Evaluation of probiotic properties of Levilactobacillus brevis isolated from hawthorn vinegar.

Probiotic microorganisms are increasing their interest today due to the benefits they provide to humans. Vinegar is the process of processing foods containing carbohydrates that can be fermented by acetic acid bacteria and yeasts. Hawthorn vinegar is also important in terms of amino acids, aromatic compounds, organic acids, vitamins and minerals it contains. Depending on the variety of microorganisms in it, the content of hawthorn vinegar changes, especially its biological activity. Bacteria were isolated from handmade hawthorn vinegar obtained in this study. After performing its genotypic characterization, it has been tested that it can grow in low pH environment, survive in artificial gastric and small intestinal fluid, survive against bile acids, surface adhesion characteristics, antibiotic susceptibility, adhesion, and degrade various cholesterol precursors. According to the results obtained, the studied isolate is Levilactobacillus brevis, it can reproduce best at pH 6.3, survives 72.22% in simulated gastric juice, 69.59% in small intestinal fluid, and 97% adhesion to HTC-116. Partially reproduces even in the presence of 2% ox-bile, surface hydrophobicity is 46.29% for n-hexadecane. It has been determined that it can degrade 4 different cholesterol precursors except for Sodium thioglycolate and is generally resistant to antibiotics except for CN30 and N30. Considering the experimental findings of Levilactobacillus brevis isolated from hawthorn vinegar for the first time, it can be said that Levilactobacillus brevis has probiotic properties.

Complete genome sequence of Buttiauxella phage vB_ButM_GuL6.

We present here the results of the analysis of the complete genome sequence of a lytic bacteriophage, vB_ButM_GuL6, which is the first virus isolated from Buttiauxella. Electron microscopy revealed that vB_ButM_GuL6 belongs to the family Myoviridae, order Caudovirales. The genome of vB_ButM_GuL6 is a linear, circularly permuted 178,039-bp dsDNA molecule with a GC content of 43.4%. It has been predicted to contain 282 protein-coding genes and two tRNA genes, tRNA-Met and tRNA-Gly. Using bioinformatics approaches, 99 (36%) of the vB_ButM_GuL6 genes were assigned a putative function. Genome-wide comparisons and phylogenetic analysis indicated that vB_ButM_GuL6 represents a new species of the subfamily Tevenvirinae and is most closely related to Escherichia virus RB43. These phages, together with Cronobacter phages Miller, CfP1, and IME-CF2, likely form a new genus within the subfamily Tevenvirinae.

Occurrence of entomopathogenic fungi in tejocote (Crataegus mexicana) orchard soils and their pathogenicity against Rhagoletis pomonella.

AIMS: To determine the abundance and diversity of entomopathogenic fungi in tejocote orchard soils and evaluate their ability to infect Rhagoletis pomonella Walsh., the main pest of tejocote. METHODS AND RESULTS: Surveys were made in two locations in Mexico state and two in Puebla state. Soil from selected locations was baited for entomopathogenic fungi with Galleria mellonella (L.). All isolates were identified morphologically to genus level and to species level using Bloc and elongation factor 1-α gene sequence information, respectively; Beauveria bassiana ((Bals.-Criv.) Vuill.), B. pseudobassiana (S.A. Rehner & Humber) and Metarhizium robertsii (J.F. Bisch., Rehner & Humber) were found, with B. bassiana being the most abundant and widely distributed. Pathogenicity of five selected B. bassiana isolates and three M. robertsii isolates was evaluated against larvae and pupae of R. pomonella. All isolates infected larvae resulting in an average mortality of 35%. Pupae were not susceptible; however, adults emerging from inoculated pupae did die due to infection. CONCLUSIONS: At least three species of entomopathogenic fungi are present in the soil from tejocote orchards, with B. bassiana being the most abundant and widely distributed. Rhagoletis pomonella larvae were more susceptible to infection than pupae. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study has produced new information about the distribution of entomopathogenic fungi in cultivated soils from this region of North America, contributing to a better understanding of their natural occurrence and underpinning the development of biological control approaches.

Comparative analysis of the Hrp pathogenicity island of Rubus- and Spiraeoideae-infecting Erwinia amylovora strains identifies the IT region as a remnant of an integrative conjugative element.

The Hrp pathogenicity island (hrpPAI) of Erwinia amylovora not only encodes a type III secretion system (T3SS) and other genes required for pathogenesis on host plants, but also includes the so-called island transfer (IT) region, a region that originates from an integrative conjugative element (ICE). Comparative genomic analysis of the IT regions of two Spiraeoideae- and three Rubus-infecting strains revealed that the regions in Spiraeoideae-infecting strains were syntenic and highly conserved in length and genetic information, but that the IT regions of the Rubus-infecting strains varied in gene content and length, showing a mosaic structure. None of the ICEs in E. amylovora strains were complete, as conserved ICE genes and the left border were missing, probably due to reductive genome evolution. Comparison of the hrpPAI region of E. amylovora strains to syntenic regions from other Erwinia spp. indicates that the hrpPAI and the IT regions are the result of several insertion and deletion events that have occurred within the ICE. It also suggests that the T3SS was present in a common ancestor of the pathoadapted Erwinia spp. and that insertion and deletion events in the IT region occurred during speciation.

Cacopsylla melanoneura has no relevance as vector of apple proliferation in Germany.

Long-term field surveys on the distribution and natural infection rates of Cacopsylla melanoneura were carried out in commercial and abandoned apple-proliferation-infected orchards throughout Germany, northern Switzerland, and eastern France. Although the infection rates of some orchards reached up to 80%, only 0.09% of all C. melanoneura collected on apple were infected by the pathogen 'Candidatus Phytoplasma mali'. Despite higher population densities, no infected individual was found on wild hawthorn. Individuals of C. melanoneura were not able to transmit phytoplasmas to healthy plants, and even the acquisition of 'Ca. P. mali' from infected plants was very inefficient. Quantitative real-time polymerase chain reaction demonstrated that the very few infected individuals of C. melanoneura harbored phytoplasma concentrations 10,000 times lower than individuals of C. picta, the main vector species in Germany. Oviposition bioassays showed that hawthorn is the preferred reproduction host plant for C. melanoneura in Germany, not apple. Because hawthorn is not a suitable host plant for 'Ca. P. mali', it does not play a role in the spread of apple proliferation. In contrast to data reported from northwestern Italy, C. melanoneura developed on either apple or hawthorn has no relevance as a vector of apple proliferation in Germany. The existence of epidemiologically different populations is proposed.

Childhood delayed septic arthritis of the knee caused by Serratia fonticola.

We report a first documented case of Serratia fonticola infection in a child with septic arthritis, after falling off his bicycle and an infection with hawthorn thorns. The aetiologic agent was found to be a S. fonticola strain which was first isolated from two synovial fluid samples, only after culture enrichment, with failure of DNA amplification. Accurate diagnostic was done, despite S. fonticola is often considered as an opportunistic pathogenic bacterium. Alone ciprofloxacin treatment was not sufficient to counteract the infection, which was eradicated only after surgical drainage performed twice successively, with secondary removal of a remaining thorn, and treatment with third generation cephalosporin combined with ciprofloxacin for another three months.

Isolation and characterisation of Beauveria bassiana isolates from phylloplanes of hedgerow vegetation.

A leaf imprinting technique combined with a selective medium was used to document the natural occurrence of Beauveria bassiana on phylloplanes of typical hedgerow plants (grasses, stinging nettle and hawthorn) in May, July and September in a hedgerow in Denmark. The density of B. bassiana (as measured by numbers of colony forming units) was greatest in September and on lower nettle leaves. B. bassiana was isolated from phylloplanes in a different hedgerow the following year and a similar picture of occurrence was found. Genetic diversity of selected in vitro isolates were characterised by Universally Primed (UP) PCR, and 13 distinguishable banding patterns were found at the two localities. Of these, four were shared between the field sites and all plant species harboured isolates of B. bassiana with at least two different banding patterns. The isolation method described represents a valuable tool for studying naturally occurring B. bassiana and for rapid isolation of indigenous strains of the fungus for future development of biocontrol agents. The significance of the findings for the life-cycle of B. bassiana is discussed.

Bacteriocin Serratine-P as a biological tool in the control of fire blight Erwinia amylovora.

Fire blight, caused by the bacterium Erwinia amylovora (Burill Winslow et al.), is the most important bacterial disease in European pear growing. It can cause a lot of damage in some countries on apple and on pear trees in orchards and also in the fruit tree nurseries. In Belgium, the disease is present since 1972. Control of fire blight in Belgian fruit orchards is made on a broad basis of measurements in and around the fruit trees. The use of an antibiotic is allowed for application only during the primary blossom period under strict controlled regulations. The use of antobiotics in agriculture is strongly discussed on the European level today and will probably disappear in the near future. Therefore, the research on fire blight control concentrates on the possibilities of biological control with antagonistic bacteria such as Pantoea agglomerans (Erwinia herbicola), Bacillus subtilis or Pseudomonas syringae strain A 506. The use of Serratine-P, a phage tail-like bacteriocin, produced by Serratia plymiticum, shows an interesting antibacterial activity against Erwinia amylovora. Its mode of action consists in the perforation of the cytoplasmic membrane of the target cell, inducing perturbations in cellular exchanges and a final lysis of the bacterial cell. In this paper some trials are discussed on the use of Serratine-P at different doses and on different infection types on pear trees. The results indicate interesting protection possibilities on blossom- and fruit infections.