Search results for "Molecular Epidemiology"
showing 10 items of 142 documents
Molecular Epidemiology and Immunology of Hepatitis B Virus Infection – An Update
2003
Hepatitis B virus (HBV) continues to be one of the most important viral pathogens in humans. This review provides an update on the molecular epidemiology and immunology of HBV infection. DNA sequencing has allowed replacement of the initial serotypic classification of HBV strains by a more systematic genotype system that currently consists of 7 members (genotypes A–G). More recently, sequence analysis of virus isolates from many individual patients has revealed the occurrence of certain mutational hot spots in the genome, some of which appear to correlate with the patient’s immunological and/or disease status; however, cause and effect are not always easily discernible. This holds particula…
epiPATH: an information system for the storage and management of molecular epidemiology data from infectious pathogens.
2007
Abstract Background Most research scientists working in the fields of molecular epidemiology, population and evolutionary genetics are confronted with the management of large volumes of data. Moreover, the data used in studies of infectious diseases are complex and usually derive from different institutions such as hospitals or laboratories. Since no public database scheme incorporating clinical and epidemiological information about patients and molecular information about pathogens is currently available, we have developed an information system, composed by a main database and a web-based interface, which integrates both types of data and satisfies requirements of good organization, simple…
Expansion of the CRF19_cpx Variant in Spain
2015
Abstract Background HIV-1 CRF19_cpx, is a recombinant variant found almost exclusively in Cuba and recently associated to a faster AIDS onset. Infection with this variant leads to higher viral loads and levels of RANTES and CXCR4 co-receptor use. Objectives The goal of this study was to assess the presence of CRF19_cpx in the Spanish province of Valencia, given its high pathogenicity. Study design 1294 HIV-1 protease-reverse transcriptase (PR/RT) sequences were obtained in Valencia (Spain), between 2005 and 2014. After subtyping, the detected CRF19_cpx sequences were aligned with 201 CRF19_cpx and 66 subtype D sequences retrieved from LANL, and subjected to maximum-likelihood phylogenetic a…
Homozygous Familial Hypercholesterolemia in Spain Prevalence and Phenotype-Genotype Relationship
2016
Background— Homozygous familial hypercholesterolemia (HoFH) is a rare disease characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and extremely high risk of premature atherosclerotic cardiovascular disease. HoFH is caused by mutations in several genes, including LDL receptor ( LDLR ), apolipoprotein B ( APOB ), proprotein convertase subtilisin/kexin type 9 ( PCSK9 ), and LDL protein receptor adaptor 1 ( LDLRAP1 ). No epidemiological studies have assessed HoFH prevalence or the clinical and molecular characteristics of this condition. Here, we aimed to characterize HoFH in Spain. Methods and Results— Data were collected from the Spanish Dyslipidemia Regist…
Molecular epidemiology and whole genome sequencing analysis of clinical Mycobacterium bovis from Ghana
2019
[Background]: Bovine tuberculosis (bTB) caused by Mycobacterium bovis is a re-emerging problem in both livestock and humans. The association of some M. bovis strains with hyper-virulence, MDR-TB and disseminated disease makes it imperative to understand the biology of the pathogen.
Cluster of cases of Salmonella enterica serotype Rissen infection in a general hospital, Italy, 2007.
2009
In 2007, three strains of Salmonella enterica serotype Rissen (S. Rissen) were isolated in the laboratory of diagnostic microbiology of the General Hospital of Prato, Tuscany, Italy, over a 1 month and half interval of time. The first isolate was recovered on January 26 from an outpatient with enteritis. Then, two strains were isolated on February 16 and March 11 respectively, from central venous catheters of patients who were being hospitalized in two departments of the Hospital. An epidemiologically linked cluster of cases of salmonellosis was suspected. The three strains were submitted to single enzyme-amplified fragment length polymorphism (SE-AFLP) and XbaI macrorestriction and pulsed-…
Limited cross-border infections in patients newly diagnosed with HIV in Europe
2013
Background: International travel plays a role in the spread of HIV-1 across Europe. It is, however, not known whether international travel is more important for spread of the epidemic as compared to endogenous infections within single countries. In this study, phylogenetic associations among HIV of newly diagnosed patients were determined across Europe.Results: Data came from the SPREAD programme which collects samples of newly diagnosed patients that are representative for national HIV epidemics. 4260 pol sequences from 25 European countries and Israel collected in 2002-2007 were included.We identified 457 clusters including 1330 persons (31.2% of all patients). The cluster size ranged bet…
Telomere length and physical performance at older ages:an individual participant meta-analysis
2013
<p>Background: Telomeres are involved in cellular ageing and shorten with increasing age. If telomere length is a valuable biomarker of ageing, then telomere shortening should be associated with worse physical performance, an ageing trait, but evidence for such an association is lacking. The purpose of this study was to examine whether change in telomere length is associated with physical performance.</p>\ud \ud <p>Methods: Using data from four UK adult cohorts (ages 53–80 years at baseline), we undertook cross-sectional and longitudinal analyses. We analysed each study separately and then used meta-analytic methods to pool the results. Physical performance was measured us…
Viral Sequence Analysis of Occult HBV Infection and Its Reactivation in Immunosuppressed Patients
2012
Mechanisms associated with reactivation of hepatitis B virus (HBV) in patients with occult HBV infection (OBI) remain unclear. In some cases immunosuppression is an enhancer of viral replication. However, not all patients with OBI who undergo immunosuppression experience reactivation. This study explores the role of viral heterogeneity as a determinant of occult HBV reactivation. HBV genotype, mutation patterns and quasispecies were assessed by sequencing the PreS/S region of 16 patients with OBI undergoing chemotherapy, 3 of whom experienced a OBI reactivation. The latter were also assessed at the time of reactivation. Phylogenetic analysis identified low nucleotide and amino acid diversit…
CTX-M β-Lactamase-Producing Escherichia coli in French Hospitals: Prevalence, Molecular Epidemiology, and Risk Factors▿
2007
ABSTRACT In 2004, 65 CTX-M-producing Escherichia coli isolates were collected from infected patients in four French hospitals. The bla CTX-M-15 genes were predominant. Pulsed-field gel electrophoresis highlighted a clonal propagation of CTX-M-15-producing strains belonging to phylogenetic group B2, notably in the community. The main risk factors for acquiring these isolates were urinary tract infections or the presence of a urinary catheter in diabetic or renal failure patients.