Physiological traits of the symbiotic bacterium Teredinibacter turnerae isolated from the mangrove shipworm Neoteredo reynei

Nutrition in the Teredinidae family of wood-boring mollusks is sustained by cellulolytic/nitrogen fixing symbiotic bacteria of the Teredinibacter clade. The mangrove Teredinidae Neoteredo reynei is popularly used in the treatment of infectious diseases in the north of Brazil. In the present work, the symbionts of N. reynei, which are strictly confined to the host's gills, were conclusively identified as Teredinibacter turnerae. Symbiont variants obtained in vitro were able to grow using casein as the sole carbon/nitrogen source and under reduced concentrations of NaCl. Furthermore, cellulose consumption in T. turnerae was clearly reduced under low salt concentrations. As a point of interest, we hereby report first hand that T. turnerae in fact exerts antibiotic activity. Furthermore, this activity was also affected by NaCl concentration. Finally, T. turnerae was able to inhibit the growth of Gram-negative and Gram-positive bacteria, this including strains of Sphingomonas sp., Stenotrophomonas maltophilia, Bacillus cereus and Staphylococcus sciuri. Our findings introduce new points of view on the ecology of T. turnerae, and suggest new biotechnological applications for this marine bacterium

Molecular evidence of ribosomal DNA (rDNA) amplification of a minichromosome derived from Drosophila arizonae in D. mulleri-D. arizonae hybrid males

We present data supporting cytogenetic observations on nucleolar dominance in hybrids between Drosophila arizonae and D. mulleri. Our approach was to compare the rDNA restriction patterns between the parental species and their hybrids. Results demonstrated that the minichromosome attached to the nucleolus in hybrid males is derived from D. arizonae

Molecular evidence of ribosomal DNA (rDNA) amplification of a minichromosome derived from Drosophila arizonae in D. mulleri-D. arizonae hybrid males

We present data supporting cytogenetic observations on nucleolar dominance in hybrids between Drosophila arizonae and D. mulleri. Our approach was to compare the rDNA restriction patterns between the parental species and their hybrids. Results demonstrated that the minichromosome attached to the nucleolus in hybrid males is derived from D. arizonae.Departamento de Genética Instituto de Biologia Universidade Federal do Rio de Janeiro (UFRJ), Caixa Postal 68011, 21944-970 Rio de Janeiro, RJLaboratôrio de Genética Universidade Estadual Paulista (UNESP), Caixa Postal 136, 15010-210 Sao Jose do Rio Preto, SPLaboratôrio de Genética Universidade Estadual Paulista (UNESP), Caixa Postal 136, 15010-210 Sao Jose do Rio Preto, S

Alta frequência de leveduras potencialmente patogênicas no leite de cabra in natura e no queijo de cabra cremoso no Sul do Brasil

Existem poucos relatos sobre isolamento, contagem e identificação de leveduras no leite de cabra in natura e derivados. O objetivo desse estudo foi avaliar a diversidade de leveduras encontradas no leite de cabra cru e no queijo cremoso de cabra coletados na região metropolitana de Porto Alegre, Brasil. Foi desenvolvida a técnica de HMA (Heteroduplex Mobility Assay) simplificada da região 26S rDNA D1/D2 para confirmar rapidamente a identificação de isolados pertencentes às espécies potencialmente patogênicas. Leveduras foram isoladas em 59% das amostras. Cinquenta e seis leveduras foram isoladas e identificadas nos gêneros Bullera, Candida, Cryptococcus, Debaryomyces, Dekkera, Pichia, Rhodotorula, Sporodiobolus, Trichosporon, Yarrowia e Zygoascus. A contagem média de leveduras no leite de cabra foi superior a 2 log UFC.mL-1, enquanto que a contagem no queijo foi superior a 3 log UFC.g-1. A atividade lipolítica esteve presente em 92% dos isolados, enquanto que apenas 14% tiveram atividade proteolítica. Doze isolados ascomicéticos potencialmente patogênicos foram identificados pela metodologia convencional de identificação de leveduras e correspondem às espécies Candida parapsilosis, Candida tropicalis e Pichia guilliermondii. Todos tiveram sua identificação confirmada pela técnica de HMA simplificada. Nenhum dos isolados potencialmente patogênicos foram resistentes aos antifúngicos testados. Mais estudos são necessários para avaliar o real significado do isolamento dessas leveduras clinicamente relevantes.There are few reports concerning isolation, counting and identification of yeasts in goat´s raw milk and derivates. The objective of this study was to evaluate the diversity of yeasts found in raw goat milk and goat creamed cheese collected in a Metropolitan area in Porto Alegre - Brazil. A simplified HMA (Heteroduplex Mobility Assay) of the 26S rDNA D1/D2 region was developed in order to rapidly confirm the identification of the isolates belonging to potentially pathogenic species. Yeasts were isolated from 59% of the samples. Fifty six strains were isolated and identified in the genera Bullera, Candida, Cryptococcus, Debaryomyces, Dekkera, Pichia, Rhodotorula, Sporodiobolus, Trichosporon, Yarrowia and Zygoascus. The average yeast count in raw milk was superior to 2 log UFC.mL-1, while cheese count was superior to 3 log UFC.g-1. Lipolytic activity was present in almost 92% of the isolates, while only 14% had proteolytic activity. Twelve potentially pathogenic ascomycetic isolates were identified by the conventional yeast identification methodology, and correspond to the species Candida parapsilosis, Candida tropicalis and Pichia guilliermondii. All of them had their identities confirmed by the simplified HMA assay. None of the isolates belonging to potentially pathogenic species were resistant to the antifungal agents tested. More studies are necessary to evaluate the real significance of the isolation of these clinically relevant yeasts

GENETIC FINE STRUCTURE OF THE <i>Y</i> CHROMOSOME OF <i>DROSOPHILA HYDEI</i>

ABSTRACT A genetic map of the Y chromosome of Drosophila hydei has been constructed from deletion/complementation experiments, with the aid of male sterile mutants of the Y chromosome. A central conclusion of our experiments is that not more than a single complementation group can be detected in each of the lampbrush loop forming sites. Additional complementation groups, functionally independent of lampbrush loops, reside between these loci. Six complementation groups have been defined by several methods of mapping. An additional ten complementation groups are indicated, but their exact definition requires further investigation. The "synthetic sterility" of mutations in these ten loci contributes to the difficulty in unequivocally establishing their individual boundaries. Mapping problems also arise from the instability of certain mutants.</jats:p

Identification of Bacterial Infection in Neotropical Primates

Emerging infectious diseases usually arise from wild animal populations. In the present work, we performed a screening for bacterial infection in natural populations of New World primates. The blood cell bulk DNAs from 181 individuals of four Platyrrhini genera were PCR screened for eubacterial 16S rRNA genes. Bacteria were detected and identified in 13 distinct individuals of Alouatta belzebul, Alouatta caraya, and Cebus apella monkeys from geographically distant regions in the states of Mato Grosso and Pará, Brazil. Sequence analyses showed that these Platyrrhini bacteria are closely related not only to human pathogens Pseudomonas spp. but also to Pseudomonas simiae and sheep- Acari infecting Pseudomonas spp. The identified Pseudomonas possibly represents a group of bacteria circulating in natural monkey populations