Skip to main content

Characterization of Erwinia amylovora strains

The three main aims of the study were the assessment of the genetic relationship between a deviating Erwinia amylovora strain isolated from Amelanchier sp. (Maloideae) grown in Canada and other strains from Maloideae and Rosoideae, the investigation of the variability of the PstI fragment of the pEA29 plasmid using restriction fragment length polymorphism (RFLP) analysis and the determination of the number of short-sequence DNA repeats (SSR) by DNA sequence analysis in representative strains.

METHODS AND RESULTS:
Ninety-three strains obtained from 12 plant genera and different geographical locations were examined by repetitive-sequences PCR using Enterobacterial Repetitive Intergenic Consensus, BOX and Repetitive Extragenic Palindromic primer sets.

Upon the unweighted pair group method with arithmetic mean analysis, a deviating strain from Amelanchier sp. was analysed using amplified ribosomal DNA restriction analysis (ARDRA) analysis and the sequencing of the 16S rDNA gene.

This strain showed 99% similarity to other E. amylovora strains in the 16S gene and the same banding pattern with ARDRA. The RFLP analysis of pEA29 plasmid using MspI and Sau3A restriction enzymes showed a higher variability than that previously observed and no clear-cut grouping of the strains was possible.

The number of SSR units reiterated two to 12 times. The strains obtained from pear orchards showing for the first time symptoms of fire blight had a low number of SSR units.

CONCLUSIONS:
The strains from Maloideae exhibit a wider genetic variability than previously thought. The RFLP analysis of a fragment of the pEA29 plasmid would not seem a reliable method for typing E. amylovora strains. A low number of SSR units was observed with first epidemics of fire blight.

SIGNIFICANCE AND IMPACT OF THE STUDY:
The current detection techniques are mainly based on the genetic similarities observed within the strains from the cultivated tree-fruit crops. For a more reliable detection of the fire blight pathogen also in wild and ornamentals Rosaceous plants the genetic features of deviating E. amylovora strains have to be studied in detail.


"Characterization of Erwinia amylovora strains from different host plants using repetitive-sequences PCR analysis, and restriction fragment length polymorphism and short-sequence DNA repeats of plasmid pEA29.
Barionovi D, Giorgi S, Stoeger AR, Ruppitsch W, Scortichini M
J Appl Microbiol. 2006 May ; 100(5): 1084-94 (Hubmed.org)



Highlight :
Treatment Of Rosacea | Acne Rosacea Antibiotic | Acne Rosacea | Rosacea Creams

Popular posts from this blog

Prevalence Of And Associated Factors For Dry Eye In A Spanish adult population

To estimate the prevalence of dry eye and to investigate its relationship with lifestyle and systemic factors in a general adult population in north-western Spain. METHODS: A dry eye questionnaire was administered and objective tests were performed in 654 individuals [mean age (Standard deviation): 63.6 (14.4) years, range: 40-96, 37.2% males]. Subjects were considered symptomatic when one or more of the symptoms of the questionnaire were present often or all the time. Schirmer test or= 3 and fluorescein staining >or= 1 were considered indicative of signs. Dry eye was defined as the simultaneous presence of symptoms and at least one sign. A design based analysis was performed and all calculations were weighted to give unbiased estimates. RESULTS: Dry eye prevalence was 11.0% (95%confidence interval [CI] 8.6-13.3). Dry eye was found to be more frequent in women (11.9%, 95%CI 8.8-15.1) than in men (9.0%, 95%CI 5.3-12.6), and was significantly associated with aging (p autoimmune diseas...
Read more

Treatments For Rosacea

The specific treatments for rosacea is determined by your physician based on: Your age, general health and medical history. How advanced is the eruption. Tolerance to specific medications, procedures or therapies. Their expectations for the trajectory of the eruption. Your opinion or preference. Treatments for rosacea may include : Modifications to diet Antibiotics. Cortisone ointment. Laser surgery Use sunscreen with a sun protection factor Currently there are several treatments for rosacea are used, depending on the events that it has. At the initial stage, to prevent the dilation of blood vessels and the consequent need to avoid red hot environments, exposure to sunlight, extreme changes in temperature and food hot or too much seasoning. When pustules that resemble pimples, prescribed oral antibiotics such as tetracycline. Another alternative treatments for rosacea is the topical antibiotics such as metronidazole. Also is using retinoids, which regulate the sebum production of the ...
Read more

Treatment Of Rosacea With Intense Pulsed Light

Rosacea is a common skin condition but the treatments currently available are not satisfactory. OBJECTIVES: To assess the efficacy of intense pulsed light (IPL) for treatment of stage I rosacea (flushing, erythema and telangiectasia). METHODS: Thirty-four patients were treated, 25 women and nine men, mean age 47 years. The treatment employed was IPL 515-1200 nm, with a 560 nm cut-off filter. The fluence range was 24-32 J cm(-2). Four treatments were administered on the face at 3-week intervals. Erythema values were measured at baseline and at the end of the treatment period on the cheeks and chin. Digital photographs were assessed by a consultant dermatologist on a 10-point visual analogue scale (VAS). Patients' assessments were also made using a 10-point VAS. Outcome measures were repeated 6 months after treatment. RESULTS: After four treatments the mean reduction of the erythema values was 39% on the cheeks (P The severity of rosacea was reduced on average by 3.5 points on the 10...
Read more