Characterization of Bacillus velezensis 32a metabolites and their synergistic bioactivity against crown gall disease.

Crown gall disease caused by Agrobacterium tumefaciens is considered to be the main bacterial threat of stone fruit plants in Mediterranean countries. In a previous study, Bacillus velezensis strain 32a was isolated from Tunisian rhizosphere soil and revealed high antagonistic potential against A. tumefaciens strains.

Bacterial endophytes inhabiting desert plants provide protection against seed rot caused by Fusarium verticillioides and promote growth in maize.

Background: Fusarium maize ear and root rot disease caused by Fusarium verticillioides has become one of the most serious fungal diseases associated with maize production. Due to their abilities to promote plant development and manage diseases, bacterial endophytes provide a more promising approach for treating this vascular disease.

Results: This work was undertaken for the selection and identification of promising isolates as plant growth promoters and biocontrol agents against F.

Desirable traits for a good biocontrol agent against fire blight disease.

Aims: This study aimed to improve the screening strategy for the selection of biocontrol agents with high biocontrol efficacy against fire blight disease.

Methods And Results: A two-step screening procedure consisting of in-vitro laboratory tests and an ex-vivo test system using detached pear leaves was applied to 43 Bacillus strains originated from the rhizosphere and the aerial parts of apple and pear plants. The grouping of the studied strains and the tested traits based on the principal component analysis and the two-way hierarchical cluster analysis showed that siderophore production and biofilm formation are the most desirable traits in a Bacillus biocontrol agent to control fire blight disease and that rhizospheric originating strains are the most effective.

Two Novel Strains ( and Species) with Promising Potential for the Biocontrol of , the Causal Agent of Septoria Tritici Blotch of Wheat.

Two novel Algerian field-collected isolates were selected for their antifungal activity against (teleomorph ). The novel strains, termed Alg.24B1 and Alg.

Agrobacterium tumefaciens C58 presence affects Bacillus velezensis 32a ecological fitness in the tomato rhizosphere.

The persistence of pathogenic Agrobacterium strains as soil-associated saprophytes may cause an inconsistency in the efficacy of the biocontrol inoculants under field condition. The study of the interaction occurring in the rhizosphere between the beneficial and the pathogenic microbes is thus interesting for the development of effective biopesticides for the management of crown gall disease. However, very little is still known about the influence of these complex interactions on the biocontrol determinants of beneficial bacteria, especially Bacillus strains.

Lipopeptides from Bacillus amyloliquefaciens strain 32a as promising biocontrol compounds against the plant pathogen Agrobacterium tumefaciens.

Despite the potential biological importance of lipopeptides from Bacillus amyloliquefaciens as antimicrobial compounds, their effects on Agrobacterium tumefaciens biofilms have not been previously studied. These latter are important virulence factors for the development and re-occurrence of crown gall disease. As part of the development of a new biopesticide acting as anti-biofilm and biocontrol agent, we investigated for the first time the ability of a mixture of lipopeptides produced by B.

Comparison of reverse hybridization and ompA sequencing methods applied on Chlamydia trachomatis strains from Tunisia.

Two techniques based on ompA amplification of Chlamydia trachomatis were compared, being reverse hybridization (RHM) and ompA sequencing (OSA), to investigate the concordance between them and to study the epidemiological relevance of each method. In addition, phylogenetic analysis was performed on the ompA sequences. One hundred and seven C.

Antibiosis and Gene Presence As Prevalent Traits for the Selection of Efficient Biocontrol Agents against Crown Gall Disease.

This study aimed to improve the screening method for the selection of biocontrol agents against crown gall disease. The relationship between the strain biocontrol ability and their studied traits was investigated to identify the most important factors to be considered for the selection of effective biocontrol agents. In fact, previous selection procedure relying only on antibacterial activity was shown to be not suitable in some cases.

Identification of a dominant Chlamydia trachomatis strain in patients attending sexual transmitted infection clinic and female sex workers in Tunisia using a high resolution typing method.

Background: The distribution of Chlamydia trachomatis genotypes in Tunisia was previously studied using the reverse hybridization method. In this study, we used multilocus sequence typing (MLST) to describe Chlamydia trachomatis genetic diversity among heterosexual populations in Tunisia. The obtained sequence types (STs) were compared with those from a heterosexual population from Amsterdam, the Netherlands.

Lipopeptides from a novel Bacillus methylotrophicus 39b strain suppress Agrobacterium crown gall tumours on tomato plants.

Background: This study aims to characterise the antibacterial activity of a novel Bacillus methylotrophicus strain named 39b against tumourigenic Agrobacterium tumefaciens C58 and B6 strains. It also aims to identify the compound that is responsible for its activity and to evaluate its efficiency to control crown gall disease in tomato plants.

Results: B.

Chlamydia trachomatis genovar distribution in clinical urogenital specimens from Tunisian patients: high prevalence of C. trachomatis genovar E and mixed infections.

Background: This epidemiological study was carried out in Sfax (south of Tunisia) and focused on genital Chlamydia trachomatis (C. trachomatis) genovar distribution.

Methods: One hundred and thirty seven genital samples from 4067 patients (4.

Sexually transmitted infections among female sex workers in Tunisia: high prevalence of Chlamydia trachomatis.

Objectives: The aim of this study was to determine the prevalence of Chlamydia trachomatis infection and other sexually transmitted infections (STI) in female sex workers (FSW) in Tunisia.

Methods: 188 prostitutes from three Tunisian towns were enrolled at their weekly medical visit. Demographic and sexual behaviour data were collected.

A proposed mouse model to study male infertility provoked by genital serovar E, Chlamydia trachomatis.

Chlamydia trachomatis is a common sexually transmitted pathogen. The impact of chlamydial infection on male infertility is controversial. The aim of this study was to assess the role of C trachomatis human genital serovar E on sperm function, induction of apoptosis in spermatozoa, and reproductive performance, using the Swiss male mice model.

Diagnostic value of enzyme-linked immunosorbent assays using hypothetical proteins CT226 and CT795 as antigens in Chlamydia trachomatis serodiagnosis.

The CT226 and the CT795 proteins were produced as purified recombinant proteins and were used as antigens in enzyme-linked immunosorbent assay (ELISA) tests for the detection of Chlamydia trachomatis IgG antibodies. The performances of the developed ELISA tests were compared with our in-house microimmunofluorescence test and the species-specific pELISA test using a panel of 342 sera. Our results indicate that the performance of the CT795 ELISA test was higher than that of the CT226 ELISA test according to the microimmunofluorescence and to the pELISA.

Evaluation of an in silico predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of Chlamydia trachomatis infections.

Background: The OmcB protein is one of the most immunogenic proteins in C. trachomatis and C. pneumoniae infections.

Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of Chlamydophila pneumoniae IgA antibodies.

Background: Serologic diagnosis of Chlamydophila pneumoniae (Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measurement of Cpn antibodies.