Use Of Isolation Research Articles

Исследование методов экстракции ДНК из сырого молока

This article presents the results of work on the study of the effectiveness of various methods of DNA isolation for use in the analysis of biosafety of milk and dairy products by PCR. Some components of milk, such as proteases and calcium ions, can significantly reduce the effectiveness of PCR and lead to distortion of the results. We have given quantitative (DNA concentration) and qualitative assessments (amplification followed by gel electrophoresis) to commercial DNA purification kits «DNA-sorb-S-M» and «DNA-Extran-2». The results obtained indicate the applicability of the selected kits for the isolation of deoxyribonucleic acids from raw milk, the quality and quantity of which allows them to be used for the successful subsequent molecular genetic analysis of the safety and authenticity of milk.

Interlaboratory evaluation of quality control methods for circulating cell-free DNA extraction

Analysis of circulating cell-free DNA (ccfDNA) isolated from liquid biopsies is rapidly being implemented into clinical practice. However, diagnostic accuracy is significantly impacted by sample quality and standardised approaches for assessing the quality of ccfDNA are not yet established. In this study we evaluated the application of nucleic acid “spike-in” control materials to aid quality control (QC) and standardisation of cfDNA isolation for use in in vitro diagnostic assays. We describe an approach for the design and characterisation of in-process QC materials, illustrating it with a spike-in material containing an exogenous Arabidopsis sequence and DNA fragments approximating to ccfDNA and genomic DNA lengths. Protocols for inclusion of the spike-in material in plasma ccfDNA extraction and quantification of its recovery by digital PCR (dPCR) were assessed for their suitability for process QC in an inter-laboratory study between five expert laboratories, using a range of blood collection devices and ccfDNA extraction methods. The results successfully demonstrated that spiking plasmid-derived material into plasma did not deleteriously interfere with endogenous ccfDNA recovery. The approach performed consistently across a range of commonly-used extraction protocols and was able to highlight differences in efficiency and variability between the methods, with the dPCR quantification assay performing with good repeatability (generally CV <5%). We conclude that initial findings demonstrate that this approach appears “fit for purpose” and spike-in recovery can be combined with other extraction QC metrics for monitoring the performance of a process over time, or in the context of external quality assessment.

An alternative approach for daily perineal care of patients with indwelling urinary catheterization: Photodynamic inactivation with cationic porphyrin derivatives

Background: Catheter-associated urinary tract infections (CAUTI) constitute a significant portion of healthcare-associated infections. Using antiseptic for routine daily perineal care of patients with IUC may reduce CAUTIs. Aim: This study aimed to examine antimicrobial photodynamic inactivation (aPDI) against clinical isolates for use in the daily perineal care of patients with IUC. In addition, it was also aimed to compare the antimicrobial activities of aPDI and 0.1% chlorhexidine gluconate. Methods: In this in-vitro study, cationic porphyrin derivatives (CPDs) were used as photosensitizers in the experiments. CPDs, named PM, PE, PN, and PL were synthesized by the researchers. A diode laser device emitting light with a wavelength of 450 nm (blue light) was used as the light source. Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Klebsiella pneumoniae with multidrug-resistant (MDR) properties and Candida albicans were used. Photosensitizer (PS), aPDI, light (L), and control (C) groups in aPDI experiments; control (C) and chlorhexidine gluconate 0.1% groups were used in the chlorhexidine gluconate experiments. Survival was calculated based on CFU/mL in the control group. Results: In experiments, combinations of 25 J/cm² with 6.25 and 3.125 µM PM, PE reduced E. coli, K. pneumoniae, MRSA, and C. albicans survival in the range of 8.70 to 11.53 log₁₀. In aPDI experiments performed with 6.25 and 3.125 µM PN and PL concentrations at the same energy density, reductions in the range of 4.41 to 0.17 log₁₀ were observed in all four clinical isolates. In experiments where 1.5625 µM concentration was used, survival decreased in the range of 8.29 to 10.87 log₁₀ in PM and PE, while antimicrobial activity was limited in PN and PL. In the 0.1% chlorhexidine gluconate experiments, the survival reduction in all four clinical isolates ranged from 8.87 to 10.24 log₁₀. Conclusion: For PM and PE, a very strong aPDI was obtained in C. albicans, E.coli, K. pneumoniae, and MRSA at low concentrations and energy density. The same antimicrobial activity was found in experiments using 0.1% chlorhexidine gluconate. In this context, we would like to inform you that aPDI to be performed with a combination of 25 J/cm² at 6.25 and 3.125 µM concentrations of PM and PE has the potential to be an antiseptic in the daily perineal care of patients with IUC.

Performance‐based testing specifications for seismic isolators

AbstractThis paper presents a study that determines the conditions of testing for determining the bounding properties of seismic isolators for use in analysis and design in a test that is meant to be a replacement of tests Items 2(a) and 3 of ASCE/SEI‐7. Then separately, the study determines the conditions of testing for determining the adequacy of isolators in the maximum considered earthquake in a test is meant to be a replacement of test Item 4 of ASCE/SEI‐7. The test conditions are determined by performing analyses with models that account for the time‐variant properties of the isolators and by computing the resultant isolator displacements. In performing the work, a large number of isolation systems (total of 96 systems, single friction pendulum, triple friction pendulum and lead‐rubber), three different seismic hazards as measured by the spectral acceleration at the period of one second, and a large collection of bi‐directional ground motions with short‐ and long‐duration characteristics (71 pairs of each duration, 96 systems, three seismic hazards) were considered. Fundamental in this methodology is the use of analysis models in which the properties of the isolators (friction or characteristic strength) are dependent on the instantaneous temperature at the sliding interfaces or in the lead core.

Comparative Genomic Analysis Reveals Genetic Diversity and Pathogenic Potential of Haemophilus seminalis and Emended Description of Haemophilus seminalis.

Haemophilus seminalis is a newly proposed species that is phylogenetically related to Haemophilus haemolyticus. The distribution of H. seminalis in the human population, its genomic diversity, and its pathogenic potential are still unclear. This study reports the finding of our comparative genomic analyses of four newly isolated Haemophilus strains (SZY H8, SZY H35, SZY H36, and SZY H68) from human sputum specimens (Guangzhou, China) along with the publicly available genomes of other phylogenetically related Haemophilus species. Based on pairwise comparisons of the 16S rRNA gene sequences, the four isolates showed <98.65% sequence identity to the type strains of all known Haemophilus species but were identified as belonging to H. seminalis, based on comparable phenotypic and genotypic features. Additionally, the four isolates showed high genome-genome relatedness indices (>95% ANI values) with 17 strains that were previously identified as either "Haemophilus intermedius" or hemin (X-factor)-independent H. haemolyticus and therefore required a more detailed classification study. Phylogenetically, these isolates, along with the two previously described H. seminalis isolates (a total of 23 isolates), shared a highly homologous lineage that is distinct from the clades of the main H. haemolyticus and Haemophilus influenzae strains. These isolates present an open pangenome with multiple virulence genes. Notably, all 23 isolates have a functional heme biosynthesis pathway that is similar to that of Haemophilus parainfluenzae. The phenotype of hemin (X-factor) independence and the analysis of the ispD, pepG, and moeA genes can be used to distinguish these isolates from H. haemolyticus and H. influenzae. Based on the above findings, we propose a reclassification for all "H. intermedius" and two H. haemolyticus isolates belonging to H. seminalis with an emended description of H. seminalis. This study provides a more accurate identification of Haemophilus isolates for use in the clinical laboratory and a better understanding of the clinical significance and genetic diversity in human environments. IMPORTANCE As a versatile opportunistic pathogen, the accurate identification of Haemophilus species is a challenge in clinical practice. In this study, we characterized the phenotypic and genotypic features of four H. seminalis strains that were isolated from human sputum specimens and propose the "H. intermedius" and hemin (X-factor)-independent H. haemolyticus isolates as belonging to H. seminalis. The prediction of virulence-related genes indicates that H. seminalis isolates carry several virulence genes that are likely to play an important role in its pathogenicity. In addition, we depict that the genes ispD, pepG, and moeA can be used as biomarkers for distinguishing H. seminalis from H. haemolyticus and H. influenzae. Our findings provide some insights into the identification, epidemiology, genetic diversity, pathogenic potential, and antimicrobial resistance of the newly proposed H. seminalis.

Technology of protein isolate from peas (Pisum sativum var. arvense)

The object of research is pea (Pisum sativum var. arvense) and pea protein isolate. The chemical composition of pea (Pisum sativum var. arvense) was studied to determine its potential as a new raw material for obtaining protein isolate by pH-shifting treatment. The obtained results confirm the effectiveness of using peas to obtain protein isolate for use in the food industry instead of soy protein isolate. Peas are low in lipids (1.61 % on dry matter), high in crude protein (19.21 % on dry matter), ash (3.41 % on dry matter) and minerals (Se, Fe, Zn, Mn, Cu, Mg, P). The ratio of essential amino acids to replaceable amino acids (0.78), which is higher than the amount recommended by the World Health Organization. Vegetable protein is an alternative to animal protein in the food industry. Protein isolate from peas was obtained by pH-shifting treatment and its chemical composition and functional properties were determined. After pH-shifting treatment, the chemical composition of protein and mineral substances did not show significant changes. The protein content of pea protein isolate was 82.2 %, and the yield of pea protein isolate was 5.6 %. To confirm the functional properties of pea protein isolate, the indicators of moisture-holding capacity (1.05 ml/g) and fat-holding capacity (0.82 ml/g) were investigated. Peas and protein isolate from it showed high functional properties and high-quality chemical composition of proteins and minerals for use in the technology of sausage products, which should be the focus of further research.

Fermentation medium optimization, molecular modelling and docking analysis of the alginate lyase of a novel Pseudomonas sp. LB56 isolated from seaweed waste

Alginate lyase has the potential for the ecofriendly depolymerization of alginate and generation of value-added products important in agriculture, bioenergy, food processing, medical diagnostic and pharmaceutical industries. Substantial research has focused on the cost-effective production of alginate lyase via screening of potent microbial isolates for use as biocatalysts and the optimization of fermentation media with low-cost feedstocks. This study evaluated the alginate lyase-producing efficacy of a novel Pseudomonas sp. LB56 (GenBank accession no. MT176182) isolated from Sargassum seaweed waste. The feedstock for solid-state fermentation (SSF) was decomposed Sargassum biomass amended with cow dung. The production of alginate lyase was maximal using 9.5 g Sargassum, 14 g cow dung and at pH 8 after optimization via a 23–factorial central composite design. Comparative modelling and molecular docking studies were conducted to elucidate the 3D structure of the alginate lyase of this novel isolate, as well as to investigate its catalytic interactions with different polymeric sizes of alginate [polymannuronate (mannuronate disaccharide and mannuronate trisaccharide), polyguluronate (guluronate disaccharide and guluronate trisaccharide) and alginate]. The overall results suggest that biowaste (Sargassum seaweed amended with cow dung) can be used as a feedstock for economical production of alginate lyase. Additionally, the identified active site residues of alginate lyase, which were shared by different polymers of alginate, can be tailored via rational and/or combinatorial approaches for efficient biotransformation of alginate-enriched wastes into biologically active alginate oligomers and third generation biofuels.

Experimental investigation of a spherical rubber isolator for use in low income countries

This paper presents an experimental study of a low-cost seismic isolator that can be used for the protection of low-rise houses in low-income countries. The isolator is based on rolling of a rubber sphere on flat or spherical concrete surfaces. Using a closely spaced grid of such spheres may allow for avoiding of the diaphragm slab at the isolation level, or of reducing its thickness. Avoiding the cost of this extra slab is crucial for building seismically isolated low-rise dwellings economically feasible in low-income regions of the globe.The effects of the geometry of the rolling surface (i.e., flat or concave), of the diameter of the rolling sphere (i.e., 25, 50 or 100 mm), and of the applied compressive load on the seismic behavior of such isolation bearings were investigated. Initially, the rubber isolators were subjected to monotonic uniaxial compression to examine their behavior under vertical loading. Subsequently, cyclic tests were performed to obtain the lateral force–displacement diagram of the isolation system. Finally, a slab supported by 4 isolators was subjected to a group of 61 ground motions. Eight different configurations were tested, leading to a total of 488 dynamic tests.It was found that the restoring force of such systems can originate not only from the curvature of the concrete surface, but also from the vertical motion induced by the drastic change of the shape of the rubber spheres, as well. In fact, for the configurations tested, the vertical motion sourcing from shape of the deformed sphere was much larger than the vertical motion sourcing from the curvature of the concrete surfaces.Moreover, equations offering the coefficient of friction as a function of the vertical load, the size and the deformation of the sphere were derived. This is crucial for design, as the governing parameter for the design of the rubber spheres is not material failure, but excessive compressive deformation that leads to undesirably high rolling friction. Dynamic tests proved that the proposed low-cost rolling rubber isolators can substantially reduce the accelerations transmitted to the superstructure The cost of the tested 25 mm, 50 mm and 100 mm diameter natural rubber spheres is 0.6 $, 3 $ and 17$, respectively.

Selection of Filovirus Isolates for Vaccine Development Programs.

The continuing outbreaks of ebola virus disease highlight the ongoing threat posed by filoviruses. Fortunately, licensed vaccines and therapeutics are now available for Zaire ebolavirus. However, effective medical countermeasures, such as vaccines for other filoviruses such as Sudan ebolavirus and the Marburg virus, are presently in early stages of development and, in the absence of a large outbreak, would require regulatory approval via the U.S. Food and Drug Administration (FDA) Animal Rule. The selection of an appropriate animal model and virus challenge isolates for nonclinical studies are critical aspects of the development program. Here, we have focused on the recommendation of challenge isolates for Sudan ebolavirus and Marburg virus. Based on analyses led by the Filovirus Animal and Nonclinical Group (FANG) and considerations for strain selection under the FDA Guidance for the Animal Rule, we propose prototype virus isolates for use in nonclinical challenge studies.

Straw Competition and Wheat Root Endophytism of Trichoderma gamsii T6085 as Useful Traits in the Biological Control of Fusarium Head Blight.

Trichoderma gamsii T6085 has been investigated for many years as a beneficial isolate for use in the biocontrol of Fusarium head blight (FHB) of wheat caused primarily by Fusarium graminearum. Previous work focused on application of T6085 to wheat spikes at anthesis, whereas application to soil before or at sowing has received limited attention. In the present study, the competitive ability of T6085 on plant residues against F. graminearum was investigated. Results showed a significant reduction of wheat straw colonization by the pathogen and of the development of perithecia, not only when T6085 was applied alone but also in the presence of a F. oxysporum isolate (7121), well known as a natural competitor on wheat plant residues. T6085 was able to endophytically colonize wheat roots, resulting in internal colonization of the radical cortex area, without reaching the vascular system, as confirmed by confocal microscopy. This intimate interaction with the plant resulted in a significant increase of the expression of the plant defense-related genes PAL1 and PR1. Taken together, competitive ability, endophytic behavior, and host resistance induction represent three important traits that can be of great use in the application of T6085 against FHB not only on spikes at anthesis but potentially also in soil before or at sowing.

Extra-Heavy Crude Oil Degradation by Alternaria sp. Isolated from Deep-Sea Sediments of the Gulf of Mexico

The Gulf of Mexico (GoM) is an important source of oil for the United States and Mexico. There has been growing interest, particularly after the Deepwater Horizon oil spill, in characterizing the fungal diversity of the GoM and identifying isolates for use in the bioremediation of petroleum in the event of another spill. Most studies have focused on light crude oil bioremediation processes, while heavy crude oil (HCO) and extra-heavy crude oil (EHCO) have been largely ignored. In this work, we evaluated the ability of fungal isolates obtained from deep-sea sediments of the Mexican economic exclusive zone (EEZ) of the GoM to degrade HCO (16–20° API) and EHCO (7–10° API). Alternaria sp., Penicillium spp., and Stemphylium sp. grew with HCO as the sole carbon source. Remarkably, Alternaria sp. was the only isolate able to grow with EHCO as the sole carbon source, degrading up to 25.6% of the total EHCO and 91.3% of the aromatic fraction, as demonstrated by gas chromatography analysis of the saturate, aromatic, and polar fractions. These findings proved to be significant, identifying Alternaria sp. as one of the few fungi reported so far capable of degrading untreated EHCO and as a suitable candidate for bioremediation of EHCO in future studies.

Natural Pigments Production by Local Bacterial Isolates for Use as Antibacterial and Antioxidant

Among 46 local bacterial isolates capable synthetized pigments, 26% produced extracellular of blue green and fluorescent whereas 74% produced intra-cellular pigments of red, brown, yellow, orange, and rose. Seven isolates were selected as a potential candidate for the synthesis of pigments. They were Pseudomonas fluoresces, P. aeruginosa, Serratia marcescens, Azotobacter chroococcum, Micrococcus kristinae, M. luteus, and M. roseus after their morphological and biochemical studies. They capable to produce fluorescent, blue green, red, brown, orange, yellow, and rose with maximum absorbance at 400, 520, 530, 320, 440, 460, and 470 nm, with an optical density of 0.62, 1.42,1.35, 1.11, 0.45, 0.98, and 0.40, respectively. Antibacterial activity of pigments was studied against 7 bacterial pathogenic strains namely P. aeruginosa ATCC27853, Escherichia coli 0157h7 ATCC25922, Klebsiella pneumonia ATCC00607, Salmonella typhimurium ATCC25566, Listeria monocytogenes ATCC19115, Staphylococcus aureus ATCC29737, and Bacillus cereus ATCC33018. The last tested strain behaved high significant (p≤ 0.05) sensitivity for blue green, fluorescent, brown, and rose pigments while, L. monocytogenes ATCC19115 was more susceptible for red, and yellow pigments and S. aureus ATCC29737 had more inhibited by orange pigment. These bacterial pigments seemed to have antioxidant activity which inhibited the formation of diphenyl-2-picrylhydrazyl radicals with percentage ranged from 40 % to 80 %. It could therefore be stated that the bacterial pigments tested had a broad impact on foodborne pathogens and had an antioxidant effect

Most suitable types of seismic isolation for use in old mosques in Syria

The article discusses the most suitable base&#x0D; isolation bearings from the author's point of view for use in the buildings of&#x0D; old mosques in Syria, which are designed to protect such buildings from the&#x0D; effects of earthquakes that can occur at any time. Especially since many of&#x0D; such buildings have an architectural and cultural value, and are included in&#x0D; the world heritage list of UNESCO. Elastomeric&#x0D; bearings with high energy dissipation capacity (HDRB), elastomeric bearings&#x0D; with lead cores (LDRB), single friction pendulum, double friction pendulum and&#x0D; triple friction pendulum sliding (FPS) bearings are considered. What they&#x0D; consist of, their characteristics. Three, mosques in Syria that are of a great&#x0D; value from the point of view of architecture and cultural heritage are listed&#x0D; and described, and conclusions are drawn.

Calculated and experimental tests of dynamic vibration isolators for use in the suspension system of the traction vehicle cabin

The article gives a brief description of operational vibration effects on the tractor cab, protective qualities of standard rubber monoblock vibration isolators used in the systems of cabin suspension of domestic tracked tractors. The principle of operation and advantages of dynamic vibration dampers are described. The description of methods and results of calculation and experimental studies of vibration insulating properties of standard and dynamic vibration isolators is given.

Virulence and proteolytic activity of entomopathogenic fungi against the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae)

The virulence and proteolytic activity of some entomopathogenic fungi isolates, viz., Metarhizium anisopliae, Beauveria bassiana, Verticillium lecanii, and Trichoderma harzianum, against the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), were evaluated. Common maize plants (Zea mays L.) infested with females of T. urticae were treated in vivo by spraying with suspensions of 1 × 108 conidia ml−1 concentration of selected isolates. Lethal effects of fungal isolates were assessed as percentages of daily mortalities of mites, compared to the mortality in control. Virulence of the fungi isolates was estimated based on the LC50 values calculated by probit analysis for the individuals treated by 1 × 105 conidia ml−1 concentration. Proteolytic activity of isolates was assayed on casein substrate to reflect their virulence towards T. urticae. The mite mortality rates increased with increasing conidial concentrations as well as days after treatment. The mortality rate caused by M. anisopliae isolate varied from 18.75 to 85%, with LC50 value of 4.6 × 105 conidia/ml and LC90 value of 2.4 × 108 conidia/ml during 7 days, respectively. The isolate of B. bassiana caused 15 to 70% mortality, and its LC50 and LC90 values estimated 3.3 × 106 and 7.8 × 109 conidia/ml, respectively. However, V. lecanii isolate caused 11.25 to 72.50% mortality with LC50 of 5.2 × 106 conidia/ml, while T. harzianum was potentially less virulent than other isolates causing 8.75 to 63.75% mortality rate to T. urticae with LC50 of 9.4 × 106 conidia/ml. M. anisopliae showed the highest proteolytic activity at all concentrations, followed by B. bassiana in 3rd, 5th, and 7th day post treatment. These findings recommend the selection of virulent fungal isolates for use as natural and environmentally safe agents in biological control programs to combat mite pests.

Morphology, molecular characterization, and virulence of Beauveria pseudobassiana isolated from different hosts

Beauveria pseudobassiana has great potential for use in the management of various insect pests. In the present study, we aimed to explore the the virulence of B. pseudobassiana isolated from a diversity of hosts to Bombyx mori and Tenebrio molitor larvae. To this end, 15B. pseudobassiana isolates from 10 different geographical locations were identified based on morphological characteristics and molecular data. The phylogenetic positions of the isolates were evaluated according to morphological features and phylogenetic inferences based on six loci (nrSSU, nrLSU, TEF, RPB1, RPB2 and Bloc). In addition to growth in soil, the B. pseudobassiana isolates in our study were isolated from a wide host range that extended to 5 orders, 11 families, and 14 species. Moreover, anamorphically typified B. pseudobassiana was grown for the first time from teleomorph stromata. Pathogenicity of the B. pseudobassiana isolates from the different hosts was determined with two bioassays using B. mori and T. molitor larvae. The results indicated that mortality of B. mori caused by the lepidopteran isolates was significantly higher than that of isolates from other hosts, and virulence of the coleopteran isolates to T. molitor was significantly higher than that of isolates from other hosts. The host specificity of B. pseudobassiana should be studied in more detail before future consideration of isolates for use in biological control of pests.

Molecular and Aggressiveness Characterization of Isolates of Fusarium solani and Fusarium oxysporum f.sp. passiflorae Associated to Passion Fruit Wilting

This work was carried out with the objective of performing a molecular and aggressiveness characterization of F. solani and F. oxysporum f.sp. passiflorae collected in the Pantanal, Cerrado and Amazon biomes. We selected the most aggressive isolates for use in breeding programs aiming resistance to Collar Rot and Fusariosis. For inoculation of the isolates of F. oxysporum f.sp. passiflorae the washed root method was used. The molecular characterization of the isolates was carried out by partial sequencing of the Transcribed Internal Spacer of the rDNA region. The isolates of F. solani formed two distinct groups in relation to aggressiveness. Among all isolates, FSUNEMAT 40 and FSUNEMAT 46 were the most aggressive. The model with K=2 was taken as the best model to explain the genetic structure of the F. solani populations, with clear combinations of genes from both gene pools. There were three groups with respect to the aggressiveness of the isolates of F. oxysporum f.sp. passiflorae, with the isolated FOUNEMAT 22 being the most aggressive. In view of these results, the isolates of F. solani collected in P. edulis in the state of Mato Grosso presented a high molecular variability independent from the biome of origin, and this was also observed in the tests of aggressiveness. The results indicate the need to consider the molecular variability and the aggressiveness of the pathogens in the evaluation of genotypes of sour passion fruit in programs of selection of resistant cultivars.

Fungi isolated from insects in strawberry crops act as potential biological control agents of Duponchelia fovealis (Lepidoptera: Crambidae)

Entomopathogenic fungi were collected from insects, belonging to orders Lepidoptera, Coleoptera, Hemiptera, Hymenoptera, and Diptera, with signs of infection. Single-spore colonies were identified based on morphological traits and ribosomal ITS sequences. The most commonly found fungi were Fusarium oxysporum Schlechtendal and Beauveria bassiana (Balsamo-Crivelli) Vuillemin. Isolation of Trichoderma atroviride Bisset, Aspergillus flavipes (Bainier and Sartory) Thom and Church, Aspergillus iizukae Sugiyama, Penicillium mallochii Rivera, Urb and Seifert, Penicillium adametzioides S. Abe ex G. Smith, and Mucor nidicola Madden, Stchigel, Guarro and Starks associated to insects is reported for the first time. Tests with B. bassiana isolates against Duponchelia fovealis Zeller (Lepidoptera: Crambidae), showed high larval mortality in vitro and in greenhouse, demonstrating its potential as biological control agent. Understanding the fungal microbiota from insects can provide promising isolates for use in integrated pest management programs. This is the first report characterizing the mycobiota in insects collected in strawberry crops, and evaluating the pathogenicity of B. bassiana against D. fovealis, a pest that causes severe losses to farmers.

Current limitations in control of viral arthritis and tenosynovitis caused by avian reoviruses in commercial poultry

Avian reoviruses are the causative agent of viral arthritis/tenosynovitis in chickens and turkeys. Clinical signs of disease include swelling of the hock joints accompanied by lesions in the gastrocnemius and digital flexor tendons causing lameness in addition to hydropericardium. The economic impact is significant as it results in poor weight gain, increased feed conversion ratios and condemnations at the processing plant. Vaccination with both live attenuated and inactivated oil emulsion vaccines have been used successfully for decades to control the disease. Current commercial vaccine strains belong to the same serotype and are antigenically and serologically distinct from circulating variant field viruses isolated from clinical cases of tenosynovitis. Since 2012, there has been a dramatic increase in the number of clinical cases of tenosynovitis in commercial poultry and commercial vaccines are unable to provide adequate levels of protection against disease. Producers have elected to use custom inactivated vaccines in the absence of any commercially available homologous vaccines. Identification and selection of field isolates for use in autogenous vaccines can be difficult especially when multiple reoviruses are co-circulating among flocks. In addition, field data suggests that in some cases the custom vaccines are providing adequate protection against disease but as new genetic variants emerge, new vaccines are needed.

English

Environmentally friendly technologies, such as the use of bacteria (e.g. Bacillus spp.) to control fungal diseases of rice (Oryza sativa L.), represent a promising alternative for the sustainability of agricultural ecosystems. The present work aimed to isolate, identify, and evaluate (in vitro) various Bacillus spp. from the rice phylloplane for their potential to control the rice fungus Magnaporthe oryzae. Samples were taken from the phylloplane of healthy young rice plants growing in commercial fields in ten municipalities of Maranhao (Brazil), and Bacillus spp. were subsequently isolated and molecularly identified. Both experiments utilized a randomized design, and data were submitted to analysis of variance as well as means comparison by the Tukey test. Twelve bacterial isolates were obtained and identified. Using a control isolate (B25), four in vitro M. oryzae-inhibition methods were compared, with the ‘circle’ method ultimately providing the highest mycelium growth inhibition. The most promising experimental isolates for biological control were then identified as B. methylotrophicus isolates B41, B31, and B22, which achieved 90.41, 69.47, and 67.55% inhibition, respectively. This study demonstrates the potential of Maranhao Bacillus spp. isolates for use as biological fungal-control agents. Key words: biological control, pathogen, rice.