Insight into the bacterial communities of the subterranean aphid Anoecia corni.

Many insect species are associated with bacterial partners that can significantly influence their evolutionary ecology. Compared to other insect groups, aphids harbor a bacterial microbiota that has the reputation of being poorly diversified, generally limited to the presence of the obligate nutritional symbiont Buchnera aphidicola and some facultative symbionts. In this study, we analyzed the bacterial diversity associated with the dogwood-grass aphid Anoecia corni, an aphid species that spends much of its life cycle in a subterranean environment. Little is known about the bacterial diversity associated with aphids displaying such a lifestyle, and one hypothesis is that close contact with the vast microbial community of the rhizosphere could promote the acquisition of a richer bacterial diversity compared to other aphid species. Using 16S rRNA amplicon Illumina sequencing on specimens collected on wheat roots in Morocco, we identified 10 bacterial operational taxonomic units (OTUs) corresponding to five bacterial genera. In addition to the obligate symbiont Buchnera, we identified the facultative symbionts Serratia symbiotica and Wolbachia in certain aphid colonies. The detection of Wolbachia is unexpected as it is considered rare in aphids. Moreover, its biological significance remains unknown in these insects. Besides, we also detected Arsenophonus and Dactylopiibacterium carminicum. These results suggest that, despite its subterranean lifestyle, A. corni shelter a bacterial diversity mainly limited to bacterial endosymbionts.

Circulation of the Cultivable Symbiont Serratia symbiotica in Aphids Is Mediated by Plants.

Symbiosis is a common phenomenon in nature that substantially affects organismal ecology and evolution. Fundamental questions regarding how mutualistic associations arise and evolve in nature remain, however, poorly studied. The aphid-Serratia symbiotica bacterium interaction represents a valuable model to study mechanisms shaping these symbiotic interspecific interactions. S. symbiotica strains capable of living independently of aphid hosts have recently been isolated. These strains probably resulted from horizontal transfers and could be an evolutionary link to an intra-organismal symbiosis. In this context, we used the tripartite interaction between the aphid Aphis fabae, a cultivable S. symbiotica bacterium, and the host plant Vicia faba to evaluate the bacterium ability to circulate in this system, exploring its environmental acquisition by aphids and horizontal transmission between aphids via the host plant. Using molecular analyses and fluorescence techniques, we showed that the cultivable S. symbiotica can enter the plants and induce new bacterial infections in aphids feeding on these new infected plants. Remarkably, we also found that the bacterium can have positive effects on the host plant, mainly at the root level. Furthermore, our results demonstrated that cultivable S. symbiotica can be horizontally transferred from infected to uninfected aphids sharing the same plant, providing first direct evidence that plants can mediate horizontal transmission of certain strains of this symbiont species. These findings highlight the importance of considering symbiotic associations in complex systems where microorganisms can circulate between different compartments. Our study can thus have major implications for understanding the multifaceted interactions between microbes, insects and plants.

New Insights into the Nature of Symbiotic Associations in Aphids: Infection Process, Biological Effects, and Transmission Mode of Cultivable Serratia symbiotica Bacteria.

Symbiotic microorganisms are widespread in nature and can play a major role in the ecology and evolution of animals. The aphid-Serratia symbiotica bacterium interaction provides a valuable model to study the mechanisms behind these symbiotic associations. The recent discovery of cultivable S. symbiotica strains with a free-living lifestyle allowed us to simulate their environmental acquisition by aphids to examine the mechanisms involved in this infection pathway. Here, after oral ingestion, we analyzed the infection dynamics of cultivable S. symbiotica during the host's lifetime using quantitative PCR and fluorescence techniques and determined the immediate fitness consequences of these bacteria on their new host. We further examined the transmission behavior and phylogenetic position of cultivable strains. Our study revealed that cultivable S. symbiotica bacteria are predisposed to establish a symbiotic association with a new aphid host, settling in its gut. We show that cultivable S. symbiotica bacteria colonize the entire aphid digestive tract following infection, after which the bacteria multiply exponentially during aphid development. Our results further reveal that gut colonization by the bacteria induces a fitness cost to their hosts. Nevertheless, it appeared that the bacteria also offer an immediate protection against parasitoids. Interestingly, cultivable S. symbiotica strains seem to be extracellularly transmitted, possibly through the honeydew, while S. symbiotica is generally considered a maternally transmitted bacterium living within the aphid body cavity and bringing some benefits to its hosts, despite its costs. These findings provide new insights into the nature of symbiosis in aphids and the mechanisms underpinning these interactions.IMPORTANCES. symbiotica is one of the most common symbionts among aphid populations and includes a wide variety of strains whose degree of interdependence on the host may vary considerably. S. symbiotica strains with a free-living capacity have recently been isolated from aphids. By using these strains, we established artificial associations by simulating new bacterial acquisitions involved in aphid gut infections to decipher their infection processes and biological effects on their new hosts. Our results showed the early stages involved in this route of infection. So far, S. symbiotica has been considered a maternally transmitted aphid endosymbiont. Nevertheless, we show that our cultivable S. symbiotica strains occupy and replicate in the aphid gut and seem to be transmitted over generations through an environmental transmission mechanism. Moreover, cultivable S. symbiotica bacteria are both parasites and mutualists given the context, as are many aphid endosymbionts. Our findings give new perception of the associations involved in bacterial mutualism in aphids.

Evidence for Gut-Associated Serratia symbiotica in Wild Aphids and Ants Provides New Perspectives on the Evolution of Bacterial Mutualism in Insects.

Many insects engage in symbiotic associations with diverse assemblages of bacterial symbionts that can deeply impact on their ecology and evolution. The intraspecific variation of symbionts remains poorly assessed while phenotypic effects and transmission behaviors, which are key processes for the persistence and evolution of symbioses, may differ widely depending on the symbiont strains. Serratia symbiotica is one of the most frequent symbiont species in aphids and a valuable model to assess this intraspecific variation since it includes both facultative and obligate symbiotic strains. Despite evidence that some facultative S. symbiotica strains exhibit a free-living capacity, the presence of these strains in wild aphid populations, as well as in insects with which they maintain regular contact, has never been demonstrated. Here, we examined the prevalence, diversity, and tissue tropism of S. symbiotica in wild aphids and associated ants. We found a high occurrence of S. symbiotica infection in ant populations, especially when having tended infected aphid colonies. We also found that the S. symbiotica diversity includes strains found located within the gut of aphids and ants. In the latter, this tissue tropism was found restricted to the proventriculus. Altogether, these findings highlight the extraordinary diversity and versatility of an insect symbiont and suggest the existence of novel routes for symbiont acquisition in insects.

Variation in lipid synthesis, but genetic homogeneity, among Leptopilina parasitic wasp populations.

Lipid synthesis can have a major effect on survival and reproduction, yet most insect parasitoids fail to synthesize lipids. For parasitic wasps in the genus Leptopilina, however, studies have suggested that there is intraspecific variation in the ability for lipid synthesis. These studies were performed on only few populations, and a large-scale investigation of both lipogenic ability and population genetic structure is now needed. Here, we first examined lipogenic ability of nine Leptopilina heterotoma populations collected in 2013 and found that five of nine populations synthesized lipids. The 2013 populations could not be used to determine genetic structure; hence, we obtained another 20 populations in 2016 that were tested for lipogenic ability. Thirteen of 20 populations (all Leptopilina heterotoma) were then used to determine the level of genetic differentiation (i.e., haplotype and nucleotide diversity) by sequencing neutral mitochondrial (COI) and nuclear (ITS2) markers. None of the 2016 populations synthesized lipids, and no genetic differentiation was found. Our results did reveal a nearly twofold increase in mean wasp lipid content at emergence in populations obtained in 2016 compared to 2013. We propose that our results can be explained by plasticity in lipid synthesis, where lipogenic ability is determined by environmental factors, such as developmental temperature and/or the amount of lipids carried over from the host.

Reduced inotropic reserve is predictive of further degradation in left ventricular ejection fraction in patients with Duchenne muscular dystrophy.

AIMS: Duchenne muscular dystrophy (DMD), an inherited X-linked muscular disease, is associated with dilated cardiomyopathy that is responsible for death in 40% of patients. Our objective was to determine whether inotropic reserve is predictive of LV trend over time. METHODS AND RESULTS: A total of 69 DMD patients (age 12.2±2.3 years) were investigated. At baseline, LVEF and the presence of inotropic reserve (defined as an increase in LVEF >10% during dobutamine infusion) were investigated using radionuclide ventriculography. During follow-up (FU), LVEF was remeasured after a mean 29±19 months delay. In the whole population, mean LVEF was 58±8% at baseline and declined to 54±11% during FU (P =0.004). At baseline, 21 patients (30.4%) had LVEF <55% and 38 had no LV inotropic reserve. LVEF declined in the 38 patients (55.1%) without LV inotropic reserve (58±8% to 52±10%, P =0.001), and not in the other patients (58±8% to 57±11%, P =0.516) (P =0.042 for trends in LVEF between groups after adjustment for age, FU duration, and baseline LVEF). Fewer patients with vs. without inotropropic reserve at baseline show a depressed LVEF <55% during follow-up(35.5% vs. 63.2%, respectively, P =0.030). Similar findings were observed in the subgroups of patients with LVEF >45% or 55% at baseline. CONCLUSION: Inotropic reserve assessment allows the distinction of DMD patients who will vs. those who will not show a deterioration in LVEF, thus offering a sensitive approach for delineating the presence and progression of cardiovascular disease in these patients.

Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

Upper limb strength and function changes during a one-year follow-up in non-ambulant patients with Duchenne Muscular Dystrophy: an observational multicenter trial.

INTRODUCTION: Upper limb evaluation of patients with Duchenne Muscular Dystrophy is crucially important to evaluations of efficacy of new treatments in non-ambulant patients. In patients who have lost ambulation, there are few validated and informative outcome measures. In addition, longitudinal data demonstrating sensitivity to clinical evolution of outcome measures over short-term periods are lacking. PATIENTS AND METHODS: We report here the results of a one-year multicenter study using specifically designed tools to assess grip, pinch strength, and hand function in wheelchair-bound patients. Our study assessed 53 non-ambulant patients with Duchenne muscular dystrophy aged 17.1 ± 4.8 years (range: 9 - 28.1 years). The average Brooke functional score of these patients was 4.6 ± 1.1. The average forced vital capacity was 44.5% predicted and 19 patients used non-invasive ventilation. Patients were assessed at baseline, 6 months, and one year using the Motor Function Measure and innovative devices (namely the MyoSet composed of MyoGrip, MyoPinch, and MoviPlate). RESULTS: Our study confirmed preliminary data previously reported regarding feasibility of use and of reliability of the MyoSet and the correlation at baseline between distal strength and clinical outcomes such as FVC, Brooke score, age, and duration since loss of ambulation. A significant correlation was observed between the distal upper limb strength and clinical variables. The sensitive dynamometers (MyoGrip and MyoPinch) and MoviPlate captured a 12-month change in non-ambulant Duchenne muscular dystrophy patients of all ages. TRIAL REGISTRATION: ClinicalTrials.gov NCT00993161 NCT00993161.

[Foot deformities in children]. / Podologie de l'enfant en pratique quotidienne.

The child comes in specialist consultation very often. Only after a good examination, we can quiet parents. Flatfoot, cavus foot toewalking can be alone symptom for a general disease. Then it is important to think to it and to do some others checkup. It may be necessary to have some opinion from different paediatric specialists like orthopaedic, neuroiogic, myologic. The follow-up of child allows to find a good evolution or some disease.

[Conservative treatment of clubfoot: the Functional Method and its long-term follow-up]. / Carpik ayagin konservatif tedavisi: Fonksiyonel Yöntem ve uzun dönemli izlem.

Despite the presence of a considerable number of papers published in the international literature, talipes equinovarus keeps its secrets. Conservative methods of treatment are currently accepted as advantageous over surgery. Prediction of the future of a clubfoot after treatment is not possible, for this reason, a long-term follow-up is needful. A true Functional Method based solely on gentle manipulations has been used for more than thirty years. Its aim is to correct the deformity and to allow the child to walk without delay. The principle of this method is to distract joint contractures prior to progressive correction of the deformity. No selection is made regarding the severity of the deformity and its etiology. Family plays an important role in performing routine manipulations at home. Concerning this Functional Method, three main series have been published by our team, with excellent-good results accounting for up to 77%. We believe that our Functional Method of conservative treatment of clubfoot is an appropriate way for correction of the deformity and its stabilization.

Functional treatment of clubfoot: a new series of 350 idiopathic clubfeet with long-term follow-up.

A new series of 350 previously unreported cases of clubfoot treated by the functional method are reported. One hundred and eighteen clubfeet were unilateral and 116 were bilateral. The follow-up ranged from 11 to 18 years, with an average of 14 years. The improvements in the technique of physical therapy increased the rate of good results up to 77% compared with our previously published series. In an effort to objectively compare these results with other series, the authors assessed all clubfeet using the "at birth classification" published in 1995. Outcome evaluation was performed when the patients were 6 years old, and final evaluation at the end of growth of the foot. This is the first major series to be assessed according to such objective criteria, as much before the inception of treatment as at the end of growth. The results of this new series have been compared with those obtained in our former series.