Microbial biomass activity of a sodic Lixisol reclaimed with gypsum and clean water irrigation in urban vegetable systems of Burkina Faso     

Nongma Zongo  Juliane Dao  Désiré Jean-Pascal Lompo  Kathrin Stenchly  Christoph Steiner  Delphine Manka'abusi  Michel Papaoba Sedogo  Andreas Buerkert  Rainer Georg Joergensen 《植物养料与土壤学杂志》2023,186(2):188-195

Background

Little is known about the effects of gypsum application to remediate saline–sodic soils in the tropics and the role of microbial indicators in soil reclamation.

Aims

Our study aimed at (1) remediating a highly weathered, irrigated sodic Lixisol under prolonged urban crop production by clean water and gypsum application and (2) to determine the remediation effects on soil microbial indices.

Methods

A three-factorial on-farm experiment with maize (Zea mays L.) was used to study effects on soil microbial biomass of (1) soil degradation at two levels of salinity, (2) irrigation with clean water and wastewater, and (3) the impact of added gypsum during a typical growing season.

Results

At the high-degradation site, the 0.5 M K₂SO₄ extractable carbon (C) content was 40% higher than at the low-degradation site. In addition, microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were 20% lower than at the low-degradation site, while fungal ergosterol was even 40% lower, leading to a 33% lower ergosterol/MBC ratio. Wastewater irrigation increased MBN but decreased ergosterol content at the low-degradation site while having no effect at the high-degradation site. Gypsum amendment led to higher MBN at the low-degradation site but to lower MBN at the high-degradation site. Gypsum amendment always increased the ergosterol content whereby this increase was stronger at the low-degradation site, especially in combination with wastewater irrigation.

Conclusions

From a microbial perspective, high soil degradation levels should be avoided by treatment of a saline–sodic wastewater prior to its use for irrigation rather than relying on future remediation strategies of affected field sites.  相似文献   

Leptospira exposure in the human environment in France: A survey in feral rodents and in fresh water     

Aviat F  Blanchard B  Michel V  Blanchet B  Branger C  Hars J  Mansotte F  Brasme L  De Champs C  Bolut P  Mondot P  Faliu J  Rochereau S  Kodjo A  Andre-Fontaine G 《Comparative immunology, microbiology and infectious diseases》2009,32(6):463-476

This paper confirms the important role of rodents to be maintenance hosts of leptospires. Their role is related to renal carriage and shedding of leptospires into urine, thus contaminating fresh water. Serological and carriage of feral rodents trapped in France were determined by MAT and hap1PCR specific for pathogenic leptospires. In same areas, fresh water samples were analyzed by hap1PCR. The overall seroprevalence was 44% in 649 rodents and was similar regardless of the species. Seroprevalence for leptospirosis is about 20-53% according to species. hap1PCR (516 kidneys) showed that renal carriage was higher in brown rats (34.7%) and muskrats (15.8%) than in coypus (3.3%). hap1PCR demonstrates a significative difference (P-value > 10(-12)) for the renal carriage between the different species: muskrats and rats are more efficient maintenance hosts than coypu but all infect water. Moreover 5/38 water samples associated with human cases were hap1PCR positive and 1/113 in controlled waters.  相似文献   

Comparative field evaluation of two rapid immunochromatographic tests for the diagnosis of bovine tuberculosis in African buffaloes (Syncerus caffer)     

A.L. Michel  M. Simões 《Veterinary immunology and immunopathology》2009,127(1-2):186-189

Panels of sera from African buffalo with confirmed bovine tuberculosis and from known uninfected controls were used to evaluate the performance of two commercial rapid chromatographic immunoassays (A and B) for the detection of antibodies to Mycobacterium bovis. The sensitivity was 33% and 23%, respectively, while the specificity was determined at 90% and 94%, respectively. Overall the performance of both diagnostic tests under field conditions was not found sufficiently high to support their use in bovine tuberculosis management and control strategies in South African game reserves.  相似文献   

Differential induction of MyD88- and TRIF-dependent pathways in equine monocytes by Toll-like receptor agonists     

Monica D. Figueiredo  Michel L. Vandenplas  David J. Hurley  James N. Moore 《Veterinary immunology and immunopathology》2009,127(1-2):125-134

Our understanding of the innate immune response in the horse has been limited by a lack of definitive data concerning cell signaling in response to microbial products. Toll-like receptors (TLRs) recognize conserved molecular motifs of microbes and elicit immune responses through their coupling with intracellular adaptor molecules, particularly MyD88 and TRIF. To provide a more definitive characterization of TLR signaling in the horse, the objectives of this study were to: (1) characterize the responses of equine monocytes to TLR ligands that signal through MyD88, TRIF or both in other species, and (2) determine the profiles of gene expression initiated utilizing these adaptor molecules. Monocytes were used to establish concentration response curves for Escherichia coli lipopolysaccharide (LPS; TLR4 ligand) and N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteinyl-[S]-seryl-[S]-lysyl-[S]-lysyl-[S]-lysyl-[S]-lysine x 3 HCl (Pam₃CSK₄; TLR2 ligand) based on expression of procoagulant activity (PCA) and production of tumor necrosis factor-alpha (TNF-α); effects of polyinosine–polycytidylic acid (Poly I:C; TLR3 ligand) were determined by quantifying expression of mRNA for interferon-beta (IFN-ß). Expression of genes associated with the MyD88- (TNF-α, IL-1ß, IL-6 and IL-10) and TRIF-dependent pathways (IFN-ß, IP-10, RANTES and TRAF1) were measured at intervals spanning 20 h. LPS and Pam₃CSK₄ induced significantly higher expression of TNF-α, IL-1ß, and IL-10 than did Poly I:C. Poly I:C induced significantly higher expression of IFN-ß, IP-10 and RANTES than did either the TLR2 or TLR4 ligands. High concentrations of E. coli LPS did not significantly increase expression of genes associated with the TRIF-dependent pathway. The results of this study suggest that equine monocytes utilize a common intracellular pathway in response to TLR2 and TLR4 ligands, but a distinct pathway in response to TLR3 ligands.  相似文献   

Polymorphism Analysis of Microsatellites Associated with Seven Candidate Genes for Equine Cryptorchidism     

Mathieu Diribarne  Anne Vaiman  Michel Péchayre  E. Pailhoux  Xavier Mata  Gérard Guérin  Stéphane Chaffaux 《Journal of Equine Veterinary Science》2009

Association of seven candidate genes with cryptorchidism was investigated in the Thoroughbred. A pedigree composed of 23 cryptorchids and 24 nonaffected horses, sharing a common ancestor, was constituted. Sixteen microsatellite markers were developed either from bacterial artificial chromosomes (BAC) isolated for each candidate gene or by in silico screening. DNA from our pedigree was genotyped for these microsatellites. Statistical analysis of the allelic and genotypic frequencies observed with these markers did not reveal any association between the candidate genes and the cryptorchidism phenotype in our horse panel.  相似文献   

Diagnostic imaging of the equine tarsal region using radiography and ultrasonography. Part 1: the soft tissues     

Vanderperren K  Raes E  Hoegaerts M  Saunders JH 《Veterinary journal (London, England : 1997)》2009,179(2):179-187

The equine tarsus is the most commonly affected hindlimb region associated with lameness. Diagnostic imaging is routinely applied but because of its complexity, being composed of 10 multifaceted bones and different joints, multiple ligaments, tendons and bursae, imaging this region can be a challenge. This is the first part of a two-part review of the structures and disorders of the equine tarsus. It describes the principal disorders affecting the soft tissues of the tarsal region and addresses some of the technical aspects in taking radiographic, ultrasonographic and scintigraphic images of the different soft tissue lesions. Where applicable, comments on the diagnostic use of contrast radiography, arthroscopy and tenoscopy are made. In current clinical practice a combination of radiography and ultrasonography is still most frequently used to arrive at a diagnosis.  相似文献   

Recombinant proteins and peptides as tools for studying IgE reactivity with low-molecular-weight glutenin subunits in some wheat allergies     

Snégaroff J  Branlard G  Bouchez-Mahiout I  Laudet B  Tylichova M  Chardot T  Pecquet C  Choudat D  Raison-Peyron N  Vigan M  Kerre S  Laurière M 《Journal of agricultural and food chemistry》2007,55(24):9837-9845

Two genes of wheat low-molecular-weight glutenin subunits (LMW-GS), B16 and P73, were cloned and expressed in E. coli. They were homologous to proteins encoded respectively at Glu-B3 and Glu-D3 loci. The N-terminal and C-terminal halves of B16 (NB16 and B16C) and the two chimeras combining the halves of the two genes (B16-P73 and P73- B16) were also expressed. All these constructs were compared for their reactivity with IgE from 24 patients suffering from different forms of wheat allergies. The results confirmed that LMW-GSs bound IgE in all adult allergies tested. Strong differences in reactivity between all the constructs were observed. They were disease-dependent. In wheat-dependent exercise-induced anaphylaxis (WDEIA), the reactivity of the constructs depended partly on common epitopes with omega-5 gliadins but also on differences in molecule conformation. The presence of NB16 in the constructs greatly influenced their IgE reactivity.  相似文献   

Mutations in the CYP51 gene correlated with changes in sensitivity to sterol 14 alpha-demethylation inhibitors in field isolates of Mycosphaerella graminicola     

Leroux P  Albertini C  Gautier A  Gredt M  Walker AS 《Pest management science》2007,63(7):688-698

In France, as in many other European countries, Mycosphaerella graminicola (Fuckel) Schr?ter in Cohn (anamorph Septoria tritici), the causal agent of wheat leaf blotch, is controlled by foliar applications of fungicides. With the recent generalization of resistance to strobilurins (QoIs), reliable control is mainly dependent upon inhibitors of sterol 14 alpha-demethylation (DMIs). To date, strains with reduced sensitivity to DMIs are widespread, but disease control using members of this class of sterol biosynthesis inhibitors has not been compromised. In this study, sensitivity assays based on in vitro effects of fungicides towards germ-tube elongation allowed the characterization of seven DMI-resistant phenotypes. In four of them, cross-resistance was not observed between all tested DMIs; this characteristic concerned prochloraz, triflumizole, fluquinconazole and tebuconazole. Moreover, the highest resistant factors to most DMIs were found only in recent isolates; according to their response towards prochloraz, they were classified into two categories. Molecular studies showed that DMI resistance was associated with mutations in the CYP51 gene encoding the sterol 14 alpha-demethylase. Alterations at codons 459, 460 and 461 were related to low resistance levels, whereas, at position 381, a valine instead of an isoleucine, in combination with the previous changes, determined the highest resistance levels to all DMIs except prochloraz. Mutations in codons 316 and 317 were also found in some isolates exhibiting low resistance factors towards most DMIs.  相似文献   

Giant Galápagos tortoises; molecular genetic analyses identify a trans-island hybrid in a repatriation program of an endangered taxon     

Michel C Milinkovitch  Daniel Monteyne  Michael Russello  James P Gibbs  Howard L Snell  Washington Tapia  Cruz Marquez  Adalgisa Caccone  Jeffrey R Powell 《BMC ecology》2007,7(1):2

  相似文献   

Assessing the potential of marine Natura 2000 sites to produce ecosystem‐wide effects in rocky reefs: A case study from Sardinia Island (Italy)     

Paolo Guidetti  Piero Addis  Fabrizio Atzori  Simona Bussotti  Antonio Cal  Alessandro Cau  Jean‐Michel Culioli  Giuseppe De Lucia  Antonio Di Franco  Manfredi Di Lorenzo  Maria Cristina Follesa  Vittorio Gazale  Giorgio Massaro  Francesco Mura  Augusto Navone  David Pala  Pier Augusto Panzalis  Antonio Pusceddu  Alberto Ruiu  Angelo Cau 《水产资源保护:海洋与淡水生态系统》2019,29(4):537-545