Species-specific Susceptibility Research Articles

Antifungal Efficacy of Garlic and Olive Oil Against Candida albicans and Penicillium palitans

Background: Garlic and olive oil have long been recognized for their medicinal properties, particularly for their antimicrobial and antifungal effects. This study investigated the antifungal activity of garlic oil and olive oil against Candida albicans and Penicillium palitans, two common fungal species known to cause infections and spoilage. Methods: Fungi were cultivated on Sabouraud Dextrose Agar (SDA) medium, both unsupplemented and supplemented with varying concentrations (5%, 10%, 15%) of olive oil and garlic oil. The radial growth of the fungi was measured after seven days of incubation at 25°C. The antifungal activity was evaluated by comparing fungal growth across the different concentrations of oils. Results: Olive oil exhibited a dose-dependent inhibitory effect on C. albicans, with the highest inhibition observed at a 15% concentration, reducing growth to an average of 30 mm. Garlic oil showed even greater antifungal activity, with a 15% concentration reducing growth to 29.33 mm. In contrast, Penicillium palitans was less sensitive to both oils, though garlic oil still demonstrated moderate inhibitory effects, particularly at the 15% concentration, reducing growth to 64.33 mm. Olive oil had a less pronounced effect on P. palitans, with the highest concentration reducing growth to 61.67 mm. Conclusion: Both garlic oil and olive oil inhibited the growth of C. albicans and P. palitans, with garlic oil proving more effective, particularly at higher concentrations. C. albicans was more sensitive to both oils compared to P. palitans, suggesting species-specific susceptibility. These findings indicate the potential of natural oils, especially garlic oil, as antifungal agents, warranting further research into their mechanisms and applications.

Prevalence of Lernaea cyprinacea Infections in Indian Major Carp at Fish Farms of Bihar, India

Lernaea cyprinacea, commonly known as anchor worms, represents a significant parasitic threat to Indian Major Carp (IMC) species in the aquaculture system. Lernaea parasitizing is widely reported, affecting brood stock, fingerlings, and marketable-sized freshwater fish species globally. This study aims to comprehensively investigate Lernaea infections in ten fish farms across Bihar, India, focusing on the prevalence, intensity, water quality parameters, fish weight, and associated factors affecting the occurrence of this parasite. The research combines field surveys, laboratory analysis, and epidemiological assessments to provide a holistic understanding of the impact of Lernaea on the health and productivity of Indian major carp populations. The analysis revealed a positive correlation between host body weight and the intensity of Lernaea cyprinacea infestation. Larger fish were more susceptible to parasitic infections, highlighting a potential vulnerability associated with the size of the host. In conclusion, this study contributes valuable insights into the dynamics of Lernaea cyprinacea infections in IMC stocks, emphasizing the species-specific susceptibility and the influence of host body weight on parasitic infestations. The findings provide a foundation for informed aquaculture practices aimed at minimizing the prevalence and impact of Lernaea, thereby enhancing the overall health and productivity of fish farms in the region. In conclusion, current research confirms that Labeo catla and larger fish are very susceptible to Lernaea cyprinacea infection.

2768. In Vitro Antibiotic Susceptibility Pattern of Non-diphtheriae Corynebacterium Isolates 2012-2023, reference lab experience

Abstract Background Non-diphtheriae Corynebacterium spp. are important human pathogens responsible for a broad spectrum of clinical syndromes. Data on species-specific susceptibility patterns is limited. In this study we aim to study these susceptibility patterns over time and summarize the species-specific resistance profile that could be used by clinicians to guide therapeutic decisions. Methods We conducted a retrospective review of all the Non-diphtheriae Corynebacterium isolates that were submitted for antimicrobial susceptibility testing (AST) between January-2012 and February of 2023 to our reference lab. Results A total of 1925 Corynebacterium isolates were submitted for susceptibility testing over the study period. The most commonly identified species was C. striatum (35.6%) followed by C. amycolatum (24.4%). Figure-1 outlines the species distribution. Temporal analysis showed decreasing susceptibility rates over the study period from 47.5% to 20.6% for penicillin & from 50% to 7.6% for clindamycin. Linezolid and vancomycin were universally active against all species (Table-1). Daptomycin non-susceptibility was reported in 25% of C. jeikeium isolates (MIC=2). High level resistance to daptomycin with MIC >256 were noted in seven C. striatum and single C. amycolatum isolate. Doxycycline has the highest susceptibility rates among the tested oral agents after linezolid for the non-striatum species. Significant variation in species-specific susceptibility pattern was noted and summarized in Table 1. C. striatum was associated with concerning resistance rates to beta-lactams, tetracyclines, trimethoprim-sulfamethoxazole & fluoroquinolones with limited reliable oral treatment options beside linezolid. C. kroppenstedtii (associated with granulomatous mastitis) showed high susceptibility rate to tetracyclines and trimethoprim-sulfamethoxazole despite prevalent penicillin resistance. Conclusion Non-diphtheriae Corynebacterium spp are commonly isolated from clinical specimens and are associated with various clinical syndromes. Significant variation in resistance profile exists between different species. Prevalent resistance among the most common species such as C. Striatum is associated with therapeutic challenges. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria Audrey N. Schuetz, MD, Merck: Advisor/Consultant

Value of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF) in Discriminating Candida Species

Abstract Background Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI TOF-MS) allows rapid and accurate identification of Candida species. Phenotypic identification of Candida species remains labor- and time consuming, and the results may sometimes be inconclusive. Rapid and reliable species identification of Candida is essential for antifungal treatment due to speciesspecific susceptibility patterns. Objectives We evaluated the performance of MALDI TOF-MS (VITEK MS) compared with conventional VITEK 2 YST (V2C) for identification of clinically important Candida strains. Subject and Methods A total of 50 Candida isolates collected from different clinical samples submitted to the Main Microbiology Laboratory Ain Shams University Hospitals, were included in this study. Candida species were identified by conventional phenotypic tests as Gram stain, culture morphology and with automated V2C panels as well as with VITEK MS. Results There was a total agreement of (100%) between VITEK MS and V2C at the level of the genus and (96%) at the level of the species. The most common isolates identified were C.tropicalis followed by C. albicans in urinary samles. Conclusion VITEK MS is a rapid and reliable method in comparison to V2C for identification of Candida strains in Microbiology Clinical Laboratory.

Incorporating caudate species susceptibilities and climate change into models of Batrachochytrium salamandrivorans risk in the United States of America

Worldwide, amphibians are threatened by several factors including climate change and pathogens. One emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal) has caused die-offs of European salamander populations, representing a conservation concern for hotspots of salamander diversity in the United States of America (U.S.A). While Bsal has not been detected in the U.S.A., previous work has suggested high invasion potential. As species susceptibility to Bsal is temperature dependent, we expect climate change to impact Bsal risk, which has not been explored. Here, we used predicted changes in environmental conditions, species-specific susceptibility estimates, and novel approaches assessing introduction risks to estimate current and future Bsal invasion risk. To generate predictions, we used geospatial data representing introduction risks, species susceptibility, and climatic suitability. Across climatic scenarios, our models predicted greatest overall risk of Bsal emergence in the southeastern and northwestern U.S.A. Bsal climatic suitability was greatest in the northwest, whereas the greatest number of susceptible species was predicted in the southeast. Under future scenarios, we predicted that climatically suitable areas for Bsal will be reduced by 3–14 % under the most extreme climate model.

Equine Crofton Weed (Ageratina spp.) Pneumotoxicity: What Do We Know and What Do We Need to Know?

Crofton weed (Ageratina adenophora) is a global and highly invasive weed, with ingestion causing severe respiratory disease in horses, leading to irreversible and untreatable pulmonary fibrosis and oedema. While reports of equine pneumotoxicity remain common in Australia and New Zealand, equine pneumotoxicity may be underdiagnosed in other countries where Crofton weed is endemic but poorly differentiated. The pathogenesis of Crofton weed toxicity following ingestion has been well described in a number of different animal models, including rodents, rabbits, and goats. However, induced toxicity is organ-selective across different animal species, and these vastly differ from the pathogenesis described in horses, both clinically and after experimental exposure. Sources of variation may include species-specific susceptibility to different toxins present in the plant, different mechanistic processes of toxicity, and species differences in toxin biotransformation and bioactivation across different organs. Considering disease severity and Crofton weed's invasiveness globally, assessing published toxicological and exposure data is necessary to advance research, identify specific toxins for horses, and possible prophylactic and therapeutic strategies. This review presents an overview of the available literature on equine toxicity, parallels between toxicity in horses and other animal species, and important aspects to be included in the future research agenda.

Experimental transmission of piscine orthoreovirus-1 (PRV-1) in different life stages of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta)

Piscine orthoreovirus -1 (PRV-1) causes the disease heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon, and the virus has been detected in wild anadromous Atlantic salmon and brown trout. However, the infection prevalence, viral kinetics, and disease severity in different life stages of Atlantic salmon and brown trout are unknown. The current study aimed to evaluate and compare susceptibility to PRV-1 infection and development of HSMI in different life stages of anadromous Atlantic salmon (Salmo salar) and brown trout (Salmo trutta). We challenged Atlantic salmon and brown trout fry, parr, and post-smolts with PRV-1 by bath, cohabitation, or IP injection. The kinetics of viral infection and disease development were evaluated by RT-qPCR, in situ hybridization, and histology. Our results indicated that PRV-1 infection prevalence and viral kinetics depend on the developmental stage and challenge method in both Atlantic salmon and brown trout. All developmental stages of Atlantic salmon and brown trout can be infected with PRV-1. However, brown trout showed a lower infection prevalence, with positive cases exhibiting only mild infections without any pathological changes in the target organs, while all life stages of Atlantic salmon developed heart lesions characteristic of HSMI. These results strongly suggest that brown trout are less susceptible to PRV-1 infection than Atlantic salmon and further confirm the species-specific susceptibility and disease development for PRV-1 infection.

The Importance of Gram-stained Smears in the Diagnosis of Nocardia Infections

Nocardia species are low virulence bacteria found in nature. They can be an infectious agent, especially in patients with risk factors such as underlying immunosuppression, chronic lung disease, and malignancy. They can be easily overlooked because they are not seen frequently and has no pathognomonic symptoms. With this study, it was aimed to draw attention to the importance of microscopic examination of Gram-stained smears in the diagnosis of Nocardia infections in routine microbiology laboratories. Cases in which Nocardia spp. were detected in their clinical samples between November 2014-December 2015 in Hacettepe University Medical Faculty Hospital were included in the study. In the direct microscopic examination of Gram-stained smears of the samples arriving to the laboratory, the incubation periods of the cultures of the samples compatible with Nocardia spp. were extended. Then relevant colonies were identified by conventional microbiological methods and also by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS, bioMerieux, France) automated system. Species-level identification of Nocardia isolates was performed by 16S rRNA gene sequence analysis. To demonstrate the genetic relationship between Nocardia isolates, pulsed-field gel electrophoresis (PFGE) was performed. In vitro susceptibility of the isolates against amoxicillin-clavulanate (AMC), linezolid, moxifloxacin, trimethoprim-sulfamethoxazole (TMP-SXT), amikacin, imipenem, clarithromycin, cefepime, cefotaxime, ceftriaxone, and ciprofloxacin was determined using the gradient strip method (E-test). A total of 19 Nocardia spp. strains were isolated from eight patients. Four cases exhibited repeated growth of Nocardia spp. up to a period of nine months. The most frequently isolated species was N.cyriacigeorgica, which was identified in four cases. Other species isolated from patients were N.asteroides, N.transvalensis, N.farcinicia, and N.asiatica/arthritidis. When the results obtained with DNA sequence analysis and MALDI-TOF MS were compared, 16 (84.2%) of 19 isolates were correctly identified to the genus level and 9 (47.4%) to the species level with MALDI-TOF MS, while three (15.8%) isolates could not be identified, and seven (36.8%) isolates were misidentified. According to the PFGE results, it was determined that the strains isolated from the same patient were genetically identical. All isolates were susceptible to amikacin, cefepime, cefotaxime, ceftriaxone, imipenem, linezolid, and except one isolate to TMP-SXT. Among the study isolates, the most common resistance was against ciprofloxacin (62.5%), followed by clarithromycin (37.5%). N.cyriacigeorgica was determined as the most frequently detected and the most resistant species to antibiotics in the study population. Direct microscopic examination of clinical specimens is one of the most valuable methods for the identification of Nocardia-type bacteria, which is difficult to isolate in microbiology laboratories. With this study, the importance of examining Gram-stained clinical samples was emphasized in the identification of Nocardia species, which can emerge with a wide variety of clinical forms and can be easily overlooked. In addition, antibiotic susceptibility profiles of the isolated bacteria were determinedto contribute to species-specific susceptibility profiles. Accurate identification of Nocardia species will contribute to clinical and epidemiological studies.

Generation of self-replicating airway organoids from the cave nectar bat Eonycteris spelaea as a model system for studying host–pathogen interactions in the bat airway epithelium

ABSTRACT Bats are reservoir hosts for various zoonotic viruses with pandemdic potential in humans and livestock. In vitro systems for studying bat host–pathogen interactions are of significant interest. Here, we establish protocols to generate bat airway organoids (AOs) and airway epithelial cells differentiated at the air–liquid interface (ALI-AECs) from tracheal tissues of the cave-nectar bat Eonycteris spelaea. In particular, we describe steps which enable laboratories that do not have access to live bats to perform extended experimental work upon procuring an initial batch of bat primary airway tissue. Complete mucociliary differentiation required treatment with IL-13. E. spelaea ALI-AECs supported productive infection with PRV3M, an orthoreovirus for which Pteropodid bats are considered the reservoir species. However, these ALI-AECs did not support SARS-CoV-2 infection, despite E. spelaea ACE2 receptor being capable of mediating SARS-CoV-2 spike pseudovirus entry. This work provides critical model systems for assessing bat species-specific virus susceptibility and the reservoir likelihood for emerging infectious agents.

Cation ATPase (ATP4) Orthologue Replacement in the Malaria Parasite Plasmodium knowlesi Reveals Species-Specific Responses to ATP4-Targeting Drugs.

ABSTRACTSeveral unrelated classes of antimalarial compounds developed against Plasmodium falciparum target a parasite-specific P-type ATP-dependent Na+ pump, PfATP4. We have previously shown that other malaria parasite species infecting humans are less susceptible to these compounds. Here, we generated a series of transgenic Plasmodium knowlesi orthologue replacement (OR) lines in which the endogenous pkatp4 locus was replaced by a recodonized P. knowlesi atp4 (pkatp4) coding region or the orthologous coding region from P. falciparum, Plasmodium malariae, Plasmodium ovale subsp. curtisi, or Plasmodium vivax. Each OR transgenic line displayed a similar growth pattern to the parental P. knowlesi line. We found significant orthologue-specific differences in parasite susceptibility to three chemically unrelated ATP4 inhibitors, but not to comparator drugs, among the P. knowlesi OR lines. The PfATP4OR transgenic line of P. knowlesi was significantly more susceptible than our control PkATP4OR line to three ATP4 inhibitors: cipargamin, PA21A092, and SJ733. The PvATP4OR and PmATP4OR lines were similarly susceptible to the control PkATP4OR line, but the PocATP4OR line was significantly less susceptible to all ATP4 inhibitors than the PkATP4OR line. Cipargamin-induced inhibition of Na+ efflux was also significantly greater with the P. falciparum orthologue of ATP4. This confirms that species-specific susceptibility differences previously observed in ex vivo studies of human isolates are partly or wholly enshrined in the primary amino acid sequences of the respective ATP4 orthologues and highlights the need to monitor efficacy of investigational malaria drugs against multiple species. P. knowlesi is now established as an important in vitro model for studying drug susceptibility in non-falciparum malaria parasites.

The FraDiv experiment: Biodiversity-ecosystem functioning research meets reforestation practice

European ash-rich forest ecosystems are transforming rapidly under the influence of ash dieback, putting many associated species at risk. Forest managers face the urgent challenge to deal with the loss of European ash (Fraxinus excelsior L.) as a key tree species to maintain species richness and ecosystem functioning. The project FraDivexp, located in Schleswig-Holstein, Germany, aims at counteracting detrimental effects of progressive ash decline by testing alternative tree species in a Biodiversity-Ecosystem Functioning (BEF) experiment along a hydrological gradient. Here, we provide insight into how a BEF-approach can be combined with silvicultural management practice to meet the needs for both ecological research and reforestation. At the same time, we present first data on the survival of the planted saplings.In winter 2019/2020, FraDivexp was established with autochthonous tree species considered potential substitutes for the functioning of ash. At 12 sites, plantations including Fraxinus excelsior, Acer platanoides L., Carpinus betulus L., Tilia cordata Mill. and Ulmus laevis Pall. were planted directly underneath the remains of collapsing forest canopies involving all monocultures, and all combinations of 2-, 4- and 5-species mixtures. One year after planting of 25,200 trees, total mortality was at 5% with U. laevis showing lowest mortality while establishment of A.platanoides was least successful. In this early phase of FraDivexp tree mortality was species-specific and driven by initial individual tree size, pH-values in the topsoil and canopy openness, while there was no effect associated with tree diversity. Analysis of further biotic factors showed high mortality of A.platanoides in areas with a high cover of Rubus spp. in the herb layer, indicating species-specific susceptibility to different site conditions. Overall, low mortality (compared to other BEF experiments on arable land) suggests an advantage of establishing a BEF experiment within an existing forest matrix. Simultaneously, this study shows that differences in environmental context dependency among species need to be considered more explicitly, when recommending management strategies. To ensure successful establishment of reforestations with substitute tree species is the first step to efficiently counteract the massive loss of ash trees with the aim of maintaining biodiversity and ecosystem functioning.

Interspecific differences in oxidative DNA damage after hydrogen peroxide exposure of sea urchin coelomocytes.

Interspecific comparison of DNA damage can provide information on the relative vulnerability of marine organisms to toxicants that induce oxidative genotoxicity. Hydrogen peroxide (H2O2) is an oxidative toxicant that causes DNA strand breaks and nucleotide oxidation and is used in multiple industries including Atlantic salmon aquaculture to treat infestations of ectoparasitic sea lice. H2O2 (up to 100 mM) can be released into the water after sea lice treatment, with potential consequences of exposure in nontarget marine organisms. The objective of the current study was to measure and compare differences in levels of H2O2-induced oxidative DNA damage in coelomocytes from Scottish sea urchins Echinus esculentus, Paracentrotus lividus, and Psammechinus miliaris. Coelomocytes were exposed to H2O2 (0-50 mM) for 10 min, cell concentration and viability were quantified, and DNA damage was measured by the fast micromethod, an alkaline unwinding DNA method, and the modified fast micromethod with nucleotide-specific enzymes. Cell viability was >92% in all exposures and did not differ from controls. Psammechinus miliaris coelomocytes had the highest oxidative DNA damage with 0.07 ± 0.01, 0.08 ± 0.01, and 0.07 ± 0.01 strand scission factors (mean ± SD) after incubation with phosphate-buffered saline, formamidopyrimidine-DNA glycosylase, and endonuclease-III, respectively, at 50 mM H2O2. Exposures to 0.5 mM H2O2 (100-fold dilution from recommended lice treatment concentration) induced oxidative DNA damage in all three species of sea urchins, suggesting interspecific differences in vulnerabilities to DNA damage and/or DNA repair mechanisms. Understanding impacts of environmental genotoxicants requires understanding species-specific susceptibilities to DNA damage, which can impact long-term stability in sea urchin populations in proximity to aquaculture farms.

Human Breast Milk: A Source of Potential Probiotic Candidates.

This study focuses on the isolation of lactobacilli/bifidobacteria from human breast milk and their first characterization, in the perspective to find new probiotic candidates to be included in food products. More specifically, breast-milk-isolated strains demonstrated a very good aptitude to adhere to intestinal cells, in comparison with L. rhamnosus GG strain, taken as reference. The same behavior has been found for hydrophobicity/auto-aggregation properties. A remarkable antagonistic activity was detected for these isolates not only against spoilage and pathogenic species of food interest, but also against the principal etiological agents of intestinal infections. Indeed, isolated strains impaired spoilage and pathogenic species growth, as well as biofilm formation by gut pathogens. In addition, breast milk strains were characterized for their antibiotic susceptibility, displaying species-specific and strain-specific susceptibility patterns. Finally, to assess their technological potential, the fermentation kinetics and viability of breast milk strains in pasteurized milk were investigated, also including the study of the volatile molecule profiles. In this regard, all the strains pointed out the release of aroma compounds frequently associated with the sensory quality of several dairy products such as acetic acid, diacetyl, acetoin, acetaldehyde. Data here reported point up the high potential of breast-milk-isolated strains as probiotics.

Animal models for studying COVID-19, prevention, and therapy: Pathology and disease phenotypes.

Translational models have played an important role in the rapid development of safe and effective vaccines and therapeutic agents for the ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Animal models recapitulating the clinical and underlying pathological manifestations of COVID-19 have been vital for identification and rational design of safe and effective vaccines and therapies. This manuscript provides an overview of commonly used COVID-19 animal models and the pathologic features of SARS-CoV-2 infection in these models in relation to their clinical presentation in humans. Also discussed are considerations for selecting appropriate animal models for infectious diseases such as COVID-19, the host determinants that can influence species-specific susceptibility to SARS-CoV-2, and the pathogenesis of COVID-19. Finally, the limitations of currently available COVID-19 animal models are highlighted.

Enhanced apoptosis as a possible mechanism to self-limit SARS-CoV-2 replication in porcine primary respiratory epithelial cells in contrast to human cells

The ability of SARS-CoV to infect different species, including humans, dogs, cats, minks, ferrets, hamsters, tigers, and deer, pose a continuous threat to human and animal health. Pigs, though closely related to humans, seem to be less susceptible to SARS-CoV-2. Former in vivo studies failed to demonstrate clinical signs and transmission between pigs, while later attempts using a higher infectious dose reported viral shedding and seroconversion. This study investigated species-specific cell susceptibility, virus dose-dependent infectivity, and infection kinetics, using primary human (HRECs) and porcine (PRECs) respiratory epithelial cells. Despite higher ACE2 expression in HRECs compared to PRECs, SARS-CoV-2 infected, and replicated in both PRECs and HRECs in a dose-dependent manner. Cytopathic effect was particularly more evident in PRECs than HRECs, showing the hallmark morphological signs of apoptosis. Further analysis confirmed an early and enhanced apoptotic mechanism driven through caspase 3/7 activation, limiting SARS-CoV-2 propagation in PRECs compared to HRECs. Our findings shed light on a possible mechanism of resistance of pigs to SARS-CoV-2 infection, and it may hold therapeutic value for the treatment of COVID-19.

Avian disease surveillance on the island of San Cristóbal, Galápagos.

Endemic island species face unprecedented threats, with many populations in decline or at risk of extinction. One important threat is the introduction of novel and potentially devastating diseases, made more pressing due to accelerating global connectivity, urban development, and climatic changes. In the Galápagos archipelago two important wildlife diseases: avian pox (Avipoxvirus spp.) and avian malaria (Plasmodium spp. and related Haemosporidia) challenge endemic species. San Cristóbal island has seen a paucity of disease surveillance in avian populations, despite the island's connectedness to the continent and the wider archipelago. To survey prevalence and better understand the dynamics of these two diseases on San Cristóbal, we captured 1205 birds of 11 species on the island between 2016 and 2020. Study sites included urban and rural lowland localities as well as rural highland sites in 2019. Of 995 blood samples screened for avian haemosporidia, none tested positive for infection. In contrast, evidence of past and active pox infection was observed in 97 birds and identified as strains Gal1 and Gal2. Active pox prevalence differed significantly with contemporary climatic conditions, being highest during El Niño events (~11% in 2016 and in 2019 versus <1% in the La Niña year of 2018). Pox prevalence was also higher at urban sites than rural (11% to 4%, in 2019) and prevalence varied between host species, ranging from 12% in medium ground finches (Geospiza fortis) to 4% in Yellow Warblers (Setophaga petechial aureola). In the most common infected species (Small Ground Finch: Geospiza fuliginosa), birds recovered from pox had significantly longer wings, which may suggest a selective cost to infection. These results illustrate the threat future climate changes and urbanization may present in influencing disease dynamics in the Galápagos, while also highlighting unknowns regarding species‐specific susceptibilities to avian pox and the transmission dynamics facilitating outbreaks within these iconic species.

In vitro teratogenicity testing using a 3D, embryo-like gastruloid system

Pharmaceuticals intended for use in patients of childbearing potential need to be tested for teratogenicity before marketing. Several pharmaceutical companies use animal-free in vitro models which allow a more rapid selection of lead compounds and contribute to 3Rs principles (‘replace, reduce and refine’) by streamlining the selection of promising compounds submitted to further regulatory studies in animals. Currently available in vitro models typically rely on adherent monolayer cultures or disorganized 3D structures, both of which lack the spatiotemporal and morphological context of the developing embryo. A newly developed 3D ‘gastruloid’ model has the potential to achieve a more reliable prediction of teratogenicity by providing a robust recapitulation of gastrulation-like events alongside morphological coordination at relatively high-throughput. In this first proof-of-concept study, we used both mouse and human gastruloids to examine a panel of seven reference compounds, with associated in vivo data and known teratogenic risk, to quantitatively assess in vitro teratogenicity. We observed several gross morphological effects, including significantly reduced elongation or decreased size of the gastruloids, upon exposure to several of the reference compounds. We also observed aberrant gene expression using fluorescent reporters, including SOX2, BRA, and SOX17, suggestive of multi-lineage differentiation defects and disrupted axial patterning. Finally, we saw that gastruloids recapitulated some of the known in vivo species-specific susceptibilities between their mouse and human counterparts. We therefore suggest that gastruloids represent a powerful tool for teratogenicity assessment by enabling relevant physiological recapitulation of early embryonic development, demonstrating their use as a novel in vitro teratogenic model system.

From Acid Rain to Low Precipitation: The Role Reversal of Norway Spruce, Silver Fir, and European Beech in a Selection Mountain Forest and Its Implications for Forest Management

Research Highlights: We make use of long term observation data from a selection forest in Bavaria. Despite the changing environmental conditions, stand level productivity remains constant over time. Maintaining species and structural diversity by forest management can contribute to resilient forest ecosystems. Background and Objectives: Forests in mountains are similarly affected by environmental changes like those in northern latitudes as species are closer to the edge of their ecological niche. There are recent studies that report species-specific responses to climate change in unmanaged, mono-layered mountain mixed forests. We analyze how environmental changes modify the growth of multi-layered, managed selection forest, which are often targeted for stabilization and risk prevention. We pose the central hypothesis that different species-specific susceptibility to disturbances and structural diversity contribute to ecosystem stability. Materials and Methods: Based on the long-term experiment Freyung 129 in the montane zone of the Bavarian Forest, Germany we analyze long term chronologies of periodic single tree and stand growth of Norway Spruce, silver fir, and European beech in dependence of environmental factors and forest management. Results: First, we show that despite environmental changes in terms of air pollution and drought stress, productivity at stand level persists constantly because of structural diversity and species traits. Second, we show that the species-specific contribution to total stand growth and growth distribution among stem diameter classes may change over time; the species interactions balance total growth. Third, we reveal a role reversal of tree species growth pattern. N. spruce was superior in growth in the first half and was replaced by s. fir in the second half of the survey period. Fourth, we identify the interplay of different stress factors on species-specific growth as the main cause for species-specific asynchronous but growth stabilizing reaction pattern. Finally, we show that density regulation was limited in its impacts to mitigate prevailing stress factors. Conclusions: We discuss the reasons for the observed stability of productivity. We interpret results, where especially the diversity of species and structure typical for selection forests result in stable productivity and wider plateau of the density-productivity relationship, and the suitability of the selection forest concept for risk prevention and stress resilience. We conclude that species composition and stand structure of selection forestry in mixed mountain contribute to climate smart forestry.

Long-Term Projections of the Natural Expansion of the Pine Wood Nematode in the Iberian Peninsula

The invasive pine wood nematode (PWN), Bursaphelenchus xylophilus, causal agent of pine wilt disease, was first reported in Europe, near Lisbon, in 1999, and has since then spread to most of Portugal. We here modelled the spatiotemporal patterns of future PNW natural spread in the Iberian Peninsula, as dispersed by the vector beetle Monochamus galloprovincialis, using a process-based and previously validated network model. We improved the accuracy, informative content, forecasted period and spatial drivers considered in previous modelling efforts for the PWN in Southern Europe. We considered the distribution and different susceptibility to the PWN of individual pine tree species and the effect of climate change projections on environmental suitability for PWN spread, as we modelled the PWN expansion dynamics over the long term (&gt;100 years). We found that, in the absence of effective containment measures, the PWN will spread naturally to the entire Iberian Peninsula, including the Pyrenees, where it would find a gateway for spread into France. The PWN spread will be relatively gradual, with an average rate of 0.83% of the total current Iberian pine forest area infected yearly. Climate was not found to be an important limiting factor for long-term PWN spread, because (i) there is ample availability of alternative pathways for PWN dispersal through areas that are already suitable for the PWN in the current climatic conditions; and (ii) future temperatures will make most of the Iberian Peninsula suitable for the PWN before the end of this century. Unlike climate, the susceptibility of different pine tree species to the PWN was a strong determinant of PWN expansion through Spain. This finding highlights the importance of accounting for individual tree species data and of additional research on species-specific susceptibility for more accurate modelling of PWN spread and guidance of related containment efforts.

Aggregation Propensity of Serum Amyloid A1 in Captive Zoo and Free‐living Wild Animals

AA Amyloidosis is the most common form of amyloid disease, occurring in humans, domestic animals, wildlife and captive zoo animals and is defined by the misfolding of serum amyloid A (SAA), an apolipoprotein of high-density lipoprotein (HDL). SAA is a positive acute phase protein that is synthesized by the liver during chronic states of inflammation or stress, depositing mainly in the liver, spleen and kidneys. AA amyloidosis poses the highest risk to zoo species within captivity given the diverse number of species susceptible to the disease, transmissibility of the disease, pre-disposing factors, and close housing conditions in zoo facilities. Susceptibility to AA amyloidosis may be dependent upon the propensity of SAA to aggregate in different species. Variation in the 104 amino acid sequence of the SAA protein may contribute to the likelihood that SAA will misfold under chronic conditions. While the proteolytic cleavage or removal of the C-terminal tail of SAA is known to result in formation of fibrils, the molecular mechanism of SAA aggregation is not completely understood. This study proposes to investigate areas of the SAA1 peptide that are likely to misfold and how mutation has led to evolutionary divergence and species-specific susceptibility to the disease. A bioinformatic analysis was performed to predict the aggregation score (Tango program). Homology and variance in each SAA1 peptide were demonstrated via sequence alignment prepared in BioEdit. A phylogenetic analysis prompted us to identify potential mutations for the design of a peptide library. Using bioinformatic (tango program) and thioflavin-T fluorescence assays, we studied the aggregation propensity of SAA1 fragments derived from amyloidogenic species and non-amyloidogenic species. Aggregation propensity in the first 1-25 amino acids was assessed via Tango to which SAA1 in humans, felids, mice and equids were predicted to be most susceptible to aggregation, while SAA1 in avian and reptile taxa were least likely to aggregate. A ThT experiment performed on fragments belonging to 8 different species demonstrated that fragments from felids, mice and humans are highly prone to aggregate and supportive of bioinformatic results. SAA1 fragment peptides derived from the rainbow trout and Chinese soft-shelled turtles exhibited a low propensity of aggregation. Mutation in the SAA1 peptide may contribute to the amyloidogenicity of the protein, which may help identify high-risk species and establish an evolutionary basis for the disease. Evaluation and identification of peptide residues that have a higher propensity to aggregate, in addition to the evaluation of conditions that may contribute to misfolding, will help direct the development of small molecule therapeutics that prevent AA amyloidosis.