Search results for "parasitology"
showing 10 items of 1410 documents
Pisolithus albus, a new record for Italy
2018
The results of macroscopic and microscopic observations have highlighted the presence of P. albus also in Italy. The distribution of this species in the Italian territory seems much wider than previously realised and most of the herbarium samples previously identified as P. arhizus should probably be re-analyzed using morphological, microscopic and molecular criteria.
Genomic characterization of a local epidemic Pseudomonas aeruginosa reveals specific features of the widespread clone ST395
2017
International audience; Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with several clones being frequently associated with outbreaks in hospital settings. ST395 is among these so-called 'international' clones. We aimed here to define the biological features that could have helped the implantation and spread of the clone ST395 in hospital settings. The complete genome of a multidrug resistant index isolate (DHS01) of a large hospital outbreak was analysed. We identified DHS01-specific genetic elements, among which were identified those shared with a panel of six independent ST395 isolates responsible for outbreaks in other hospitals. DHS01 has the fifth largest chromosome of …
Constitutive activation of MexT by amino acid substitutions results in MexEF-OprN overproduction in clinical isolates of Pseudomonas aeruginosa
2018
ABSTRACT When overproduced, the multidrug efflux system MexEF-OprN increases the resistance of Pseudomonas aeruginosa to fluoroquinolones, chloramphenicol, and trimethoprim. In this work, we demonstrate that gain-of-function mutations in the regulatory gene mexT result in oligomerization of the LysR regulator MexT, constitutive upregulation of the efflux pump, and increased resistance in clinical isolates.
Neither Diplectanum nor specific: a dramatic twist to the taxonomic framework of Diplectanum (Monogenea: Diplectanidae).
2019
The taxonomy of the genus Diplectanum has been exclusively based on morphological features, with 28 nominal species parasitic on perciform fishes recognised. We used molecular data, to our knowledge for the first time, to evaluate the taxonomic framework of Diplectanum, infer the relationships amongst species attributed to this genus, re-assess the degree of host specificity and explore the population genetic structure of Diplectanum spp. parasitising Mediterranean sciaenids, which are potential target fish species for aquaculture diversification in the region. A minimum of 10 specimens of Diplectanum spp. were sequenced per host species (Argyrosomus regius, Sciaena umbra, Umbrina canariens…
The protein and microRNA cargo of extracellular vesicles from parasitic helminths – current status and research priorities
2020
Helminth parasites have a remarkable ability to persist within their mammalian hosts, which is largely due to their secretion of molecules with immunomodulatory properties. Although the soluble components of helminth secretions have been extensively studied, the discovery that helminths release extracellular vesicles (EVs) has added further complexity to the host-parasite interaction. Whilst several studies have begun to characterise the molecules carried by helminth EVs, work aimed at investigating their biological functions has been hindered by a lack of helminth-specific EV markers. To begin to address this, we summarised helminth EV literature to date. With a focus on the protein and mi…
Role of AxyZ Transcriptional Regulator in Overproduction of AxyXY-OprZ Multidrug Efflux System in Achromobacter Species Mutants Selected by Tobramycin
2017
ABSTRACT AxyXY-OprZ is an RND-type efflux system that confers innate aminoglycoside resistance to Achromobacter spp. We investigated here a putative TetR family transcriptional regulator encoded by the axyZ gene located upstream of axyXY-oprZ . An in-frame axyZ gene deletion assay led to increased MICs of antibiotic substrates of the efflux system, including aminoglycosides, cefepime, fluoroquinolones, tetracyclines, and erythromycin, indicating that the product of axyZ negatively regulates expression of axyXY-oprZ . Moreover, we identified an amino acid substitution at position 29 of AxyZ (V29G) in a clinical Achromobacter strain that occurred during the course of chronic respiratory tract…
Genome-Wide Estimation of the Spontaneous Mutation Rate of Human Adenovirus 5 by High-Fidelity Deep Sequencing
2016
Rates of spontaneous mutation determine the ability of viruses to evolve, infect new hosts, evade immunity and undergo drug resistance. Contrarily to RNA viruses, few mutation rate estimates have been obtained for DNA viruses, because their high replication fidelity implies that new mutations typically fall below the detection limits of Sanger and standard next-generation sequencing. Here, we have used a recently developed high-fidelity deep sequencing technique (Duplex Sequencing) to score spontaneous mutations in human adenovirus 5 under conditions of minimal selection. Based on >200 single-base spontaneous mutations detected throughout the entire viral genome, we infer an average mutatio…
Epidemiological analysis of human fascioliasis in northeastern Punjab, Pakistan.
2016
A coprological study was performed to assess human fascioliasis in 7200 subjects inhabiting rural communities of localities close to the capital city of Lahore in the northeastern part of the very highly populated Punjab province, Pakistan, a country where human infection had never been reported before 2005. The analysis of 1200 subjects including 50 subjects/month throughout a two-year study in each of six localities surveyed provided an overall prevalence of 1.18%, with a range between 0.67% and 1.75% according to localities. Infection rates did not differ according to gender, excepting a higher rate in females (1.13% vs 0.77%) in one locality. Prevalences according to age groups proved t…
New contribution to the knowledge of two species of culicids inhabiting a mountainous rural area of Spain: Aedes (Rusticoidus) refiki (Medschid, 1928…
2017
espanolEntre final de abril y principio de mayo de 2017, en un area de montana con altitudes superiores a 1.500 msnm, se capturaron dos especies de mosquitos (Diptera, Culicidae) poco comunes: Aedes (Rusticoidus) refiki y Aedes (Ochlerotatus) pullatus. Se recolectaron 626 ejemplares, con densidades larvarias mayoritarias de Ae. refiki (87%). Se describio una nueva asociacion larvaria entre ambas especies, hasta la fecha desconocida. Los culicidos se localizaron en un entorno habitualmente nevado en invierno, del Parque Natural del Alto Tajo (Guadalajara, Comunidad de CastillaLa Mancha) y en los Montes Universales (Teruel, Comunidad Auto- noma de Aragon). En consecuencia, se presentan como p…
Tillage intensity and pasture in rotation effectively shape soil microbial communities at a landscape scale
2018
International audience; Soil microorganisms are essential to agroecosystem functioning and services. Yet, we still lack information on which farming practices can effectively shape the soil microbial communities. The aim of this study was to identify the farming practices, which are most effective at positively or negatively modifying bacterial and fungal diversity while considering the soil environmental variation at a landscape scale. A long-term research study catchment (12 km2 ) representative of intensive mixed farming (livestock and crop) in Western Europe was investigated using a regular grid for soil sampling (n = 186). Farming systems on this landscape scale were described in terms…