Effects of microplastics pollution on the abundance and composition of interstitial meiofauna

Introduction: Pollution by microplastics is a global problem in marine environments, which impacts microorganisms and ecosystems at several spatial levels. Sandy beaches are depositional environments where microplastics tend to accumulate in large quantities. The co-occurrence of interstitial meiofauna and microplastics in sand grains raises the question on whether the accumulation of microplastics in the sediments affects the abundance and composition of the meiofaunal communities. Objective: To test the hypothesis that microplastics affect the meiofauna of urban sandy beaches. Methods: We studied the three main urban sandy beaches of Santa Marta, Colombia: El Rodadero, Santa Marta Bay, and Taganga. All are similar in morphology and external pressures, and differ from other beaches in the region. In April 2019 we collected 81 sand samples, equally distributed in the intertidal zone (upper, mid, and lower intertidal levels). We applied generalized linear models to abundance, and multivariate permutational tests to community composition. Results: We identified 17 taxonomic groups of meiofauna, and microplastic particles (mainly 45-500 micron fibres) evenly distributed across beaches and intertidal levels. There was more meiofauna at the mid intertidal level, and in fine and medium grain sediment. At the lower intertidal level, sites with more microplastics had less meiofauna. Abundance of microplastics explained 39 % of the variation in meiofaunal community composition at lower intertidal levels. Conclusions: The accumulation of microplastics might have a negative impact on these meiofaunal interstitial communities. This is not surprising: if microplastics occupy the same physical space as these animals, they might presumably modify the structure of sediments and the composition of interstitial water.

Introducción: La contaminación por microplásticos es un problema global en los ecosistemas marinos, con impacto sobre microorganismos y ecosistemas en varios niveles espaciales. Las playas arenosas son ambientes de deposición donde se tiende a acumular gran cantidad de microplásticos. La co-ocurrencia de meiofauna intersticial y microplásticos en granos de arena plantea la pregunta de que si la acumulación de microplásticos en sedimentos afecta la abundancia y composición de comunidades de meiofauna. Objetivo: Probar la hipótesis de que microplásticos afectan la meiofauna de playas arenosas urbanas. Métodos: Estudiamos las tres principales playas arenosas urbanas de Santa Marta, Colombia: El Rodadero, Bahía Santa Marta y Taganga. Estas son similares en morfología y presiones externas, y difieren de las otras playas de la región. En abril 2019 recolectamos 81 muestras de arena, distribuidas de manera equidistante en la zona intermareal (nivel intermareal superior, medio y bajo). Aplicamos modelos lineales generalizados de abundancia, y pruebas permutacionales multivariantes a la composición de comunidades. Resultados: Identificamos 17 grupos taxonómicos de meiofauna, y partículas de microplástico (principalmente fibras de 45-500 micras) distribuidos equitativamente a lo largo de las playas y niveles intermareales. Hubo más meiofauna en el nivel intermareal medio, y en sedimentos de grano mediano y fino. A niveles intermareales más bajos, sitios con más microplásticos tuvieron menos meiofauna. La abundancia de los microplásticos explicó el 39 % de la variación en comunidades de meiofauna a niveles intermareales bajos. Conclusión: La acumulación de microplásticos podría tener un impacto negativo sobre las comunidades de meiofauna intersticial. Esto no es de sorprender: si los microplásticos ocupan el mismo volumen físico que estos animales, estos podrían presuntamente modificar la estructura de sedimentos y la composición del agua intersticial.

CD8+ T-cell Exhaustion Phenotype in Human Asymptomatic and Ocular Toxoplasmosis.

This work analyzed exhaustion markers in CD8+ T-cell subpopulations in 21 samples of peripheral blood mononuclear cells (PBMCs) from individuals with ocular toxoplasmosis (n = 9), chronic asymptomatic toxoplasmosis (n = 7), and non-infected people (n = 5) by using RT-qPCR and flow cytometry techniques. The study found that gene expression of PD-1 and CD244, but not LAG-3, was higher in individuals with ocular toxoplasmosis versus individuals with asymptomatic infection or uninfected. Expression of PD1 in CD8+ central memory (CM) cells was higher in nine individuals with toxoplasmosis versus five uninfected individuals (p = .003). After ex vivo stimulation, an inverse correlation was found between the exhaustion markers and quantitative clinical characteristics (lesion size, recurrence index, and number of lesions). A total exhaustion phenotype was found in 55.5% (5/9) of individuals with ocular toxoplasmosis. Our results suggest that the CD8+ exhaustion phenotype is involved in the pathogenesis of ocular toxoplasmosis.

Evaluation of the acceptability of point of care diagnostic test for prenatal toxoplasmosis (translational research phase III).

BACKGROUND: A new point of care test (POC) was developed that is promising as a tool to enhance impact of prenatal care programs for toxoplasmosis, however, no reports exist about its use or acceptability for healthcare personnel and mothers in Colombia. METHODS: This was a translational research - phase III study of the acceptability of a new POC test (Toxoplasma ICT IgG-IgM, LDBio) for qualitative diagnosis of toxoplasmosis in 783 pregnant women and 30 health personnel in primary health care sites in the city of Armenia, Quindío (Colombia). Along with collection of the results of diagnostic POC and confirmatory test and demographic information, we evaluated acceptability through measure of the willingness, credibility, and satisfaction by using questionnaires with a Likert scale during routine prenatal care visits. RESULTS: POC positivity was 46.5% among pregnant participants and was significantly related to socioeconomic factors, including education level (p = 0.00000000) and insurance status (p = 0.00000015). A total of 93-97% of healthcare personnel indicated agreement to positive statements regarding total satisfaction and total credibility of the LDBio test, but qualitative questions identified "Difficulty in the test procedure" as the most common response about barriers to apply the test. Greater than 90% of pregnant participants agree that POC test should be routine for all pregnant woman and permanently implemented. CONCLUSIONS: The test had near complete acceptability. In future studies it is necessary to examine the effect of non-differentiation between IgG and IgM isotypes.

Frequency of natural antibodies and concordance analysis for anti-TOXOPLASMA IgM tests in Colombian sera of pregnant women.

Interpretation of IgM anti-Toxoplasma can be problematic given the phenomena of "natural" IgM. We analyzed 1,503 sera obtained during prenatal care program, and we established natural and false-positive results by doing follow-up. In 101 samples the concordance between enzyme linked immunosorbent assay (ELISA) and two semi-automatized systems: electro-chemiluminescence immunoassay (ELECSYS) and vitek immunodiagnostic assay system (VIDAS) was calculated. In 1,503 serum, 71 (4,7%) had ELISA IgG negative and ELISA IgM positive results and in 44 of these had a second sample 4 weeks later. In second samples, 27 (61,3 %) were IgM and IgG negative (false positive result in the first sample) and 13 (29,5%) were ELISA IgM positive and IgG negative (natural IgM). ELISA assay had a poor concordance with enzyme-linked fluorescent immunoassay as well as ELECSYS tests, contrarily, enzyme-linked fluorescent immunoassay and ELECSYS had optimal concordance, with 100 of 101 sera obtaining the same result by both tests. We recommended to use automatized assays to measure IgM anti-Toxoplasma.

Conocimientos, actitudes y prácticas sobre toxoplasmosis en dos comunas de Armenia, Quindío, con alta prevalencia de la infección / Knowledge, attitudes, and practices related to toxoplasmosis in two districts of high prevalence in Armenia, Quindío / Conhecimentos, atitudes e práticas sobre toxoplasmose em duas comunas de Armenia, Quindío, com alta prevalência de infecção

Resumen Objetivo: Describir los conocimientos, las actitudes y las prácticas acerca de la toxoplasmosis en dos comunas de Armenia, Quindío, con alta prevalencia de la infección. Metodología: Estudio descriptivo con población de dos comunas de Armenia, Quindío. Se aplicó un cuestionario autodiligenciado tipo conocimientos, actitudes y prácticas. Esta herramienta incluyó elementos sobre el parásito Toxoplasma gondii, sus vías de transmisión, aspectos clínicos, diagnósticos y de tratamiento generales, así como prácticas para evitar la infección. El instrumento se aplicó antes y después de una intervención educativa. Se describieron las frecuencias en el número de respuestas correctas antes y después de la intervención para cada comuna. Resultados: Participaron 27 personas, con una media de edad de 57 años. El 59 % fueron mujeres. El 48% había completado la educación media y el 40,7 % la primaria. El conocimiento del agente causal antes de la intervención fue del 22 %, mientras que posterior a la intervención fue del 92,3 % en la comuna 1 y del 81,8 % en la comuna 6. Posterior a la intervención, cerca del 90 % de los encuestados reconoció la retina como la principal estructura afectada y todos los encuestados reconocieron el consumo de agua hervida como factor protector. Conclusión: Los conocimientos sobre la toxoplasmosis en las dos comunas eran limitados. Luego de la intervención educativa, se evidenció un aumento en el porcentaje de respuestas correctas en la mayoría de las preguntas. Se recomienda realizar nuevas intervenciones educativas y en salud pública, para evaluar los efectos de estas a largo plazo.

Abstract Objective: To describe knowledge, attitudes and practices related to toxoplasmosis in two districts of high prevalence in Armenia, Quindío. Methodology: descriptive study; the population of two districts of Armenia, Quindío were engaged. A self-administered questionnaire regarding knowledge, attitudes, and practices was applied. This tool included elements related to Toxoplasma gondii, its transmission pathways, general clinical, diagnostic and treatment aspects, as well as practices to prevent infection. The instrument was applied before and after an educational intervention. Frequencies were described as the number of correct answers before and after the intervention for each district. Results: 27 people participated, with an average age of 57 years. 59 % were women; 48 % had completed high school and 40.7 % had completed elementary school. Before the intervention, the knowledge of the causal agent was 22 %, while after the intervention, it was 92.3 % in district 1 and 81.8 % in district 6. After the intervention, about 90 % of participants recognized the retina as the main compromised structure and all participants recognized the consumption of boiled water as a protective factor. Conclusion: The knowledge regarding toxoplasmosis in the two districts was limited. After the educational intervention, there was an increase in the percentage of correct answers in most of the questions. New educational and public health interventions are recommended to assess the long-term effects of these interventions.

Resumo Objetivos: O objetivo deste estudo é descrever os problemas, as ações e as práticas sobre a toxoplasmose nas comunidades da Armênia, Quindío, onde se nota alta prevalência da infecção. Metodologia: Este é um estudo descritivo que abrange uma população de duas comunas na Armênia, Quindío. Foi implementada uma ferramenta, que consiste em questionários destinados àquela população e aplicáveis pelos seus próprios membros, que correspondem a conhecimentos, atitudes e práticas. Essa ferramenta inclui elementos sobre o parasito Toxoplasma gondii, suas vias de transmissão, aspectos clínicos gerais, diagnósticos e tratamento, e práticas de prevenção. O instrumento foi aplicado antes e após uma intervenção educativa exata. Foram descritas as frequências do número de acertos, antes e depois da intervenção para cada comuna. Resultados: participaram 27 pessoas, com média de idade de 57 anos, das quais 59 % eram mulheres e 48 % tinham ensino médio completo e 40,7 % ensino primário. O conhecimento do agente causal antes da intervenção havia em 22 %, enquanto que após a intervenção, passou para 92,3 % na comuna 1, e 81,8 % na comuna 6. Após a intervenção, cerca de 90 % dos entrevistados reconheceram a retina como a estrutura mais afetada e todos os entrevistados reconheceram que o consumo de água fervida é um fator de proteção. Conclusão: Desconhecimento sobre a toxoplasmose nas duas comunas. Após a intervenção educativa, houve evidência de aumento do percentual de acertos na maioria das questões. Recomenda-se a realização de novas intervenções educacionais e de saúde pública, para avaliar os efeitos destas a longo prazo na populacão.

High frequency of ocular toxoplasmosis in Quindío, Colombia and risk factors related to the infection.

OBJECTIVES: To determine the frequency of retinochoroidal lesions by ocular toxoplasmosis and their relationships with risk factors, in residents of two districts with high exposure to Toxoplasma, in Armenia-Quindío, Colombia. METHODS: Cross-sectional analyses of fundoscopy screening, serological tests, and questionnaires were performed to determine risk factors associated with ocular toxoplasmosis retinochoroidal lesions. Differences in proportions were analyzed using the chi-squared test. RESULTS: Of 161 individuals examined, 17 (10.5%) exhibited retinochoroidal scars suggestive of old inactive Toxoplasma gondii infection. All 17 individuals were seropositive for T. gondii antibodies. Consumption of bottled water was protective against T. gondii infection among individuals in this study. There were no specific epidemiological risk factors associated with ocular toxoplasmosis retinochoroidal lesions. CONCLUSION: Ocular toxoplasmosis is an important cause of visual impairment in Armenia-Quindío, Colombia. The consumption of boiled or bottled water is a major preventive public health measure to reduce infection by T. gondii and the subsequent onset of OT.

Attention, memory, and executive functions profile in a prospective cohort of patients with malignant glioma.

A prospective cohort study was structured to examine patient's tumor mass factors that could determine a specific cognitive function profile in patients with Malignant Glioma who survived after the Stupp protocol, while adjusting for previously explored confounding factors. Neuropsi - Attention and Memory (Second edition) was applied after tumor resection, but before any other oncological treatment. Follow-up neuropsychological evaluation was conducted when patients completed the Stupp protocol treatment scheme. To estimate the mean difference between follow-up and baseline Neuropsi subtest scores, a Bayesian Mixed Effects Model was fitted with three random-effect regressors representing tumor locations, co-administered medications and by-patient cognitive performance variability. Sixteen patients were included. Temporal lobe tumors were the most frequent (31.2%) and more than three-fourths of those were located in the left lobe; such results agree with the clinical and statistical significance that supports an impairment in the Semantic Verbal Fluency subtest (Mean score change = -5.97, 95% Credible Interval = [-8.01, -3.80]). The findings suggest that any potential variants in a determined cognitive dysfunction profile could be more influenced by tumor location than any other variable related to the patient's tumor mass or administered oncological medications; however, because the limited sample representativeness, additional studies are required.

Clinical, Socio-economic and Environmental Factors Related with Recurrences in Ocular Toxoplasmosis in Quindío, Colombia.

PURPOSE: To identify the sociodemographic, clinical, and environmental factors associated with recurrences in ocular toxoplasmosis (OT). METHODS: Retrospective analysis of clinical records of patients who consulted in the Health Centre at Universidad del Quindío between 2004 and 2017. Patients with retinochoroiditis due to Toxoplasma gondii infection and follow up >12 months were included. Comparisons were made with a recurrence index adjusted for months of follow up. For the statistical analysis, the Kruskal-Wallis test and analysis of variance (ANOVA) tests were performed in Epi Info 7.2 and SPSS 14.0. A statistical significance is shown if p ≤ 0.05. RESULTS: A total of 58 patients were included, with median age of 28 years (range 1-61) and 55.1% were women. The median of recurrences was 1.4 (range 0.6-16.6). High recurrence index was present in 43.1% of the patients. A higher size of lesions was observed in low socioeconomic groups (p = .016) and patients with congenital infection had more bilateral compromise (p = .002). Intake of boiled water was related to a lower recurrence index (p = .04). CONCLUSIONS: Low socioeconomic level was associated with bigger lesions and congenital infection was related with higher frequency of bilateral OT. Finally, intake of boiled water is related to a lower recurrence index of OT.

Niveles de 25-hidroxivitamina D y riesgo cardiovascular en una población estudiantil universitaria de Armenia-Colombia / 25-hydroxyvitamin D levels and cardiovascular risk in a university student population of Armenia-Colombia

RESUMEN Objetivo: Describir la relación entre los niveles de 25-hidroxivitamina D y el riesgo cardiovascular en universitarios de Armenia- (Colombia). Materiales y métodos: Estudio descriptivo de corte transversal, durante 2017-2018. Se calculó el riesgo cardiovascular mediante las escalas Framingham, Framingham Colombia y OMS/ISH. Se determinaron los niveles de lípidos, insulina, citocinas y 25-hidroxivitamina D. Posteriormente se realizaron pruebas de Anova, regresión múltiple y prueba chi cuadrado. Se consideró un nivel de significancia cuando p<0,05. Resultados: La edad promedio fue 21,05 años (IC95: 20,62 - 21,48) y el promedio de vitamina D fue 27,7 ng/ml (IC95: 26,52 - 28,88). Hubo diferencias estadísticamente significativas por sexo (p=0,009), siendo más frecuente la deficiencia e insuficiencia en el sexo femenino. El promedio de Puntaje Framingham fue -4,02±3,7. La variación explicada (R2) del Puntaje Framingham tiene relación con colesterol (p<0,001), cHDL (p<0,001) y vitamina D (p=0,039). El Porcentaje Framingham se relaciona con edad (p=0,031), perímetro abdominal (p=0,005), interferón-y (p<0,001) e interleucina-6 (p=0,050). Conclusión: La deficiencia e insuficiencia de vitamina D fueron condiciones prevalentes en esta población. La variación explicada del modelo de puntaje Framingham se asoció con colesterol, cHDL y vitamina D. El porcentaje de Framingham tuvo relación con la edad, el perímetro abdominal, interferón-y e interleucina-6.

ABSTRACT Objective: To describe the correlation between 25-hydroxyvitamin D levels and cardiovascular risk in Armenia-Colombia. Materials and methods: During 2017-2018 was conducted a descriptive cross-sectional study. The cardiovascular risk was determined by Framingham, Framingham Colombia and OMS/ISH scores. Lipids, insulin, cytokines and 25-hydroxyvitamin D were measured. Then Anova test, multiple regression and Chi-square test were performed. Values below p<0.05 were considered statistically significant. Results: The average age was 21.05 years old (CI95: 20,62 - 21,48) and the average vitamin D levels was 27.7 ng/ml (CI95: 26,52 - 28,88). Statistically significant differences were also found by sex (p=0,009), deficiency and insufficient vitamin D were more frequent in women. The Framingham score was -4.02±3.7. There is a relation between the explained variation (R2) of the score with cholesterol (p<0.001), HDL cholesterol (p<0.001) and vitamin D (p=0.039). Framingham percentage is related to age (p=0.031), abdominal perimeter (p=0.005), interferon-Y (p<0.001) and interleukin-6 (p=0.050). Conclusion: Vitamin D deficiency and insufficiency were prevalent conditions. The explained variation of the Framingham score model is associated with cholesterol, HDL cholesterol and vitamin D. And the Framingham percentage with age, abdominal perimeter, interferon-Y and interleukin-6.

Intestinal necrosis caused by acute mesenteric ischemia associated with pregnancy: A case report and literature review.

INTRODUCTION: Mesenteric ischaemia associated with pregnancy is a rare disease with a high mortality rate and its prognosis depends on the time passing between diagnosis and final management. PRESENTATION OF CASE: A 38-year-old Peruvian woman developed intestinal necrosis during week 35 of her pregnancy because of mesenteric ischaemia associated with her pregnancy. DISCUSSION: Given the findings of extensive intestinal necrosis, surgical resection was performed, causing short bowel syndrome. Histopathological analysis confirmed that the immediate cause of the patient's ischaemia was venous thrombosis associated with her gestation. CONCLUSION: Acute mesenteric ischaemia should be considered as a possible diagnosis in pregnant woman with risk factors for thrombophilia presenting with abdominal pain.

The Innate Immune Response to Herpes Simplex Virus 1 Infection Is Dampened in the Newborn Brain and Can Be Modulated by Exogenous Interferon Beta To Improve Survival.

Newborns are particularly susceptible to severe forms of herpes simplex virus 1 (HSV-1) infection, including encephalitis and multisystemic disseminated disease. The underlying age-dependent differences in the immune response that explain this increased susceptibility relative to the adult population remain largely understudied. Using a murine model of HSV-1 infection, we found that newborn mice are largely susceptible to intracranial and intraperitoneal challenge while adult mice are highly resistant. This age-dependent difference correlated with differential basal-level expression of components of innate immune signaling pathways, which resulted in dampened interferon (IFN) signaling in the newborn brain. To explore the possibility of modulating the IFN response in the newborn brain to recapitulate the adult phenotype, we administered exogenous IFN-ß in the context of disseminated HSV-1 infection. IFN-ß treatment resulted in significantly increased survival and delayed viral neuroinvasion in the newborn. These effects were associated with changes in the type I IFN response in the brain, reduced viral replication in the periphery, and the stabilization of the blood-brain barrier (BBB). Our study reveals important age-dependent differences in the innate immune response to HSV-1 infection and suggests a contribution of the BBB and the brain parenchyma in mediating the increased susceptibility to HSV-1 infection observed in the newborn. These results could provide the basis for potential new therapeutic strategies for life-threatening HSV-1 infection in newborns.IMPORTANCE Herpes simplex virus (HSV) is a ubiquitous human pathogen affecting 50 to 80% of the population in North America and Europe. HSV infection is commonly asymptomatic in the adult population but can result in fatal encephalitis in the newborn. Current treatment with acyclovir has improved mortality in the newborn; however, severe neurologic sequelae are still a major concern following HSV encephalitis. For this reason, there is a critical need to better understand the underlying differences in the immune response between the two age groups that could be used to develop more effective treatments. In this study, we investigated differences in the innate immune response to viral infection in the brains of newborn and adult mice. We found that, similar to humans, newborn mice are more susceptible to HSV infection than the adult. Increased susceptibility was associated with dampened innate immune responses in the newborn brain that could be rescued by administering interferon beta.

Cortical Spreading Depression in the Setting of Traumatic Brain Injury.

Cortical spreading depression (CSD) is a pathophysiologic phenomenon that describes an expanding wave of depolarization within the cortical gray matter. Originally described over 70 years ago, this spreading depression disrupts neuronal and glial ionic equilibrium, leading to increased energy demands that can cause a metabolic crisis. This results in secondary insult, further perpetuating brain injury and neuronal death. Initially not thought to be of clinical significance, the view of CSD was modified with the advent of intracranial electroencephalography, or electrocorticography. With these improved monitoring techniques, CSD has been identified as a major mechanism by which traumatic brain injury (TBI) imparts its negative sequalae. TBI is a heterogenous disease process that runs the gamut of clinical presentations. This includes concussion, epidural and subdural hematoma, diffuse axonal injury, and subarachnoid hemorrhage. Nonetheless, CSD appears to be frequently occurring among the various types of TBI, thus allowing for the potential development of targeted therapies in an otherwise ill-fated patient cohort. Although a complete understanding of the interplay between CSD and TBI has not yet been achieved, the authors recount the efforts that have been employed over the last several decades in an effort to bridge this gap. In addition, our current understanding of the role neuroimmune cells play in CSD is discussed in the context of TBI. Finally, current therapeutic strategies using CSD as a pharmacologic target are explored with respect to their clinical use in patients with TBI.

Memory and attention recovery in patients with High Grade Glioma who completed the Stupp protocol: A before-after study.

OBJECTIVES: Advances in therapeutic schemes for High Grade Gliomas, such as the introduction of Stupp protocol, have raised interest in elucidating its effects on quality of life and cognitive function. This study aims to examine executive functions, memory and attention in patients with High Grade Gliomas, before initiation and after completion of Stupp protocol. PATIENTS AND METHODS: A before-after study was executed. Patients were selected from a consecutive sample of subjects with High Grade Gliomas who had not initiated Stupp protocol. Neuropsi - Attention and Memory test (Second edition) was employed to evaluate subjects. Inferential analysis was conducted with Bayesian Mixed Effects Model for repeated measures, using a contrast coding scheme for estimating the change between mean neurocognitive scores obtained before and after Stupp protocol. Model was fitted employing random-effect predictors accounting for concomitant administration of bevacizumab and anticonvulsants, and by-subject performance variability. As excluding patients who did not complete Stupp protocol might bias results, complementary analyses were conducted for determining if those were consistent in alternative scenarios. RESULTS: Twenty-nine patients were included; 17 (58.6%) completed Stupp protocol and both neuropsychological evaluations. Inside Fixed Effects Model, 95% credible intervals for all cognitive functions crossed the zero threshold (No change); however, in all Mixed Effects Models, credible intervals for memory and attention did not cross zero. CONCLUSION: Results showed significant recovery in memory and attention functions after treatment and suggest a confounding role for co-administered treatments and other factors related to subject cognitive performance variability. Nevertheless, these findings need to be corroborated with additional studies including more representative samples.

Effects of biocide exposure on P. Aeruginosa, E. coli and A. Baumannii complex isolates from hospital and household environments / Efectos de la exposición a biocidas en aislados ambientales de P. Aeruginosa, E. coli y del complejo A. Baumannii hospitalarios y de la comunidad

Background: Bacterial responses to biocide exposure and its effects on survival and persistence remain to be studied in greater detail. Aim: To analyse the viability and survival of environmental isolates from household and hospital settings after biocide exposure. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of chlorhexidine (CHxG), benzalkonium chloride (BAC) and triclosan (TC) were determined in isolates of Pseudomonas aeruginosa, Acinetobacter baumannii complex and Escherichia coli collected from hospital and house- holds environments. Viability was monitored after exposure and removal of biocides using agar cultures and flow cytometry. Findings: P. aeruginosa isolates showed greater tolerance for all biocides tested whereas A. baumannii complex and E. coli were less tolerant. When compared with reference strains, biocide tolerance was up to 8 to 13-fold higher for TC and BAC respectively. Flow cytometry showed that biocide exposure may induce viable but non-growing states in P. aeruginosa and E. coli isolates before becoming fully replicative. Changes in the susceptibility profile in one isolate of A. baumannii complex were observed after biocide exposure. Discussion: Bacteria isolates from hospital and households were able to recover after biocide exposure at bactericidal concentrations favouring persistence and spread of biocide-tolerant strains. This study reinforces that cleaning compliance should be monitored by non-culture based tests. Novel formulations in cleaning and disinfection protocols should be revisited in hospitals harbouring P. aeruginosa and A. baumannii multidrug resistant isolates.

Introducción: El efecto de la exposición a biocidas en las poblaciones bacterianas, su viabilidad y persistencia requieren de estudios detallados. Objetivo: analizar la viabilidad y persistencia de bacterias de ambientes hospitalarios y domésticos posterior a la exposición a biocidas. Materiales y Métodos: En un estudio experimental in vitro se determinó la concentración inhibitoria mínima (CIM) y la concentración bactericida (CBM) para chlorhexidina (CHxG), cloruro de benzalconio (BAC) y triclcosan (TC) en aislados de Pseudomonas aeruginosa (10), el complejo Acinetobacter baumannii (5) y Escherichia coli (5) obtenidos de ambientes hospitalarios y domésticos. La viabilidad y susceptibilidad bacteriana después de la exposición y remoción del biocida fue evaluada por citometria de flujo y cultivo. Resultados: Independiente de su procedencia P. aeruginosa presentó mayor tolerancia a todos los biocidas. El complejo A. baumannii y E. coli fueron hasta 8 a 13 veces más tolerantes a BAC y TC que las cepas de referencia. Se observó que la exposición a biocidas altamente efectivos induce formas viables no replicativas en P. aeruginosa y E. coli. Un aislado del complejo A baumannii presentó cambios en el perfil de susceptibilidad posterior a la exposición. Discusión: Aislados tanto de ambiente hospitalario como de la comunidad pueden recuperarse después de la exposición a concentraciones bactericidas de los biocidas favoreciendo la persistencia y diseminación de bacterias no replicativas. Por lo anterior métodos alternativos al cultivo deben utilizarse en el seguimiento de protocolos de limpieza y desinfección. Los tiempos de recuperación de la viabilidad bacteriana deben tenerse en cuenta en la formulación de protocolos para erradicar y/o controlar cepas hospitalarias de P. aeruginosa o A. baumannii multirresistentes.

A synthetic multi-cellular network of coupled self-sustained oscillators.

Engineering artificial networks from modular components is a major challenge in synthetic biology. In the past years, single units, such as switches and oscillators, were successfully constructed and implemented. The effective integration of these parts into functional artificial self-regulated networks is currently on the verge of breakthrough. Here, we describe the design of a modular higher-order synthetic genetic network assembled from two independent self-sustained synthetic units: repressilators coupled via a modified quorum-sensing circuit. The isolated communication circuit and the network of coupled oscillators were analysed in mathematical modelling and experimental approaches. We monitored clustering of cells in groups of various sizes. Within each cluster of cells, cells oscillate synchronously, whereas the theoretical modelling predicts complete synchronization of the whole cellular population to be obtained approximately after 30 days. Our data suggest that self-regulated synchronization in biological systems can occur through an intermediate, long term clustering phase. The proposed artificial multicellular network provides a system framework for exploring how a given network generates a specific behaviour.

The Type I Interferon Response and Age-Dependent Susceptibility to Herpes Simplex Virus Infection.

Herpes simplex virus type 1 (HSV-1) is a highly prevalent human neurotropic pathogen. HSV-1 infection is associated with a variety of diseases ranging from benign orolabial lesions to more serious and even life-threatening conditions such as herpes simplex keratitis and herpes simplex encephalitis (HSE). HSE is a rare occurrence among healthy adult individuals, but newborns are a particularly susceptible population. Type I IFN signaling has been identified as a crucial component of the innate immune response to the control of HSV-1 infection. In this study, we review the contribution of the type I IFN response to controlling HSV-1 infection, and differences in the early host response between adults and newborns that may contribute to the increased susceptibility to infection and central nervous system disease in newborns.

Doxorubicin encapsulated in stealth liposomes conferred with light-triggered drug release.

Stealth liposomes can be used to extend the blood circulation time of encapsulated therapeutics. Inclusion of 2 molar % porphyrin-phospholipid (PoP) imparted optimal near infrared (NIR) light-triggered release of doxorubicin (Dox) from conventional sterically stabilized stealth liposomes. The type and amount of PoP affected drug loading, serum stability and drug release induced by NIR light. Cholesterol and PEGylation were required for Dox loading, but slowed light-triggered release. Dox in stealth PoP liposomes had a long circulation half-life in mice of 21.9 h and was stable in storage for months. Following intravenous injection and NIR irradiation, Dox deposition increased ∼ 7 fold in treated subcutaneous human pancreatic xenografts. Phototreatment induced mild tumor heating and complex tumor hemodynamics. A single chemophototherapy treatment with Dox-loaded stealth PoP liposomes (at 5-7 mg/kg Dox) eradicated tumors while corresponding chemo- or photodynamic therapies were ineffective. A low dose 3 mg/kg Dox phototreatment with stealth PoP liposomes was more effective than a maximum tolerated dose of free (7 mg/kg) or conventional long-circulating liposomal Dox (21 mg/kg). To our knowledge, Dox-loaded stealth PoP liposomes represent the first reported long-circulating nanoparticle capable of light-triggered drug release.

A NEW POPULATION OF THE HOODED ANTPITTA (Grallaricula cucullata: Grallaridae) FOR THE COLOMBIAN CENTRAL ANDES / Una nueva población del Tororoi Cabecirufo (Grallaricula cucullata: Grallaridae) para los Andes de Colombia

We report a new population of the Hooded Anpitta (Grallariculla cucullata) in the Central Andes of Colombia, a threatened bird species inhabiting montane cloud forests in Colombian and Venezuelan Andes. We present capture-rate data, which suggest the occurrence of a resident with the highest population size reported for this bird species.

Presentamos una nueva población del Tororoi Cabecirrufo (Grallariculla cucullata), una especie de ave amenazada de los bosques montanos nublados de los Andes de Colombia y Venezuela. Presentamos datos de tasas de captura que indican la presencia de una población residente con el tamaño poblacional más alto reportado para la especie.

Biodegradación de polietileno de baja densidad por acción de un consorcio microbiano aislado de un relleno sanitario, Lima, Perú / Biodegradation of low density polyethylene by the action of a microbial consortium isolated from a landfill, Lima, Peru

En el presente trabajo describimos el aislamiento y la actividad de biodegradación de microorganismos sobre polietileno de baja densidad. Los microorganismos fueron aislados de materiales plásticos con evidencias de deterioro procedentes de un relleno sanitario de Lima. Las muestras fueron filtradas y preseleccionadas en medio de sales minerales a pH 5,5 y 7, para hongos y bacterias respectivamente. Se aislaron 6 cepas, identificadas como Pseudomonas sp. MP3a y MP3b, Penicillium sp. MP3a, Rhodotorula sp. MP3b, Hyalodendron sp. MP3cy una levadura no identificada. La acción degradativa del consorcio microbiano aislado fue evidenciada porvariaciones en el espectro infrarrojo del polietileno con respecto al polímero sin tratamiento, observándose la reducción del índice de carbonilo (83,89% a pH 7 y 4,08% a pH 5,5) y de terminaciones con dobles enlaces (19,77% a pH 7 y 6,47% a pH 5,5). Finalmente se determinó el porcentaje de peso perdido por el polietileno sometido a las cepas aisladas, observándose una disminución de 5,4% a pH 7 y 4,8% a pH5,5.

In this paper, we describe the isolation and biodegradation activity of microorganisms on low density polyethylene. The microorganisms were collected from plastic materials with evidence of deterioration from a landfill. The samples were filtered and selected in a mineral salts medium at pH 5.5 and 7 for bacteria and fungi respectively. Six strains were isolated, identified as Pseudomonas sp. Hyalodendron sp., Penicillium sp. and Rhodotorula sp.Microbial activity was evidenced by changes in the infrared spectrum of polyethylene with respect to the polymer without treatment. Reduction of carbonyl index (83.89% at pH 7 and 4.08% at pH 5.5) and double bonds index (19.77% at pH 7 and 6.47% at pH 5.5) were observed. Finally we determined the percentage of weight lost by the polyethylene subjected to activity of the strains, with a decrease of 5.4% at pH 7 and 4.8% at pH5, 5.