scholarly journals Divergent regional evolutionary histories of a devastating global amphibian pathogen

2021 ◽  
Vol 288 (1953) ◽  
pp. 20210782
Author(s):  
Andrew P. Rothstein ◽  
Allison Q. Byrne ◽  
Roland A. Knapp ◽  
Cheryl J. Briggs ◽  
Jamie Voyles ◽  
...  

Emerging infectious diseases are a pressing threat to global biological diversity. Increased incidence and severity of novel pathogens underscores the need for methodological advances to understand pathogen emergence and spread. Here, we use genetic epidemiology to test, and challenge, key hypotheses about a devastating zoonotic disease impacting amphibians globally. Using an amplicon-based sequencing method and non-invasive samples we retrospectively explore the history of the fungal pathogen Batrachochytrium dendrobatidis ( Bd ) in two emblematic amphibian systems: the Sierra Nevada of California and Central Panama. The hypothesis in both regions is the hypervirulent Global Panzootic Lineage of Bd ( Bd GPL) was recently introduced and spread rapidly in a wave-like pattern. Our data challenge this hypothesis by demonstrating similar epizootic signatures can have radically different underlying evolutionary histories. In Central Panama, our genetic data confirm a recent and rapid pathogen spread. However, Bd GPL in the Sierra Nevada has remarkable spatial structuring, high genetic diversity and a relatively older history inferred from time-dated phylogenies. Thus, this deadly pathogen lineage may have a longer history in some regions than assumed, providing insights into its origin and spread. Overall, our results highlight the importance of integrating observed wildlife die-offs with genetic data to more accurately reconstruct pathogen outbreaks.

2018 ◽  
Author(s):  
Marilena Meloni ◽  
Caterina Angela Dettori ◽  
Andrea Reid ◽  
Gianluigi Bacchetta ◽  
Laetitia Hugot ◽  
...  

SummaryCorsica and Sardinia form one of the ten areas with highest biodiversity in the Mediterranean and are considered one of the priority regions for conservation in Europe. In order to preserve the high levels of endemism and biological diversity at different hierarchical levels, knowledge of the evolutionary history and current genetic structure of Corso-Sardinian endemics is instrumental. Microsatellite markers were newly developed and used to study the genetic structure and taxonomic status of Ruta corsica and Ruta lamarmorae, rare endemics of Corsica and Sardinia, respectively, and previously considered a single species. Our analyses identified high levels of genetic variation within each species (P=0.883, He=0.543 for R. corsica; P=0.972, He=0.627 for R. lamarmorae). Intrinsic traits of the species (hermaphroditism, proterandry and polyploidy) and island-dependent factors (i.e. age, origin and history of the islands) might explain the detected high levels of genetic variation. We discovered differentiation between R. corsica and R. lamarmorae, and genetic structure within each species, which are consistent with the observation of low dispersal ability for both species. Our genetic results support the recent taxonomic classification of R. corsica and R. lamarmorae as separate species and suggest that they diverge at only few loci. One R. corsica population (SA) strongly differed from all other studied populations and appeared to be the product of hybridization between the two species in STRUCTURE analyses. Our results provide important insights for the conservation of the two rare endemics. Further genetic analyses are recommended for R. lamarmorae and for population SA (R. corsica).


2009 ◽  
Vol 160 (8) ◽  
pp. 232-234
Author(s):  
Patrik Fouvy

The history of the forests in canton Geneva, having led to these being disconnected from productive functions, provides a symptomatic demonstration that the services provided by the forest eco-system are common goods. Having no hope of financial returns in the near future and faced with increasing social demands, the state has invested in the purchase of forest land, financed projects for forest regeneration and improvement of biological diversity and developed infrastructures for visitors. In doing this the state as a public body takes on the provision of services in the public interest. But the further funding for this and for expenses for the private forests, which must be taken into account, are not secured for the future.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Lino Bianco

AbstractRuins are a statement on the building materials used and the construction method employed. Casa Ippolito, now in ruins, is typical of 17th-century Maltese aristocratic country residences. It represents an illustration of secondary or anthropogenic geodiversity. This paper scrutinises these ruins as a primary source in reconstructing the building’s architecture. The methodology involved on-site geographical surveying, including visual inspection and non-invasive tests, a geological survey of the local lithostratigraphy, and examination of notarial deeds and secondary sources to support findings about the building’s history as read from its ruins. An unmanned aerial vehicle was used to digitally record the parlous state of the architectural structure and karsten tubes were used to quantify the surface porosity of the limestone. The results are expressed from four perspectives. The anatomy of Casa Ippolito, as revealed in its ruins, provides a cross-section of its building history and shows two distinct phases in its construction. The tissue of Casa Ippolito—the building elements and materials—speaks of the knowledge of raw materials and their properties among the builders who worked on both phases. The architectural history of Casa Ippolito reveals how it supported its inhabitants’ wellbeing in terms of shelter, water and food. Finally, the ruins in their present state bring to the fore the site’s potential for cultural tourism. This case study aims to show that such ruins are not just geocultural remains of historical built fabric. They are open wounds in the built structure; they underpin the anatomy of the building and support insights into its former dynamics. Ruins offer an essay in material culture and building physics. Architectural ruins of masonry structures are anthropogenic discourse rendered in stone which facilitate not only the reconstruction of spaces but also places for human users; they are a statement on the wellbeing of humanity throughout history.


Open Medicine ◽  
2006 ◽  
Vol 1 (4) ◽  
pp. 392-398
Author(s):  
Kazima Bulayeva ◽  
John McGrath

AbstractWhile the season-of-birth effect is one of the most consistent epidemiological features of schizophrenia, there is a lack of consistency with respect to the interaction between season of birth and family history of schizophrenia. Apart from family history, measures related to consanguinity can be used as proxy markers of genomic heterogeneity. Thus, these measures may provide an alternate, indirect index of genetic susceptibility. We had the opportunity to explore the interaction between season of birth and measure of consanguinity in well-described genetic isolates in Daghestan, some of which are known for their relatively high prevalence of schizophrenia. Our previous population-genetic study showed Daghestan has an extremely high genetic diversity between the ethnic populations and a low genetic diversity within them. The isolates selected for this study include some with more than 200 and some with less than 100 generations of demographical history since their founding. Based on pedigrees of multiply-affected families, we found that among individuals with schizophrenia, the measure of consanguinity was significantly higher in the parents of those born in winter/spring compared to those born in summer/autumn. Furthermore, compared to summer/autumn born, winter/spring born individuals with schizophrenia had an earlier age-of-onset, and more prominent auditory hallucinations. Our results suggest that the offspring of consanguineous marriages, and thus those with reduced allelic heterogeneity, may be more susceptible to the environmental factor(s) underpinning the season-of-the effect in schizophrenia.


2017 ◽  
Vol 18 (3) ◽  
pp. 403
Author(s):  
Guntari Titik Mulyani ◽  
Sri Hartati ◽  
Yuli Santoso ◽  
Kurnia Kurnia ◽  
Agung Budi Pramono ◽  
...  

Leptospirosis is a zoonotic disease, which is caused by Leptospira interrogans. The incidence of leptospirosis in dogs varies according to region and season, and is considered as emerging infectious diseases in humans. Clinical symptoms of leptospirosis in dogs vary greatly, some dogs are asymptomatic, with mild symptoms, and others progress to severe illness until death. The study aims to determine cases of canine leptospirosis in Yogyakarta, and identify the serovar that infect them. A total of 20 dogs without symptoms, with mild symptoms, to severe symptoms of leptospirosis were collected their serum and further tested using Microscopic Agglutination Test (MAT) conducted at the Center for Veterinary Research (BBLitvet) Bogor. History of vaccination is recorded as a consideration in interpreting the MAT results. The results showed that three out of the 20 samples were positive leptospirosis. Of the three positive samples, one was identified as serovar bataviae, another one as serovar bataviae and tarrasovi, and the last as serovar bataviae, tarrasovi, ichterohaemorrhagiae, canicola, celledoni, pyrogenes, cynopteri, and rachmati, respectively. The three dogs with leptospirosis showed similar clinical symptoms i.e. Anorexia, lethargy, and fever. It can be concluded that there are cases of canine leptospirosis in Yogyakarta which is predominantly caused by Leptospira interrogans serovar bataviae. ABSTRAK Leptospirosis adalah penyakit zoonosis, yang disebabkan oleh Leptospira interrogans. Kejadian leptospirosis pada anjing bervariasi menurut wilayah dan musim, dan dianggap sebagai penyakit menular yang muncul pada manusia. Gejala klinis leptospirosis pada anjing sangat bervariasi, beberapa anjing tanpa menunjukkan gejala, dengan gejala ringan, dan yang lain melanjut menjadi penyakit yang parah sampai kematian. Penelitian ini bertujuan untuk mengetahui kasus leptospirosis pada anjing di Propinsi Daerah Istimewa Yogyakarta, dan mengidentifikasi serovar yang menginfeksinya. Sebanyak 20 ekor anjing tanpa gejala, dengan gejala ringan, sampai gejala parah leptospirosis diambil serumnya guna pemeriksaan Microscopic Agglutination Test (MAT) yang dilaksanakan di Balai Besar Penelitian Veteriner (BBLitvet), Bogor. Sejarah vaksinasi dicatat sebagai bahan pertimbangan dalam menginterpretasi hasil pemeriksaan MAT. Hasil penelitian menunjukkan bahwa tiga dari 20 sampel positif leptospirosis. Satu sampel positif terhadap serovar Bataviae, satu sampel positif terhadap serovar Bataviae dan Tarrasovi, dan satu sampel lagi positif terhadap serovar Bataviae, Tarrasovi, Ichterohaemorrhagiae, Canicola, Celledoni, Pyrogenes, Cynopteri, dan Rachmati. Anjing yang positif leptospirosis menunjukkan gejala klinis yang sama berupa anoreksia, kelemahan, dan demam. Dari hasil penelitian ini dapat disimpulkan bahwa terdapat kasus leptospirosis pada anjing di Yogyakarta yang penyebabnya dominan oleh Leptospira interrogans serovar Bataviae.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
T Barré ◽  
C Protopopescu ◽  
F Bani-Sadr ◽  
L Piroth ◽  
P Sogni ◽  
...  

Abstract Background Thanks to innovation in treatment, people living with HIV and/or HCV now live longer but are growingly facing non-communicable disease burden. HIV-HCV co-infected patients are at high risk of metabolic complications and liver-related events, which are both associated with hepatic steatosis and its progressive form, non-alcoholic steatohepatitis (NASH), a known risk factor for mortality. The fatty liver index (FLI), a non-invasive steatosis biomarker, has recently drawn attention for its clinical prognostic value, but has never been applied to HIV-HCV co-infected patients. We aimed at testing whether elevated FLI (≥60) was associated with all-cause mortality in co-infected patients. Methods Our study is based on data from ANRS CO13 HEPAVIH, a French national prospective cohort of HIV-HCV co-infected patients. Socio-behavioral and clinical data from patients clinically followed-up were used in the analysis. Using a Cox proportional hazards model for mortality from all causes (983 patients; 4,432 visits), we computed hazard ratios associated with risk factors and confounders. Results After multiple adjustment, individuals with FLI≥60 had almost double the risk of all-cause mortality (adjusted hazard ratio [95% confidence interval]: 1.91 [1.17-3.12], p = 0.009), independently of HCV cure (0.21 [0.07-0.61], p = 0.004), advanced fibrosis (1.77 [1.00-3.14], p = 0.05), history of hepatocellular carcinoma and/or liver transplantation (7.74 [3.82-15.69], p < 10-3), history of indirect clinical signs of cirrhosis (2.80 [1.22-6.41], p = 0.015), and HIV CDC clinical stage C (2.88 [1.74-4.79], p < 10-3). Conclusions An elevated fatty liver index is a risk factor for all-cause mortality in HIV-HCV co-infected patients independently of liver fibrosis and HCV cure. In the present era of nearly 100% HCV cure rates, these findings encourage the more systematic use of non-invasive steatosis biomarkers to help identify co-infected patients with higher mortality risk. Key messages A FLI≥60 is strongly associated with mortality in HIV-HCV co-infected patients. FLI could be calculated routinely to identify most at-risk patients.


2014 ◽  
Vol 10 (1) ◽  
pp. 92-93 ◽  
Author(s):  
Bernardo Dell’Osso ◽  
A. Carlo Altamura

Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are non-invasive brain stimulation techniques that, by means of magnetic fields and low intensity electrical current, respectively, aim to interefere with and modulate cortical excitability, at the level of dorsolateral prefrontal cortex, in patients with major depression and poor response to standard antidepressants. While the clinical efficacy of TMS in major depression has been extensively investigated over the last 10 years, tDCS has attracted research interest only in the last years, with fewer randomized clinical trials (RCTs) in the field. Nevertheless, in spite of the different rationale and mechanism of action of the two techniques, tDCS recent acquisitions, in relation to the treatment of major depression, seem to parallel those previously obtained with TMS, in terms of treatment duration to achieve optimal benefit and patient's history of drug-resistance. After briefly introducing the two techniques, the article examines possible common pathways of clinical use for TMS and tDCS, emerging from recent RCTs and likely orienting future investigation with non invasive brain stimulation for the treatment of major depression.


PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262561
Author(s):  
Olivia Wetsch ◽  
Miranda Strasburg ◽  
Jessica McQuigg ◽  
Michelle D. Boone

Emerging infectious diseases are increasing globally and are an additional challenge to species dealing with native parasites and pathogens. Therefore, understanding the combined effects of infectious agents on hosts is important for species’ conservation and population management. Amphibians are hosts to many parasites and pathogens, including endemic trematode flatworms (e.g., Echinostoma spp.) and the novel pathogenic amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Our study examined how exposure to trematodes during larval development influenced the consequences of Bd pathogen exposure through critical life events. We found that prior exposure to trematode parasites negatively impacted metamorphosis but did not influence the effect of Bd infection on terrestrial growth and survival. Bd infection alone, however, resulted in significant mortality during overwintering—an annual occurrence for most temperate amphibians. The results of our study indicated overwintering mortality from Bd could provide an explanation for enigmatic declines and highlights the importance of examining the long-term consequences of novel parasite exposure.


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