Transcriptomes of the interaction between Fusarium verticillioides and a Streptomyces strain reveal the fungal defense strategy under the pressure of a potential biocontrol agent

The actinobacteria Streptomyces sp. AV05 appears to be a potential biocontrol agent (BCA) against mycotoxigenic fungi. It was found to significantly inhibit F. verticillioides growth and mycotoxin production during their co-cultivation. F. verticillioides growth was durably affected while the decrease of the toxin production levels was reversible, suggesting different BCA actions. The study of both transcriptomes brought useful information on the microbial interaction. RNA-seq data indicated that the dual interaction modified genetic expression of both microorganisms as 18.5 % of the genes were differentially expressed for the fungus against 3.8 % for the actinobacteria. Fungal differentially expressed genes (DEGs) were equally up and down regulated while bacterial ones were mainly upregulated. We especially focused the analysis of DEGs on fungal defense reaction to bacterial attack. For example, if this potential BCA implements a strategy of antibiosis with the over expression of 'siderophore-interacting protein' linked to the production of bacteriocins, the fungus in a state of stress is able to adapt its metabolism by up-regulation of amidase. It could correspond to the induction of resistance gene clusters and suggest a detoxification process. Moreover fumonisins-related pathway appears underexpressed in the presence of Streptomyces that explain the reduction of fumonisin accumulation observed.

[Neonatal palliative care at home: Contribution of the regional pediatric palliative care team]

The "patients' rights and end-of-life care" act, known as the Leonetti law, has allowed implementation of palliative care in neonatology as an alternative to unreasonable therapeutic interventions. A palliative care project can be offered to newborns suffering from intractable diseases. It must be focused on the newborn's quality of life and comfort and on family support. Palliative care for newborns can be provided in the delivery room, in the neonatal unit, and also at home. Going home is possible but requires medical support. Here we describe the potential benefits of the intervention of a regional team of pediatric palliative care for newborns, both in the hospital and at home. Two clinical situations of palliative care at home started in the neonatal period and the neonatal unit are presented. They are completed by a retrospective national survey focusing on the type of support to newborns in palliative care in 2014, which was conducted in 22 French regional pediatric palliative care teams. It shows that 26 newborns benefited from this support at home in 2014. Sixteen infants were born after a pregnancy with a palliative care birth plan and ten entered palliative care after a decision to limit life-sustaining treatments. Twelve of them returned home before the 20th day of life. Sixteen infants died, six of them at home. The regional pediatric palliative care team first receives in-hospital interventions: providing support for ethical reflection in the development of the infant's life project, meeting with the child and its family, helping organize the care pathway to return home. When the child is at home, the regional pediatric palliative care team can support the caregiver involved, provide home visits to continue the clinical monitoring of the infant, and accompany the family. The follow-up of the bereavement and the analysis of the practices with caregivers are also part of its tasks.

[Problems for assessing the newborns' pain in palliative care]

Several pain scales are available for newborns, but the assessment of pain in these preverbal beings, who are in continuing neurological development, remains challenging for healthcare teams. Although neonates at the end of life are particularly vulnerable to pain and discomfort, no assessment tool has been validated in this specific population. The difficulties for assessing pain in this context are copies of those potentially encountered in other situations. Questions arise about the limits of the available scales, about possible alterations of responses to a noxious stimulus in particular contexts (extreme immaturity, brain lesions), about possibly painful situations in palliative care, about the nature of scales to choose. Data show a perception of pain at a cortical level by extremely immature infants and the ability for neonates with significant neurological injury to express pain behaviours. For some potentially painful situations (dyspnoea, gasps, hunger) neonatal data are virtually nonexistent. Fundamental scientific data and clinical data from adults and children can give some answers. One will choose scales for which the staff is trained, easily usable (preference for behavioural scales), validated for all gestational ages, reliable in the event of neurological impairment or sedation. An assessment of prolonged pain (EDIN scale or COMFORT Behaviour scale) combined with measures of acute pain (DAN or NFCS scales) is recommended. These scales should be better validated for populations of newborns and situations that are specific to palliative care. A better assessment of the parental perception and of their distress about the discomfort or pain of their child is warranted.

Influence of barley malting operating parameters on T-2 and HT-2 toxinogenesis of Fusarium langsethiae, a worrying contaminant of malting barley in Europe

The fungus Fusarium langsethiae, exclusively described in Europe at present, seems to have taken the place of other Fusarium species in barley fields over the last 5 years. It has proved to be a highly toxic type-A trichothecene producer (T-2 and HT-2 toxins). The aim of this work was to study the ecotoxinogenesis of this fungus the better to identify and manage the health risk it may pose during the beer manufacturing process. The influence of temperature and water activity on its growth rate and production of toxins are particularly assessed from a macroscopic point of view. Different cultures were grown on sterilized rehydrated barley with a water activity between 0.630 and 0.997 and a temperature ranging from 5 to 35 degrees C. Biomass specific to F. langsethiae and T-2 and HT-2 toxins were quantified by real-time polymerase chain reaction and liquid chromatography-mass spectrometry, respectively. It appears that the optimal temperature and water activity for F. langsethiae toxinogenesis are 28 degrees C and 0.997. This fungus was able to produce 2.22 g kg(-1) of these toxins in 16 days on barley in optimal production conditions. The malting process seems to be a critical step because, in its temperature range, specific production was six times higher than under optimal temperatures for fungus growth. In the short-term, this work will help redefine the process conditions for malting. In the medium-term, the results will contribute to the development of a molecular tool to diagnose the presence of this contaminant and the detection of the toxins in barley, from fields to the end product.

Topical Bioavailability of Triamcinolone Acetonide: Effect of Occlusion

BACKGROUND/AIMS

Occlusion by covering the skin with an impermeable wrap enhances skin hydration, affects drug absorption and can induce the formation of a drug reservoir within the stratum corneum. This is desired in local therapy with topical corticosteroids. The aim of the study was to investigate the effect of occlusion before (experiment 1) and after (experiment 2) application on the penetration of triamcinolone acetonide (TACA) into the stratum corneum.

METHODS

The experiments were conducted on the forearms of 10 healthy volunteers. In experiment 1, 100 microg/cm(2) TACA in acetone were applied on 3 sites per arm, one arm having been pre-occluded for 16 h. In experiment 2, the same dose was applied on 2 sites per arm, and one arm was occluded after application until skin sampling. Stratum corneum samples were removed by tape stripping at 0.5, 4 and 24 h (experiment 1) and 4 and 24 h (experiment 2) after application. Corneocytes and TACA were quantified by ultraviolet-visible spectroscopy and HPLC, respectively. The total TACA amount penetrated into the stratum corneum was evaluated by multifactor ANOVA.

RESULTS

TACA penetration into the stratum corneum with and without pre-occlusion (experiment 1) showed no significant difference and decreased with time. Occlusion after application (experiment 2) produced a marked TACA accumulation within the stratum corneum, which persisted for 24 h.

CONCLUSION

Pre-occlusion showed no effect on the topical bioavailability of TACA in the stratum corneum. In contrast, post-occlusion enhanced the TACA penetration by a factor of 2, favouring the development of a drug reservoir.

Tropenr�ckkehrerin mit papulovesikul�rem Exanthem und grippe�hnlichen Beschwerden

African tick bite fever (ATBF) is an infectious disease commonly observed in travelers to sub-Saharan Africa. Because the presentation of the disease is often not specific, ATBF is frequently not diagnosed or confused with Mediterranean spotted fever. We present the case of a 63-year-old woman with typical history and symptoms. The diagnosis of ATBF was serologically confirmed by immunofluoroscence. ATBF is an important differential diagnosis of fever in patients returning from sub-Saharan Africa.

Substrate recognition by the AAA+ chaperone ClpB

The AAA+ protein ClpB cooperates with the DnaK chaperone system to solubilize and refold proteins from an aggregated state. The substrate-binding site of ClpB and the mechanism of ClpB-dependent protein disaggregation are largely unknown. Here we identified a substrate-binding site of ClpB that is located at the central pore of the first AAA domain. The conserved Tyr251 residue that lines the central pore contributes to substrate binding and its crucial role was confirmed by mutational analysis and direct crosslinking to substrates. Because the positioning of an aromatic residue at the central pore is conserved in many AAA+ proteins, a central substrate-binding site involving this residue may be a common feature of this protein family. The location of the identified binding site also suggests a possible translocation mechanism as an integral part of the ClpB-dependent disaggregation reaction.

Poly-L-lysine enhances the protein disaggregation activity of ClpB

The Hsp100 protein ClpB is a member of the AAA+ protein family that mediates the solubilization of aggregated proteins in cooperation with the DnaK chaperone system. Unstructured polypeptides such as casein or poly-L-lysine have been shown to stimulate the ATPase activity of ClpB and thus may both act as substrates. Here we compared the effects of alpha-casein and poly-L-lysine on the ATPase and chaperone activities of ClpB. alpha-Casein stimulated ATP hydrolysis by both AAA domains of ClpB and inhibited the ClpB-dependent solubilization of aggregated proteins if present in excess. In contrast, poly-L-lysine stimulated exclusively the ATPase activity of the second AAA domain and increased the disaggregation activity of ClpB. Thus poly-L-lysine does not act as substrate, but rather represents an effector molecule, which enhances the chaperone activity of ClpB.

Roles of individual domains and conserved motifs of the AAA+ chaperone ClpB in oligomerization, ATP hydrolysis, and chaperone activity

ClpB of Escherichia coli is an ATP-dependent ring-forming chaperone that mediates the resolubilization of aggregated proteins in cooperation with the DnaK chaperone system. ClpB belongs to the Hsp100/Clp subfamily of AAA+ proteins and is composed of an N-terminal domain and two AAA-domains that are separated by a "linker" region. Here we present a detailed structure-function analysis of ClpB, dissecting the individual roles of ClpB domains and conserved motifs in oligomerization, ATP hydrolysis, and chaperone activity. Our results show that ClpB oligomerization is strictly dependent on the presence of the C-terminal domain of the second AAA-domain, while ATP binding to the first AAA-domains stabilized the ClpB oligomer. Analysis of mutants of conserved residues in Walker A and B and sensor 2 motifs revealed that both AAA-domains contribute to the basal ATPase activity of ClpB and communicate in a complex manner. Chaperone activity strictly depends on ClpB oligomerization and the presence of a residual ATPase activity. The N-domain is dispensable for oligomerization and for the disaggregating activity in vitro and in vivo. In contrast the presence of the linker region, although not involved in oligomerization, is essential for ClpB chaperone activity.

[Exanthema with emphasis of body flexure points 10 hours after administration of amoxicillin, "baboon syndrome"]

Der 57-jährige bis anhin gesunde Patient entwickelte zehn Stunden nach Einnahme von Amoxicillin ein makulopapulöses Exanthem in der Leiste, gluteal und in der Rima ani. Die Beugeseiten der Gelenke waren diskret betroffen. Die Haut war induriert, der Patient klagte über Juckreiz. Er präsentierte das Bild eines «Baboon-Syndroms», einer Sonderform einer Medikamentenallergie, die erstmals 1984 durch Andersen so benannt wurde. Es ist im Vergleich zum morbilliformen, Aminopenicillin induzierten Exanthem eher unbekannt und kann in seiner ungewöhnlichen Lokalisation differentialdiagnostische Schwierigkeiten bereiten. Im vorliegenden Fall wurde eine weitere allergologische Abklärung durchgeführt, um die «Penicillin-Allergie» zu spezifizieren.