Search results for " Parasitology"

Anhydrobiosis: Inside yeast cells

2018

International audience; Under natural conditions yeast cells as well as other microorganisms are regularly subjected to the influence of severe drought, which leads to their serious dehydration. The dry seasons are then changed by rains and there is a restoration of normal water potential inside the cells. To survive such seasonal changes a lot of vegetative microbial cells, which belong to various genera and species, may be able to enter into a state of anhydrobiosis, in which their metabolism is temporarily and reversibly suspended or delayed. This evolutionarily developed adaptation to extreme conditions of the environment is widely used for practical goals - for conservation of microorg…

Lobesia botrana larvae develop faster in the presence of parasitoids.

2013

3 pages; International audience; To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-pa…

Blastocystis sp., an emerging parasite with controversial pathogenicity. Should all human cases be treated?

2018

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.

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…

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…