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PubMed2005

Occurrence and diversity of yeasts in the mid-atlantic ridge hydrothermal fields near the Azores Archipelago.

The yeast community associated with deep-sea hydrothermal systems of the Mid-Atlantic Rift was surveyed for the first time. This study relied on a culture-based approach using two different growth media: a conventional culture medium for yeasts supplemented with sea salts (MYPss) and the same medium additionally supplemented with sulfur (MYPssS). For the evaluation of species diversity, a molecular approach involving minisatellite-primed polymerase chain reaction (MSP-PCR) strain typing and sequence analysis of the D1/D2 domains of the 26S rDNA was followed. In the seven water samples that were studied, the number of colony-forming units per liter (cfu/L) ranged from 0 to 5940. The nonpigmented yeasts were much more abundant than the pink-pigmented ones. This disproportion was not observed in studies of other marine systems and may be due to the unique conditions of hydrothermal vents, characterized by a rich animal and microbial diversity and therefore by the availability of organic compounds utilizable by yeasts. Higher counts of nonpigmented yeast were obtained using MYPss, whereas for pink yeasts, higher counts were obtained using MYPssS. Moreover, among pink yeasts, some of the MSP-PCR classes obtained were composed of isolates obtained only on MYPssS, which might be an indication that these isolates are adapted to the ecosystems of the hydrothermal vents. Twelve phylotypes belonged to the Ascomycota and seven phylotypes belonged to the Basidiomycota. The nonpigmented yeasts were identified as Candida atlantica, C. atmosphaerica, C. lodderae, C. parapsilosis, Exophiala dermatitidis, Pichia guilliermondii, and Trichosporon dermatis, whereas the pigmented yeasts were identified as Rhodosporidium diobovatum, R. sphaerocarpum, R. toruloides, and Rhodotorula mucilaginosa. Some of the yeasts that were found belong to phylogenetic groups that include species reported from other marine environments, and eight phylotypes represent undescribed species. The new phylotypes found at Mid-Atlantic Ridge hydrothermal fields represent 33% of the total number of yeast taxa that were found.

Azores↗
PubMed2000

Rodents and Leptospira transmission risk in Terceira island (Azores).

The role of rodents as Leptospira renal carriers in Terceira island was evaluated (1993-1995) through kidney culture and serology [microscopic aglutination test (MAT)] of 94 mice and rats. Fifty-nine animals were positive (n = 41 by serology + culturing; n = 11 serology; n = 7 culturing), presenting a wide distribution in man-made and natural areas. House mice had the highest bacteriological (82.9%) and serological (90.9%) rates, being strictly related to serovar arborea. Black rats were involved in the dispersion of all isolated L. interrogans sensu lato serovars (arborea, copenhageni and icterohaemorrhagiae). Logistic regression analysis and non-metric multi-dimensional scaling, relating Leptospira infection with biological and environmental variables, expressed that adult males Mus domesticus, sexually active and living in humid biotopes, mainly above 500 m, are the most likely reservoirs. This study emphasizes the role of house-mice in the epidemiology of leptospirosis in Terceira and the need of reducing the risk of Leptospira transmission through integrated control programmes, primarily focusing on adult house-mice in peri-domestic environments, before the breeding season.

Animals↗
PubMed2004

Arthropod community structure in pastures of an island archipelago (Azores): looking for local-regional species richness patterns at fine-scales.

The arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local-regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= alpha diversity) and regional species richness was estimated at the pasture level (= gamma diversity) with the 'first-order-Jackknife' estimator. Three related issues were addressed: (i). the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii). quantification of the relative contributions of alpha and beta diversity to regional diversity using additive partitioning; and (iii). the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing beta-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

Animals↗
PubMedDate not supplied

Mutant allele frequencies in domestic cats of Portugal and the Azores.

The genetic profiles of cat populations of mainland Portugal are basically similar to those of the adjacent Atlantic littoral. The profiles of Azorean populations, while relatively homogeneous among themselves, are strikingly different from the mainland. It is tentatively concluded that some form of selective migration was the most important contributing factor in establishing the differences.

Alleles↗
PubMed1996

Thermus oshimai sp. nov., isolated from hot springs in Portugal, Iceland, and the Azores, and comment on the concept of a limited geographical distribution of Thermus species.

We examined aerobic, thermophilic, gram-negative bacteria that were isolated from hot springs in Portugal and were identified as Thermus strains and placed in phenetic groups on the basis of their phenotypic characteristics. We determined the composition of the peptidoglycan, identified the respiratory quinones, and determined the mean base composition of the DNA, and the levels of DNA-DNA homology were determined by both the filter hybridization and reassociation rate methods. Thermus aquaticus, Thermus brockianus, and Thermus filiformis were not detected in this collection of organisms, although three Thermus thermophilus strains were identified. We propose that the isolates that belonged to phenetic clusters E and F are members of a new species, Thermus oshimai; the type strain of T. oshimai is strain SPS17.

Azores↗
PubMed2000

Analysis of Leptospira isolates from mainland Portugal and the Azores islands.

From 228 recent Leptospira isolates from mainland Portugal and Azorean wild mammals, 149 were characterized at the serovar level by monoclonal antibodies (MAbs), a quick serological method in epidemiological studies. In order to compare this antigenic information with that from new genetic techniques, a sample of isolates was analyzed through pulsed-field agarose gel electrophoresis (PFGE) (n=71), mapped restriction site polymorphisms (MRSPs) in PCR-amplified rRNA genes (n=45, including 13 saprophytes) and arbitrarily primed polymerase chain reaction (AP-PCR) fingerprinting (n=32). MRSP and AP-PCR lead to species identification of the studied 32 pathogenic isolates: Leptospira interrogans (n=3), Leptospira kirschneri (n=8) and Leptospira borgpetersenii (n=21). MAbs and PFGE characterized pathogenic isolates at the serovar level and resulted mainly in agreement (64%) although many discrepancies (35%) were observed.

Animals↗
PubMed2003

Population structure of São Miguel Island, Azores: a surname study.

The knowledge of a population structure may constitute a powerful tool for mapping genes underlying susceptibility to Mendelian and complex diseases. To obtain a better understanding of the population structure of São Miguel Island (Azorean Archipelago, Portugal), we carried out a surname survey using the surnames listed in the most recent telephone book (2001). We identified 1315 different surnames in a total of 27,621 subscribers. The frequency of the different surnames was used to calculate the following parameters: isonymy (I), random component of inbreeding (FST), genetic diversity according to Fisher (alpha), migration rate according to Karlin-McGregor (v) and Nei's genetic distance. Eleven localities were selected, according to population size and geographic distribution, for analysis using the above parameters. Our results show that 51% of Salga's population and 52% of Sete Cidades's population are represented by six and eight surnames, respectively. These figures demonstrate the effective isolation of these two small places, which are located at opposite ends of São Miguel Island. Salga, Achada, and Sete Cidades present the lowest values of Fisher's alpha, indicating less genetic diversity. In contrast, the capital, Ponta Delgada, presents the highest value of alpha (78.13), indicating more genetic diversity. Our data indicate that the clustering of the localities corresponds to the geographic features of the island, where localities close together tend to share similar surnames. In conclusion, the population of São Miguel is relatively homogeneous and may constitute an ideal model for genetic mapping studies.

Azores↗
PubMed2005

Surnames in the Azores: analysis of the isonymy structure.

Geographic isolation is a significant factor to consider when characterizing human populations. The knowledge of the genetic structure of isolated populations has been of great importance to disease-locus positioning and gene identification. To investigate the genetic structure of the Azorean population, we conducted a survey based on the frequencies of surnames listed in the 2001 telephone book. We calculated the following parameters: isonymy (I), the random component of inbreeding (F(ST)), genetic diversity according to Fisher (alpha), Karlin-McGregor's migration rate (v), and Nei's distance. For the 1,271 subscribers and 163 different surnames, Graciosa island presented the lowest value of abundance of surnames (alpha = 15.75), suggesting great genetic isolation compared to the other eight islands. Migration, calculated on the basis of the diversity of surnames within islands, ranged from 0.2747 (Corvo island) to 0.0026 (São Miguel island), indicating that people migrated preferentially toward the economically more developed islands. The value of the random component of inbreeding obtained for the whole population (F(ST) = 0.0039) indicates little genetic differentiation (Wright's F(ST) < 0.05). Moreover, isonymy similarity revealed using the UPGMA method shows three subclusters corresponding to the geographic distribution of the islands.

Azores↗
PubMed1990

Unusual molecular basis of Hb H disease in the Azores Islands, Portugal.

An Azorean family with Hb H disease (10% Hb H) was studied in order to elucidate its molecular basis. DNA studies on the patient only revealed a 4.2 kb "leftward" deletion of paternal origin which implies the co-inheritance of a nondeletional alpha-thalassemia determinant. Restriction endonuclease and oligonucleotide analysis allowed the exclusion of five point mutations: initiation codon (at both alpha 1- and alpha 2-globin genes), IVS-I donor splice junction pentanucleotide deletion, codon 125 CTG----CCG substitution, and Saudi Arabian polyadenylation signal mutation. These findings suggest that the molecular basis of this form of Hb H disease is probably different from those described previously.

Azores↗
PubMed1978

Joseph's disease: an autosomal dominant neurological disease in the Portuguese of the United States and the Azores Islands.

Our objective has been to trace Joseph's disease to its geographic origins and to determine the spectrum of clinical manifestations. This goal we have achieved by documenting type I and II disease within the Joseph and Sousa families. The major neuropathologic findings are a progressive neuronal loss involving the striatum, nigra, dentate nucleus of the cerebellum, and lower motor neurons in the brainstem and spinal cord. The homozygote form of the disease produces type I disease with onset in early childhood of progressive dystonia, athetosis, and spasticity. Type I disease tends to have its onset by age 25 years in heterozygotes and lasts about 15 years on the average. Type II disease, which we consider the result of a single dose of the mutant gene, usually begins somewhat later and runs its course over a 20-year period. Type III disease documented in the Thomas family is the most benign. Its onset is often in the fifth decade, and it progresses slowly into the eighth decade. Patients may benefit from antiparkinson medication including dihydroxyphenylalanine and anticholinergic agents (e.g., amantadine). A molecular marker for the disease is being sought actively, and several interesting patterns have already been documented by means of patient fibroblast cultures and two-dimensional acrylamide gel protein separations. The mutant gene is clearly outside the HLA complex but may be linked to it. The only biochemical change noted thus far is a reduced CSF level of HVA that probably reflects the loss of dopamine-synthesizing neurons in the substantia nigra and is thus a secondary effect of disease. Although the disease is a very old one which we can trace back to the early 19th century on the island of Flores, it may be recurring de novo by new gene mutations at an unstable gene locus in a genetically vulnerable population. Now that the spectrum of clinical expression has been identified and the mode of inheritance established as an autosomal dominant wherever the disease has been found, it is believed that its true incidence will become more evident by virtue of better detection and that the true incidence will actually increase because of increased assimilation of affected persons into other ethnic groups.

Adolescent↗
PubMed2006

Epidemiological characterization of congenital heart disease in São Miguel Island, Azores, Portugal.

OBJECTIVES: This study aimed to characterize the prevalence of congenital heart disease (CHD) in children born alive in São Miguel island from January 1992 to December 2001. METHODS: Based on the Azorean Registry of CHD, which includes complete clinical and personal information, 189 patients were diagnosed. RESULTS: During this 10-year period, the average prevalence of CHD is 9.16 per 1,000 live births (range 4.77-12.75). The most frequent cardiac malformations found were: ventricular septal defect (38.1%), atrial septal defect (12.2%) and patent ductus arteriosus (11.6%). Until now, four familial clusters were identified, representing a total of 13 patients. CONCLUSIONS: This first epidemiological study of CHD in the Azorean population reveals evidence for familial aggregation, which is of great interest for understanding the genes involved in these complex pathologies.

Female↗