scholarly journals Ionome Changes in Xylella fastidiosa–Infected Nicotiana tabacum Correlate With Virulence and Discriminate Between Subspecies of Bacterial Isolates

2014 ◽  
Vol 27 (10) ◽  
pp. 1048-1058 ◽  
Author(s):  
J. E. Oliver ◽  
S. A. Sefick ◽  
J. K. Parker ◽  
T. Arnold ◽  
P. A. Cobine ◽  
...  

Characterization of ionomes has been used to uncover the basis of nutrient utilization and environmental adaptation of plants. Here, ionomic profiles were used to understand the phenotypic response of a plant to infection by genetically diverse isolates of Xylella fastidiosa, a gram-negative, xylem-limited bacterial plant pathogen. In this study, X. fastidiosa isolates were used to infect a common model host (Nicotiana tabacum ‘SR1’), and leaf and sap concentrations of eleven elements together with plant colonization and symptoms were assessed. Multivariate statistical analysis revealed that changes in the ionome were significantly correlated with symptom severity and bacterial populations in host petioles. Moreover, plant ionome modification by infection could be used to differentiate the X. fastidiosa subspecies with which the plant was infected. This report establishes host ionome modification as a phenotypic response to infection.

1999 ◽  
Vol 354 (1384) ◽  
pp. 701-710 ◽  
Author(s):  
Brian G. Spratt ◽  
Martin C. J. Maiden

Asexual bacterial populations inevitably consist of an assemblage of distinct clonal lineages. However, bacterial populations are not entirely asexual since recombinational exchanges occur, mobilizing small genome segments among lineages and species. The relative contribution of recombination, as opposed to de novo mutation, in the generation of new bacterial genotypes varies among bacterial populations and, as this contribution increases, the clonality of a given population decreases. In consequence, a spectrum of possible population structures exists, with few bacterial species occupying the extremes of highly clonal and completely non–clonal, most containing both clonal and non–clonal elements. The analysis of collections of bacterial isolates, which accurately represent the natural population, by nucleotide sequence determination of multiple housekeeping loci provides data that can be used both to investigate the population structure of bacterial pathogens and for the molecular characterization of bacterial isolates. Understanding the population structure of a given pathogen is important since it impacts on the questions that can be addressed by, and the methods and samples required for, effective molecular epidemiological studies.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 725
Author(s):  
Fernando Clavijo-Coppens ◽  
Nicolas Ginet ◽  
Sophie Cesbron ◽  
Martial Briand ◽  
Marie-Agnès Jacques ◽  
...  

Xylella fastidiosa (Xf) is a plant pathogen causing significant losses in agriculture worldwide. Originating from America, this bacterium caused recent epidemics in southern Europe and is thus considered an emerging pathogen. As the European regulations do not authorize antibiotic treatment in plants, alternative treatments are urgently needed to control the spread of the pathogen and eventually to cure infected crops. One such alternative is the use of phage therapy, developed more than 100 years ago to cure human dysentery and nowadays adapted to agriculture. The first step towards phage therapy is the isolation of the appropriate bacteriophages. With this goal, we searched for phages able to infect Xf strains that are endemic in the Mediterranean area. However, as Xf is truly a fastidious organism, we chose the phylogenetically closest and relatively fast-growing organism X. albineans as a surrogate host for the isolation step. Our results showed the isolation from various sources and preliminary characterization of several phages active on different Xf strains, namely, from the fastidiosa (Xff), multiplex (Xfm), and pauca (Xfp) subspecies, as well as on X. albilineans. We sequenced their genomes, described their genomic features, and provided a phylogeny analysis that allowed us to propose new taxonomic elements. Among the 14 genomes sequenced, we could identify two new phage species, belonging to two new genera of the Caudoviricetes order, namely, Usmevirus (Podoviridae family) and Subavirus (Siphoviridae family). Interestingly, no specific phages could be isolated from infected plant samples, whereas one was isolated from vector insects captured in a contaminated area, and several from surface and sewage waters from the Marseille area.


2008 ◽  
Vol 34 (3) ◽  
pp. 228-231 ◽  
Author(s):  
Willian Mário de Carvalho Nunes ◽  
Maria Júlia Corazza ◽  
Silvana Aparecida Crestes Dias de Souza ◽  
Siu Mui Tsai ◽  
Eiko Eurya Kuramae

A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and Polymerase Chain Reaction (PCR) with primers of the hypersensitivity and pathogenicity gene (hrp). The DNA obtained was free of contamination by proteins or carbohydrates. The ratio 260nm/380nm of the DNA extracted ranged from 1.7 to 1.8. The hrp gene cluster is required by bacterial plant pathogen to produce symptoms on susceptible hosts and hypersensitive reaction on resistant hosts. This gene has been found in different bacteria as well as in Xanthomonas campestris pv. vesicatoria (9). The primers RST21 and RST22 (9) were used to amplify the hrp gene of nine different isolates of Xanthomonas axonopodis pv. phaseoli from Botucatu, São Paulo State, Brazil, and one isolate, "Davis". PCR amplified products were obtained in all isolates pathogenic to beans.


2019 ◽  
Vol 32 (1) ◽  
pp. 200-210
Author(s):  
Antônio Italcy de Oliveira Júnior ◽  
Luiz Alberto Ribeiro Mendonça ◽  
Sávio de Brito Fontenele ◽  
Adriana Oliveira Araújo ◽  
Maria Gorethe de Sousa Lima Brito

ABSTRACT Soil is a dynamic and complex system that requires a considerable number of samples for analysis and research purposes. Using multivariate statistical methods, favorable conditions can be created by analyzing the samples, i.e., structural reduction and simplification of the data. The objective of this study was to use multivariate statistical analysis, including factorial analysis (FA) and hierarchical groupings, for the environmental characterization of soils in semiarid regions, considering anthropic (land use and occupation) and topographic aspects (altitude, moisture, granulometry, PR, and organic-matter content). As a case study, the São José Hydrographic Microbasin, which is located in the Cariri region of Ceará, was considered. An FA was performed using the principal component method, with normalized varimax rotation. In hierarchical grouping analysis, the “farthest neighbor” method was used as the hierarchical criterion for grouping, with the measure of dissimilarity given by the “square Euclidean distance.” The FA indicated that two factors explain 75.76% of the total data variance. In the analysis of hierarchical groupings, the samples were agglomerated in three groups with similar characteristics: one with samples collected in an area of the preserved forest and two with samples collected in areas with more anthropized soils. This indicates that the statistical tool used showed sensitivity to distinguish the most conserved soils and soils with different levels of anthropization.


Euphytica ◽  
2011 ◽  
Vol 178 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Rosa Karla Nogueira Pestanana ◽  
Edson Perito Amorim ◽  
Cláudia Fortes Ferreira ◽  
Vanusia Batista de Oliveira Amorim ◽  
Larissa Santos Oliveira ◽  
...  

1984 ◽  
Vol 195 (1-2) ◽  
pp. 186-189 ◽  
Author(s):  
Ralf R. Mendel ◽  
Roger J. Buchanan ◽  
John L. Wray

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Muhammad Yasir ◽  
Basit Zeshan ◽  
Nur Hardy A. Daud ◽  
Izzah Shahid ◽  
Hafza Khalid

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.


Sign in / Sign up

Export Citation Format

Share Document