to climate change and should prompt localized and integrated, vector, canine, and human research, following a One Health approach. Graphical Abstract: [Figure not available: see fulltext.].publishersversionpublishe

The population structure of Borrelia lusitaniae Is reflected by a population division of its Ixodes Vector

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Populations of vector-borne pathogens are shaped by the distribution and movement of vector and reservoir hosts. To study what impact host and vector association have on tick-borne pathogens, we investigated the population structure of Borrelia lusitaniae using multilocus sequence typing (MLST). Novel sequences were acquired from questing ticks collected in multiple North African and European locations and were supplemented by publicly available sequences at the Borrelia Pubmlst database (accessed on 11 February 2020). Population structure of B. lusitaniae was inferred using clustering and network analyses. Maximum likelihood phylogenies for two molecular tick markers (the mitochondrial 16S rRNA locus and a nuclear locus, Tick-receptor of outer surface protein A, trospA) were used to confirm the morphological species identification of collected ticks. Our results confirmed that B. lusitaniae does indeed form two distinguishable populations: one containing mostly European samples and the other mostly Portuguese and North African samples. Of interest, Portuguese samples clustered largely based on being from north (European) or south (North African) of the river Targus. As two different Ixodes species (i.e., I. ricinus and I. inopinatus) may vector Borrelia in these regions, reference samples were included for I. inopinatus but did not form monophyletic clades in either tree, suggesting some misidentification. Even so, the trospA phylogeny showed a monophyletic clade containing tick samples from Northern Africa and Portugal south of the river Tagus suggesting a population division in Ixodes on this locus. The pattern mirrored the clustering of B. lusitaniae samples, suggesting a potential co-evolution between tick and Borrelia populations that deserve further investigation.This research was financially supported by the Slovak Research and Development Agency (grant number APVV-16-0463), by the Fundação para a Ciência e a Tecnologia by the transitory norm contract DL57/2016/CP1370/CT89 to Ana Cláudia Norte and MARE (MARE-UID/MAR/04292/2020), and by the National Institute of Health Doutor Ricardo Jorge, Lisbon, Portugal. The National Reference Center for Borrelia was supported by the Robert-Koch Institute, Berlin, Germany.info:eu-repo/semantics/publishedVersio

Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing population genetic structure at different spatial scales is thus a crucial step towards understanding mechanisms underlying intraspecific differentiation and diversification. Here, we studied the population genetic structure of a highly mobile species – the great tit Parus major – at different spatial scales. We analysed 884 individuals from 30 sites across Europe including 10 close-by sites (< 50 km), using 22 microsatellite markers. Overall we found a low but significant genetic differentiation among sites (FST = 0.008). Genetic differentiation was higher, and genetic diversity lower, in south-western Europe. These regional differences were statistically best explained by winter temperature. Overall, our results suggest that great tits form a single patchy metapopulation across Europe, in which genetic differentiation is independent of geographical distance and gene flow may be regulated by environmental factors via movements related to winter severity. This might have important implications for the evolutionary trajectories of sub-populations, especially in the context of climate change, and calls for future investigations of local differences in costs and benefits of philopatry at large scales

Physiological parameters and fitness in great tit Parus major populations as bioindicators pf pulp mill pollution

Tese de doutoramento em Biologia (Ecologia) apresentada à Fa. de Ciências da Univ. de Coimbr

Ecological determinants of prevalence of the male-killing bacterium Arsenophonus nasoniae

Male-killing bacteria are found in a broad range of arthropods. Arsenophonus nasoniae is a male-killing bacterium, causing a 80% reduction of the male progeny in infected Nasonia vitripennis wasps. Although the discovery of A. nasoniae dates from the early 80′s, knowledge about the biology and ecology of this endosymbiont is still scarce. One of these poorly studied features is the ecological factors underlying A. nasoniae incidence on its Nasonia spp. hosts in different geographical locations. Here, we studied the prevalence of A. nasoniae in Iberian wild populations of its host N. vitripennis. This wasp species is a common parasitoid of the blowfly Protocalliphora azurea pupae, which in turn is a parasite of hole-nesting birds, such as the blue tit (Cyanistes caeruleus). We also examined the effects of bird rearing conditions on the prevalence of A. nasoniae through a brood size manipulation experiment (creating enlarged, control and reduced broods). Both the wasp and bacterium presence were tested through PCR assays in blowfly pupae. We found A. nasoniae in almost half (47%) of nests containing blowflies parasitized by N. vitripennis. The prevalence of A. nasoniae was similar in the two geographical areas examined (central Portugal and southeastern Spain) and the probability of infection by A. nasoniae was independent of the number of blowfly pupae in the nest. Experimental manipulation of brood size did not affect the prevalence of A. nasoniae nor the prevalence of its host, N. vitripennis. These results suggest that the incidence of A. nasoniae in natural populations of N. vitripennis is high in the Iberian Peninsula, and the infestation frequency of nests by N. vitripennis carrying A. nasoniae is spatially stable in this geographical region independently of bird rearing conditions

Experimental infection by microparasites affects the oxidative balance in their avian reservoir host the blackbird Turdus merula

By draining resources, microparasites can negatively affect the host fitness, which in turn can result in reduced transmission when virulence leads to reductions in host population size. Therefore, for a microparasite to persist in nature, the level of harm it can do to its host is expected to be limited. We tested this hypothesis for tick-borne Borrelia burgdorferi sensu lato (s.l.) infections in the blackbird Turdus merula, one of the most important avian reservoir hosts in Europe. Experimental and observational data were combined to examine the physiological effects caused by B. burgdorferi s.l. infection in blackbirds. Pathogen-free blackbirds were exposed to B. burgdorferi s.l.-infected Ixodes ricinus and I. frontalis nymphs, and compared with a control group (exposed to naïve laboratory-derived I. ricinus nymphs). Their physiological status was evaluated before and after infection with B. burgdorferi s.l., through a set of immunological (erythrocyte sedimentation rate, haptoglobin, white blood cell count and heterophil/lymphocyte ratio), oxidative stress (glutathione peroxidase activity, protein carbonyls and nitric oxide) and general body condition variables (body condition, glucose and haematocrit). Infected males showed higher levels of oxidative damage to proteins (increased levels of protein carbonyls), decreased glutathione peroxidase activity and increased body mass. Infected females had higher levels of glutathione peroxidase activity after infection by B. burgdorferi s.l. than the control group. No significant effects of B. burgdorferi s.l. infection were detected on erythrocyte sedimentation rate, haptoglobin, heterophil/lymphocyte ratio, nitric oxide, glucose and haematocrit. The first experimental study on the effects of B. burgdorferi s.l. on its avian reservoir hosts shows that these bacteria may inflict non-negligible physiological costs. We speculate that during energetically demanding periods, these physiological costs may reduce host fitness and affect pathogen transmission.This research was supported by the Fund for Scientific Research – Flanders Belgium (grant G0.049.10) and the University of Antwerp (KP BOF UA 2015). This study received financial support from Fundação para a Ciência e a Tecnologia - FCT, by the strategic program of MARE (MARE – UID/MAR/04292/2013) and the fellowships to Ana Cláudia Norte (SFRH/BPD/108197/2015 and SFRH/BPD/62898/2009). Dieter Heylen and David Costantini were supported by the Fund for Scientific Research – Flanders Belgium (FWO – postdoctoral fellowships).info:eu-repo/semantics/publishedVersio

Silicose - Breve revisão e experiência de um serviço de pneumologia

A silicose é uma doença pulmonar, fibronodular intersticial difusa, causada pela inalação de sílica cristalina. A propósito desta patologia procedeu-se a uma breve revisão do tema, focando os aspectos mais importantes e, posteriormente, à análise retrospectiva dos processos de 84 doentes internados no Serviço de Pneumologia dos Hospitais da Universidade de Coimbra (HUC), num período de 10 anos, cujo diagnósticoprincipal ou secundário foi silicose. Apresentam-se os aspectos clínicos mais relevantes, bem como as conclusões retiradas desta revisão. Os autores destacam a história ocupacional dos doentes, as alterações do estudo funcional ventilatório, os achados imagiológicos e as complicações associadas.Silicosis is a diffuse interstitial fibronodular lung disease, caused by the inhalation of crystalline silica. We undertook a brief review of the topic, focusing on the most important aspects and performed a retrospective analysis of 84 patients admitted to the Pulmonology Ward of the Coimbra University Hospital over a 10-year period whose main or secondary diagnosis was silicosis. We also present the most relevant clinical features and the conclusions drawn from this review. The authors assess patients’ occupational history, changes in respiratory function study, the imaging findings and the associated complications

Telangiectasia hemorrágica hereditária e malformações arteriovenosas pulmonares - Embolização com rolhão vascular Amplatzer Hereditary hemorrhagic telangiectasia and pulmonary arteriovenous malformations - Embolization with Amplatzer vascular plug

As malformações arteriovenosas pulmonares (MAVP) estão associadas a telangiectasia hemorrágica hereditária em cerca de 70% dos casos, podendo cursar com complicações neurológicas graves decorrentes do embolismo paradoxal potencial. A terapêutica das malformações é realizada no sentido de prevenir estas complicações. Descreve-se o caso clínico de uma doente com duas MAVP, no contexto de telangiectasia hemorrágica hereditária,submetida a embolização com o rolhão vascular Amplatzer. Este novo dispositivo é cada vez mais utilizado nestas situações, salientando-se algumas das suas características e vantagens em relação a outras técnicas de embolização mais frequentemente utilizadas.Pulmonary arteriovenous malformations (PAVMs) are associated to hereditary hemorrhagic telangiectasia in about 70% of the cases. PAVMs are associated to serious neurologic complications, secondary to inherent paradoxical embolisms. Treatment of the malformations is done to prevent these complications. The authors report a clinical case of a patient with two PAVMs, with hereditary hemorrhagic telangiectasia, who was treated by embolization with na Amplatzer vascular plug, a new device increasingly used in these situations. The authors emphasise some of its characteristics and advantages when compared with other embolization techniques most commonly used