Search results for "MESH : Genetic Variation"
showing 4 items of 4 documents
Trends of extended-spectrum β-lactamase-producing Escherichia coli sequence type 131 and its H30 subclone in a French hospital over a 15-year period.
2016
International audience; Sequence type 131 (ST131) is a predominant lineage among extraintestinal pathogenic Escherichia coli. It plays a major role in the worldwide dissemination of E. coli producing extended-spectrum β-lactamases (ESBLs). Here we describe the long-term epidemiology of this clonal group in a French university hospital, where the incidence of ESBL-producing E. coli has increased from 0.018 case per 1000 patient-days in the year 2000 to 0.50 case per 1000 patient-days in 2014. The first of the 141 ST131 isolates was recovered in 2006, and the ST131 clonal group accounted for 18.1% of total ESBL-producing E. coli over the whole period (2000-2014). Subclonal typing showed that …
Diversifying selection on MHC class I in the house sparrow (Passer domesticus).
2009
10 pages; International audience; Genes of the major histocompatibility complex (MHC) are the most polymorphic loci known in vertebrates. Two main hypotheses have been put forward to explain the maintenance of MHC diversity: pathogen-mediated selection and MHC-based mate choice. Host-parasite interactions can maintain MHC diversity via frequency-dependent selection, heterozygote advantage, and diversifying selection (spatially and/or temporally heterogeneous selection). In this study, we wished to investigate the nature of selection acting on the MHC class I across spatially structured populations of house sparrows (Passer domesticus) in France. To infer the nature of the selection, we comp…
A multi-locus inference of the evolutionary diversification of extant flamingos (Phoenicopteridae).
2014
9 pages; International audience; BACKGROUND: Modern flamingos (Phoenicopteridae) occupy a highly specialized ecology unique among birds and represent a potentially powerful model system for informing the mechanisms by which a lineage of birds adapts and radiates. However, despite a rich fossil record and well-studied feeding morphology, molecular investigations of the evolutionary progression among modern flamingos have been limited. Here, using three mitochondrial (mtDNA) markers, we present the first DNA sequence-based study of population genetic variation in the widely distributed Chilean Flamingo and, using two mtDNA and 10 nuclear (nDNA) markers, recover the species tree and divergence…
Prevalence and genetic diversity of Aichi virus strains in stool samples from community and hospitalized patients.
2008
ABSTRACT Aichi virus has been proposed as a causative agent of gastroenteritis. A total of 457 stool specimens from children hospitalized with acute diarrhea and 566 stool specimens from adults and children involved in 110 gastroenteritis outbreaks were screened for the presence of Aichi virus by reverse transcription-PCR (RT-PCR) amplification of the genomic region of the 3C and 3D (3CD) nonstructural proteins. Our results show a low incidence of Aichi virus in pediatric samples and the existence of mixed infections with other microbiological agents in some cases. From the outbreak survey, it appears that the presence of Aichi virus is an indicator of mixed infections causing gastroenterit…