scholarly journals Genotyping and epidemiological metadata provides new insights into population structure of Xanthomonas isolated from walnut trees

2018 ◽  
Author(s):  
Camila Fernandes ◽  
Pedro Albuquerque ◽  
Leonor Cruz ◽  
Fernando Tavares
Keyword(s):  
Genetic Diversity ◽  
Blot Hybridization ◽  
Epidemiological Studies ◽  
The Other ◽  
Economic Losses ◽  
Plant Sample ◽  
Dot Blot ◽  
Pathogenicity Tests ◽  
Xanthomonas Arboricola ◽  
Disease Epidemics

ABSTRACTXanthomonas arboricola pv. juglandis (Xaj) is the etiological agent of walnut diseases affecting leaves, fruits, branches and trunks. Although this phytopathogen is widely spread in walnut producing regions and has a considerable genetic diversity, there is still a poor understanding of its epidemic behaviour. To shed some light on the epidemiology of these bacteria, 131 Xanthomonas isolates obtained from 64 walnut trees were included in this study considering epidemiological metadata such as year of isolation, bioclimatic regions, walnut cultivars, production regimes, host walnut specimen and plant organs. Genetic diversity was assessed by multilocus sequence analysis (MLSA) and dot blot hybridization patterns obtained with nine Xaj-specific DNA markers (XAJ1 – XAJ9). The results showed that Xanthomonas isolates grouped in ten distinct MLSA clusters and in 18 hybridization patterns (HP). The majority of isolates (112 out of 131) were closely related with X. arboricola strains of pathovar juglandis as revealed by MLSA (clusters I to VI) and hybridize with more than five Xaj-specific markers. Nineteen isolates clustered in four MLSA groups (clusters VII to X) which do not include Xaj strains, and hybridize to less than five markers. Taking this data together, was possible to distinguish 17 lineages of Xaj, three lineages of X. arboricola and 11 lineages of Xanthomonas sp. Some Xaj lineages appeared to be widely distributed and prevalent across the different bioclimatic regions and apparently not constrained by the other features considered. Assessment of type III effector genes and pathogenicity tests revealed that representative lineages of MLSA clusters VII to X were nonpathogenic on walnut, with exception for strain CPBF 424, making this bacterium particularly appealing to address Xanthomonas pathoadaptations to walnut.IMPORTANCEXanthomonas arboricola pv. juglandis is one of the most serious threats of walnut trees. New disease epidemics caused by this phytopathogen has been a big concern causing high economic losses on walnut production worldwide. Using a comprehensive sampling methodology to disclose the diversity of walnut infective Xanthomonas, we were able to identify a genetic diversity higher than previously reported and generally independent of bioclimatic regions and the other epidemiological features studied. Furthermore, co-colonization of the same plant sample by distinct Xanthomonas strains were frequent and suggested a sympatric lifestyle. The extensive sampling carried out resulted in a set of non-arboricola Xanthomonas sp. strains, including a pathogenic strain, therefore diverging from the nonpathogenic phenotype that have been associated to these atypical strains, generally considered to be commensal. This new strain might be particularly informative to elucidate novel pathogenicity traits and unveil pathogenesis evolution within walnut infective xanthomonads. Beyond extending the present knowledge about walnut infective xanthomonads, this study might contribute to provide a methodological framework for phytopathogen epidemiological studies, still largely disregarded.

scholarly journals Human parvovirus B19 infection in HIV-positive patients

2001 ◽  
Vol 34 (3) ◽  
pp. 239-242 ◽  
Author(s):  
Fábio S. Aguiar ◽  
Daniella P. Lopes ◽  
Anna Ricordi Bazin ◽  
Sérgio Setúbal ◽  
Bernard J. Cohen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Parvovirus B19 ◽  
Blot Hybridization ◽  
Epidemiological Studies ◽  
Hiv Positive ◽  
Dot Blot ◽  
Cd4 Cell Count ◽  
High Prevalence ◽  
Parvovirus B19 Infection ◽  
Cd4 Cell

Parvovirus B19 infects predominantly erythroid cells, leading to transient inhibition of erythropoiesis. Immunocompromised patients may be unable to produce neutralizing antibodies and may develop severe chronic anemia. Epidemiological studies done on Niterói population showed that B19 infection occurs periodically in late spring and summer. We report a study from 55 HIV infected patients attending an infectious diseases outpatient clinic in this city during a 5-month period in which B19 circulation was well documented. All patients were under anti-retroviral therapy. No anti-B19 IgM was found, but a high prevalence of IgG anti-B19 (91%) was observed. In six patients, B19 DNA was found by dot-blot hybridization techniques, but this was not confirmed by PCR. None of these 6 patients manifested anemia and only one had CD4 cell count below 200 x 10(7)/L. We conclude that persistent infection causing anemia is an infrequent finding in our HIV positive patients under drug therapy.

scholarly journals CRISPR genotyping as complementary tool for epidemiological surveillance of Erwinia amylovora outbreaks

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250280
Author(s):  
Rafael J. Mendes ◽  
João Pedro Luz ◽  
Conceição Santos ◽  
Fernando Tavares
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Blot Hybridization ◽  
Fruit Trees ◽  
Epidemiological Surveillance ◽  
Economic Losses ◽  
Pome Fruit ◽  
Dot Blot ◽  
Virulence Markers ◽  
Clonal Population Structure

Fire blight is a destructive plant disease caused by Erwinia amylovora affecting pome fruit trees, and responsible for large yield declines, long phytosanitary confinements, and high economic losses. In Portugal, the first major fire blight outbreaks occurred in 2010 and 2011, and although later considered eradicated, the emergence of other outbreaks in recent years stressed the need to characterize the E. amylovora populations associated with these outbreaks. In this regard, CRISPR genotyping, assessment of three virulence markers, and semi-quantitative virulence bioassays, were carried out to determine the genotype, and assess the virulence of thirty-six E. amylovora isolates associated with outbreaks occurring between 2010 and 2017 and affecting apple and pear orchards located in the country central-west, known as the main producing region of pome fruits in Portugal. The data gathered reveal that 35 E. amylovora isolates belong to one of the widely-distributed CRISPR genotypes (5-24-38 / D-a-α) regardless the host species, year and region. Ea 680 was the single isolate revealing a new CRISPR genotype due to a novel CR2 spacer located closer to the leader sequence and therefore thought to be recently acquired. Regarding pathogenicity, although dot-blot hybridization assays showed the presence of key virulence factors, namely hrpL (T3SS), hrpN (T3E) and amsG from the amylovoran biosynthesis operon in all E. amylovora isolates studied, pathogenicity bioassays on immature pear slices allowed to distinguish four virulence levels, with most of the isolates revealing an intermediate to severe virulence phenotype. Regardless the clonal population structure of the E. amylovora associated to the outbreaks occurring in Portugal between 2010 and 2017, the different virulence phenotypes, suggests that E. amylovora may have been introduced at different instances into the country. This is the first study regarding E. amylovora in Portugal, and it discloses a novel CRISPR genotype for this bacterium.

scholarly journals Genetic Diversity of Japanese Strains of Ralstonia solanacearum

2001 ◽  
Vol 91 (4) ◽  
pp. 399-407 ◽  
Author(s):  
Mitsuo Horita ◽  
Kenicki Tsuchiya
Keyword(s):  
Genetic Diversity ◽  
Polymerase Chain Reaction ◽  
Ralstonia Solanacearum ◽  
The Other ◽  
Chain Reaction ◽  
Average Similarity ◽  
Race 1 ◽  
Pathogenicity Tests ◽  
Polymerase Chain ◽  
Cluster 2

The genetic diversity of 74 Japanese strains of Ralstonia solanacearum was assessed by pathogenicity tests and the repetitive sequencebased polymerase chain reaction (rep-PCR) fingerprint method. Based on their genomic fingerprints, biovar N2 strains were divided into two distinct groups, one consisting of potato isolates belonging to race 3, and the other consisting of tomato, eggplant, pepper, and tobacco isolates belonging to race 1. Biovar 3 strains had low average similarity and were divided into five groups that differed in original host or pathogenicity. Biovar 4 strains consisted of only one group at the 80% similarity level. Comparative analysis of the rep-PCR fingerprints of 78 strains, including six biovars from Japan and various countries, revealed two main clusters. Cluster 1 comprised all biovar 3, 4, and 5 strains, biovar 1 strains from Reunion, and some biovar N2 strains from Japan. Cluster 2 included most of the biovar 1, 2, and N2 strains. The fingerprints showed low average similarity with biovar N2 strains from Japan and Brazil.

scholarly journals Development of a DNA Macroarray for the Detection and Identification of Fungal Pathogens Causing Decline of Young Grapevines

2015 ◽  
Vol 105 (10) ◽  
pp. 1373-1388 ◽  
Author(s):  
J. R. Úrbez-Torres ◽  
P. Haag ◽  
P. Bowen ◽  
T. Lowery ◽  
D. T. O’Gorman
Keyword(s):  
Fungal Pathogens ◽  
Complex Disease ◽  
Blot Hybridization ◽  
Economic Losses ◽  
Dot Blot ◽  
Planting Material ◽  
Detection And Identification ◽  
Reverse Dot Blot Hybridization ◽  
High Incidence ◽  
Vine Decline

Young vine decline (YVD) is a complex disease caused by at least 51 different fungi and responsible for important economic losses to the grapevine industry worldwide. YVD fungi are known to occur in planting material. Hence, detection prior to planting is critical to assure longevity of newly established vineyards. A DNA macroarray based on reverse dot-blot hybridization containing 102 oligonucleotides complementary to portions of the β-tubulin region was developed for detection of YVD fungi. Specificity of the array was first evaluated against 138 pure fungal cultures representing 72 different taxa from nine genera, including 37 YVD species. In total, 61 species, including 34 YVD pathogens, were detected and identified by the array. The detection limit of the array was below 0.1 pg of genomic DNA. The array was validated against artificially inoculated canes and soil and commercial planting material, with the latter showing a high incidence of YVD fungi in nursery plants otherwise not detected by traditional plating and culturing. This DNA array proved to be a rapid and specific tool to simultaneously detect and identify most YVD fungi in a single test, which has the potential to be used in commercial diagnostics or by the grapevine nursery industry to determine the health status of the planting material.

Molecular evidence for Triticum speltoides as a B-genome progenitor of wheat (Triticum aestivum)

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 543-548 ◽  
Author(s):  
Hassan Mat Daud ◽  
J. P. Gustafson
Keyword(s):  
Southern Blot ◽  
Blot Hybridization ◽  
The Other ◽  
Molecular Evidence ◽  
Dot Blot ◽  
Specific Sequence ◽  
Polyploid Wheat ◽  
B Genome ◽  
Genome Donor ◽  
A Genome

In polyploid wheat, the origin of the B-genome donor has remained relatively unknown in spite of a number of investigations attempting to identify the parental species. A project was designed to isolate and clone a genome-specific DNA sequence from Triticum speltoides L. to determine if that species could be the B-genome donor. A cloning scheme involving the prescreening of 1-kb fragments followed by colony, dot blot, and Southern blot hybridization screenings was used to isolate a speltoides-specific sequence (pSp89.XI). The methods used allowed for rapid isolation of a genome-specific sequence when screened against total DNA from closely related species. Subsequent analyses showed that the sequence was barely detected in any of the other genomes of the annual Sitopsis section. The results of dot blot and Southern blot analyses established that (i) the sequence pSP89.XI, specific to T. speltoides relative to the other species of the Sitopsis section, was present in the genomes of tetraploid and hexaploid wheat, (ii) the relative abundance of pSp89.XI seemed to decrease from the diploid to the polyploid wheats, and (iii) the existence of a related, but modified B genome in polyploid wheat compared with that in modern T. speltoides was probable. Key words : genome-specific, DNA.

Detection of Hepatitis a Virus and other Enteroviruses in Wastewater and Surface Water Samples by Gene Probe Assay

1991 ◽  
Vol 24 (2) ◽  
pp. 267-272 ◽  
Author(s):  
S. Dubrou ◽  
H. Kopecka ◽  
J. M. Lopez Pila ◽  
J. Maréchal ◽  
J. Prévot
Keyword(s):  
Surface Water ◽  
Cell Cultures ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Limit Of Detection ◽  
Blot Hybridization ◽  
Noncoding Region ◽  
Gene Probe ◽  
Dot Blot ◽  
Lower Efficiency

Enteroviruses were specifically detected by dot blot hybridization when using poliovirus type 1 (PV1) derived subgenomic radiolabeled cRNA probes (riboprobes) in environmental water specimens and in the cell cultures in which the viruses were amplificated. The riboprobe corresponding to the 5' noncoding sequence detected the majority of enteroviruses. Hepatitis A virus (HAV) was specifically detected by an HAV cRNA probe corresponding to the 5' noncoding region of its genome. By this test, the limit of detection of coxsackievirus B5 and echovirus 7 seeded in mineral water was 103 to 104 PFU/spot. In cell cultures, positive signals were observed in the lysates of cells infected by one PFU. Higher positive signals were obtained with a short PV1 probe (nt 221-670) corresponding to the 5' noncoding region, which is a well preserved sequence among the enteroviruses, than with PV1 genomic probe. Hybridization allowed a good detection of enteroviral RNAs in wastewater specimens, but with a lower efficiency in surface water. In this case, amplification of viruses in the cell cultures gave significant hybridization results.

Feasibility of Qualitative Testing of BCR-ABL and JAK2 V617F in Suspected Myeloproliperative Neoplasm (MPN) Using RT-PCR Reversed Dot Blot Hybridization (RT-PCR RDB)

2019 ◽  
Vol 19 (4) ◽  
pp. 220-227
Author(s):  
Najmiatul Masykura ◽  
Ummu Habibah ◽  
Siti Fatimah Selasih ◽  
Soegiarto Gani ◽  
Cosphiadi Irawan ◽  
...  
Keyword(s):  
Blot Hybridization ◽  
Jak2 V617f ◽  
Rt Pcr ◽  
Dot Blot ◽  
Dot Blot Hybridization

Use of monoclonal and polyclonal antibodies to detect prostatic acid phosphatase by immunoblotting.

1986 ◽  
Vol 32 (10) ◽  
pp. 1832-1835 ◽  
Author(s):  
P C Patel ◽  
L Aubin ◽  
J Côte
Keyword(s):  
Monoclonal Antibodies ◽  
Acid Phosphatase ◽  
Western Blot ◽  
Polyclonal Antibodies ◽  
Prostatic Acid Phosphatase ◽  
The Other ◽  
Dot Blot ◽  
Western Blots ◽  
Dot Blot Assay ◽  
Polyclonal Antisera

Abstract We investigated two techniques of immunoblotting--the Western blot and the dot blot--for use in detecting prostatic acid phosphatase (PAP, EC 3.1.3.2). We used polyclonal antisera to human PAP, produced in rabbits by hyperimmunization with purified PAP, and PAP-specific monoclonal antibodies in the immunoenzymatic protocols. We conclude that PAP can be readily detected by Western blots with use of polyclonal antisera, but not with monoclonal antibodies. On the other hand, using a dot blot assay, we could easily detect PAP with both polyclonal and monoclonal antibodies.

scholarly journals Exogenous Isolation of Antibiotic Resistance Plasmids from Piggery Manure Slurries Reveals a High Prevalence and Diversity of IncQ-Like Plasmids

2000 ◽  
Vol 66 (11) ◽  
pp. 4854-4862 ◽  
Author(s):  
Kornelia Smalla ◽  
Holger Heuer ◽  
Antje Götz ◽  
Dagmar Niemeyer ◽  
Ellen Krögerrecklenfort ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Ralstonia Eutropha ◽  
Blot Hybridization ◽  
Restriction Pattern ◽  
Pcr Analysis ◽  
Dot Blot ◽  
High Prevalence ◽  
Resistance Plasmids ◽  
Incq Plasmids ◽  
K 12

ABSTRACT Antibiotic resistance plasmids were exogenously isolated in biparental matings with piggery manure bacteria as plasmid donors inEscherichia coli CV601 and Pseudomonas putidaUWC1 recipients. Surprisingly, IncQ-like plasmids were detected by dot blot hybridization with an IncQ oriV probe in severalP. putida UWC1 transconjugants. The capture of IncQ-like plasmids in biparental matings indicates not only their high prevalence in manure slurries but also the presence of efficiently mobilizing plasmids. In order to elucidate unusual hybridization data (weak or no hybridization with IncQ repB or IncQ oriTprobes) four IncQ-like plasmids (pIE1107, pIE1115, pIE1120, and pIE1130), each representing a different EcoRV restriction pattern, were selected for a more thorough plasmid characterization after transfer into E. coli K-12 strain DH5α by transformation. The characterization of the IncQ-like plasmids revealed an astonishingly high diversity with regard to phenotypic and genotypic properties. Four different multiple antibiotic resistance patterns were found to be conferred by the IncQ-like plasmids. The plasmids could be mobilized by the RP4 derivative pTH10 into Acinetobactersp., Ralstonia eutropha, Agrobacterium tumefaciens, and P. putida, but they showed diverse patterns of stability under nonselective growth conditions in different host backgrounds. Incompatibility testing and PCR analysis clearly revealed at least two different types of IncQ-like plasmids. PCR amplification of total DNA extracted directly from different manure samples and other environments indicated the prevalence of both types of IncQ plasmids in manure, sewage, and farm soil. These findings suggest that IncQ plasmids play an important role in disseminating antibiotic resistance genes.

scholarly journals Morphology Characterization, Molecular Phylogeny, and Pathogenicity of Diaporthe passifloricola on Citrus reticulata cv. Nanfengmiju in Jiangxi Province, China

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 218
Author(s):  
Chingchai Chaisiri ◽  
Xiang-Yu Liu ◽  
Wei-Xiao Yin ◽  
Chao-Xi Luo ◽  
Yang Lin
Keyword(s):  
Phylogenetic Analyses ◽  
Citrus Fruit ◽  
Epidemiological Studies ◽  
Morphological Characterization ◽  
Jiangxi Province ◽  
Citrus Reticulata ◽  
Fruit Storage ◽  
Pathogenicity Tests ◽  
Rot Disease ◽  
Morphology Characterization

The Nanfengmiju (Citrus reticulata cv. Nanfengmiju), a high-quality local variety of mandarin, is one of the major fruit crops in Jiangxi Province, China. Citrus melanose and stem-end rot, two common fungal diseases of Nanfengmiju, are both caused by Diaporthe spp. (syn. Phomopsis spp.). Identification of the Diaporthe species is essential for epidemiological studies, quarantine measures, and management of diseases caused by these fungi. Melanose disease was observed on Nanfengmiju fruit in Jiangxi Province of China in 2016. Based on morphological characterization and multi-locus phylogenetic analyses, three out of 39 isolates from diseased samples were identified as D. passifloricola. Since these three isolates did not cause melanose on citrus fruit in the pathogenicity tests, they were presumed to be endophytic fungi present in the diseased tissues. However, our results indicate that D. passifloricola may persist as a symptom-less endophyte in the peel of citrus fruit, yet it may cause stem-end if it invades the stem end during fruit storage. To the best of our knowledge, this is the first report of D. passifloricola as the causal agent of the stem-end rot disease in Citrusreticulata cv. Nanfengmiju.

Sign in / Sign up

Export Citation Format

Share Document