Fatty acid metabolism and the oxidative stress response support bacterial predation.

Despite growing awareness of their importance in soil ecology, the genetic and physiological traits of bacterial predators are still relatively poorly understood. In the course of a predator evolution experiment, we identified a class of genotypes leading to enhanced predation against diverse species. RNA-seq analysis demonstrated that this phenotype is linked to the constitutive activation of a predation-specific program.

Complex transcriptional regulations of a hyperparasitic quadripartite system in giant viruses infecting protists.

Hyperparasitism is a common pattern in nature that is not limited to cellular organisms. Giant viruses infecting protists can be hyperparasitized by smaller ones named virophages. In addition, both may carry episomal DNA molecules known as transpovirons in their particles.

Diversity and dynamics of bacteria from iron-rich microbial mats and colonizers in the Mediterranean Sea (EMSO-Western Ligurian Sea Observatory): Focus on Zetaproteobacteria.

Autotrophic microaerophilic iron-oxidizing Zetaproteobacteria seem to play an important role in mineral weathering and metal corrosion in different environments. Here, we compare the bacterial and zetaproteobacterial communities of a mature iron-rich mat together with in situ incubations of different Fe-bearing materials at the EMSO-Ligure West seafloor observatory, which is located on the abyssal plain in the NW Mediterranean Sea. Our results on bacterial communities enable us to make a clear distinction between those growing on mild steel anthropic substrata and those developing on basaltic substrata.

Giant Mimiviridae CsCl Purification Protocol.

While different giant viruses' purification protocols are available, they are not fully described and they use sucrose gradient that does not reach an equilibrium. Here, we report a protocol for the purification of members of the family virions resulting from infections. Viruses are harvested after cell lysis and purified through a high density CsCl gradient to optimize the isolation of the virus from the cell debris or other potential contaminants.

Exploration of the propagation of transpovirons within Mimiviridae reveals a unique example of commensalism in the viral world.

Acanthamoeba-infecting Mimiviridae are giant viruses with dsDNA genome up to 1.5 Mb. They build viral factories in the host cytoplasm in which the nuclear-like virus-encoded functions take place.

Diversity and evolution of the emerging Pandoraviridae family.

With DNA genomes reaching 2.5 Mb packed in particles of bacterium-like shape and dimension, the first two Acanthamoeba-infecting pandoraviruses remained up to now the most complex viruses since their discovery in 2013. Our isolation of three new strains from distant locations and environments is now used to perform the first comparative genomics analysis of the emerging worldwide-distributed Pandoraviridae family.

In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba.

Acanthamoeba species are infected by the largest known DNA viruses. These include icosahedral Mimiviruses, amphora-shaped Pandoraviruses, and Pithovirus sibericum, the latter one isolated from 30,000-y-old permafrost. Mollivirus sibericum, a fourth type of giant virus, was isolated from the same permafrost sample.

Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology.

The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 μm in diameter and adenine-thymine (AT)-rich genomes of up to 1.

In vitro piperaquine susceptibility is not associated with the Plasmodium falciparum chloroquine resistance transporter gene.

Background: Dihydroartemisinin-piperaquine is a new ACT that is administered as single daily dose for three days and has been demonstrated to be tolerated and highly effective for the treatment of uncomplicated Plasmodium falciparum malaria. Piperaquine was used alone to replace chloroquine as the first-line treatment for uncomplicated malaria in China in response to increasing chloroquine resistance in the 1970s. However, the rapid emergence of piperaquine-resistant strains that resulted in the cessation of its use in China in the 1980s, suggests that there is cross-resistance between piperaquine and chloroquine.

Pandoraviruses: amoeba viruses with genomes up to 2.5 Mb reaching that of parasitic eukaryotes.

Ten years ago, the discovery of Mimivirus, a virus infecting Acanthamoeba, initiated a reappraisal of the upper limits of the viral world, both in terms of particle size (>0.7 micrometers) and genome complexity (>1000 genes), dimensions typical of parasitic bacteria. The diversity of these giant viruses (the Megaviridae) was assessed by sampling a variety of aquatic environments and their associated sediments worldwide.

Longitudinal study assessing the return of chloroquine susceptibility of Plasmodium falciparum in isolates from travellers returning from West and Central Africa, 2000-2011.

Background: Chloroquine (CQ) was the main malaria therapy worldwide from the 1940s until the 1990s. Following the emergence of CQ-resistant Plasmodium falciparum, most African countries discontinued the use of CQ, and now promote artemisinin-based combination therapy as the first-line treatment. This change was generally initiated during the last decade in West and Central Africa.

Preliminary crystallographic analysis of a polyadenylate synthase from Megavirus.

Megavirus chilensis, a close relative of the Mimivirus giant virus, is also the most complex virus sequenced to date, with a 1.26 Mb double-stranded DNA genome encoding 1120 genes. The two viruses share common regulatory elements such as a peculiar palindrome governing the termination/polyadenylation of viral transcripts.

Differential association of Plasmodium falciparum Na+/H+ exchanger polymorphism and quinine responses in field- and culture-adapted isolates of Plasmodium falciparum.

Plasmodium falciparum isolates with decreased susceptibility to quinine are increasingly being found in malaria patients. Mechanisms involved in this resistance are not yet understood. Several studies claim that alongside mutations in the Pfcrt and Pfmdr1 genes, the Pfnhe-1 Na(+)/H(+) exchanger polymorphism plays a role in decreasing susceptibility.

Reduced in vitro susceptibility to artemisinin derivatives associated with multi-resistance in a traveller returning from South-East Asia.

Decreased in vitro susceptibility to dihydroartemisinin (21.2 nM) and artesunate (16.3 nM) associated with decreased susceptibility or resistance to quinine (1131 nM), mefloquine (166 nM), lumefantrine (114 nM), pyronaridine (70.

Polymorphism of Plasmodium falciparum Na(+)/H(+) exchanger is indicative of a low in vitro quinine susceptibility in isolates from Viet Nam.

Background: The Plasmodium falciparum NA+/H+ exchanger (pfnhe1, gene PF13_0019) has recently been proposed to influence quinine (QN) susceptibility. However, its contribution to QN resistance seems to vary geographically depending on the genetic background of the parasites. Here, the role of this gene was investigated in in vitro QN susceptibility of isolates from Viet Nam.

Genetic structure of Plasmodium falciparum and elimination of malaria, Comoros archipelago.

The efficacy of malaria control and elimination on islands may depend on the intensity of new parasite inflow. On the Comoros archipelago, where falciparum malaria remains a major public health problem because of spread of drug resistance and insufficient malaria control, recent interventions for malaria elimination were planned on Moheli, 1 of 4 islands in the Comoros archipelago. To assess the relevance of such a local strategy, we performed a population genetics analysis by using multilocus microsatellite and resistance genotyping of Plasmodium falciparum sampled from each island of the archipelago.

Quinine-resistant malaria in traveler returning from Senegal, 2007.

We describe clinical and parasitologic features of in vivo and in vitro Plasmodium falciparum resistance to quinine in a nonimmune traveler who returned to France from Senegal in 2007 with severe imported malaria. Clinical quinine failure was associated with a 50% inhibitory concentration of 829 nmol/L. Increased vigilance is required during treatment follow-up.

Apoptotic pulsed dendritic cells induce a protective immune response against Toxoplasma gondii.

Infection with the intracellular protozoan parasite Toxoplasma gondii may cause severe sequelae in foetuses and life-threatening neuropathy in immunocompromised patients. We recently reported that vaccination with T. gondii-pulsed dendritic cells induces protective humoral and cellular immune responses against this intracellular pathogen in CBA/J mice.

Antimalarial drug susceptibility and point mutations associated with drug resistance in 248 Plasmodium falciparum isolates imported from Comoros to Marseille, France in 2004 2006.

A total of 248 Plasmodium falciparum isolates were sampled in travelers with malaria who came to Marseille, France from Comoros to investigate in vitro activities of antimalarial drugs and molecular markers of drug resistance. Of the 248 isolates, 126 were maintained in culture. Of these, 53% were resistant to chloroquine, and 3% had reduced susceptibility to quinine, mefloquine, and atovaquone; 1% had reduced susceptibility to halofantrine and dihydroartemisinin; 7% had reduced susceptibility to monodesethylamodiaquine; 37% had reduced susceptibility to cycloguanil; and none had reduced susceptibility to lumefantrine.

Evoked potentials and cerebral blood flow in solvent induced psycho-organic syndrome.

Epidemiological studies have provided evidence that neuropsychiatric symptoms are induced by long term exposure to solvents; individual diagnosis with psychometric tests, however, is not always possible (for example, when the patient has linguistic difficulties). Therefore evoked potentials and cerebral blood flow were studied in 50 patients occupationally exposed to solvents who were referred to our department and for whom a solvent induced psycho-organic syndrome was suspected. Degree of exposure was evaluated by its duration (mean 13.

Comparison of performance of healthy volunteers given prazepam alone or combined with ethanol. Relation to drug plasma concentrations.

The interaction between a single dose of 20 mg of prazepam and 0.5 g/kg body weight ethanol was investigated in 12 healthy male volunteers by nine objective performance tests, eight visual analogue self-rating scales and measurement of prazepam and ethanol plasma concentrations, using a double-blind three-way crossover design. The volunteers were each given three treatments (prazepam+ethanol, placebo+ethanol and prazepam alone), separated by a 2-week interval.