31 research outputs found
Saccharothrix algeriensis NRRL B-24137: biocontrol properties, colonization and induced systemic resistance towards Botrytis cinerea on grapevine and Arabidopsis thaliana
In this thesis, the desert soil isolate, Saccharothrix algeriensis NRRL B-24137, has been evaluated for its bioactive properties towards the phytopathogenic fungus Botrytis cinerea, for its colonization of Vitis vinifera L., and Arabidopsis thaliana as well as to study the mechanisms of induced systemic resistance (ISR) towards B. cinerea. The results obtained allowed us firstly to show that Sa. algeriensis NRRL B-24137 can exhibit strong antifungal properties towards B. cinerea and that some metabolites can be responsible of this antifungal activity. Although these metabolites are still under consideration and that this study needs further works, we have demonstrated then the colonization properties of the desert soil isolate with grapevine plants. The results showed that the strain can form rhizospheric as well as endophytic subpopulations with grapevine plants (Cabernet Sauvignon cultivar graffed on 44-53 M rootstock) at early step of colonization. Then we have demonstrated that the beneficial strain could induce a systemic resistance towards B. cinerea. Although the mechanisms are not yet well understood, preliminary parts of this work demonstrated that the genes responsible of glucanase production, chitinase as well as inhibitor of polygalacturonase activity do not seems to be primed during the systemic resistance phenomenon. Finally we demonstrated that the interaction between Sa. algeriensis NRRL B-24137 and Arabidopsis thaliana plants results in a close association due also to a rhizo- and endophytic colonization of the model plant. The beneficial strain can also induce a systemic resistance in A. thaliana towards B. cinerea and analyzes of plant mutants have allowed to determine parts of the mechanisms involved in ISR as well as new mechanisms that could be trigerred by beneficial microbes
Saccharothrix algeriensis NRRL B-24137: biocontrol properties, colonization and induced systemic resistance towards Botrytis cinerea on grapevine and Arabidopsis thaliana
Au cours de cette thèse, un isolat de sol de désert, Saccharothrix algeriensis NRRL B-24137, a été évalué pour ses propriétés bioactives contre le champignon phytopathogène Botrytis cinerea, pour sa colonization sur Vitis vinifera L., et Arabidopsis thaliana ainsi qu’en vue d’étudier les méchanismes de résistance systémique induite (ISR) contre B. cinerea. Les résultats obtenus nous ont permis premièrement de montrer que Sa. algeriensis NRRL B-24137 peut présenter des activités antifongiques contre B. cinerea et que des métabolites peuvent être responsables de cette activité antifongique. Bien que ces métabolites soient encore en cours d’étude et que cette étude mérite d’être approfondie, nous avons démontré ensuite les propriétés de colonisation de l’isolat du sol du désert chez la vigne. Les résultats ont permis de montrer que la souche peut former des populations rhizosphèriques ainsi que des sous-populations endophytiques chez des plants de vigne (Cabernet Sauvignon sur porte-greffe 44-53 M) à des étapes précoces de colonisation. Puis nous avons démontré que la souche bénéfique peut induire une résistance systémique contre B. cinerea. Bien que les mécanismes impliqués ne soient pas encore compris, des parties préliminaires de ces travaux démontrent que les expressions de gènes responsables de la production de glucanase, chitinase ainsi qu’un inhibiteur de polygalacturonase ne semblent pas potentialisés pendant le phénomène de résistance systémique. Enfin nous avons démontré l’interaction entre Sa. algeriensis NRRL B-24137 et Arabidopsis thaliana qui résulte dans une association intime dûe également à colonisation rhizosphèrique et endophytique de la plante modèle. La souche bénéfique peut églement induire un phénomène de résistance systémique sur A. thaliana contre B. cinerea et les analyses de plantes mutées ont permis de determiner des parties des mécanismes impliqués dans l’ISR aini que des nouveaux mécanismes impliqués qui peuvent être induits par des microbes bénéfiques. ABSTRACT : In this thesis, the desert soil isolate, Saccharothrix algeriensis NRRL B-24137, has been evaluated for its bioactive properties towards the phytopathogenic fungus Botrytis cinerea, for its colonization of Vitis vinifera L., and Arabidopsis thaliana as well as to study the mechanisms of induced systemic resistance (ISR) towards B. cinerea. The results obtained allowed us firstly to show that Sa. algeriensis NRRL B-24137 can exhibit strong antifungal properties towards B. cinerea and that some metabolites can be responsible of this antifungal activity. Although these metabolites are still under consideration and that this study needs further works, we have demonstrated then the colonization properties of the desert soil isolate with grapevine plants. The results showed that the strain can form rhizospheric as well as endophytic subpopulations with grapevine plants (Cabernet Sauvignon cultivar graffed on 44-53 M rootstock) at early step of colonization. Then we have demonstrated that the beneficial strain could induce a systemic resistance towards B. cinerea. Although the mechanisms are not yet well understood, preliminary parts of this work demonstrated that the genes responsible of glucanase production, chitinase as well as inhibitor of polygalacturonase activity do not seems to be primed during the systemic resistance phenomenon. Finally we demonstrated that the interaction between Sa. algeriensis NRRL B-24137 and Arabidopsis thaliana plants results in a close association due also to a rhizo- and endophytic colonization of the model plant. The beneficial strain can also induce a systemic resistance in A. thaliana towards B. cinerea and analyzes of plant mutants have allowed to determine parts of the mechanisms involved in ISR as well as new mechanisms that could be trigerred by beneficial microbes
Polymorphism analysis in estrogen receptors alpha and beta genes and their association with infertile population in Pakistan
Studies on polymorphism of estrogen receptor (ESR) alpha and beta genes have been mostly implicated in infertility, but the results have been controversial due to lack of comprehensive data. The present study focused on association of ESR genes with both male and female infertility. In ESRα, PvuII (rs2234693) and XbaI (rs9340799) were studied while in ESRβ gene, risk of infertility was determined for silent G/A RsaI (rs1256049) polymorphism. Total 124 subjects (74 cases and 50 controls) were part of this study having primary infertility. Restriction fragment length polymorphism (RFLP) was performed with PvuII, XbaI and RsaI to determine polymorphism. Correlation between age and follicle stimulating hormone (FSH) of cases and controls was determined and no association was found between infertility and FSH hormone. Heterozygous AG genotype of XbaI polymorphism (P= 2.505e-06) and heterozygous TC genotype (P= 0.00003) in PvuII polymorphism were strongly associated with risk of infertility. In ESRβ gene, there was lack of polymorphism for RsaI in our population as all subjects were homozygous (GG). Haplotype frequencies showed that XbaI and PvuII polymorphisms are in strong linkage disequilibrium. This study shows that in our population XbaI and PvuII polymorphisms of ESRα are associated with risk of infertility
Presence and Antibiotic Resistance of MDR Salmonella Isolates Recovered from Zea mays L. Farms Located near the Poultry Farms in Faisalabad-Pakistan
Background: Salmonella is the major food-borne pathogen associated with food products and causative agent of salmonellosis. Discharge of untreated wastes and leakage of poultry drainage in irrigation water might be the significant source of contamination in fields. The aim of this study was to investigate the presence of Salmonella in the rhizosphere and phyllo sphere of Zea mays L farm, following irrigation with ditch water contaminated with poultry drainage.Methods: Total 6 maize farms in and around Faisalabad (Pakistan) were selected nearby the poultry farm area. Irrigated water, rhizosphere and leaves were analyzed for presence of Salmonella. A total of 160 samples were collected from different farms. Samples were cultivated on SS agar media and incubated at 37oC.Results: Out of 160 samples, 39 showed positive growth for bacterial contamination. 18 samples were confirmed as Salmonella by morphological and biochemical characteristics. Our results indicated the presence of Salmonella isolates from irrigated water (n=10), from rhizosphere (n=5), from phyllo sphere (n=1) and from roots (n=2). Antibiotics susceptibility pattern of Salmonella isolates against routinely used antibiotics had indicated that 71% isolates were resistant to Tetracycline and Amikacin, and 65% resistance to Chloramphenicol. All the isolates were sensitive to Levofloxacin, Tobramycin, Cefepime, Gentamycin, Cefoxitin and Sulfamethoxale. All isolates were intermediate resistant to cefuroxime and ampicillin.Conclusion: From obtained result it is confirmed that Salmonella spp. have been found in irrigation water mixed with poultry drainage and could be a source of Salmonella contamination to the crops located near the poultry farms.Keywords: Rhizosphere; Zea mays L., Ditch water; Phyllo-sphere; Irrigation water
Cutaneous Candidiasis
Cutaneous candidiasis is a multipicture infection of the skin, generally caused by yeast like fungus c.albicans or other species of genus candida such as candida parapsilosis, candida tropicalis, candida glabrata but these species are unusual, secondary to skin diseases. Candida is flora of gut microbiota, rather than skin, although it is present on skin at some instances. Certain factor of candida species such as ability to evade host defense by biofilm formation, filamentous form and presence of tissue damaging enzyme phospholipase are attributed to pathogenicity. Cutaneous candida infection may occur in patient HIV/AIDS, cancer receiving chemotherapy, antibiotics, steroids therapy and in organ transplantation. Vesicles, pustules, maceration and fissuring are common symptoms on perineum, axilla and interriginous areas. Systemic and topical therapies are common treatment with different drugs. Single drug therapy as combination of anti-fungal, antibacterial and topical corticosteroid has marvelous results. Nystatin, Clotrimaziole and miconazole are efficiently reviewed topical drugs with 73–100% cure
Actinobacteria: Potential Candidate as Plant Growth Promoters
Plant growth enhancement using plant beneficial bacteria has been viewed in the sustainable agriculture as an alternative to chemical fertilizers. Actinobacteria, among the group of important plant-associated bacteria, have been widely studied for its plant growth promotion activities. Actinobacteria are considered as a limelight among agriculturists for their beneficial aspects toward plants. They are naturally occurring spore-forming bacteria inhabiting the soil and known for their plant growth-promoting and biocontrol properties. The mechanisms behind these activities include nitrogen fixation, phosphate solubilization, siderophore production, and other attributes such as antifungal production of metabolites, phytohormones, and volatile organic compound. All these activities not only enhance the plant growth but also provide resistance in plants to withstand unfavorable conditions of the environment. Hence, this chapter emphasizes on the plant growth traits of actinobacteria and how far it was studied for enhanced growth and bio-fortification
Potential of siltstone and its composites with biochar and magnetite nanoparticles for the removal of cadmium from contaminated aqueous solutions: Batch and column scale studies
© 2020 Elsevier Ltd The present study is the first attempt to evaluate the pilot and batch scale adsorption potential of siltstone (SS) and its nanocomposites with biochar (EDB/SS), magnetite nanoparticles (MNPs/SS) and MNPs/EDB/SS for Cd removal from contaminated water. The SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were characterized with FTIR, XRD, BET, SEM, TEM, TGA and point of zero charge (PZC). The effects of adsorbent dosage, contact time, initial Cd concentration, pH and presence of competing ions were evaluated on the Cd removal and its adsorption. The order for Cd removal was: MNPs/EDB/SS \u3e MNPs/SS \u3e EDB/SS \u3e SS (95.86–99.72% \u3e 93.10–98.5% \u3e 89.66.98–98.40% \u3e 74.90–90%). Column scale experiments yielded maximum retention (95%) of Cd even after 2 h of injection at 100 mg Cd/L. The exhausted SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were reused without losing significant adsorption potential. Similarly, maximum Cd adsorption (117.38 mg/g) was obtained with MNPs/EDB/SS at dose 1.0 g/L. The results revealed that coexisting cations reduced the Cd removal due to competition with Cd ions. The experimental results were better explained with Freundlich isotherm model and pseudo 2nd order kinetic models. The results revealed that SS and its composites can be used efficiently for the removal of Cd from contaminated water
Carbapenem Resistance: Mechanisms and Drivers of Global Menace
The emergence of carbapenem-resistant bacterial pathogens is a significant and mounting health concern across the globe. At present, carbapenem resistance (CR) is considered as one of the most concerning resistance mechanisms and mainly found in gram-negative bacteria of the Enterobacteriaceae family. Although carbapenem resistance has been recognized in Enterobacteriaceae from last 20 years or so, recently it emerged as a global health issue as CR clonal dissemination of various Enterobacteriaceae members especially E. coli, and Klebsiella pneumoniae are reported from across the globe at an alarming rate. Phenotypically, carbapenems resistance is in due to the two key mechanisms, like structural mutation coupled with β-lactamase production and the ability of the pathogen to produce carbapenemases which ultimately hydrolyze the carbapenem. Additionally, penicillin-binding protein modification and efflux pumps are also responsible for the development of carbapenem resistance. Carbapenemases are classified into different classes which include Ambler classes A, B, and D. Several mobile genetic elements (MGEs) have their potential role in carbapenem resistance like Tn4401, Class I integrons, IncFIIK2, IncF1A, and IncI2. Taking together, resistance against carbapenems is continuously evolving and posing a significant health threat to the community. Variable mechanisms that are associated with carbapenem resistance, different MGEs, and supplementary mechanisms of antibiotic resistance in association with virulence factors are expanding day by day. Timely demonstration of this global health concern by using molecular tools, epidemiological investigations, and screening may permit the suitable measures to control this public health menace
Visualization of grapevine root colonization by the Saharan soil isolate Saccharothrix algeriensis NRRL B-24137 using DOPE-FISH microscopy
Background and aim There is currently a gap of
knowledge regarding whether some beneficial bacteria
isolated from desert soils can colonize epi- and
endophytically plants of temperate regions. In this
study, the early steps of the colonization process of
one of these bacteria, Saccharothrix algeriensis NRRL
B-24137, was studied on grapevine roots to determine
if this beneficial strain can colonize a non-natural host
plant. An improved method of fluorescence in situ
hybridization (FISH), the double labeling of oligonucleotide
probes (DOPE)-FISH technique was used to
visualize the colonization behavior of such bacteria as well as to determine if the method could be used to
track microbes on and inside plants.
Methods A probe specific to Saccharothrix spp. was
firstly designed. Visualization of the colonization behavior
of S. algeriensis NRRL B-24137 on and inside
roots of grapevine plants was then carried out with
DOPE-FISH microscopy.
Results The results showed that 10 days after inoculation,
the strain could colonize the root hair zone, root
elongation zone, as well as root emergence sites by
establishing different forms of bacterial structures as
revealed by the DOPE-FISH technique. Further observations
showed that the strain could be also endophytic
inside the endorhiza of grapevine plants.
Conclusions Taking into account the natural niches of
this beneficial strain, this study exemplifies that, in
spite of its isolation from desert soil, the strain can
establish populations as well as subpopulations on and
inside grapevine plants and that the DOPE-FISH tool
can allow to detect it