Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
Zootaxa ; 5178(6): 501-531, 2022 Aug 31.
Article in English | MEDLINE | ID: mdl-36095713

ABSTRACT

A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbean slope of Tenorio Volcano in Bijagua, Alajuela Province, Costa Rica. A molecular phylogenetic analysis supports its inclusion in the genus Tlalocohyla. Morphological, morphometric, larval, and acoustic characteristics further distinguish it from other species in the genus and support its uniqueness. The new species is closely related to T. picta and T. smithii, and is separated by at least 500 kilometers from the nearest known occurrence of a population of T. picta in southern Honduras. The new species is readily distinguished from all other Tlalocohyla by its brilliant green coloration marked with a pronounced, incomplete light dorsolateral stripe that is bordered above by a diffuse reddish-brown stripe. Its dorsum is marked with bold reddish brown spots and its ventral skin is fully transparent. This new Tlalocohyla is currently only known from the type locality, where it inhabits a lentic wetland system with an emergent herbaceous vegetation-dominated benthic zone, surrounded by tropical rainforest. A description of its bioacoustic repertoire and information on natural history, reproduction and habitat preference of this new species are provided.


Subject(s)
Anura , Rana clamitans , Animals , Costa Rica , Phylogeny , Quaternary Ammonium Compounds
2.
Neuroreport ; 33(2): 72-80, 2022 01 19.
Article in English | MEDLINE | ID: mdl-34954771

ABSTRACT

OBJECTIVE: During diabetes, there are increased blood glucose levels and oxidative stress. The relationship between oxidative stress and the phosphorylation of AMP-activated protein kinase at the hypothalamic level has been little studied. The objective of this study was to analyze the relationship between oxidative stress and AMP-activated protein kinase activation in Wistar rats with hyperphagia and hyperglycemia. METHODS: Rats at 7, 14, and 28 days with diabetes were used. Control rats were included. Food intake was calculated to determine hyperphagia. The hypothalamus was extracted to evaluate oxidative stress markers by spectrophotometry; phosphorylation of AMP-activated protein kinase, growth hormone receptor 1a, and neuropeptide Y expression were determined by Western blot. RESULTS: There was a significant increase in the consumption of food in the experimental groups. The level of malondialdehyde decreased in the 7-day group (33%) and increased significantly in the 28-day group (90%), glutathione peroxidase activity increased in the 7-day group (70%) and decreased in the 28-day group (34%), and the phosphorylation of AMP-activated protein kinase increased significantly in the 28-day group (86%). Under ex-vivo conditions in animals with 28 days of hyperglycemia, glutathione peroxidase activity increased 195%, the malondialdehyde level decreased 87%, phosphorylation of AMP-activated protein kinase decreased 53%, and growth hormone receptor 1a expression decreased 66%, when treating hyperglycemic hypothalamic tissue with an antioxidant. NPY expression increased in hyperglycemia, and antioxidant treatment did not regulate its expression. CONCLUSIONS: The activation of AMP-activated protein kinase is related with an increase in oxidative stress markers in hyperglycemic and hyperphagic rats.


Subject(s)
AMP-Activated Protein Kinases , Diabetes Mellitus, Experimental , AMP-Activated Protein Kinases/metabolism , Animals , Diabetes Mellitus, Experimental/metabolism , Eating , Hyperphagia , Hypothalamus/metabolism , Oxidative Stress , Rats , Rats, Sprague-Dawley , Rats, Wistar
3.
Rev. colomb. psiquiatr ; 50(4): 243-251, oct.-dic. 2021. tab
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1376927

ABSTRACT

RESUMEN Introducción: La diabetes es una de las principales pandemias en los últimos anos. Su asociación con depresión incrementa el riesgo de mortalidad y morbilidad. La coexistencia de ambas patologías produce un mal manejo de la diabetes, lo que conlleva a una peor calidad de vida. Objetivo: Determinar la frecuencia de depresión en pacientes con diabetes mellitus y el efecto que tienen ambas patologías sobre la calidad de vida en pacientes que acuden de forma ambulatoria a establecimientos de salud públicos de Lima y Callao. Métodos: Análisis secundario de la base de datos del Estudio Epidemiológico de Salud Mental de depresión en adultos diabéticos. El instrumento empleado para determinar el episodio depresivo fue el MINI (Entrevista Neuropsiquiátrica Internacional) mientras que la calidad de vida fue medida empleando el Índice de Calidad de Vida de Mezzich. Se obtuvo información de diagnóstico de diabetes tipo1ó2del registro médico diario (HIS) de atención. Resultados: La frecuencia de depresión en los 471 pacientes con diabetes fue 5,8% en las últimas dos semanas. Mientras que la frecuencia anual fue 8,6% y en algún momento de la vida 31,8%. Ser mujer se asoció con mayor frecuencia de depresión. La calidad de vida fue menor en los pacientes con diabetes y depresión (p<0,005). Conclusiones: La frecuencia de depresión en pacientes con diabetes que son atendidos en forma ambulatoria en centros de salud públicos es mayor a la población general y su calidad de vida se ve reducida significativamente, lo que plantea la necesidad de considerar la depresión como un factor aditivo a la carga de morbilidad de esta condición.


ABSTRACT Introduction: Diabetes is one of the main pandemics in recent years. Its association with depression increases the risk of mortality and morbidity. The coexistence of both diseases leads to poor management of diabetes, which leads to a worse quality of life. Objective: To determine the frequency of depression in patients with diabetes mellitus and the effect of both pathologies on the quality of life in patients who attend outpatient appointments at public health facilities in Lima and Callao. Methodology: Secondary analysis of the Epidemiological Study of Mental Health of depression in diabetic adults. The instrument used to determine the depressive episode was the MINI (Mini-International Neuropsychiatric Interview) while quality of life was measured using the Mezzich Quality of Life Index. Diagnosis information of type 1 or 2 diabetes was obtained from the daily medical record (HIS) of care. Results: The frequency of depression in the 471 patients with diabetes was 5.8% in the last two weeks. While the annual frequency was 8.6% and 31.8% at some point in life. Being a woman was associated with a greater frequency of depression. Quality of life was lower in patients with diabetes and depression (p < 0.005). Conclusions: The frequency of depression in patients with diabetes who are treated on an outpatient basis in public health centres is higher than the general population and their quality of life is significantly reduced, which raises the need for considering depression as an additional factor to the burden of morbidity of this condition.

4.
Rev Colomb Psiquiatr (Engl Ed) ; 50(4): 243-251, 2021.
Article in English, Spanish | MEDLINE | ID: mdl-34742694

ABSTRACT

INTRODUCTION: Diabetes is one of the main pandemics in recent years. Its association with depression increases the risk of mortality and morbidity. The coexistence of both diseases leads to poor management of diabetes, which leads to a worse quality of life. OBJECTIVE: To determine the frequency of depression in patients with diabetes mellitus and the effect of both pathologies on the quality of life in patients who attend outpatient appointments at public health facilities in Lima and Callao. METHODOLOGY: Secondary analysis of the Epidemiological Study of Mental Health of depression in diabetic adults. The instrument used to determine the depressive episode was the MINI (Mini-International Neuropsychiatric Interview) while quality of life was measured using the Mezzich Quality of Life Index. Diagnosis information of type 1 or 2 diabetes was obtained from the daily medical record (HIS) of care. RESULTS: The frequency of depression in the 471 patients with diabetes was 5.8% in the last two weeks. While the annual frequency was 8.6% and 31.8% at some point in life. Being a woman was associated with a greater frequency of depression. Quality of life was lower in patients with diabetes and depression (p < 0.005). CONCLUSIONS: The frequency of depression in patients with diabetes who are treated on an outpatient basis in public health centres is higher than the general population and their quality of life is significantly reduced, which raises the need for considering depression as an additional factor to the burden of morbidity of this condition.


Subject(s)
Diabetes Mellitus, Type 2 , Quality of Life , Adult , Depression/epidemiology , Female , Health Facilities , Humans , Outpatients
6.
Article in English | MEDLINE | ID: mdl-34618750

ABSTRACT

INTRODUCTION: Brain metastases (BM) in soft-tissue sarcomas (STS) is associated with poor prognosis. This large population analysis presents (1) demographic and clinical variables of these patients, (2) potential risk factors, (3) impact of BM on overall survival, and (4) treatment strategies. METHODS: Patients with STS and BM were identified from the Surveillance, Epidemiology, and End Results database. Demographic and clinical variables, as well as treatment modalities, were analyzed. Overall 5-year survival was calculated using the Kaplan-Meier method, and the survival difference was assessed using the log-rank test. A multivariate analysis was performed using the Cox proportional hazard regression to determine the risk factors. RESULTS: Twenty-two patients (22/8,433) with STS presented BM at diagnosis. A multivariate analysis showed that women and American Indians/Alaska Natives had a greater risk of presenting BM. The most common histological subtype to metastasize to the brain was alveolar soft part sarcoma (4/22). In 54.5% of patients with BM, the tumor had also metastasized to the lung, although having synchronous bone, liver, and lung metastases showed the greatest increase in risk for presenting BM (odd ratio [OR] = 1,857.7, confidence interval [CI] 95%, 88.4 to 3,9046.6, P < 0.0001). Individually, bone metastasis increased the risk of presenting BM the most (OR = 205.0, CI 95%, 30.5 to 1,379.6, P < 0.0001). The mean survival of patients with BM was 10.22 months. The standard treatment approach included surgery, radiation therapy, and chemotherapy. CONCLUSION: BM in patients with STS represents an infrequent but lethal event. Women and American Indians/Alaska Natives are at a higher risk of presenting BM, as well as patients with synchronous metastases. Patients are mainly managed with systemic therapy.


Subject(s)
Brain Neoplasms , Sarcoma, Alveolar Soft Part , Soft Tissue Neoplasms , Brain Neoplasms/therapy , Cohort Studies , Female , Humans , Prognosis
7.
Travel Med Infect Dis ; 44: 102163, 2021.
Article in English | MEDLINE | ID: mdl-34534686

ABSTRACT

BACKGROUND: Currently, there is no formally accepted pharmacological treatment for COVID-19. MATERIALS AND METHODS: We included COVID-19 outpatients of a Peruvian primary care center from Lima, Peru, who were treated between April 30 - September 30, 2020, with hydroxychloroquine and azithromycin. Logistic regression was applied to determine factors associated with case-fatality rate. RESULTS: A total of 1265 COVID-19 patients with an average age of 44.5 years were studied. Women represented 50.1% of patients, with an overall 5.9 symptom days, SpO2 97%, temperature of 37.3 °C, 41% with at least one comorbidity and 96.1% one symptom or sign. No patient treated within the first 72 h of illness died. The factors associated with higher case fatality rate were age (OR = 1.06; 95% CI 1.01-1.11, p = 0.021), SpO2 (OR = 0.87; 95% CI 0.79-0.96, p = 0.005) and treatment onset (OR = 1.16; 95% CI 1.06-1.27, p = 0.002), being the latter the only associated in the multivariate analysis (OR = 1.18; 95% CI 1.05-1.32, p = 0.005). 0.6% of our patients died. CONCLUSIONS: The case fatality rate in COVID-19 outpatients treated with hydroxychloroquine/azithromycin was associated with the number of days of illness on which treatment was started.


Subject(s)
COVID-19 Drug Treatment , Hydroxychloroquine , Adult , Azithromycin/therapeutic use , Drug Therapy, Combination , Female , Humans , Hydroxychloroquine/therapeutic use , Oxygen Saturation , SARS-CoV-2 , Time-to-Treatment
8.
PLoS One ; 16(8): e0255144, 2021.
Article in English | MEDLINE | ID: mdl-34343179

ABSTRACT

AIMS: The objective of this study is to analyze how the impact of Diabetes Mellitus [DM] in patients with COVID-19 varies according to altitudinal gradient. METHODS: We obtained 1,280,806 records from adult patients with COVID-19 and DM to analyze the probability of COVID-19, development of COVID-19 pneumonia, hospitalization, intubation, admission to the Intensive Care Unit [ICU] and case-fatality rates [CFR]. Variables were controlled by age, sex and altitude of residence to calculate adjusted prevalence and prevalence ratios. RESULTS: Patients with DM had a 21.8% higher prevalence of COVID-19 and an additional 120.2% higher prevalence of COVID-19 pneumonia. The adjusted prevalence was also higher for these outcomes as well as for hospitalization, intubation and ICU admission. COVID-19 and pneumonia patients with DM had a 97.0% and 19.4% higher CFR, respectively. With increasing altitudes, the probability of being a confirmed COVID-19 case and the development of pneumonia decreased along CFR for patients with and without DM. However, COVID-19 patients with DM were more likely to require intubation when residing at high altitude. CONCLUSIONS: The study suggests that patients with DM have a higher probability of being a confirmed COVID-19 case and developing pneumonia. Higher altitude had a protective relationship against SARS-CoV-2 infection; however, it may be associated with more severe cases in patients with and without DM. High altitude decreases CFR for all COVID-19 patients. Our work also shows that women are less affected than men regardless of altitude.


Subject(s)
Altitude , COVID-19/pathology , Diabetes Mellitus/pathology , Adult , Aged , COVID-19/mortality , COVID-19/virology , Diabetes Complications , Diabetes Mellitus/epidemiology , Female , Hospitalization/statistics & numerical data , Humans , Intensive Care Units , Male , Mexico/epidemiology , Middle Aged , Prevalence , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index , Survival Rate
9.
Dis Aquat Organ ; 144: 89-98, 2021 Apr 08.
Article in English | MEDLINE | ID: mdl-33830072

ABSTRACT

Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the most concerning pathogens to threaten species in the wild. We sampled for ranaviruses in wild amphibians at 8 sites in Costa Rica, spanning broad climatic zones and taxonomic associations. Seven of these sites are inhabited by highly threatened amphibian species that persist at low global population sizes after population declines due to amphibian chytridiomycosis. One of the surveyed sites is occupied by an introduced amphibian species, which is relatively rare in Central America but may be an important pathway for long-distance transport of ranaviruses. We detected ranavirus using quantitative polymerase chain reaction in 16.3% of the 243 individuals and among 5 of our 8 sites, but not at the site with the introduced species. Infection prevalence varied among species and sites, but not with mean annual temperature or mean annual precipitation. Infection intensity did not vary with species, site, temperature, or precipitation. Our results show that ranavirus infection is spatially widespread in Costa Rica, affecting a broad range of host species, and occurs across climatic zones-though we encountered no mortality or morbidity in our sampled species. Ranaviruses are known to cause intermittent mass mortality in amphibian populations, and the threatened species sampled here are likely vulnerable to population impacts from emerging ranaviruses. Therefore, we believe the potential impacts of ranaviruses on amphibian populations in tropical regions have likely been underestimated, and that they should be viewed as a potential major stressor to threatened amphibians in tropical regions.


Subject(s)
DNA Virus Infections , Ranavirus , Amphibians , Animals , Central America , Costa Rica/epidemiology , DNA Virus Infections/epidemiology , DNA Virus Infections/veterinary
11.
Microbiology (Reading) ; 167(3)2021 03.
Article in English | MEDLINE | ID: mdl-33529150

ABSTRACT

Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized - genetically and morphologically - several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas, Streptomyces, Enterobacter, Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.


Subject(s)
Amphibians/microbiology , Antibiosis , Bacteria/genetics , Batrachochytrium/growth & development , Mycoses/veterinary , Animals , Bacteria/classification , Bacteria/isolation & purification , Bacterial Physiological Phenomena , Batrachochytrium/physiology , Costa Rica , Endangered Species , Genotype , Microbiota , Mycoses/microbiology , Phylogeny
15.
PLoS One ; 15(1): e0226846, 2020.
Article in English | MEDLINE | ID: mdl-31940318

ABSTRACT

BACKGROUND: A Demographic and Family Health Survey (ENDES, for Encuesta Demográfica y de Salud Familiar in Spanish) is carried out annually in Peru. Based on it, the anemia prevalence was 43.6% in 2016 and 43.8% in 2017 using the WHO cutoff value of 11 g/dL and the altitude-correction equation. OBJECTIVE: To assess factors contributing to anemia and to determine its prevalence in Peruvian children 6 to 35 months old. METHODS: We used the MEASURE DHS-based ENDES survey to obtain representative data for11364 children from 6 to 35 months old on hemoglobin and health determinants. To evaluate normal hemoglobin levels, we used the original WHO criterion of the 5th percentile in children without chronic malnutrition and then applied it to the overall population. Relationships between hemoglobin and altitude levels, usage of cleaning methods to sanitize water safe to drink, usage of solid fuels and poverty status were tested using methodology for complex survey data. Percentile curves were made for altitude intervals by plotting hemoglobin compared to age. The new anemia rates are presented in graphs by Peruvian political regions according to the degree of public health significance. RESULTS: Hemoglobin increased as age and altitude of residence increased. Using the 5th percentile, anemia prevalence was 7.3% in 2016 and 2017. Children from low altitudes had higher anemia prevalence (8.5%) than those from high altitudes (1.2%, p<0.0001). In the rainforest area of Peru, anemia prevalence was highest (13.5%), while in the highlands it was lowest (3.3%, p<0.0001). With access to safe drinking water and without chronic malnutrition, anemia rates could be reduced in the rainforest by 45% and 33%, respectively. CONCLUSION: Anemia prevalence in Peruvian children from 6 to 35 months old was 7.3% in 2016 and 2017.


Subject(s)
Altitude , Anemia/epidemiology , Age Distribution , Child, Preschool , Female , Humans , Infant , Male , Peru/epidemiology , Prevalence
16.
Acta Biomed ; 91(4): e2020161, 2020 11 10.
Article in English | MEDLINE | ID: mdl-33525210

ABSTRACT

BACKGROUND: The spectrum of pre-existing renal disease is known as a risk factor for severe COVID-19 outcomes. However, little is known about the impact of COVID-19 on patients with diabetic nephropathy in comparison to patients with chronic kidney disease. METHODS: We used the Mexican Open Registry of COVID-19 patients 11 to analyze anonymized records of those who had symptoms related to COVID-19 to analyze the rates of SARS-CoV-2 infection, development of COVID-19 pneumonia, admission, intubation, Intensive Care Unit admission and mortality. Robust Poisson regression was used to relate sex and age to each of the six outcomes and find adjusted prevalences and adjusted prevalence ratios. Also, binomial regression models were performed for those outcomes that had significant results to generate probability plots to perform a fine analysis of the results obtained along age as a continuous variable. RESULTS: The adjusted prevalence analysis revealed that that there was a a 87.9% excess probability of developing COVID-19 pneumonia in patients with diabetic nephropathy, a 5% excess probability of being admitted, a 101.7% excess probability of intubation and a 20.8% excess probability of a fatal outcome due to COVID-19 pneumonia in comparison to CKD patients (p<0.01).  Conclusions: Patients with diabetic nephropathy had nearly a twofold rate of COVID-19 pneumonia, a higher probability of admission, a twofold probability of intubation and a higher chance of death once admitted compared to patients with chronic kidney disease alone. Also, both diseases had higher COVID-19 pneumonia rates, intubation rates and case-fatality rates compared to the overall population.


Subject(s)
COVID-19/complications , Diabetic Nephropathies/complications , Renal Insufficiency, Chronic/complications , Adult , Aged , COVID-19/epidemiology , COVID-19/therapy , Female , Hospitalization/statistics & numerical data , Humans , Intensive Care Units , Intubation, Intratracheal , Male , Mexico/epidemiology , Middle Aged
17.
Article in English, Spanish | MEDLINE | ID: mdl-33734990

ABSTRACT

INTRODUCTION: Diabetes is one of the main pandemics in recent years. Its association with depression increases the risk of mortality and morbidity. The coexistence of both diseases leads to poor management of diabetes, which leads to a worse quality of life. OBJECTIVE: To determine the frequency of depression in patients with diabetes mellitus and the effect of both pathologies on the quality of life in patients who attend outpatient appointments at public health facilities in Lima and Callao. METHODOLOGY: Secondary analysis of the Epidemiological Study of Mental Health of depression in diabetic adults. The instrument used to determine the depressive episode was the MINI (Mini-International Neuropsychiatric Interview) while quality of life was measured using the Mezzich Quality of Life Index. Diagnosis information of type 1 or 2 diabetes was obtained from the daily medical record (HIS) of care. RESULTS: The frequency of depression in the 471 patients with diabetes was 5.8% in the last two weeks. While the annual frequency was 8.6% and 31.8% at some point in life. Being a woman was associated with a greater frequency of depression. Quality of life was lower in patients with diabetes and depression (p <0.005). CONCLUSIONS: The frequency of depression in patients with diabetes who are treated on an outpatient basis in public health centres is higher than the general population and their quality of life is significantly reduced, which raises the need for considering depression as an additional factor to the burden of morbidity of this condition.

18.
Neurochem Int ; 131: 104565, 2019 12.
Article in English | MEDLINE | ID: mdl-31586591

ABSTRACT

Astrocytes take up glucose via the 45 kDa isoform of the Glucose Transporter 1 (GLUT-1), and in this work we have investigated whether histamine regulates GLUT-1 expression in rat cerebro-cortical astrocytes in primary culture. Cultured astrocytes expressed histamine H1 and H3 receptors (H1Rs and H3Rs) as evaluated by radioligand binding. Receptor functionality was confirmed by the increase in the intracellular concentration of Ca2+ (H1R) and the inhibition of forskolin-induced cAMP accumulation (H3R). Quantitative RT-PCR showed that histamine and selective H1R and H3R agonists (1 h incubation) significantly increased GLUT-1 mRNA to 153 ±â€¯7, 163 ±â€¯2 and 168 ±â€¯13% of control values, respectively. In immunoblot assays, incubation (3 h) with histamine or H1R and H3R agonists increased GLUT-1 protein levels to 224 ±â€¯12, 305 ±â€¯11 and 193 ±â€¯13% of control values, respectively, an action confirmed by inmunocytochemistry. The effects of H1R and H3R agonists were blocked by the selective antagonists mepyramine (H1R) and clobenpropit (H3R). The pharmacological inhibition of protein kinase C (PKC) prevented the increase in GLUT-1 protein induced by either H1R or H3R activation. Furthermore, histamine increased ERK-1/2 phosphorylation, and the effect of H1R and H3R activation on GLUT-1 protein levels was reduced or prevented, respectively, by MEK-1/2 inhibition. These results indicate that by activating H1Rs and H3Rs histamine regulates the expression of GLUT-1 by astrocytes. The effect appears to involve the phospholipase C (PLC) → diacylglycerol (DAG)/Ca2+→ PKC and PLC → DAG/Ca2+ → PKC → MAPK pathways.


Subject(s)
Astrocytes/metabolism , Cerebral Cortex/metabolism , Glucose Transporter Type 1/biosynthesis , Histamine Agonists/pharmacology , Animals , Animals, Newborn , Calcium/metabolism , Cerebral Cortex/cytology , Cerebral Cortex/drug effects , Cyclic AMP/metabolism , Histamine/metabolism , Immunohistochemistry , MAP Kinase Signaling System/drug effects , Primary Cell Culture , Protein Kinase Inhibitors/pharmacology , Rats , Rats, Wistar , Receptors, Histamine H1/drug effects , Receptors, Histamine H1/metabolism , Receptors, Histamine H3/drug effects , Receptors, Histamine H3/metabolism
19.
Nat Ecol Evol ; 3(3): 381-389, 2019 03.
Article in English | MEDLINE | ID: mdl-30778181

ABSTRACT

Animal-associated microbiomes are integral to host health, yet key biotic and abiotic factors that shape host-associated microbial communities at the global scale remain poorly understood. We investigated global patterns in amphibian skin bacterial communities, incorporating samples from 2,349 individuals representing 205 amphibian species across a broad biogeographic range. We analysed how biotic and abiotic factors correlate with skin microbial communities using multiple statistical approaches. Global amphibian skin bacterial richness was consistently correlated with temperature-associated factors. We found more diverse skin microbiomes in environments with colder winters and less stable thermal conditions compared with environments with warm winters and less annual temperature variation. We used bioinformatically predicted bacterial growth rates, dormancy genes and antibiotic synthesis genes, as well as inferred bacterial thermal growth optima to propose mechanistic hypotheses that may explain the observed patterns. We conclude that temporal and spatial characteristics of the host's macro-environment mediate microbial diversity.


Subject(s)
Anura/microbiology , Climate , Microbiota , Urodela/microbiology , Animals , Bacteria/classification , Bacterial Physiological Phenomena , Skin/microbiology
20.
Front Microbiol ; 9: 2001, 2018.
Article in English | MEDLINE | ID: mdl-30233511

ABSTRACT

Amphibian skin is a suitable environment for rich communities of microorganisms, both beneficial and detrimental to the host. The amphibian cutaneous microbiota has been hypothesized to play an important role as symbionts, protecting their hosts against disease. Costa Rica has one of the most diverse assemblages of amphibians in the world and we know very little about the microbiota of these tropical animals. For comparison with other studies, we explore the diversity of the skin bacterial communities employing16S rRNA amplicon sequencing of swab samples from twelve species of frogs at La Selva Biological Station in Sarapiquí, Heredia province. The predominant phylum detected in our studies was Proteobacteria, followed by Bacteroidetes and Actinobacteria, with these three phyla representing 89.9% of the total bacterial taxa. At the family level, Sphingobacteriaceae and Comamonadaceae were highly represented among samples. Our results suggest that host species and host family are significant predictors of the variation in microbiota composition. This study helps set the foundation for future research about microbiota composition and resilience to unfavorable conditions, leading to improvement in managing strategies for endangered amphibian species.

SELECTION OF CITATIONS
SEARCH DETAIL
...