scholarly journals Biochemical and Molecular Characterization of 18 Agrobacterium vitis Isolates

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 439E-439
Author(s):  
Fokar Mohamed ◽  
Richard Durham

Agrobacterium vitis is the causal organism of crown gall in grapevine. Infection is particularly severe in areas that experience winter damage to vines. Improving resistance to A. vitis will require a detailed knowledge about this organism. In this study, 18 grapevine isolates of A. vitis were collected from different locations near Lubbock, Texas. Isolates were subjected to a phenotypic characterization using 12 biochemical tests, including production of alkali from L-tartrate, production of 3-ketolactose, utilization of citrate, and others. Previously characterized isolates of A. vitis and A. tumefaciens obtained from the American Type Culture Collection served as positive and negative controls in these assays. Isolates were also evaluated for host range, tumor morphology, and opine utilization, and were compared at the molecular level by restriction fragment length polymorphism analysis of the oncogenic regions of the T-DNA plasmid. Although all isolates were able to metabolize tartrate and grow on Roy–Sasser media, there was much variability based on other tests. Twelve of 18 isolates were able to utilize octopine as a sole carbon source. All isolates tested thus far have been pathogenic on tomato and tests on grapevines are underway.

Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 201-209 ◽  
Author(s):  
A. J. Gevens ◽  
R. S. Donahoo ◽  
K. H. Lamour ◽  
M. K. Hausbeck

Green and yellow snap bean plants with water-soaked foliar lesions, stem necrosis, pod blight, and overall plant decline were observed in four commercial fields in three Michigan counties during 2003 to 2005. All fields were cropped to cucurbits that exhibited symptoms of Phytophthora capsici infection in recent years. In all, 680 isolates of P. capsici were obtained from bean stems, petioles, leaves, and pods; the pathogen was not recovered from roots. Koch's postulates were completed with representative isolates, confirming P. capsici as the causal organism. Select isolates also were pathogenic on cucumber fruit, causing symptoms consistent with P. capsici infection. The majority of the P. capsici isolates collected were sensitive to the fungicide mefenoxam and were of the A1 mating type. Under laboratory conditions, six P. capsici isolates from snap bean (2003) were pathogenic on 12 different commercial bean cultivars, including soybean. Infected bean plants exhibited water-soaked lesions, foliar necrosis, and wilting. We subjected 131 isolates collected from 2003 and 2004 to amplified fragment length polymorphism analysis to investigate diversity among isolates and geographical populations and to determine whether bean P. capsici isolates were similar to isolates from a cucurbit host. This is the first in-depth study of P. capsici on snap bean in Michigan. Although bean cultivars previously were considered a suitable rotation for crops susceptible to P. capsici, this is no longer a recommended practice.


Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Harmesh Sahay ◽  
Surendra Singh ◽  
Rajeev Kaushik ◽  
Anil Saxena ◽  
Dilip Arora

AbstractCulture dependent phenotypic characterization and 16S rDNA based phylogenetic analyses were applied to study the aerobic halophilic bacterial population present in the Pulicat brackish-water Lake of India. Five different media were employed for isolation of bacteria. A total of 198 morphotypes were recovered, purified and screened for salt tolerance in nutrient agar medium amended with 5–25% NaCl. Based on 16S rDNA restriction fragment length polymorphism analysis with three restriction endonucleases, 51 isolates tolerant to 5% or more NaCl were grouped into 29 clusters. Phylogenetic analysis using 16S rRNA gene sequences revealed that 29 strains could further be allocated into two clades: 19 to Firmicutes and 10 to γ-Proteobacteria. Firmicutes included low G+C Gram-positive bacteria related to family Bacillaceae, which included five genera Bacillus, Virgibacillus, Rummelibacillus, Alkalibacillus and Halobacillus. Another genera included in Firmicutes was Salimicrobium halophilum. In the γ-Proteobacteria group, all the isolates belonged to one genus Halomonas, represented by six different species Halomonas salina, H. shengliensis, H. salifodinae, H. pacifica, H. aquamarina and H. halophila. Most of the isolates exhibited cellulase, xylanase, amylase and protease activities.


2021 ◽  
Vol 26 (6) ◽  
pp. 3090-3094
Author(s):  
IONUT SORESCU ◽  
LUMINITA MARIA ROMASCU ◽  
MARIA IONESCU ◽  
ANDREI POPOVICI ◽  
COSTIN STOICA ◽  
...  

Objective: the isolation and phenotypically identification of a Gallibacterium anatis biovar haemolytica strain from a hen with hemorrhagic ooforitis; the antimicrobial susceptibility testing of this isolate. Methods and results: a strain of G. anatis biovar haemolytica, was isolated and phenotypic identified by morphological, cultural and biochemical characters examination, with API 20 E, API 20 NE, API STAPH, API ZYM tests and ABIS online software. The antimicrobial susceptibility of the isolate was performed using the standard disk diffusion method. Conclusions: a strain of G. anatis biovar haemolytica was isolated and phenotypically identified from a hen. From our knowledge, this is the first reporting in Romania of isolation and identification of G. anatis biovar haemolytica. The Gah IDSA 161 strain could be phenotypic identified only by ABIS on line software, Pasteurellaceae Database version, unifying the results of four API kits and other biochemical tests. The isolate showed a multi-drug resistant profile to tetracyclines (tetracycline, oxitetracycline, doxicyclin), floroquinolones (enrofloxacin, ciprofloxacin), ampicillin, trimethoprim, nalidixic acid, clindamycin, and it was susceptible to sulfonamide, sulfomethoxazole/trimethoprim, gentamicin, cephalothin, streptomycin, amoxicilin/clavulanic acid.


1994 ◽  
Vol 40 (2) ◽  
pp. 152-154
Author(s):  
Robert S. Fulghum

Phenotypic characterization of Pseudomonas strain WRF shows it to be a member of Pseudomonas putida most closely resembling biovar A. The organism has been deposited in the American Type Culture Collection as ATCC 35546.Key words: Pseudomonas WRF characterization, Pseudomonas putida, one-carbon metabolism, siderophores, peptide-bound flavin enzymes.


2009 ◽  
Vol 47 (01) ◽  
Author(s):  
K Hochrath ◽  
S Hillebrandt ◽  
F Lammert ◽  
B Rathkolb ◽  
H Fuchs ◽  
...  

Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.


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