55 research outputs found
Arbuscular mycorrhizal fungi species associated with rhizosphere of Phoenix dactylifera L. in Morocco
A survey of arbuscular mycorrhizal fungi (AMF) diversity and date palm (Phoenix dactylifera L.) tree root colonization in arid areas was undertaken in ten palm groves located along the Ziz valley (Tafilalet, south-west Morocco). The frequency and the mean intensity of root colonization reached 72 and 43% respectively and the spore population varied from 238 to 1840 spores/10g of soil. The AMF colonization levels of field date palm roots were found to be negatively correlated with soil phosphorus content (r2 =-0,64). A total of ten AMF species were trapped from the 10 studied sites with a population of 4 to 7 species per sites. The isolated species included: Glomus mosseae, G. fasciculatum, G. constrictum, G. aggregatum, G. macrocarpum, 3 undescribed species of Acaulospora and two of Scutellospora genera. The latter two species were trapped only at the second trapping cycle.Keywords: AMF, diversity, Morocco, palm grove, Phoenix dactylifer,
Mycorrhizal fungi as natural bio-fertilizers: How to produce and use
This technical handbook provides an easy to follow guide describing the process on how to produce home-made mycorrhizal inoculants using different types of propagation units and how inoculants can be applied as bio-fertilizers in the nursery and during field transplantation for improving the growth and stress tolerance of crop plants
Antimicrobial susceptibility of urinary Klebsiella pneumoniae and the emergence of carbapenem-resistant strains: A retrospective study from a university hospital in Morocco, North Africa
Introduction: Urinary tract infections (UTIs) due to multi-drug resistant Klebsiella pneumoniae (K. pneumoniae) strains are increasing worldwide and have become a major public health problem.Objectives: The aim of this study was to determine the current and local antimicrobial susceptibility of urinary K. pneumoniae isolated from inpatients and outpatients in a university hospital.Subjects and methods: A retrospective study was carried out, covering a 3-year period from January 2010 to December 2012. It focused on all the K. pneumoniae strains isolated from the urine samples analyzed at the microbiology laboratory of the Avicenne Teaching Hospital, Marrakech, Morocco, North Africa.Results: K. pneumoniae represented 22% of all the urinary Enterobacteriaceae isolated during the study period. The bacterial resistance rates of K. pneumoniae isolates not producing extended spectrum - lactamase (ESBL) were as follows: trimethoprim sulfamethoxazole “T/S” (61%), amoxicillin/clavulanic acid (51%), ciprofloxacin (32%), gentamicin (21%) and amikacin (11%). ESBL producing K. pneumoniae strains accounted for 25.5% of all the urinary K. pneumoniae isolates and showed resistance to T/S (89%), gentamicin (89%), ciprofloxacin (84%) and amikacin (50%). For the first time in our region, we also noted the emergence of carbapenem-resistant strains that accounted for 7% of all the urinary ESBL-producing K. pneumoniae isolates.Keywords: Urinary; Klebsiella pneumoniae; Antimicrobial resistanc
Molecular characterization of extended spectrum β-lactamase-producing Escherichia coli in a university hospital in Morocco, North Africa
Introduction: β-Lactams are among the most widely prescribed antibiotics in human medicine. However, because of their massive and usually inappropriate use, resistance to these drugs has increased markedly, especially due to extended-spectrum β-lactamase (ESBL) production.Objectives: The aims of this study were to determine the prevalence of urinary Escherichia coli strains isolated from urine samples taken from patients diagnosed with urinary tract infections (UTIs), to evaluate their current antimicrobial susceptibility pattern and to look for blaSHV, blaTEM and blaCTX-M genes in these multi-drug resistant isolates.Subject and methods: A retrospective survey was made over 3 years from 2010 to 2012. It included all uropathogenic E. coli strains isolated from urine samples taken from consulting and hospitalized patients in the Avicenne Teaching Hospital in Marrakech, Morocco.Results: E. coli was the etiologic agent in 63% of reported UTIs due to Enterobacteriacae. In all, the prevalence of ESBL-producing E. coli reached 6% of all urinary Enterobacteriaceae isolates in 2012. The bacterial resistance rates of ESBL-producing E. coli isolates were as follows: amoxicillin/clavulanic acid (100%), trimethoprim/sulfamethoxazole (76%), gentamicin (66%), ciprofloxacin (82%) and amikacin (56%). None of these strains was resistant to carbapenems. The ESBL production patterns observed included single production of CTX-M (70%), SHV (12%) and TEM (0%). Some ESBL-producing E. coli isolates produced combinations of 2 ESBLs belonging to different groups: CTX-M+SHV (12%) and CTX-M+TEM (6%).Conclusion: The results of this work report, for the first time in the Marrakech region, the ESBL production pattern with CTX-M being most common among the ESBL-producing urinary E. coli. Moreover, a major finding is the production of multiple ESBL types by some urinary E. coli isolates.KEYWORDS Urinary; Extended-spectrum β-lactamase (ESBL); E. coli; Antibiotics; Resistanc
Characterization of plant growth-promoting mechanisms of rhizobacteria from the rhizosphere of date palms in tafilalet oases
Tafilalet is the largest oases in Morocco, but it is threatened by climatic and environmental stress like drought, soil degradation as well as plant diseases, in particular Fusarium wilt of date palm caused by Fusarium oxysporum f.sp albedinis (Foa). Soils are poor in terms of organic matter, nutrient concentrations and biological activity resulting in a dramatic decrease in date palm growth. Improving date palm productivity is regularly achieved by the excessive application of chemical fertilizers, which are harmful for human health and environment. In this work, we aimed at screening the plant growth-promoting rhizobacteria (PGPRs) and at the same time acting as biocontrol agents against Foa. Rhizobacteria associated with date palm and spontaneous plants in Tafilalet oases have been isolated and functionally characterized. Several plant growth promoting and biocontrol traits were investigated, including nutrients solubilization, and the production secondary metabolites and enzymes. Results showed that 97 % of strains was effective in N-fixation, 36 % in ammonia production, 90 % in P-solubilization. The Siderophores and Indol 3-acetic acid production were observed at 30 and 32 strains respectively. Besides, 78 % of strains had an inhibitory effect against Foa, in which 42 % completely inhibited the mycelia growth on PDA medium. Several strains produced cellulase, protease, amylase, chitinase and other secondary metabolites like hydrogen cyanide. Based on these results, consortia of efficient PGPRs could be selected and used as efficient microorganisms for future greenhouse and field experiments
Effect of PGPR and mixed cropping on mycorrhizal status, soil fertility, and date palm productivity under organic farming system
A field study was carried out for two years at an organic farm under arid climate in Morocco to investigate the effect of an integrated biofertilization approach on Arbuscular Mycorrhizal Fungal (AMF) abundance and infectivity, soil fertility, yield, and fruit quality of date palm. The biofertilization approach included three management practices namely application of compost, inoculation with a consortium of native PGPR strains originally isolated from date palms of Drâa-Tafilalet region (Pseudomonas koreensis, Serratia nematodiphila, S. marcescens, and Klebsiella sp.) and using mixed-cropping with sorghum. Accordingly, four treatments were established in this study: 1) mixed-cropping with sorghum, 2) PGPR inoculation, 3) sorghum + PGPR, and 4) control (without sorghum or PGPR). All treatments received compost as organic amendment. Results revealed that mixed-cropping with sorghum significantly increased AMF colonization intensity and spore density by more than 50% and 29%, respectively. Sorghum association also resulted in a significant increase in organic matter concentrations of up to 2.95% against 2.45% in monocropping soils. The integrated biofertilization approach resulted in the highest yield with an increase rate of 10.6% and 12.1% in the first and the second year, respectively compared to date palms receiving compost alone. Similarly, the mineral composition and quality characteristics of date fruits were significantly improved. The enhancement of soil fertility and date palm productivity under harsh environmental conditions represents a first step towards the adoption of sustainable practices in the region and in similar areas
Unique arbuscular mycorrhizal fungal communities uncovered in date palm plantations and surrounding desert habitats of Southern Arabia
The main objective of this study was to shed light on the previously unknown arbuscular mycorrhizal fungal (AMF) communities in Southern Arabia. We explored AMF communities in two date palm (Phoenix dactylifera) plantations and the natural vegetation of their surrounding arid habitats. The plantations were managed traditionally in an oasis and according to conventional guidelines at an experimental station. Based on spore morphotyping, the AMF communities under the date palms appeared to be quite diverse at both plantations and more similar to each other than to the communities under the ruderal plant, Polygala erioptera, growing at the experimental station on the dry strip between the palm trees, and to the communities uncovered under the native vegetation (Zygophyllum hamiense, Salvadora persica, Prosopis cineraria, inter-plant area) of adjacent undisturbed arid habitat. AMF spore abundance and species richness were higher under date palms than under the ruderal and native plants. Sampling in a remote sand dune area under Heliotropium kotschyi yielded only two AMF morphospecies and only after trap culturing. Overall, 25 AMF morphospecies were detected encompassing all study habitats. Eighteen belonged to the genus Glomus including four undescribed species. Glomus sinuosum, a species typically found in undisturbed habitats, was the most frequently occurring morphospecies under the date palms. Using molecular tools, it was also found as a phylogenetic taxon associated with date palm roots. These roots were associated with nine phylogenetic taxa, among them eight from Glomus group A, but the majority could not be assigned to known morphospecies or to environmental sequences in public databases. Some phylogenetic taxa seemed to be site specific. Despite the use of group-specific primers and efficient trapping systems with a bait plant consortium, surprisingly, two of the globally most frequently found species, Glomus intraradices and Glomus mosseae, were not detected neither as phylogenetic taxa in the date palm roots nor as spores under the date palms, the intermediate ruderal plant, or the surrounding natural vegetation. The results highlight the uniqueness of AMF communities inhabiting these diverse habitats exposed to the harsh climatic conditions of Southern Arabia
Place des biomarqueurs sériques et urinaires dans la néphropathie lupique
Le lupus érythémateux systémique est une maladie auto-immune non spécifique d’organe, touchant préférentiellement les femmes jeunes.Il est caractérisé par une importante production d’auto-anticorps, en particulier les auto-anticorps anti-nucléaires. Les manifestations cliniques sont variables, avec des atteintes cutanées et articulaires fréquentes, et une complication majeure, l’atteinte rénale.L’atteinte rénale ou néphropathie lupique est une manifestation grave dans le lupus érythémateux systémique, intéressant 30 à 60% des patients.De ce fait, un pronostic précoce de l’atteinte rénale permettrait d’appliquer un traitement préventif.La ponction biopsie rénale est largement utilisée pour diagnostiquer la néphropathie lupique, mais elle reste un examen invasif pour le patient avec des risques de complications. Certains biomarqueurs dosés dans le sang et les urines sont déjà utilisés en routine pour suivre l'atteinte rénale du lupus (anti-ADN natif, complément, protéinurie…). Cependant, ces marqueurs manquent de spécificité vis-à -vis d’une atteinte rénale lupique. Il est donc important de rechercher d’autres marqueurs, qui permettraient de diagnostiquer et de surveiller l’atteinte rénale du lupus. Dans ce travail de thèse, nous avons mis en évidence les principaux biomarqueurs potentiels proposés dans la littérature. En effet, la recherche de biomarqueurs dans la néphropathie lupique est un enjeu important pour une meilleure prise en charge des patients
Usage de plateformes d’enseignement à distance dans l’enseignement supérieur marocain : avantages pédagogiques et difficultés d’appropriation
The purpose of this study is how students, who are discovering for the first time ICT training in a Moroccan university, they appropriated the tools of a platform E-Learning. This study showed that students who used the platform are more frequently those who had difficulty in being present on campus. The platform enabled them to overcome the distance that separates students from areas of training institutions. From the perspective of gender, females were more likely toconnect and show greater motivation to use the appropriate tools of the platform to learn. But students have focused on the lack of tutorial system in the appropriation of different tools in their projects. The results are significant and tell us the type of ownership that are the students with a platform.However, they can’t give us a fairly accurate vision without further research taking into account other variables and actors
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