Communal nesting is the optimal strategy for heat conservation in a social marsupial: lessons from biophysical models.

Endothermy, understood as the maintenance of continuous and high body temperatures owing to the combination of metabolic heat production and an insulative cover, is severely challenged in small endotherms inhabiting cold environments. As a response, social clustering combined with nest use (=communal nesting) is a common strategy for heat conservation. To quantify the actual amount of energy that is saved by this strategy, we studied the social marsupial Dromiciops gliroides (monito del monte), an endemic species of the cold forests of southern South America. It is hypothesized that sociability in this marsupial was driven by cold conditions, but evidence supporting this hypothesis is unclear. Here, we used taxidermic models ('mannequins') to experimentally test the energetic benefits of clustering combined with nest use. To do this, we fitted and compared cooling curves of solitary and grouped mannequins, within and outside of a nest, at the typical winter ambient temperatures of their habitat (5°C). We found that the strategy that minimized euthermic cost of maintenance was the combination of nest use and clustering, thus supporting communal nesting as a social adaptation to cope with the cold. Considering the basal metabolic rate of monitos, our estimates suggest that the savings represents almost half of energy consumption per day (in resting conditions). This study shows how simple biophysical models could help to evaluate bioenergetic hypotheses for social behavior in cold-adapted endotherms.

Perfil Epidemiológico da Febre Maculosa no Brasil / Epidemiological Profile of Spotted Fever in Brazil

Introdução: A Febre Maculosa é uma doença febril aguda, causada pela bactéria Rickettsia rickettsii e transmitida pela picada de carrapatos infectados. Atualmente, ocorre um aumento da incidência e das mortes pela doença em diversas áreas do Brasil, o que pode significar um surto e a necessidade de alerta. Metodologia: Estudo quantitativo, descritivo, transversal, que embasou sua busca nas plataformas de notificações brasileiras (DATASUS e SINAN) e boletins epidemiológicos no período de 2007 a 2019. Resultados: O número de casos e a mortalidade demonstraram valores maiores nos meses correspondentes à fase de ninfa do carrapato vetor, com incidência maior na zona rural, na região sudeste e durante o lazer. Além disso, a faixa etária mais atingida foi de 40 a 59 anos, com predominância da população masculina. Os valores maiores apresentados nas zonas rurais, assim como grupo etário e sexo se devem às atividades realizadas que expõem mais os indivíduos ao ambiente natural dos vetores, à sazonalidade dos carrapatos e à presença da Mata Atlântica. Nota-se a presença de grande subnotificação no Brasil. Conclusão: Constata-se a necessidade de desenvolver de políticas de prevenção e disseminar informações sobre o ciclo da doença, manifestações clínicas, prevenção e tratamento.

Introduction: Spotted Fever is an acute febrile disease, caused by the bacteria Rickettsia rickettsii and transmitted by the bite of infected ticks. Currently, there is an increase in the incidence and deaths from the disease in several areas of Brazil, which may mean an outbreak and the need for alert. Methodology: Quantitative, descriptive, cross-sectional study that based its search on the Brazilian notification platforms (DATASUS and SINAN) and newsletters. Results: The number of cases and mortality showed higher values in months corresponding to the vector tick nymph phase (from June to September), with a higher incidence in countryside, in southeast region and at moments of leisure practice. In addition, the most affected age group was 40 to 59 years old, in male population. Higher values presented in countryside, as well as age group and sex are due to activities that expose individuals more to natural environment of vectors, the seasonality of the ticks and the presence of the Atlantic Forest. In addition, there is a large underreporting in Brazil. Conclusion: It´s necessary to develop prevention policies, as well as disseminate information about disease cycle, clinical manifestations, prevention and treatment.

Multilocus genotyping of Giardia duodenalis in Brazilian children.

BACKGROUND: Giardia duodenalis is a parasite of several mammalian species, including humans, distributed worldwide. This research aimed to identify the molecular assemblages/sub-assemblages of G. duodenalis and to determine the intra-assemblage genetic variation of the different genes of assemblages A and B in pre-school children in the cities of Araguari and Uberlândia, Minas Gerais, Brazil. METHODS: The molecular characterization followed ß-giardin (bg), glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) protocols. RESULTS: Of 226 stool samples, G. duodenalis cysts were found in 45 (19.9%). The tpi gene was amplified in 34 samples: 16 assemblage A, 14 B and four mixed samples A/B. The gdh gene was amplified in 32 samples, including 14 A, 16 B and two A/B. For the bg gene, 19 samples were sequenced: nine assemblage A, five B, three E, and two mixed, A/E and B/E. Animal-specific assemblage E were identified by bg, but were not confirmed for other genes. Twelve samples were characterized by full agreement of the three genes. Two new multilocus genotyping (MLGs) for assemblage A and two new MLGs for assemblage B were also described. CONCLUSIONS: These findings substantiate the importance of using more than one gene protocol since the sensitivity and genetic variability changes with the locus used.Access numbers: The GenBank access numbers for the nucleotide sequences reported in this article are: JQ794877-JQ794890, JX033113-JX033118.

Performance of glutamate dehydrogenase and triose phosphate isomerase genes in the analysis of genotypic variability of isolates of Giardia duodenalis from livestocks.

Giardia duodenalis is a small intestinal protozoan parasite of several terrestrial vertebrates. This work aims to assess the genotypic variability of Giardia duodenalis isolates from cattle, sheep and pigs in the Southeast of Brazil, by comparing the standard characterization between glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) primers. Fecal samples from the three groups of animals were analyzed using the zinc sulphate centrifugal flotation technique. Out of 59 positive samples, 30 were from cattle, 26 from sheep and 3 from pigs. Cyst pellets were stored and submitted to PCR and nested-PCR reactions with gdh and tpi primers. Fragment amplification of gdh and tpi genes was observed in 25 (42.4%) and 36 (61.0%) samples, respectively. Regarding the sequencing, 24 sequences were obtained with gdh and 20 with tpi. For both genes, there was a prevalence of E specific species assemblage, although some isolates have been identified as A and B, by the tpi sequencing. This has also shown a larger number of heterogeneous sequences, which have been attribute to mixed infections between assemblages B and E. The largest variability of inter-assemblage associated to the frequency of heterogeneity provided by tpi sequencing reinforces the polymorphic nature of this gene and makes it an excellent target for studies on molecular epidemiology.

Desmame precoce no município de São José da Lapa - Minas Gerais: um plano de ação

A lactação é considerada uma prática fundamental para promoção, proteção e apoio à saúde de crianças. Apesar da importância do aleitamento materno para a criança, a mãe e a família, o desmame precoce ainda é bastante frequente. O objetivo deste estudo foi propor plano de ação para redução do desmame precoce na ESF Inácia de Carvalho do município de São José da Lapa. Foram feitas uma revisão de literatura narrativa e uma proposta de intervenção pautada na reflexão dos achados durante atividades do módulo de planejamento do Curso de Especialização em Saúde da Família. A revisão abrangeu consulta nas bases de dados Scielo, Lilacs, bem como monografias sobre o tema. A amamentação não é totalmente questão de instinto. Ela tem que ser aprendida. A revisão de literatura revelou que a maioria das gestante-nutrizes precisa ter apoio constante, tanto dos familiares quanto dos profissionais de saúde. Assim procurou-se construir uma proposta de intervenção neste sentido.