Covid-19 em Viçosa-MG: análise quantitativa, vacinal, etária e de gênero das pessoas infectadas e os impactos da vacinação / Covid-19 in Viçosa-MG: quantitative, vaccine, age, and gender analysis of infected people and the impacts of vaccination

Este estudo teve como objetivo analisar o número de casos e óbitos por Covid-19 em relação a gênero e idade, quantidade total de vacinas aplicadas e relação entre a aplicação das vacinas e número de mortes, de janeiro a novembro de 2021, na cidade e região de Viçosa, Minas Gerais. Os dados foram fornecidos pelo Setor de Vigilância Epidemiológica do município e pelos boletins diários da prefeitura. Em média, houve mais de mil casos de infectados/mês de janeiro a julho, a maior parte adultos do gênero feminino. A mortalidade também foi maior entre as mulheres. Foi registrada queda do número de casos e de mortes coincidente com a aplicação da primeira dose de vacina em pessoas sem comorbidades e com início de aplicação da segunda dose nos grupos prioritários. Tal achado indica a importância da imunização coletiva no controle da pandemia.

This study aimed to analyze the number of cases and deaths from Covid-19 in relation to gender and age, the total vaccines applied, and the relationship between the vaccine application and the number of deaths between January and November 2021, in the municipality and region of Viçosa, state of Minas Gerais. Data were provided by the Epidemiological Surveillance Sector of the municipality of Viçosa and by the Daily Bulletins, published by the city hall. On average, there were more than 1,000 cases per month from January to July, mostly female adults. Mortality was also higher for females. There was a drop in the number of cases and deaths, coincident with the application of the first dose of vaccine in people without comorbidities and the initial period of application of the second dose in priority groups, indicating the importance of collective immunization to control the pandemic.

Anthropogenic influence on the distribution, abundance and diversity of sandfly species (Diptera: Phlebotominae: Psychodidae), vectors of cutaneous leishmaniasis in Panama

In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL). There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.

Report of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) in a cutaneous-leishmaniasis-endemic area of Panama

Lutzomyia longipalpis is the primary vector of the parasite responsible for visceral leishmaniasis in the Americas. In the present study, Lu. longipalpis was found in a domiciliary area in Limón, a district in Capira, a region in which cutaneous leishmaniasis is endemic in Panama. Previously, this species has been found in a humid forest in this same region. Finding Lu. longipalpis in domiciliary areas indicates that this species may be adapting to new habitats and that it may play a role in the transmission of leishmaniasis in Panama.

Prediction of social structure and genetic relatedness in colonies of the facultative polygynous stingless bee Melipona bicolor (Hymenoptera, Apidae)

Stingless bee colonies typically consist of one single-mated mother queen and her worker offspring. The stingless bee Melipona bicolor (Hymenoptera: Apidae) shows facultative polygyny, which makes this species particularly suitable for testing theoretical expectations concerning social behavior. In this study, we investigated the social structure and genetic relatedness among workers from eight natural and six manipulated colonies of M. bicolor over a period of one year. The populations of M. bicolor contained monogynous and polygynous colonies. The estimated genetic relatedness among workers from monogynous and polygynous colonies was 0.75 ± 0.12 and 0.53 ± 0.16 (mean ± SEM), respectively. Although the parental genotypes had significant effects on genetic relatedness in monogynous and polygynous colonies, polygyny markedly decreased the relatedness among nestmate workers. Our findings also demonstrate that polygyny in M. bicolor may arise from the adoption of related or unrelated queens.

Genetic variability in five populations of Partamona helleri (Hymenoptera, Apidae) from Minas Gerais State, Brazil

Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (Ho = 0.099-0.137) and expected (He = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F ST =0.025). AMOVA further showed that most of the total genetic variation (94.24 percent) in P. helleri was explained by the variability within local populations.

Detection of diploid males in a natural colony of the cleptobiotic bee Lestrimelitta sp (Hymenoptera, Apidae)

When working at quantifying the genome size of stingless bees, it was observed that males of Lestrimelitta sp possessed the same amount of nuclear DNA as the females. Thus, we used flow cytometry (FCM) and cytogenetic analysis to confirm the ploidy of these individuals. The males analyzed proved to be diploid, since, through cytometric analysis, it was demonstrated that the mean genome size of both males and females was the same (C = 0.463 pg), and, furthermore, cytogenetic analysis demonstrated that both had 2n = 28 chromosomes.

Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)

Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers.

Cytogenetic characterization of Partamona cupira (Hymenoptera, Apidae) by fluorochromes

Four colonies of the stingless bee Partamona cupira (Hymenoptera: Apidae) were cytogenetically analyzed using conventional staining and the fluorochromes CMA3 e DAPI. The females have 2n = 34 chromosomes (2K=32+2). Some females, however, presented an additional large B acrocentric chromosome, to a total of 2n = 35. Chromosome B and the chromosomal pairs 2, 9 and 10 showed CMA3+ bands, indicating an excess of CG base-pairs. A clear association was verified between the P. helleri B chromosome SCAR marker and the presence of a B chromosome in P. cupira. The data obtained suggests that B chromosomes in P. helleri and P. cupira share a common origin.

Cytogenetic characterization of Melipona rufiventris Lepeletier 1836 and Melipona mondury Smith 1863 (Hymenoptera, Apidae) by C banding and fluorochromes staining

The stingless bees Melipona rufiventris and M. mondury were analyzed cytogenetically by conventional staining with Giemsa, C-banding and sequential staining with the fluorochromes CMA3/DA/DAPI. Both species presented 2n = 18 and n = 9, except for one colony of M. rufiventris, in which some individuals had 2n = 19 due to the presence of a B chromosome. After Giemsa staining and C-banding the chromosomes appeared very condensed and presented a high heterochromatic content, making it difficult to localize the centromere and therefore to visualize the chromosomes morphology. The constitutive heterochromatin was located in interstitial chromosome regions covering most of the chromosomes extension and consisted mainly of AT, as shown by DAPI staining. The euchromatin was restricted to the chromosome extremities and was GC-rich, as evidenced by CMA3 staining. The B chromosome was CMA3-negative and DAPI-positive, a heterochromatic constitution similar to that of the A genome chromosomes.

Genetic variability in Partamona helleri (Hymenoptera: Apidae) populations with and without B chromosomes / Variabilidade genética em populações de Partamona helleri (Hymenoptera: Apidae) com e sem cromossomos B

Partamona helleri individuals have already been found with up to four B chromosomes. This study assessed whether these chromosomes would have any effect on the P. helleri genetic variability. Twenty colonies were selected and divided into three groups: 1) colonies in which no individual possessed B chromosomes; 2) colonies in which some, but not all, individuals possessed B chromosomes, and, 3) colonies in which all the individuals possessed Bchromosomes. The DNA from 8 individuals of each colony was analyzed using the PCR-RAPD technique. The heterozygosity values estimated were 0.168, 0.159 and 0.16643 for the three groups, respectively. The molecular analysis of variance showed that 94.16% of the genetic variability was due to differences within the groups, while only 5.84% was distributed among the groups. These data and the graphic dispersion analysis performed suggest that the B chromosomes have no significant effect on P. helleri genetic variability.

Em Partamona helleri já foram encontrados indivíduos com até quatro cromossomos B. Neste trabalho, avaliou-se se estes cromossomos teriam algum efeito sobre a variabilidade genética de P. helleri. Vinte colônias foram selecionadas e divididas em três grupos: 1) colônias nas quais nenhum indivíduo possuía cromossomos B; 2) colônias nas quais alguns indivíduos possuíam cromossomos B e outros não e, 3) colônias nas quais todos os indivíduos possuíam cromossomos B. O DNA de 8 indivíduos de cada colônia foi analisado através da técnica de PCR-RAPD. Os valores da heterozigosidade estimada foram 0,168, 0,159 e 0,166 para os três grupos, respectivamente. A análise molecular de variância demonstrou que 94,16 % da variabilidade genética foi devida a diferenças dentro dos grupos, enquanto apenas 5,84% estava distribuída entre os mesmos. Estes dados e a análise de dispersão gráfica realizada sugerem que os cromossomos B não têm nenhum efeito significativo sobre a variabilidade genética de P. helleri.

Genetic divergence between populations of the stingless bee uruçu amarela (Melipona rufiventris group, Hymenoptera, Meliponini): is there a new Melipona species in the Brazilian state of Minas Gerais?

Allozyme, microsatellite and random amplified polymorphic DNA (RAPD) molecular markers were used to investigate the within and between population genetic variability and between population genetic differentiation of the Brazilian stingless bee uruçu amarela (nominally Melipona rufiventris Lepeletier, 1836) present in savanna and Atlantic forest habitats of the Brazilian state of Minas Gerais (MG). We found low levels of within population variability, although there were a large number of private alleles that specifically characterized these populations. The F ST values indicated a high level of genetic diversity between populations. Analysis of molecular variance (AMOVA) showed a high degree of population differentiation between the savanna and Atlantic forest habitats, confirmed by population pairwise F ST data. Principal coordinates analysis and unweighted pair-group method using an arithmetic average (UPGMA) dendrograms also confirmed that in Minas Gerais the savanna populations (M. rufiventris) were genetically distinct from those present in the Atlantic forest (M. mondury). In addition, populations from locations near the towns of Dom Bosco and Brasilândia de Minas were genetically different from those collected in other localities in the savanna. Our data indicate that populations of uruçu amarela found in the savanna and Atlantic forest habitats of Minas Gerais state should be treated separately for conservation purposes and that special attention should be given to the populations found in the region of Dom Bosco and Brasilândia de Minas until their taxonomic status is clarified.

Aspectos biológicos e médico-sanitários dos triatomíneos / Sanytary and biological aspects of triatomines

A importância dos triatomíneos em parasitologia humana liga-se ao fato deles serem transmissores do Trypanosoma cruzi, agente causal da doença de Chagas. A doença de Chagas era primitivamente restrita ao ambiente silvestre, mas à medida em que o homem foi entrando em contato com focos naturais e provocou desequilíbrios ecológicos, os triatomíneos infectados foram se adaptando a casas rurais de má qualidade, constituindo assim, um problema de saúde humana. Sua epidemiologia e as tecnologias disponíveis limitam o controle da transmissao natural à intervençao sobre o vetor. Entretanto, o grande número de reservatórios animais e a inexistência de drogas que possam ser usadas em larga escala, tornam impossível o esgotamento das fontes de infecçao. Desta forma, a vigilância epidemiológica contínua, a construçao de casas rurais higiênicas e a conscientizaçao da populaçao sao os principais investimentos a serem feitos para se chegar ao efetivo controle da doença.