scholarly journals Comparative Genomics of Xanthomonaseuroxanthea and Xanthomonas arboricola pv. juglandis Strains Isolated from a Single Walnut Host Tree

2021 ◽  
Vol 9 (3) ◽  
pp. 624
Author(s):  
Camila Fernandes ◽  
Leonor Martins ◽  
Miguel Teixeira ◽  
Jochen Blom ◽  
Joël F. Pothier ◽  
...  
Keyword(s):  
Extracellular Enzymes ◽  
Walnut Tree ◽  
Size Number ◽  
A Genome ◽  
Type 3 Secretion System ◽  
Xanthomonas Arboricola ◽  
Chromosomal Sequences ◽  
Related Proteins ◽  
Type 3 ◽  
Genome Comparisons

The recent report of distinct Xanthomonas lineages of Xanthomonas arboricola pv. juglandis and Xanthomonas euroxanthea within the same walnut tree revealed that this consortium of walnut-associated Xanthomonas includes both pathogenic and nonpathogenic strains. As the implications of this co-colonization are still poorly understood, in order to unveil niche-specific adaptations, the genomes of three X. euroxanthea strains (CPBF 367, CPBF 424T, and CPBF 426) and of an X. arboricola pv. juglandis strain (CPBF 427) isolated from a single walnut tree in Loures (Portugal) were sequenced with two different technologies, Illumina and Nanopore, to provide consistent single scaffold chromosomal sequences. General genomic features showed that CPBF 427 has a genome similar to other X. arboricola pv. juglandis strains, regarding its size, number, and content of CDSs, while X. euroxanthea strains show a reduction regarding these features comparatively to X. arboricola pv. juglandis strains. Whole genome comparisons revealed remarkable genomic differences between X. arboricola pv. juglandis and X. euroxanthea strains, which translates into different pathogenicity and virulence features, namely regarding type 3 secretion system and its effectors and other secretory systems, chemotaxis-related proteins, and extracellular enzymes. Altogether, the distinct genomic repertoire of X. euroxanthea may be particularly useful to address pathogenicity emergence and evolution in walnut-associated Xanthomonas.

scholarly journals Selection of target genes for pcr diagnostics of Xanthomonas arboricola virulent for cereals and brassicas

2021 ◽  
Vol 104 (2) ◽  
pp. 87-96
Author(s):  
E. I. Kyrova* ◽  
A. N. Ignatov
Keyword(s):  
Target Genes ◽  
Detection System ◽  
Draft Genome ◽  
Pcr Analysis ◽  
Specific Pcr ◽  
Xanthomonas Species ◽  
Type 3 Secretion System ◽  
Xanthomonas Arboricola ◽  
Physiological Tests ◽  
Type 3

Plant pathogenic xanthomonads virulent to wheat, rye, barley, tomato, sunflower, and brassicas were isolated in Russia in 2001–2008. Physiological tests and multilocus sequence typing analysis confirmed their position within the Xanthomonas arboricola species. The obtained draft genome sequence of representative strain 3004 from barley plants, which is also virulent to sunflower, brassicas, and chestnut, demonstrated an absence of the Type 3 Secretion System T3SS and an evidence for the lateral gene transfer of some other virulence genes from distantly related bacteria. It was concluded that T4SS genes can be used as the target for group-specific PCR analysis of the emerging pathogen. It was proposed to use virD4, virB3, virB4, and virB9 genes to design a detection system. After preliminary experiments with classic PCR for the chosen genes, primers and TaqMan(R) probe were designed to specifically amplify a 121 bp fragment of the VirD4 gene. Amplification products were obtained for all target Xanthomonas arboricola strains and were not detected in other Xanthomonas species, or in other pathogenic or epiphytic bacteria occurring on these host plants. The assay readily detected Xanthomonas arboricola infection in diseased plants and from bacterial colonies isolated on semi-selective media, and was more sensitive and specific than traditional plating methods.

scholarly journals Genomic Characterization Provides an Insight into the Pathogenicity of the Poplar Canker Bacterium Lonsdalea populi

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 246
Author(s):  
Xiaomeng Chen ◽  
Rui Li ◽  
Yonglin Wang ◽  
Aining Li
Keyword(s):  
Genome Sequence ◽  
Extracellular Enzymes ◽  
De Novo ◽  
Whole Genome Sequence ◽  
Hybrid Poplars ◽  
A Genome ◽  
Conserved Genes ◽  
Genomic Characterization ◽  
Molecular Bases ◽  
Insight Into

An emerging poplar canker caused by the gram-negative bacterium, Lonsdalea populi, has led to high mortality of hybrid poplars Populus × euramericana in China and Europe. The molecular bases of pathogenicity and bark adaptation of L. populi have become a focus of recent research. This study revealed the whole genome sequence and identified putative virulence factors of L. populi. A high-quality L. populi genome sequence was assembled de novo, with a genome size of 3,859,707 bp, containing approximately 3434 genes and 107 RNAs (75 tRNA, 22 rRNA, and 10 ncRNA). The L. populi genome contained 380 virulence-associated genes, mainly encoding for adhesion, extracellular enzymes, secretory systems, and two-component transduction systems. The genome had 110 carbohydrate-active enzyme (CAZy)-coding genes and putative secreted proteins. The antibiotic-resistance database annotation listed that L. populi was resistant to penicillin, fluoroquinolone, and kasugamycin. Analysis of comparative genomics found that L. populi exhibited the highest homology with the L. britannica genome and L. populi encompassed 1905 specific genes, 1769 dispensable genes, and 1381 conserved genes, suggesting high evolutionary diversity and genomic plasticity. Moreover, the pan genome analysis revealed that the N-5-1 genome is an open genome. These findings provide important resources for understanding the molecular basis of the pathogenicity and biology of L. populi and the poplar-bacterium interaction.

scholarly journals The HrpG/HrpX Regulon of Xanthomonads—An Insight to the Complexity of Regulation of Virulence Traits in Phytopathogenic Bacteria

2021 ◽  
Vol 9 (1) ◽  
pp. 187
Author(s):  
Doron Teper ◽  
Sheo Shankar Pandey ◽  
Nian Wang
Keyword(s):  
Regulatory Network ◽  
Regulatory Networks ◽  
Focal Point ◽  
Genetic Regulation ◽  
Transcriptional Regulators ◽  
Secretion System ◽  
In Planta ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Made In

Bacteria of the genus Xanthomonas cause a wide variety of economically important diseases in most crops. The virulence of the majority of Xanthomonas spp. is dependent on secretion and translocation of effectors by the type 3 secretion system (T3SS) that is controlled by two master transcriptional regulators HrpG and HrpX. Since their discovery in the 1990s, the two regulators were the focal point of many studies aiming to decipher the regulatory network that controls pathogenicity in Xanthomonas bacteria. HrpG controls the expression of HrpX, which subsequently controls the expression of T3SS apparatus genes and effectors. The HrpG/HrpX regulon is activated in planta and subjected to tight metabolic and genetic regulation. In this review, we cover the advances made in understanding the regulatory networks that control and are controlled by the HrpG/HrpX regulon and their conservation between different Xanthomonas spp.

scholarly journals Interaction of Escherichia coli O157:H7 with Leafy Green Produce

2009 ◽  
Vol 72 (7) ◽  
pp. 1531-1537 ◽  
Author(s):  
JUAN XICOHTENCATL-CORTES ◽  
ETHEL SÁNCHEZ CHACÓN ◽  
ZEUS SALDAÑA ◽  
ENRIQUE FREER ◽  
JORGE A. GIRÓN
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Foodborne Pathogen ◽  
Enterohemorrhagic Escherichia Coli ◽  
Animal Products ◽  
Atpase Gene ◽  
Type 3 Secretion System ◽  
Human Infections ◽  
Type 3

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen responsible for human diarrheal disease. EHEC lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. Human infections are associated with consumption of tainted animal products and fresh produce. How the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. The goals of the present study were to investigate the environmental conditions and surface structures that influence the interaction of EHEC O157:H7 with baby spinach and lettuce leaves in vitro. Independently of the production of Shiga toxin, EHEC O157:H7 colonizes the leaf surface via flagella and the type 3 secretion system (T3SS). Ultrastructural analysis of EHEC-infected leafy greens revealed the presence of flagellated bacteria, and mutation of the fliC flagellin gene in EHEC EDL933 rendered the bacteria significantly less adherent, suggesting the involvement of flagella in the bacteria-leaf interaction. EDL933 mutated in the escN (ATPase) gene associated with the function of the T3SS but not in the eae (intimin adhesin) gene required for adherence to host intestinal cells had significantly reduced adherence compared with that of the parental strain. The data suggest a compelling role of flagella and the T3SS in colonization of leafy green produce. Colonization of salad leaves by EHEC strains may be a strategy that ensures survival of these bacteria in the environment and allows transmission to the human host.

scholarly journals Cytosolic Assembly Among Bacterial Type 3 Secretion System Proteins Revealed by High-Throughput Single-Molecule Tracking

2018 ◽  
Vol 114 (3) ◽  
pp. 534a
Author(s):  
Julian Rocha ◽  
Charles Richardson ◽  
Mingxing Zhang ◽  
Andreas Diepold ◽  
Andreas Gahlmann
Keyword(s):  
High Throughput ◽  
Single Molecule ◽  
Secretion System ◽  
Single Molecule Tracking ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Bacterial Type

scholarly journals Genomic Avenue to Avian Colisepticemia

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Sagi Huja ◽  
Yaara Oren ◽  
Eva Trost ◽  
Elzbieta Brzuszkiewicz ◽  
Dvora Biran ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Analysis ◽  
Virulence Factors ◽  
Iron Uptake ◽  
Secretion System ◽  
Economic Losses ◽  
Content Type ◽  
E Coli ◽  
Type 3 Secretion System ◽  
Type 3

ABSTRACTHere we present an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78 that represent the major cause of avian colisepticemia, an invasive infection caused by avian pathogenicEscherichia coli(APEC) strains. It is associated with high mortality and morbidity, resulting in significant economic consequences for the poultry industry. To understand the genetic basis of the virulence of avian septicemic E. coli, we sequenced the entire genome of a clinical isolate of serotype O78—O78:H19 ST88 isolate 789 (O78-9)—and compared it with three publicly available APEC O78 sequences and one complete genome of APEC serotype O1 strain. Although there was a large variability in genome content between the APEC strains, several genes were conserved, which are potentially critical for colisepticemia. Some of these genes are present in multiple copies per genome or code for gene products with overlapping function, signifying their importance. A systematic deletion of each of these virulence-related genes identified three systems that are conserved in all septicemic strains examined and are critical for serum survival, a prerequisite for septicemia. These are the plasmid-encoded protein, the defective ETT2 (E. colitype 3 secretion system 2) type 3 secretion system ETT2sepsis, and iron uptake systems. Strain O78-9 is the only APEC O78 strain that also carried the regulon coding for yersiniabactin, the iron binding system of theYersiniahigh-pathogenicity island. Interestingly, this system is the only one that cannot be complemented by other iron uptake systems under iron limitation and in serum.IMPORTANCEAvian colisepticemia is a severe systemic disease of birds causing high morbidity and mortality and resulting in severe economic losses. The bacteria associated with avian colisepticemia are highly antibiotic resistant, making antibiotic treatment ineffective, and there is no effective vaccine due to the multitude of serotypes involved. To understand the disease and work out strategies to combat it, we performed an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78, the major cause of the disease. We identified several potential virulence factors, conserved in all the colisepticemic strains examined, and determined their contribution to growth in serum, an absolute requirement for septicemia. These findings raise the possibility that specific vaccines or drugs can be developed against these critical virulence factors to help combat this economically important disease.

scholarly journals Role of the acquisition of a type 3 secretion system in the emergence of novel pathogenic strains of Xanthomonas

2018 ◽  
Vol 20 (1) ◽  
pp. 33-50 ◽  
Author(s):  
Valérian Meline ◽  
Wesley Delage ◽  
Chrystelle Brin ◽  
Camille Li-Marchetti ◽  
Daniel Sochard ◽  
...  
Keyword(s):  
Secretion System ◽  
Type 3 Secretion System ◽  
Type 3

scholarly journals High-Quality Draft Genome Sequence of Xanthomonas arboricola pv. juglandis CPBF 1521, Isolated from Leaves of a Symptomatic Walnut Tree in Portugal without a Past of Phytosanitary Treatment

2018 ◽  
Vol 7 (16) ◽  
Author(s):  
Camila Fernandes ◽  
Jochen Blom ◽  
Joël F. Pothier ◽  
Fernando Tavares
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
High Quality ◽  
Content Type ◽  
Walnut Tree ◽  
Phytosanitary Treatment ◽  
Xanthomonas Arboricola

Here, we report the draft genome sequence of Xanthomonas arboricola pv. juglandis CPBF 1521, isolated from symptomatic leaves of an ornamental walnut in a public site in Portugal without any record of phytosanitary treatment.

scholarly journals Salmonella persisters undermine host immune defenses during antibiotic treatment

Science ◽  
2018 ◽  
Vol 362 (6419) ◽  
pp. 1156-1160 ◽  
Author(s):  
Daphne A. C. Stapels ◽  
Peter W. S. Hill ◽  
Alexander J. Westermann ◽  
Robert A. Fisher ◽  
Teresa L. Thurston ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Macrophage Polarization ◽  
Physiological State ◽  
Innate Immune Responses ◽  
Macrophage Infection ◽  
Immune Defenses ◽  
Type 3 Secretion System ◽  
Type 3 ◽  
Inflammatory Macrophage

Many bacterial infections are hard to treat and tend to relapse, possibly due to the presence of antibiotic-tolerant persisters. In vitro, persister cells appear to be dormant. After uptake of Salmonella species by macrophages, nongrowing persisters also occur, but their physiological state is poorly understood. In this work, we show that Salmonella persisters arising during macrophage infection maintain a metabolically active state. Persisters reprogram macrophages by means of effectors secreted by the Salmonella pathogenicity island 2 type 3 secretion system. These effectors dampened proinflammatory innate immune responses and induced anti-inflammatory macrophage polarization. Such reprogramming allowed nongrowing Salmonella cells to survive for extended periods in their host. Persisters undermining host immune defenses might confer an advantage to the pathogen during relapse once antibiotic pressure is relieved.

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