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Hajar Ben Moussa Jacques Pédron Nicole Hugouvieux-Cotte-Pattat Marie-Anne Barny 《Environmental microbiology》2023,25(11):2465-2480
Historically, research on Soft Rot Pectobacteriacea (SRP) has focused on economically important crops and ornamentals and knowledge of these bacteria outside the plant context remains poorly investigated. Recently, two closely related species Pectobacterium aquaticum and Pectobacterium quasiaquaticum were isolated from water and have not been isolated from any plant yet. To identify the distinctive characteristics of these two species, we performed a comparative genomic analysis of 80 genomes representing 19 Pectobacterium species and performed an evolutionary reconstruction. Both water species underwent a reduction in genome size associated with a high pseudogene content. A high gene loss was predicted at the emergence of both species. Among the 199 gene families missing from both P. aquaticum and P. quasiaquaticum genomes but present in at least 80% of other Pectobacterium genomes, COG analysis identified many genes involved in nutrient transport systems. In addition, many type II secreted proteins were also missing in both species. Phenotypic analysis revealed that both species had reduced pectinolytic activity, a biofilm formation defect, were highly motile and had reduced virulence on several plants. These genomic and phenotypic data suggest that the ecological niche of P. aquaticum and P. quasiaquaticum may differ from that of other Pectobacterium species. 相似文献
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Daniel Oyanedel Yannick Labreuche Maxime Bruto Hajar Amraoui Etienne Robino Philippe Haffner Tristan Rubio Guillaume M. Charrière Frédérique Le Roux Delphine Destoumieux-Garzón 《Environmental microbiology》2020,22(10):4264-4278
A major debate in evolutionary biology is whether virulence is maintained as an adaptive trait and/or evolves to non-virulence. In the environment, virulence traits of non-obligatory parasites are subjected to diverse selective pressures and trade-offs. Here, we focus on a population of Vibrio splendidus that displays moderate virulence for oysters. A MARTX (Multifunctional-autoprocessing repeats-in-toxin) and a type-six secretion system (T6SS) were found to be necessary for virulence toward oysters, while a region (wbe) involved in O-antigen synthesis is necessary for resistance to predation against amoebae. Gene inactivation within the wbe region had major consequences on the O-antigen structure, conferring lower immunogenicity, competitive advantage and increased virulence in oyster experimental infections. Therefore, O-antigen structures that favour resistance to environmental predators result in an increased activation of the oyster immune system and a reduced virulence in that host. These trade-offs likely contribute to maintaining O-antigen diversity in the marine environment by favouring genomic plasticity of the wbe region. The results of this study indicate an evolution of V. splendidus towards moderate virulence as a compromise between fitness in the oyster as a host, and resistance to its predators in the environment. 相似文献
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Hosseini Sayedeh Azimeh Seidi Morvarid Yaghoobi Hajar 《Molecular biology reports》2022,49(9):8485-8493
Molecular Biology Reports - MicroRNAs (miRNAs) are one of the main factors in cancer development and can alter the activity of proto-oncogenic or tumor suppressor genes. The miR-17-92 cluster,... 相似文献
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Entamoeba histolytica strain 200:NIH cultured axenically for about 15 years produced lesions and abscesses in inbred adult hamsters following intrahepatic, intraperitoneal, and intradermal inoculation. These amebae, even in much higher doses, inoculated into the ceca of adult and young hamsters failed to produce lesions or to become established there. On the other hand, 200:NIH axenic amebae passaged through hamster liver (substrain 200:NIH-L) were able to become established and to produce lesions in the ceca of very young hamsters (1- and 3-week-old), the degree of pathogenicity appearing to be inversely proportional to age of the hamster. 相似文献
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L. Schade D. Mesa A.R. Faria J.R. Santamaria C.A. Xavier D. Ribeiro F.N. Hajar V.F. Azevedo 《Letters in applied microbiology》2022,74(4):498-504
The pathogenesis of psoriasis, an immune-mediated chronic inflammatory skin disease, remains unclear. Studies have shown an association between psoriasis and intestinal inflammation; in this context, the influence of the gut microbiota on the immune response of psoriasis has become a focus of recent research. The present research evaluated the composition and diversity of the gut microbiota of 21 participants with psoriasis from a Brazilian referral dermatology service compared to 24 healthy controls. A stool sample was collected from each participant at the time of inclusion in the study, and the samples were analysed by sequencing the 16S rRNA gene. The recruitment of research participants involved matching between groups by sex, age, body mass index, comorbidities and smoking and the exclusion of several criteria that could potentially influence the gut microbiota and the interpretation of the data. There was an increase in the Dialister genus and Prevotella copri species in patients with psoriasis compared to the control group. A reduction in the Ruminococcus, Lachnospira and Blautia genera, as well as in the Akkermansia muciniphila species, was also verified in the psoriasis group compared to the control group. Furthermore, patients with psoriasis exhibited less gut microbiota diversity than controls. 相似文献
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The Tropical managed Forests Observatory: a research network addressing the future of tropical logged forests
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Plinio Sist Ervan Rutishauser Marielos Peña-Claros Alexander Shenkin Bruno Hérault Lilian Blanc Christopher Baraloto Fidèle Baya Fabrice Benedet Katia Emidio da Silva Laurent Descroix Joice Nunes Ferreira Sylvie Gourlet-Fleury Marcelino Carneiro Guedes Ismail Bin Harun Riina Jalonen Milton Kanashiro Haruni Krisnawati Mrigesh Kshatriya Philippa Lincoln Lucas Mazzei Vincent Medjibé Robert Nasi Marcus Vinicius N. d'Oliveira Luis C. de Oliveira Nicolas Picard Stephan Pietsch Michelle Pinard Hari Priyadi Francis. E. Putz Ken Rodney Vivien Rossi Anand Roopsind Ademir Roberto Ruschel Nur Hajar Zamah Shari Cintia Rodrigues de Souza Farida Herry Susanty Eleneide Doff Sotta Marisol Toledo Edson Vidal Thales A.P. West Verginia Wortel Toshihiro Yamada 《应用植被学》2015,18(1):171-174
While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories. 相似文献