Search results for "phylogeny"
showing 10 items of 1398 documents
Surveillance of human astrovirus circulation in Italy 2002-2005: emergence of lineage 2c strains.
2010
AbstractBy screening faecal samples collected over four consecutive years (2002-2005) from hospitalized children with diarrhoea in Palermo, Italy, astroviruses (HAstVs) were detected in 3.95% of the patients. The predominant type circulating was HAstV-1 but, in 2002, only HAstV-2 and -4 were identified. Interestingly, the HAstVs-2 detected appeared to be consistently different in 5′ end of their open reading frame 2 from the previously described subtypes. These novel type 2 strains were included in a new 2c lineage based on the phylogenetic analysis and the presence of nine peculiar substitutions.
Recombinant norovirus GII.g/GII.12 gastroenteritis in children.
2011
Recombinant GII.g/GII.12 norovirus (NoV) strains emerged in 2008 in Australia and subsequently have been associated with gastroenteritis outbreaks worldwide. In the winter season 2009-2010 GII.12 strains caused 16% of the NoV outbreaks in the United States. During 2009-2010 we also identified GII.g/GII.12 strains during surveillance of sporadic cases of gastroenteritis in Italian children. Severity scores were calculated for the GII.g/GII.12 NoV infections using the Vesikari scale and in two out of three paediatric cases they exceeded the median value calculated for concomitant GII.4 infections. Upon sequence analysis, the Italian strains were found to be recombinant viruses and displayed d…
Genetic heterogeneity and recombination in human type 2 astroviruses
2012
ABSTRACT Novel lineages of human astrovirus (HAstV) types 2, 2c, and 2d have been identified. Upon sequencing of the 3′ end of the genome, the type 2c and 2d HAstVs were found to be open reading frame 1b (ORF1b)-ORF2 recombinant, with ORF1b being derived from type 3 and type 1 HAstVs, respectively. An ORF2 interlineage recombinant strain, 2c/2b, was also identified.
Systematics of Mepraia (Hemiptera-Reduviidae): cytogenetic and molecular variation.
2009
The haematophagous insects of the subfamily Triatominae (Hemiptera-Reduviidae) have great epidemiological importance as vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Mepraia was originally described as a monotypic genus comprised of Mepraia spinolai, distributed along coastal areas of northern Chile (from Region I to the Metropolitan Region). Recently, some M. spinolai populations have been ranked as a new species named Mepraia gajardoi. Several populations along the distribution range of the genus were sampled, and genetic differentiation was studied based upon the analysis of three molecular markers: cytogenetics (karyotype and chromosome behaviour during meiosis us…
Nuclear rDNA pseudogenes in Chagas disease vectors: Evolutionary implications of a new 5.8S+ITS-2 paralogous sequence marker in triatomines of North,…
2013
A pseudogene, paralogous to rDNA 5.8S and ITS-2, is described in Meccus dimidiata dimidiata, M. d. capitata, M. d. maculippenis, M. d. hegneri, M. sp. aff. dimidiata, M. p. phyllosoma, M. p. longipennis, M. p. pallidipennis, M. p. picturata, M. p. mazzottii, Triatoma mexicana, Triatoma nitida and Triatoma sanguisuga, covering North America, Central America and northern South America. Such a nuclear rDNA pseudogene is very rare. In the 5.8S gene, criteria for pseudogene identification included length variability, lower GC content, mutations regarding the functional uniform sequence, and relatively high base substitutions in evolutionary conserved sites. At ITS-2 level, criteria were the shor…
In vitro activity of 20 antibiotics against Cupriavidus clinical strains
2020
International audience
Phylogenetic Distribution of Polysaccharide-Degrading Enzymes in Marine Bacteria
2021
Deconstruction is an essential step of conversion of polysaccharides, and polysaccharide-degrading enzymes play a key role in this process. Although there is recent progress in the identification of these enzymes, the diversity and phylogenetic distribution of these enzymes in marine microorganisms remain largely unknown, hindering our understanding of the ecological roles of marine microorganisms in the ocean carbon cycle. Here, we studied the phylogenetic distribution of nine types of polysaccharide-degrading enzymes in marine bacterial genomes. First, we manually compiled a reference sequence database containing 961 experimentally verified enzymes. With this reference database, we annota…
Molecular Epidemiology of Caliciviruses Causing Outbreaks and Sporadic Cases of Acute Gastroenteritis in Spain
2002
ABSTRACT The molecular epidemiology of human caliciviruses (HuCVs) causing sporadic cases and outbreaks of acute gastroenteritis around eastern Spain (Catalonia and the Valencian Community) was studied by reverse transcription-PCR (RT-PCR) and by sequencing part of the RNA polymerase gene in open reading frame 1. HuCVs were detected in 44 of 310 stool specimens (14.19%) negative for other enteric pathogens obtained from children with acute gastroenteritis. Norwalk-like viruses (NLVs) were the most common cause of the gastroenteritis outbreaks investigated here. They were detected in 14 out of 25 (56%) outbreaks with an identified pathogen. Genotypes producing both sporadic cases and outbrea…
Hybridization of mouse lemurs: different patterns under different ecological conditions
2011
Abstract Background Several mechanistic models aim to explain the diversification of the multitude of endemic species on Madagascar. The island's biogeographic history probably offered numerous opportunities for secondary contact and subsequent hybridization. Existing diversification models do not consider a possible role of these processes. One key question for a better understanding of their potential importance is how they are influenced by different environmental settings. Here, we characterized a contact zone between two species of mouse lemurs, Microcebus griseorufus and M. murinus, in dry spiny bush and mesic gallery forest that border each other sharply without intermediate habitats…
Oxygen as a morphogenic factor in sponges: expression of a tyrosinase gene in the sponge Suberites domuncula
2004
Sponges live in a symbiotic relationship with microorganisms, especially bacteria. Here we show, using the demosponge Suberites domuncula as a model, that the sponge expresses the enzyme tyrosinase which synthesizes diphenols from monophenolic compounds. It is assumed that these products serve as carbon source for symbiotic bacteria to grow.