Phylogeographic pattern and extensive mitochondrial DNA divergence disclose a species complex within the Chagas disease vector Triatoma dimidiata.

ABSTARCT: Previous studies have shown that "bioequivalent" generic products of vancomycin are less effective in vivo against Staphylococcus aureus than the innovator compound. Considering that suboptimal bactericidal effect has been associated with emergence of resistance, we aimed to assess in vivo the impact of exposure to innovator and generic products of vancomycin on S. aureus susceptibility. A clinical methicillin-resistant S. aureus (MRSA) strain from a liver transplant patient with persistent bacteremia was used for which MIC, minimum bactericidal concentration (MBC), and autolytic properties were determined. Susceptibility was also assessed by determining a population analysis profile (PAP) with vancomycin concentrations from 0 to 5 mg/liter. ICR neutropenic mice were inoculated in each thigh with ∼7.0 log(10) CFU. Treatment with the different vancomycin products (innovator and three generics; 1,200 mg/kg of body weight/day every 3 h) started 2 h later while the control group received sterile saline. After 24 h, mice were euthanized, and the thigh homogenates were plated. Recovered colonies were reinoculated to new groups of animals, and the exposure-recovery process was repeated until 12 cycles were completed. The evolution of resistance was assessed by PAP after cycles 5, 10, 11, and 12. The initial isolate displayed reduced autolysis and higher resistance frequencies than S. aureus ATCC 29213 but without vancomycin-intermediate S. aureus (VISA) subpopulations. After 12 cycles, innovator vancomycin had significantly reduced resistant subpopulations at 1, 2, and 3 mg/liter, while the generic products had enriched them progressively by orders of magnitude. The great capacity of generic vancomycin to select for less susceptible organisms raises concerns about the role of therapeutic inequivalence of any antimicrobial on the epidemiology of resistance worldwide

Population genetic structure of Brazilian shrimp species (Farfantepenaeus sp., F. brasiliensis, F. paulensis and Litopenaeus schmitti: Decapoda: Penaeidae)

Penaeid shrimps are important resources for worldwide fisheries and aquaculture. In the Southwest Atlantic, Farfantepenaeus brasiliensis, F. paulensis, F. subtilis, Farfantepenaeus sp. and Litopenaeus schmitti are among the most important commercially exploited species. Despite their high commercial value, there is little information available on the different aspects of their biology or genetics and almost no data on their stock structure. We used allozymes to estimate variability levels and population genetic structure of F. brasiliensis, F. paulensis, L. schmitti and the recently detected species Farfantepenaeus sp. along as much as 4,000 km of Brazilian coastline. No population heterogeneity was detected in F. brasiliensis or L. schmitti along the studied area. In contrast, F ST values found for Farfantepenaeus sp. and F. paulensis indicate that the populations of those two species are genetically structured, comprising different fishery stocks. The largest genetic differences in F. paulensis were found between Lagoa dos Patos (South) and the two populations from Southeast Brazil. In Farfantepenaeus sp., significant differences were detected between the population from Recife and those from Fortaleza and Ilhéus

Very Low Levels of Genetic Variation in Natural Peridomestic Populations of the Chagas Disease Vector Triatoma sordida (Hemiptera: Reduviidae) in Southeastern Brazil

Submitted by Sandra Infurna ([email protected]) on 2019-01-03T11:26:55Z No. of bitstreams: 1 josejuberg_etal_IOC_2009.pdf: 556487 bytes, checksum: 160473a67c5471fd72c07fbf57e198c2 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-01-03T11:35:25Z (GMT) No. of bitstreams: 1 josejuberg_etal_IOC_2009.pdf: 556487 bytes, checksum: 160473a67c5471fd72c07fbf57e198c2 (MD5)Made available in DSpace on 2019-01-03T11:35:25Z (GMT). No. of bitstreams: 1 josejuberg_etal_IOC_2009.pdf: 556487 bytes, checksum: 160473a67c5471fd72c07fbf57e198c2 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Doenças Parasitárias. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Departamento de Genética. Laboratório de Biodiversidade Molecular. Rio de Janeiro, RJ, Brasil.Levels of genetic variation and population structure were determined for 181 Triatoma sordida insects from four populations of southeastern Brazil, through the analysis of 28 allozyme loci. None of these loci presented fixed differences between any pair of populations, and only two revealed polymorphism, accounting for low levels of heterozygosity ( H e = 0.027), and low genetic distances ( D < 0.03) among populations. F ST and Contingency Table results indicated the existence of genetic structure among populations ( F ST = 0.214), which were incompatible with the isolation by distance model (Mantel test: r = 0.774; P = 0.249)

Sotalia dolphins in their potential sympatry zone: Searching for hybrids in the Amazonian estuary

The two Sotalia species (the marine S. guianensis and the freshwater S. fluviatilis) have only recently been recognized, and both face several conservation challenges. We investigated the existence of hybridization between the two species in their possible area of sympatry in the Amazon Estuary, in northern Brazil. A fast and cheap PCR-RFLP diagnostic method using nuclear DNA was developed to discriminate between the two species, while allowing the detection of hybrids. All samples that could be identified (N = 51) were identified as S. guianensis, and no hybrids were detected. Our results, coupled with previous mitochondrial data, suggest that S. fluviatilis is not present in the Amazon delta. Thus, sympatry with S. guianensis, if it does occur, may be restricted to upstream areas of the Amazon River. Copyright © Marine Biological Association of the United Kingdom 2018

Crassostrea talonata, a new threat to native oyster (Bivalvia: Ostreidae) culture in the Southwest Atlantic

Genetic analyses of oyster seeds collected from settlement plates (in southeast Brazil Santa Catarina, N = 207) and from marsh plants (Argentina, Samborombón Bay, N = 20) revealed that most seeds did not belong to any of the oyster species recorded for the Atlantic. Phylogenetic analyses based on mitochondrial (Cytochrome c Oxidase subunit I and large ribosomal subunit) and nuclear (ribosomal Internal Transcribed Spacer 2) sequences positioned that species in the Asian oyster cluster of Crassostrea, suggesting an invasive origin and identifying the species as C. talonata, a species described for China and also recently found in Peru. The predominance of this species in cultivation settlement plates indicates that it outcompetes C. gasar, native of the South-Atlantic, making it a nuisance species for oyster cultivation. Since specimens of C. talonata have been found from the mouth of the Amazon to the coast of Argentina, it is likely that the species has a large ecological plasticity and possibly a strong invasive capacity, making it a major threat to oyster culture in the area. This is the first record of C. talonata for the Atlantic.Fil: Cavaleiro, Nathalia P.. Universidade Federal Do Rio de Janeiro. Instituto de Biología; BrasilFil: Lazoski, Cristiano. Universidade Federal Do Rio de Janeiro. Instituto de Biología; BrasilFil: Tureck, Cláudio R.. Universidade Da Região de Joinville; BrasilFil: Melo, Cláudio M.R.. Universidade Federal de Santa Catarina; BrasilFil: do Amaral, Vanessa S.. Universidade Federal do Espírito Santo; BrasilFil: Lomovasky, Betina Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Absher, Theresinha M.. Universidade Federal do Paraná; BrasilFil: Solé-Cava, Antonio M.. Universidade Federal Do Rio de Janeiro. Instituto de Biología; Brasi

Correction: Molecular and Morphological Differentiation of Common Dolphins (Delphinus sp.) in the Southwestern Atlantic: Testing the Two Species Hypothesis in Sympatry.

The taxonomy of common dolphins (Delphinus sp.) has always been controversial, with over twenty described species since the original description of the type species of the genus (Delphinus delphis Linnaeus, 1758). Two species and four subspecies are currently accepted, but recent molecular data have challenged this view. In this study we investigated the molecular taxonomy of common dolphins through analyses of cytochrome b sequences of 297 individuals from most of their distribution. We included 37 novel sequences from the Southwestern Atlantic Ocean, a region where the short- and long-beaked morphotypes occur in sympatry, but which had not been well sampled before. Skulls of individuals from the Southwestern Atlantic were measured to test the validity of the rostral index as a diagnostic character and confirmed the presence of the two morphotypes in our genetic sample. Our genetic results show that all common dolphins in the Atlantic Ocean belong to a single species, Delphinus delphis. According to genetic data, the species Delphinus capensis is invalid. Long-beaked common dolphins from the Northeastern Pacific Ocean may constitute a different species. Our conclusions prompt the need for revision of currently accepted common dolphin species and subspecies and of Delphinus delphis distribution