Annual killifish adaptations to ephemeral environments: diapause I in two Austrolebias species

Background: Many organisms are able to survive in extreme environments by entering a state of dormancy. In dormancy, vital activities are reduced until environmental conditions are compatible with active life. Annual killifishes show a special developmental pattern characterized by a phase of dispersion-reaggregation of the blastomeres that separates epiboly from organogenesis, and the capability to enter dormancy in diapause. High tolerance to environmental stress confers annual killifish embryos the condition of extremophiles. At present, the questions of our research group are focused on the understanding of the mechanisms involved in diapause regulation through an interdisciplinary approach. As a first step, it is necessary to characterize diapauses at orphological and physiological levels and to evaluate induction cues under laboratory conditions. In this context, we characterized diapause I in two Austrolebias species. Results: Our experimental approach to induce apause I was successful and revealed the co-existence of two diapause I phenotypes named A and B instead of one. These phenotypes showed a tendency for lower total extractable RNA content compared with active developmental stages (80–100% epiboly and early reaggregate). Conclusions: These phenotypes are alternative diapause I stages and may have ecological relevance because both were found in embryos in natural ponds. Developmental Dynamics 246:848–857, 2017. VC 2017 Wiley Periodicals, Inc.CSIC: 147_C61034

Enteroparasites in dog feces from the riverside public area of Viedma (Río Negro, Argentinean Patagonia)

Las parasitosis intestinales caninas constituyen un problema de salud ambiental, cumpliendo no solo las mascotas sino el agua y el suelo un papel importante en la transmisión parasitaria. Algunas especies por su carácter zoonótico son además de importancia en la salud pública. El objetivo del presente trabajo fue evaluar el grado de contaminación fecal en la ribera pública del río Negro en Viedma y realizar la detección de enteroparásitos en heces caninas. Entre abril de 2015 y marzo de 2016 se realizó un muestreo aleatorio, sistemático, polietápico y estacional a lo largo de 3 kilómetros, registrando la totalidad de las heces caninas observadas y recolectando un total de 531 fracciones de ellas. El diagnóstico coproparasitológico de las muestras se realizó por duplicado mediante la técnica de flotación de Sheather modificada. El total de heces observadas fue de 2574. De las muestras analizadas el 25,6 resultaron positivas y el 79,4% de ellas estuvo monoparasitada. Los taxones parásitos detectados fueron Isospora canis (8,1%), Sarcocystis spp. (11,8%), Taenia spp. (0,7%), Toxocara canis (22,8%), Toxascaris leonina (2,9%), Trichuris vulpis (40,4%), Eucoleus bohemi (2,2%) y Ancylostomatidae (33,8%). Solo se encontró diferencia estadística significativa entre los muestreos de otoño e invierno. Por primera vez, en esta clase de estudios y en la Patagonia argentina, se registra E. bohemi en heces caninas. La presencia de esta especie y de T. leonina podrían indicar la interacción entre cánidos domésticos y silvestres. De los enteroparásitos encontrados se reconocen por su importancia zoonótica Sarcocystis spp., Taenia spp., T. canis y los Ancylostomatidae. Los resultados obtenidos son importantes para profundizar en campañas de salud pública tendientes a concientizar a la población en general y a los agentes y profesionales de la salud en particular, y generar conductas de tenencia responsable de mascotas.Dog enteroparasites are an environmental health problem, considering some species are zoonotic and represent an important public health problem. Water, soil and pets play an important role in parasitic transmission. The aim of this study was to evaluate the degree of fecal contamination and the presence of enteroparasites in dog feces collected on the public waterfront of the Negro river of Viedma city. Between April 2015 and March 2016 a random, systematic, multistage, and seasonal sampling was carried out along 3 kilometers, recording all the feces observed and collecting a total of 531 samples of dog stools. The coproparasitological diagnosis was done by duplicate using the modified Sheather flotation technique. Overall enteroparasite prevalence was 25,6% and the 79,41% of them present only one parasitic taxon. The parasites detected were Isospora canis (8,1%), Sarcocystis spp. (11,8%), Taenia spp. (0.7%), Toxocara canis (22,8%), Toxascaris leonina (2,9%), Trichuris vulpis (33,8%), Eucoleus bohemi (2,2%) and Ancylostomatidae (40,4%). For the first time, the presence of E. bohemi in canine feces in Patagonian Argentina is recorded. Sarcocystis spp., Taenia spp., T. canis, and Ancylostomidae eggs are recognized for their zoonotic importance. The presence of T. leonina and E. bohemi could indicate interaction between domestic and wild canids. The results obtained are important in order to deepen public health campaigns for awareness among the population in general and health agents and professionals in particular, to generate responsible pet ownership behavior.Fil: Winter, Marina. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; Argentina. Universidad Nacional de Río Negro. Sede Atlántica; ArgentinaFil: Perera, Nélida. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Marigual, Guillermina. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Corominas, María José. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Mora, Mercedes. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Lecertua, Andrea. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Ávila, Agustín. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; ArgentinaFil: Arezo, Marcos. Gobierno de la Provincia de Rio Negro. Ministerio de Salud; Argentin

Análisis de los mecanismos de determinación y diferenciación del sexo en Austrolebias charrua (Cyprinodontiformes: Rivulidae)

Tribunal: Dr. Omar Macadar, Dras. Annabel Ferreira y Estela Castillo.Orientador: Dra. Nibia Berol

Characterization of partial Hox gene sequences in annual fish of the subfamily Cynolebiatinae (Cyprinodontiformes, Rivulidae)

Hox genes encode a family of transcription factors implicated in conferring regional identity along the anteroposterior axis in developing animal embryos. These genes are organized in genomic clusters, expressed collinearly and highly conserved in vertebrates. Among teleost, South American annual killifishes of the Cynolebiatinae subfamily represent an excellent model in development studies because their embryos are capable of undergoing reversible developmental arrest (diapause) at three well-defined morphological stages. They are also an excellent model for evolutionary studies due to the high rates of mutation of their mitochondrial genome, their karyotypic divergence and their morphological variability. In this study, three partial homeobox sequences were isolated from different species of the Cynolebiatinae subfamily. Phylogenetic analyses and sequence comparisons revealed that they belong to the anterior Hox complex group, specifically to paralogue groups 1 and 3. This is the first time that partial Hox genes have been described in species of the Cynolebiatinae subfamily

Sex determination in annual fishes: searching for the master sex-determining gene in Austrolebias charrua (Cyprinodontiformes, Rivulidae)

Evolution of sex determination and differentiation in fishes involves a broad range of sex strategies (hermaphroditism, gonochorism, unisexuality, environmental and genetic sex determination). Annual fishes inhabit temporary ponds that dry out during the dry season when adults die. The embryos exhibit an atypical developmental pattern and remain buried in the bottom mud until the next rainy season. To elucidate genomic factors involved in the sex determination in annual fish, we explored the presence of a candidate sex-specific gene related to the cascade network in Austrolebias charrua. All phylogenetic analyses showed a high posterior probability of occurrence for a clade integrated by nuclear sequences (aprox. 900 bp) from both adults (male and female), with partial cDNA fragments of A. charrua from juveniles (male) and the dsx D. melanogaster gene. The expressed fragment was detected from blastula to adulthood stages showing a sexually dimorphic expression pattern. The isolated cDNA sequence is clearly related to dsx D. melanogaster gene and might be located near the top of the sex determination cascade in this species

Embryonic developmental arrest in the annual killifish Austrolebias charrua: A proteomic approach to diapause III.

Diapause is a reversible developmental arrest faced by many organisms in harsh environments. Annual killifish present this mechanism in three possible stages of development. Killifish are freshwater teleosts from Africa and America that live in ephemeral ponds, which dry up in the dry season. The juvenile and adult populations die, and the embryos remain buried in the bottom mud until the next rainy season. Thus, species survival is entirely embryo-dependent, and they are perhaps the most remarkable extremophile organisms among vertebrates. The aim of the present study was to gather information about embryonic diapauses with the use of a "shotgun" proteomics approach in diapause III and prehatching Austrolebias charrua embryos. Our results provide insight into the molecular mechanisms of diapause III. Data are available via ProteomeXchange with identifier PXD025196. We detected a diapause-dependent change in a large group of proteins involved in different functions, such as metabolic pathways and stress tolerance, as well as proteins related to DNA repair and epigenetic modifications. Furthermore, we observed a diapause-associated switch in cytoskeletal proteins. This first glance into global protein expression differences between prehatching and diapause III could provide clues regarding the induction/maintenance of this developmental arrest in A. charrua embryos. There appears to be no single mechanism underlying diapause and the present data expand our knowledge of the molecular basis of diapause regulation. This information will be useful for future comparative approaches among different diapauses in annual killifish and/or other organisms that experience developmental arrest

Impacto de la vacuna EG95 contra la hidatidosis ovina en el programa de control de la provincia de Río Negro, Argentina. Ocho años de trabajo (informe preliminar) /Pilot field trial of the EG95 vaccine against ovine cystic echinococcosis in Rio Negro, Ar

Cystic echinococcosis is endemic in the Rio Negro province ofArgentina. After 30 years of control using praziquantel in dogs,the transmission rate to humans and sheep has decreased significantly,however transmission persistsThe objective of the study is to assess the impact of the inclusionof the EG95 vaccine in sheep in the control program.The vaccine was applied to lambs from communities of nativepeoples which included 70 producers (Anecón Grande, MamuelChoique, Nahuel Pan y Río Chico Abajo).From 2009 on, lambs received two doses of the EG95 vaccinewhen they were 30 and 60 days of age, followed by a singlebooster injection when the animals were 1 year of age. Thetransmission of Echinococcus granulosus was assessed throughnecropsy in mature sheep, Arecoline test and coproantigen testin dogs and register of new clinical cases in inhabitants of thearea. A total of 29.323 doses of EG95 vaccine were applied tolambs in the 2009-2017 period, working with 4 groups of 2 veterinarieseach, covering 83.5% with one doses, 80.1% with twodoses and 85.7% with three doses. Before the vaccine was introduced,in necropsy of sheep of 6 years old showed that 45.7%were infected with E. granulosus. The rate decreased to 21.1% in2006. The number of cysts per animal decreased from 1.4% to0.3. The number of producers with infected animals decreasedfrom 84.2% to 22.2%. The humoral response to the vaccination,in field conditions, showed an increased in antibodies with thesecond dose, reaching its maximum after the booster at one yearof age for many years and keeping constant.In dogs, 4.7% was found positive using arecoline purgationand 20.3% of the farms were infected using coproantigen test.The impact assessment showed a 5.6% of dogs positive to thearecoline test. Only a new case of echinococcosis was detectedin kids with a 10 cm cyst, and its origin was probably before thevaccination. EG95 vaccine has been effective to prevent the infectionin ovines up to six years of age, in spite of the difficultiesof achieving better coverage. The transmission to dogs and humanbeings has to be determined.La Equinococosis quística es endémica en la provincia de Río Negro, Argentina. En esta región, después de 30 años de control usando praziquantel en perros, la velocidad de transmisión a los seres humanos se ha reducido significativamente, sin embargo, persiste la transmisión. El objetivo fue evaluar en los distintos hospederos el impacto de la introducción de la vacuna EG95 en el programa de control. La vacuna fue aplicada en corderos de comunidades de pueblos originarios que incluyeron a 79 productores (Anecón Grande, Mamuel Choique, Nahuel Pan y Río Chico abajo). Los corderos recibieron a partir de 2009 dos dosis de la vacuna EG95 a los 30 y 60 días de edad seguido de un refuerzo cuando los animales tenían 1 año de edad. La transmisión de Echinococcus granulosus fue evaluada mediante necropsia de  ovejas adultas, test de arecolina y test de coproantígenos en perros y registro de nuevos casos clínicos en pobladores del área, Un total de 29323 dosis de vacuna EG95 se aplicaron en corderos, en el período 2009-2017 trabajando con 4 equipos de 2 veterinarios cada uno, alcanzando una cobertura de 83.5% con una dosis, 80.1% con dos dosis y 85.7% con tres dosis. Antes de la introducción de la vacuna, el 45.7% de los ovinos de 6 años fueron positivos a la necropsia, valor que disminuyó a 21.1% en 2016. El número de quistes por animal disminuyó de 1.4 a 0.3. El número de productores con animales infectados disminuyó de 84.2% al 22.2%. La respuesta humoral a la vacunación, en condiciones de campo, mostro un aumento de títulos de anticuerpos con la aplicación de la segunda dosis, alcanzando su máximo luego del refuerzo al año y por varios años, manteniéndose constante. Los estudios iniciales en perros mostraron unaprevalencia al test de arecolina del 4.7% y 20.3% de productores con transmisión presente al test de coproantígenos. La evaluación de impacto mostro un 5.6% de perros positivos al test de arecolina. Solo se detectó un caso nuevo de equinococosis en niños con un quiste de 10 cm, cuyo origen fuera probablemente anterior a la introducción de la vacuna. La vacuna EG95 ha sido eficiente en prevenir la infección en ovinos de hasta 6 años de edad, a pesar de las dificultades operativas para alcanzar mejores coberturas, restando definir su impacto en la transmisión al perro y al hombre

Surgical site infection after gastrointestinal surgery in children : an international, multicentre, prospective cohort study

Introduction Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings. Methods A multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI). Results Of 1159 children across 181 hospitals in 51 countries, 523 (45 center dot 1%) children were from high HDI, 397 (34 center dot 2%) from middle HDI and 239 (20 center dot 6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12 center dot 8% (51/397) in middle HDI and 24 center dot 7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI. Conclusion The odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.Peer reviewe

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially