scholarly journals Isolation and Characterization of Virulence Gene psvA on a Plasmid of Pseudomonas syringae pv. eriobotryae.

1999 ◽  
Vol 65 (5) ◽  
pp. 501-509 ◽  
Author(s):  
Hiroshi KAMIUNTEN
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Gene ◽  
Isolation And Characterization

scholarly journals Isolation and Characterization of the Gene Coding for the Amidinotransferase Involved in the Biosynthesis of Phaseolotoxin in Pseudomonas syringae pv. phaseolicola

2001 ◽  
Vol 14 (4) ◽  
pp. 545-554 ◽  
Author(s):  
Gustavo Hernández-Guzmán ◽  
Ariel Alvarez-Morales
Keyword(s):  
Aspartic Acid ◽  
Pseudomonas Syringae ◽  
Sequence Similarity ◽  
Insertion Mutant ◽  
Halo Blight ◽  
Streptomyces Spp ◽  
Isolation And Characterization ◽  
Gene Coding ◽  
Blight Disease

Pseudomonas syringae pv. phaseolicola is the causal agent of the “halo blight” disease of beans. A key component in the development of the disease is a nonhost-specific toxin, Nδ-(N'-sulphodiaminophosphinyl)-ornithyl-alanyl-homoarginine, known as phaseolotoxin. The homoarginine residue in this molecule has been suggested to be the product of Larginine:lysine amidinotransferase activity, previously detected in extracts of P. syringae pv. phaseolicola grown under conditions of phaseolotoxin production. We report the isolation and characterization of an amidinotransferase gene (amtA) from P. syringae pv. phaseolicola coding for a polypeptide of 362 residues (41.36 kDa) and showing approximately 40% sequence similarity to Larginine:inosamine-phosphate amidinotransferase from three species of Streptomyces spp. and 50.4% with an Larginine:glycine amidinotransferase from human mitochondria. The cysteine, histidine, and aspartic acid residues involved in substrate binding are conserved. Furthermore, expression of the amtA and argK genes and phaseolotoxin production occurs at 18°C but not at 28°C. An amidinotransferase insertion mutant was obtained that lost the capacity to synthesize homoarginine and phaseolotoxin. These results show that the amtA gene isolated is responsible for the amidinotransferase activity detected previously and that phaseolotoxin production depends upon the activity of this gene.

scholarly journals Isolation and characterization of a sequence type 25 carbapenem-resistant hypervirulent Klebsiella pneumoniae from the mid-south region of China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Li ◽  
Zi-Yan Huang ◽  
Ting Yu ◽  
Xiao-Yan Tao ◽  
Yong-Mei Hu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Control Strategies ◽  
Virulence Gene ◽  
Sequence Type ◽  
Pfge Typing ◽  
Main Cluster ◽  
Carbapenem Resistant ◽  
Isolation And Characterization

Abstract Background The molecular characterization of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates is not well studied. Our goal was to investigate the molecular epidemiology of CR-hvKP strains that were isolated from a Chinese hospital. Results All clinical carbapenem-resistant K. pneumoniae (CR-KP) isolates were collected and identified from patient samples between 2014 and 2017 from a Chinese hospital. The samples were subjected to screening for CR-hvKP by string test and the detection of the aerobactin gene. CR-hvKP isolates were further confirmed through neutrophil phagocytosis and a mice lethality assay. The CR-hvKP isolates were investigated for their capsular genotyping, virulence gene profiles, and the expression of carbapenemase genes by PCR and DNA sequencing. Multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to exclude the homology of these isolates. Twenty strains were identified as CR-hvKP. These strains were resistant to imipenem and several other antibiotics, however, most were susceptible to amikacin. Notably, two isolates were not susceptible to tigecycline. Capsular polysaccharide synthesis genotyping revealed that 17 of the 20 CR-hvKP strains belonged to the K2 serotype, while the others belonged to serotypes other than K1, K2, K5, K20, and K57. The strains were found to be positive for 10 types of virulence genes and a variety of these genes coexisted in the same strain. Two carbapenemase genes were identified: blaKPC-2 (13/20) and blaNDM-1 (1/20). PFGE typing revealed eight clusters comprising isolates that belonged to MLST types ST25, ST11 and ST375, respectively. PFGE cluster A was identified as the main cluster, which included 11 isolates that belong to ST25 and mainly from ICU department. Conclusions Our findings suggest that hospital-acquired infections may contribute in part to the CR-hvKP strains identified in this study. It also suggests that ST25 CR-hvKP strain has a clonal distribution in our hospital. Therefore, effective surveillance and strict infection control strategies should be implemented to prevent outbreak by CR-hvKP strains in hospitals setting.

Isolation and Characterization of Bacteriophages Against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

2016 ◽  
Vol 26 (2) ◽  
pp. 385-393 ◽  
Author(s):  
Ji-Gang Yu ◽  
Jeong-A Lim ◽  
Yu-Rim Song ◽  
Sunggi Heu ◽  
Gyoung Hee Kim ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Canker ◽  
Canker Disease ◽  
Isolation And Characterization

Isolation and characterization of syringacin W-1, a bacteriocin produced by Pseudomonas syringae pv. syringae

1986 ◽  
Vol 32 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Mary L. Smidt ◽  
Anne K. Vidaver
Keyword(s):  
Pseudomonas Syringae ◽  
Inner Core ◽  
Deae Cellulose ◽  
Sedimentation Coefficient ◽  
Temperature Stability ◽  
Ultrafiltration Rate ◽  
Isolation And Characterization ◽  
Outer Sheath ◽  
Shaped Particle

Syringacin W-1, a bacteriocin produced by Pseudomonas syringae pathovar syringae strain PsW-1, is a 20 × 75 nm rod-shaped particle composed of an inner core and outer sheath. Production of syringacin W-1 in broth was induced with 0.1 μLg/mL mitomycin C. The bacteriocin was purified from culture lysates using ultrafiltration, rate zonal centrifugation in sucrose gradients, and DEAE-cellulose chromatography. Purity was evaluated by subjecting syringacin W-1 preparations to electrophoresis in polyacrylamide gels under nondenaturing and denaturing conditions. The chemical composition was principally protein (67.2%), and also comigrating nonessential carbohydrate (10–35%). The physical properties of purified syringacin W-1 were a sedimentation coefficient of 104 for rod-shaped particles, pH stability of 5.2–8.2, and temperature stability from −20 to 40 °C. The bacteriocin was resistant to proteases and to 12 of 13 surfactants tested.

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