Titers Of Bacteria Research Articles

Regulated cleavage and translocation of FERONIA control immunity in Arabidopsis roots.

Plant roots exhibit localized immunity (LI) mainly in the transition zone (TZ) and elongation zone (EZ). Plasma membrane-localized receptor-like kinases (RLKs) can mediate the plant's response to rhizosphere bacteria. However, how RLKs are involved in triggering LI in roots remains unclear. Here we identified dual actions for the RLK FERONIA (FER) in the LI response of Arabidopsis (Arabidopsis thaliana). The FER cytoplasmic domain is cleaved and translocated to the nucleus (FERN) to activate LI in the TZ and EZ in response to colonization by beneficial and pathogenic bacteria. In the absence or cessation of bacterial infection, full-length FER is plasma membrane-localized to maintain growth. Upon colonization and invasion by a high titre of bacteria, mature RAPID ALKALINIZATION FACTOR23 peptide accumulates and activates the matrix metalloproteinase At2-MMP, which triggers FER cytoplasmic domain cleavage specifically in the TZ and EZ to activate LI. This work demonstrates that two molecular forms of a single RLK balance growth and immunity via LI activation in Arabidopsis roots.

Chocolate with probiotic microcapsules is a new product of functional nutrition

Probiotics can help improve digestion, strengthen the immune system and even fight diseases. But until now, there was no easy way to introduce enough probiotics into our body. Microencapsulated probiotics offer a solution to this problem. They are small enough to be easily digested, and are protected from the aggressive environment of the stomach. Chocolate represents a ubiquitous and popular consumable, yet probiotics within food matrices necessitate strategies for stress mitigation and enhancement of viability. One such method involves the encapsulation of probiotic cells within alginate microspheres, amenable for incorporation into chocolate matrices. In this regard, the aim of study is to explore the effect of microencapsulation on the survival of probiotics in chocolate. Conventional microbiological methods were used: growing bacteria in liquid and solid media, determining the titer of bacteria using the Koch method. The results demonstrated the successful production of chocolate containing microcapsules of probiotics with favourable organoleptic properties. Enhanced viability preservation of Lactobacillus rhamnosus GG in microcapsules compared to free cells was observed.

Development of Technology for the production of finished forms of Medicinal probiotics

The study aimed to develop a technology for the production of a finished form of medicinal probiotic agents against human intestinal infections based on active strains of lactic acid and propionic acid bacteria with a wide range of biological activity and resistance to antibiotics. From the laboratory collection of lactic acid and propionic acid bacteria isolated from the intestines of healthy people, two associations of bacteria were compiled with antagonism against test cultures of Staphylococcus aureus, Salmonella gallinarum, Mycobacterium B5, Candida albicans, Pasteurella multocida, Bacillus subtilis, Escherichia coli 8739, Klebsiella pneumoniae ATCC 700603 and ATCC BAA 2524, Staphylococcus aureus 3316 and 9, Salmonella enteritidis 35382, and Pseudomonas aeruginosa 835, as well as the ability to produce hydrolytic enzymes amylase and proteinase, B vitamins, and essential amino acids. The resistance of the selected associations of lactic acid and propionic acid bacteria to the used antibiotics has been studied, which will allow for using them, if necessary, in the complex therapy of diseases. Technology for the production of probiotic medication from these associations has been developed. It was found that the most active preparation in terms of bacterial titer and antagonistic activity and the most stable one during storage for 6 months was the liquid preparation obtained by growing association No. 2 (L. plantarum 2v/A-6+L. brevis B-3/A-26+L. acidophilus 27w/60+P. shermanii 8) on nutrient medium No. 1 (De Man, Rogosa and Sharpe agar with CoCl2) using 7% sucrose and 1.5% gelatin as a protector. The liquid preparation from association No. 5 grown on medium No. 1 showed a more complete preservation of production-valuable signs during storage compared to the results of using nutrient medium No. 4, while the use of protector No. 1 was more optimal. To test the stability during the storage of dry preparation forms, an accelerated method was used by warming them up for 15 minutes at 60°C. It was found that after warming up, the best preservation of viable bacterial cells was observed in association No. 2 on nutrient media No. 1 and No. 4, in association No. 5 on medium No. 4 dried with protector No. 2 (7% sucrose and 1.5% gelatin + 7% skim milk powder), while the titer of bacteria was equal to 1.2×109, 3.5×108, and 2.0±0.2×108 colony-forming units/g, respectively. Antagonistic activity in these association variants was observed against all test cultures taken into the study with zones of suppression of their growth ranging from 10 to 24 mm.

SELECTION OF CONDITIONS FOR OBTAINING ECOLOGICALLY PURE DRY PROBIOTIC AGAINST MIXED INTESTINAL INFECTION FOR FARM ANIMALS

As a result of the study, the best viability of monocultures and associations under freeze drying has been determined. The best two protective media during storage and their composition are the following: media No.1 includes (%) sodium acetate - 2.5; sodium citrate - 2.5; sucrose - 10.0; and protective media No.2 containштп (%) sucrose 8.0; gelatin - 1.5; skim milk - 5.0. Thus the titer of bacteria equaled to values of 6.0x1010 and 4.2x1010 CFU / g, respectively. When determining the stability of dried preparations during storage of probiotic bacteria and their association, the best protective medium is No. 2 (sucrose 8.0%; gelatin - 1.5%; skim milk - 5.0%). The antagonistic activity of monocultures (lactic acid bacteria Lactobacillus plantarum1, Streptococcus salivarius 20n, Lactobacillus fermentum 15, propionic acid bacteria Propionibacterium shermanii 34) and associations based on these monocultures is preserved practically at the initial level upon freeze drying. A probiotic based on lactic acid and propionic acid bacteria can be used as a therapeutic and prophylactic agent against dyspepsia for farm animals. At the same time, there is no need for the use of antibiotics and other antibacterial agents for the treatment of diseased animals.

Prospects for the Application of Sensor Elements for Detecting the Presence of Bacteria in Real Time

A study was made of the response of a sensor element based on polydiphenylenephthalide to a change in the composition of the air medium during the cultivation of Enterobacter asburiae UOM 3 bacteria in a liquid nutrient medium. Registration of changes in the resistance of the sensor element in response to volatile organic compounds released by bacterial cells was carried out by measuring the current-voltage characteristics at specified time intervals. The results showed the relationship between the number of bacteria and the change in the resistance of the sensor element, due to the release of waste products of microorganisms. With an increase in the titer of bacteria by 3 orders of magnitude, the resistance of the sensor under the influence of volatile organic compounds accumulated in the medium decreased by 2 orders of magnitude. It is assumed that sensors based on polydiphenylenephthalide can be used to determine the presence of bacteria in various materials and media.

Fountains as potential sources of aerogenic risk for urban populations

Introduction. Fountains (office and outdoor), being small decorative structures used to improve the parameters of the human life environment, in the process of their work during the generation of a water jet, determine the creation of spray and aerosol fractions, thereby allowing the loss of a certain volume of liquid when air moves and wind carryover. The biological safety of the operation of such hydraulic structures depends on the composition of the microflora of the water in the main reservoir of the fountain, especially in the warm season. Materials and methods. For the period 2010-2020, the study of the composition of the microflora of water in the main reservoirs of the existing fountains and in the sedimented spray-aerosol mixture formed during the operation of these hydraulic structures was carried out. Results. At water temperatures above +18 °C and the absence of a disinfection system or its regular complete replacement, fountains were found to have a significant level of contamination with bacterial and fungal pathogens, including mycobacterium tuberculosis; the number of microorganisms of the E. coli group in office and open city fountains. The amount of Clostridial flora and streptococci in open fountains significantly exceeds the standard indicators (p <0.05). Limitations. When studying the trends in concentration of liquid particles in the air, the methodology of K.Y. Kondratiev et al. (1988) and V.M. Khvata et al. (1991) was used. The studies were carried out in accordance with the Interstate standard “Water. Methods of sanitary and bacteriological analysis for field conditions” GOST 24849-2014, 2016. Conclusion. The microflora of the operating fountain, in the absence of disinfection of water or its regular replacement, is characterized by a high titer of bacteria of the E. coli group, streptococci, staphylococci, mycobacterium tuberculosis, mold and yeast fungi. The one of the conditions for the excessive growth of these microorganisms in this hydraulic system is the water temperature above 18 °C. In the sedimented aerosol near the active fountain, a bacterial and fungal spectrum of pathogenic microorganisms similar to the water is found. Fountains (external and office) can be considered as sources of aerogenic household infection of the population of modern cities, which requires strict adherence to sanitary norms and rules that ensure the biological safety of these hydraulic structures.

Возможная роль представителей кишечного микробиома в биотрансформации арил-, пиридилсодержащих фосфинов и их производных (по данным спектроскопии ЯМР 31Р)

Organophosphorus compounds (OPCs) are used in many areas of human activity. Unique physicochemical properties and high biological activity not only determine the applied value of OPCs but also give them the properties of xenobiotics that are harmful to human health, which largely depend on the state of the endogenous microbiota. The purpose of this work is to assess the effect of pyridyl- and aryl-containing phosphines, their oxides, and sulfides on the growth of Bifidobacterium bifidum and Escherichia coli and to identify possible patterns of biotransformation of OPCs using 31P NMR spectroscopy. Bacteria were cultivated in thioglycollate medium containing the tested phosphorus compounds. At the stationary growth phase was determined the cell concentration and were recorded spectra 31P NMR. It was shown that the most reliable (p<0,05) and opposite effect on the growth dynamics of both species of bacteria was exhibited by phosphine sulfides 1 and 3: PS1 (pyridyl) reduced the population reproduction rate by 35–40%, and PS3 (aryl) increased it by 45–60%. At the same time, OPCs themselves were most likely not metabolized. Phosphine oxides reduced the average titer of bacteria compared to the control, and PO3 caused complete cell elimination after 24 hours cultivation. In the medium with PO2 was identified PS2 appeared, which may be caused by the biologically mediated process of oxide-to-sulfide conversion. All phosphines are chemically labile and they were oxidized abiotically to oxides and sulfides. Formed sulfides could be the reason for a significant increase (to 35%) in the growth rate bacteria population both species. Five new unidentified organophosphorus compounds (UPC) were recorded on medias with B. bifidum, some of which may belong to the products of biotransformation of the original OPCs. Some organic phosphates, homologous to the phosphine oxides tested, have a δp value neighboring to the taken NMR spectra. This may indicate the way of their biological transformation: oxidation of the CP bond in the phosphine oxides to an ester bond of organic phosphates. This ability of bifidobacteria to metabolize OPCs will make it possible to develop a therapeutic strategy based on the use of B. bifidum as a microorganism that degrades phosphorus-containing xenobiotics.

Titer and Prevalence of Fusobacterium Nucleatum in Histological Section of Human Oral Epithelial Cells in Patients with Chronic Periodontitis

Introduction: Anaerobic bacteria in the oral microbial flora are involved in many infections of the oral cavity and surrounding structures. Fusobacterium nucleatum is believed to differ from other bacteria in its interaction with oral mucosal epithelial cells. The aim of this study was to determine the prevalence of Fusobacterium nucleotum in the epithelial cells of the oral mucosa of patients with periodontitis compared with healthy individuals.
 Materials and Methods: In this case-control study, Realtime-PCR technique used to detect the Fusobacterium nucleatum in gingival samples of 15 patients with chronic periodontitis and 15 individuals with clinically healthy gingival specimens. The results analyzed by Fisher's exact and Independent t-tests with a significance level of less than 0.05.
 Results: The Fisher's exact test showed that the F.nucleatum in patients with periodontitis was higher than the healthy population. Also Independent t-test showed that average titer of bacteria in patients with Periodontitis was significantly more than people without gingival inflammation (p value < 0.001).
 Conclusion: There is a statistically significant relationship between periodontitis and the presence of F.nucleatum in epithelial cells of oral mucusa.

Phenoloxidase and Melanization Innate Immune Activities in Green Darner Dragonfly Nymphs (<i>Anax junius</i>)

Insects in the Order Odonata are highly subject to infection by gregarine parasites. However, despite the important ecological roles that insects play in every ecosystem in which they exist, little research has been devoted to the description of insect immunity. Insects rely heavily on the rapid actions of innate immune mechanisms to prevent infection. We characterized the melanization response in the hemolymph of green darner dragonfly (Anax junius) nymphs. Incubation of chymotrypsin-activated hemolymph with L-DOPA resulted in volume- and time-dependent production of dopaquinone via the phenoloxidase (PO) enzyme, with biphasic accumulation of product. The PO activity was temperature-dependent, with a stepwise increase from 20℃ - 35℃ and maximum activity measured at 35℃ - 40℃. The formation of product was also inhibited in a concentration-dependent manner by diethylcarbonate, a specific inhibitor of PO activity, which indicated that the observed activity was due to the presence of PO enzyme. The rate of formation and quantity of melanin was dependent on exposure to different titers of bacteria. This is the first characterization of both PO activity and melanization response in green darner dragonflies.

Особливості біохімічних властивостей окремих представників мікробіоти пародонтальних кишень при генералізованому пародонтиті

Chronic inflammatory-dystrophic lesions of periodontal tissues are widespread in Ukraine and the world diseases with complex etiology and pathogenesis. The purpose of the study: to establish the biochemical and cultural properties of microorganisms in periodontal pockets in patients with acute generalized periodontitis using a bacteriological method. Materials and methods: the contents of the periodontal pocket were taken from 10 patients with subsequent seeding on nutrient and differential diagnostic media in the bacteriological laboratory. Cultural, as well as the biochemical, and enzymatic properties of bacterial isolates were identified. Results: Pathogenic and opportunistic microorganisms (aerobes and facultative anaerobes), which had a wide range of biochemical properties (additional factors of colonization and pathogenic action) were identified. Purulent microflora was detected in 70.00% of cases. Isolates of Streptococcus, Staphylococcus and P. aeruginosa were predominantly β-hemolytic (except for E. faecalis and S. pneumoniae). The identified bacteria of the intestinal group and the Klebsiella family were lactose- and glucose-positive, K. oxytoca was the most enzymatically active microorganism. Conditionally pathogenic microorganisms of periodontal tissues and oral cavity, as well as the human body as a whole, belong to the facultative microbiota. It is shown that the level of inflammatory process varies with the number of associates of opportunistic pathogens isolated from the inflammatory process. In titers of 102–104 CFU / ml, representatives of the facultative microbiota, as a rule, do not show their pathogenic qualities. At the same time, biochemical properties are essential in the potential ability of opportunistic pathogens to acquire signs of pathogenicity. The titer of bacteria, their hemolytic and proteolytic properties significantly affect the level of virulence of microorganisms. The ability to hemolysis of erythrocytes, found in most isolates, allows to attribute the isolated strains to potentially pathogenic. It is established that the persistence of opportunistic pathogens with a high level of virulence determines the course and intensity of the inflammatory process of periodontal tissues. Conclusions: The study of the role of pathogenic and opportunistic microorganisms in the development and maintenance of long-term inflammation of periodontal tissues is a topical issue in medical science and is necessary for the verification of treatment regimens and compliance with infection control

Comparative analysis of the detectability of microorganisms in the prostatic fluid and ejaculate according to the results of bacteriological analysis

Introduction. Currently the chronic prostatitis (NIH type IV) remains insufciently studied and difcult to treat with antibiotics. When making the diferential diagnosis of chronic prostatitis it is generally accepted by the EAU and Russian guidelines that the detected microorganisms in the prostatic fuid and the ejaculate practically do not difer from each other. The tactics of treating patients with asymptomatic prostatitis by means of antibacterial drugs remains disputable. Most reputable authors believe that this category of patients shall receive treatment in case of infertility, pregnancy miscarriage or forthcoming surgery on the prostate gland. Recently, EAU guidelines have expressed doubts regarding the identity of the microbiota found in the prostatic secretions and the ejaculate.The study objective. Comparative analysis of the detectability of microorganisms in prostatic secretions and the ejaculate by means of bacteriological analysis among the men with chronic prostatitis of category IV.Materials and methods. The study involved 117 men who went to the urological clinic to pregravid examination or on the occasion of infertility. All patients were diagnosed with prostatitis of category IV based on a standard examination, and then a bacteriological analysis of prostatic secretions and ejaculate was performed. During the research the prostatic fuid and ejaculate were taken simultaneously and the analysis was carried out in one and the same bacteriological laboratory. In case the titer of the detected microorganisms was signifcant, the patients were ofered to undergo treatment without the use of antibiotics but with combination of bovhyaluronidase azoximer with prostate protectors and/or OM-89; after that a control bacteriological study was performed.Results. In the prostatic secretions and in the semen, the most commonly found gram-positive microorganisms were Staphylococcus spp. and Enterococcus spp.; the representatives of the Enterobacteriaceae were found less frequently. It was statistically proven that the titer of bacteria in the prostatic secretions was considerably higher than that in the ejaculate (p <0.01). Sterile cultures were statistically-proven to be more frequent in ejaculate compared with prostatic secretions (13.7 % vs 3.4 %, p <0.01). When analyzing the coincidences for bacteria, low concordance was obtained for all identifed microorganisms (gram-positive bacteria varied from 48.3 to 79.5 %, gram-negative bacteria varied from 57.1 to 80.0 %). After the combined therapy, the bacterial mass signifcantly decreased in the prostate secretion from 104.3 ± 1.6 CFU/ml to 103.3 ± 2.0 CFU/ml (p = 0.008), while in the semen the bacterial mass decreased from 103.5 ± 1.8 CFU/ml to 102.6 ± 2.1 CFU/ml (p = 0.02). In the prostatic secretions, there was a statistically-proven decrease in the number of gram-negative bacteria (p = 0.05). As soon as the treatment was completed all the patients demonstrated the normalized number of leukocytes according to microscopy of prostate secretions or spermogram.Conclusion. The ejaculate is a more sterile biomaterial compared with the prostatic fuid, which should be taken into account in the diferential diagnostics of the chronic prostatitis of category IV and MAGI. The use of non-antibacterial treatment regimens, such as bovhyaluronidase azoximer, prostate protectors and OM-89, can reduce the titer of bacteria to insignifcant values both in the prostatic secretions and in the semen; and in some cases make the ejaculate sterile.

Vaccination with virus-like particles containing hemagglutinin protects the lungs of mice with postifluenza bacterial pneumonia: virological, microbiological and clinical data

Influenza is a severe viral disease, a frequent complication of which is a secondary bacterial pneumonia. Influenza vaccines prevent secondary bacterial complications. Virus-like particles are one of the promising areas for the development of new vaccines. The aim of this work is to study the correlation of the pathomorphological characteristics of the lungs with clinical, virological, and microbiological markers of the disease at vaccination with virus-like particles (VLPs), containing hemagglutinin (HA) of influenza virus (HA-Gag-VLPs) in a murine model of secondary bacterial pneumonia induced by S. pneumoniae after influenza infection. BALB/c mice were vaccinated with VLPs containing influenza HA. After 21 days, mice were infected with two strains of influenza viruses, homologous and non-homologous, and 5 days after viral infection, were infected with S. pneumoniae. The vaccination effect was evaluated by morphological, virological (titer of the virus in the lungs) and microbiological (titer of bacteria in the lungs) data, and was confirmed by clinical data (survival, change in body weight). Immunization with HA-Gag-VLPs, followed by infection with a homologous influenza virus and S. pneumoniae, reduced the area of foci of inflammation, inhibited the replication of the virus and bacteria in the lungs, and also protected animals from death and reduced their weight loss. Immunization with HA-Gag-VLPs upon infection with a heterologous strain and S. pneumoniae did not affect these criteria. The immunization with HA-Gag-VLPs prevented the viral replication, providing a reduction of S. pneumoniae titer and the degree of lung damage, protecting animals from the disease in a murine model of secondary bacterial pneumonia, induced by S. pneumoniae, after influenza infection with homologous strain of the virus.

The intensity of ethylene release by soybean plants under the influence of fungicides in the early stages of legume-rhizobial symbiosis

The effect of pre-sowing treatment of soybean seeds with fungicides on the intensity of ethylene release, the processes of nodulation and nitrogen fixation in different symbiotic systems in the early stages of ontogenesis were investigated. The objects of the study were selected symbiotic systems formed with the participation of soybean (Glycine max (L.) Merr.) Diamond variety, strains Bradyrhizobium japonicum 634b (active, virulent) and 604k (inactive, highly virulent) and fungicides Maxim XL 035 PS (fludioxonil, 25 g/L, metalaxyl, 10 g/L), and Standak Top (fipronil, 250 g/L, thiophanate methyl, 225 g/L, piraclostrobin, 25 g/L). Before sowing, the seeds of soybean were treated with solutions of fungicides, calculated on the basis of one rate of expenditure of the active substance of each preparation indicated by the producer per ton of seed. One part of the seeds treated with fungicides was inoculated with rhizobium culture for 1 h (the titre of bacteria was 107 cells/mL). To conduct the research we used microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. It is found that, regardless of the effectiveness of soybean rhizobial symbiosis, the highest level of ethylene release by plants was observed in the stages of primordial leaf and first true leaf. This is due to the initial processes of nodulation – the laying of nodule primordia and the active formation of nodules on the roots of soybeans. The results show that with the participation of fungicides in different symbiotic systems, there are characteristic changes in phytohormone synthesis in the primordial leaf stage, when the nodule primordia are planted on the root system of plants. In particular, in the ineffective symbiotic system, the intensity of phytohormone release decreases, while in the effective symbiotic system it increases. At the same time, a decrease in the number of nodules on soybean roots inoculated with an inactive highly virulent rhizobia 604k strain due to the action of fungicides and an increase in their number in variants with co-treatment of fungicides and active virulent strain 634b into the stage of the second true leaf were revealed. It was shown that despite a decrease in the mass of root nodules, there is an increase in their nitrogen-fixing activity in an effective symbiotic system with the participation of fungicides in the stage of the second true leaf. The highest intensity of ethylene release in both symbiotic systems was recorded in the stage of the first true leaf, which decreased in the stage of the second true leaf and was independent of the nature of the action of the active substances of fungicides. The obtained data prove that the action of fungicides changes the synthesis of ethylene by soybean plants, as well as the processes of nodulation and nitrogen fixation, which depend on the efficiency of the formed soybean-rhizobial systems and their ability to realize their symbiotic potential under appropriate growing conditions.

The study of the antifungal activity of the Bacillus subtilis BZR 336g strain under the conditions of periodic cultivation with the addition of citric acid, corn extract and some microelements

We studied the antifungal activity of the Bacillus subtilis BZR 336g strain against the test culture of the fungus Fusarium oxysporum var. orthoceras App. et Wr. BZR 6, depending on the addition of citric acid crystalline hydrate, a microelements solution and corn extract to the liquid nutrient medium. It was found that citric acid at a concentration of 15 g/l improves the bioavailability of microelements and increases antifungal activity. Corn extract and microelements without the formation of a chelate form with citric acid do not affect the fungicidal properties of B. subtilis BZR 336g. However, the corn extract at a concentration of 3 g / l increases the titer of bacteria in the liquid culture from 2 ± 0.1 × 108 to 1 ± 0.08 × 108 CFU/ml. The combined use of the studied components allowed us to achieve a significant increase in the antifungal activity of B. subtilis BZR 336g by 3.1 times. At the same time, the effect of synergism in their complex interaction was noted, which is probably due to a qualitative and quantitative change in the composition of B. subtilis BZR 336g antifungal metabolites.

Influence of fungicides on activities of enzymes of phenolic metabolism in the early stages of formation and functioning of soybean symbiotic apparatus

We studied the effect of complex seed treatment with fungicides and rhizobium culture on the activity of phenolic metabolism enzymes – polyphenol oxidase and guaiacol peroxidase in the early stages of the formation and functioning of various symbiotic systems Glycine max – Bradyrhizobium japonicum. In the research we used microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. The objects of the study were selected symbiotic systems formed with the participation of soybean (Glycine max (L.) Merr.), Diamond variety, strains Bradyrhizobium japonicum 634b (active, virulent) and 604k (inactive, highly virulent) and fungicides Maxim XL 035 PS (fludioxonil, 25 g/L, metalaxyl, 10 g/L), and Standak Top (fipronil, 250 g/L, thiophanate methyl, 225 g/L, piraclostrobin, 25 g/L). Before sowing, the seeds of soybean were treated with solutions of fungicides, calculated on the basis of one rate of expenditure of the active substance of each preparation indicated by the producer per ton of seed. One part of the seeds treated with fungicides was inoculated with rhizobium culture for 1 h (the titre of bacteria was 108 cells in 1 ml). The other part of the fungicide-treated seeds was not inoculated by rhizobium culture. As a result of the research, it was revealed that an effective symbiotic system formed with the participation of soybean plants and the active strain rhizobia 634b is characterized by a high level of polyphenol oxidase activity and low guaiacol peroxidase in roots and root nodules in the stages of second and third true leaves. Such changes in the activity of enzymes occurred along with the formation of nodules which actively fixed the molecular nitrogen of the atmosphere. An ineffective symbiotic system (strain 604k) is characterized by an elevated level of polyphenol oxidase activity in the roots and guaiacol peroxidase in the root nodules, which is accompanied by activation of the process of nodulation. Treatment of soybean seeds with fungicides in an effective symbiotic system leads to a change in the activity of the enzymes of the phenolic metabolism, which induced adaptive changes in plant metabolism and growth of nitrogenase activity of the root nodules. The recorded changes in the activity of both enzymes for the action of fungicides in the ineffective symbiotic system can be considered as a kind of response of the plant to the treatment and were observed along with the reduction of the processes of nodulation into the stage of the third true leaf.

Short communication: Effect of freezer storage time and thawing method on the recovery of Mycoplasma bovis from bovine colostrum

Mycoplasma bovis is an important cause of mastitis in dairy cattle, and pneumonia, arthritis, and otitis in calves. Milk and colostrum are considered important sources of infection for calves. knowledge on the effect of on-farm freezing (-18°C) and thawing methods on the recovery of M. bovis from colostrum samples is missing. In this study, 2 separate experiments were performed. The first experiment consisted of a longitudinal study examining the survival [as measured by log(10) reduction] of 2 M. bovis strains in frozen colostrum over 14 wk. The second experiment examined the effect of different thawing temperatures (45 and 20°C), thawing frequencies (once or twice), and initial colostrum titer (104 or 106 cfu/mL) on M. bovis survival. A single freeze-thaw cycle led to an approximate 1 log reduction of M. bovis titer, independent of the thawing temperature. Freezing for 14 wk did not significantly further reduce the titer of bacteria compared with freezing for 2 wk. A second freeze-thaw cycle further reduced the M. bovis count by approximately 0.5 log compared with a single freeze-thaw cycle. Thawing temperature and initial bacterial concentration did not significantly affect M. bovis reduction. In conclusion, storage of colostrum samples in the freezer at -18°C during epidemiological studies, herd monitoring, or test and cull programs will probably have little influence on qualitative bacteriological test results for M. bovis. The epidemiological or clinical relevance of an approximate 1 log reduction of M. bovis in colostrum is currently unclear.

Dynamics of Huanglongbing-associated Bacterium Candidatus Liberibacter asiaticus in Citrus aurantifolia Swingle (Mexican Lime).

The bacterial disease citrus huanglongbing (HLB), associated with "Candidatus Liberibacter asiaticus" (C.Las) has severely impacted the citrus industry, causing a significant reduction in production and fruit quality. In the present study, it was monitored the C.Las population dynamics in symptomatic, HLB-positive Mexican lime trees (Citrus aurantifolia Swingle) in a tropical, citrus-producing area of Mexico. The objective of this study was to identify the dynamics of the population of huanglongbing-associated bacterium Candidatus Liberibacter asiaticus and its insect vector in Citrus aurantifolia Swingle (Mexican lime). Leaf samples were collected every 2 months over a period of 26 months for quantification of bacterial titers and young and mature leaves were collected in each season to determine preferential sites of bacterial accumulation. The proportion of living and dead bacterial cells could be determined through the use of quantitative real-time PCR in the presence of ethidium monoazide (EMA-qPCR). It was observed a lower bacterial titer at high temperatures in the infected trees relative to titers in mild weather, despite a higher accumulation of the insect vector Diaphorina citri in these conditions. This study also revealed seasonal fluctuations in the titers of bacteria in mature leaves when compared to young leaves. No statistically significant correlation between any meteorological variable, C.Las concentration and D. citri population could be drawn. Although, HLB management strategies have focused on vector control, host tree phenology may be important. The evaluation of citrus phenology, C.Las concentration, ACP population and environmental conditions provides insights into the cyclical, seasonal variations of both the HLB pathogen and its vector. These findings should help in the design of integrative HLB control strategies that take into account the accumulation of the pathogen and the presence of its vector.

THE SCIENTIFIC BASIS FOR THE CREATION OF NEW FORMS OF MICROBIAL BIOCHEMICALS

Herein we summarize the results of a comprehensive study aimed on the creation of liquid form of biological products for symbiotic and associative rhizobacteria. The objects of study were nodule bacteria from the rhizosphere of galegae (Rhizobium galegae), soybean (Bradyrhizobium japonicum) and associative rhizobacteria (Arthrobacter mysorens, Azospirillum brasilense, Agrobacterium radiobacter), as well as plants of soybean (Glycine max L.), barley (Hordeum L.), alfalfa (Medicago L.), etc. As carriers for bacteria, we used gamma-sterile peat, vermiculite and improved sterile liquid media on the basis of components of vegetable or synthetic origin, with the introduction of nutrients and stabilizers (humates, glycerine, potassium sorbate, carboxymethylcellulose, etc.). The efficacy of tested products and forms were compared in a biological survey carried out in different regions of the Russian Federation. Under the conditions of Leningrad Region the effectiveness was evaluated for the preparations based on recently used and perspective strains of alfalfa nodule bacteria Sinorhizobium meliloti. An optimized combination of stabilizers, nutrients and protective substrates provided a long-term storage and high efficiency of biological products. Nevertheless, plant nutrient media (bean broth) did not provide the required quality. Using bean medium for cultivation it is possible to obtain the desired titer of bacteria in the product, but their numbers are rapidly decreasing. Furthermore, preparations obtained with use of bean broth lose quality after 2-3 months after the beginning of storage because of extraneous microflora therein. The new forms of biochemicals designed on the basis of a synthetic nutrient medium can be stored at room temperature for at least 6 months, when sterile-packed in plastic bottles. High bacteria titer (3.6-4.2 billion CFU/ml of liquid formulation) was obtained after cultivation. It is shown that an improved liquid form has a high efficiency. Its application on leguminous plants increased grain yield by 20-40 % in soy, and by 15-25 % in peas. Productivity of cereal crops (wheat, barley) increased by 15-25 %, and the productivity of alfalfa was 20-45 % higher. A significant increase in crop quality was found to be due to higher protein content. The effectiveness of biological products considerably depended on agroecological conditions and biological features of the crops. Using different strains of nodule bacteria Sinorhizobium meliloti in the Leningrad Region allowed us to create the effective plantmicrobe systems. Thus on the sod-podzolic soil the strain A-4 was most effective providing yield increase by more than 25 %, while on sod-carbonate soil it was the strain A-5 which increased the productivity of alfalfa by 140 %.

English

Ralstonia solanacearum is a gram-negative soil-borne bacterium capable of infection of hundreds of vegetable species over more than 50 botanical families, causing bacterial wilt, except for bananas, when the disease is called Moko. It deserves special attention, from all other plant pathogenic bacteria, for its high phenotypic and genotypic plasticity, a characteristic that makes disease control extremely difficult. In this context, frequent and necessary surveys are conduct in the attempt of characterizing the prevailing strains of R. solanacearum in each region where the disease has been reported. However, knowledge about occurrence and diversity of R. solanacearum in Brazil is fragmented and in some cases, based on inconclusive studies with few strains, little representative of a given region. The need to obtain a greater picture guided this review. The occurrence of this bacterium in Brazilian States and the possible causes for its dissemination are presented, with emphasis on studies of genetic variability of populations of R. solanacearum in the country. The compiled results report a wide distribution of the bacterium in Brazil and great variability of its populations among locations. Partly due to the difficulty of detecting small titer of bacteria in samples, paucity of information about the origin of inoculum in certain regions is observed, as well as the need for detecting the presence of the pathogen in asymptomatic plants, potato tubers with latent infections, soil, and water, which are the major causes of bacterial dissemination into areas without any disease history.

Kliniczna ocena stanu jamy ustnej oraz właściwości fizycznych i mikrobiologicznych śliny u otyłych pacjentów

Background. The results of several studies show not only a relationship of obesity with systemic diseases, but also with changes in the oral environment.Objectives. The aim of this study was to carry out clinical evaluation of oral status, the amount of saliva, bacterial titers for Streptococcus mutans and Lactobacillus spp., and to analyze hygienic habits in people with obesity.Material and Methods. The study included 125 people, of both sexes, aged 20–65 years. The study group consisted of patients from the Clinic of Internal Medicine, Metabolism and Dietetics at the Poznan University of Medical Sciences with a BMI > 25 kg/m2; a control group – patients from the Clinic of Conservative Dentistry and Periodontology at the Poznan University of Medical Sciences with normal weight (BMI < 25 kg/m2). Diabetics were excluded from the study. All participants were asked to complete a short questionnaire. During the clinical trial the authors rated the incidence of dental caries (DMF-t and DMF-s), the state of oral hygiene (API, PLI), the state of gums (SBI, GI), and periodontal pocket depth (PPD). The material for laboratory analysis constituted unstimulated and stimulated mixed saliva. For microbiological tests the authors used CRT bacteria® Ivoclar Vivadent with a component for Streptococcus mutans and Lactobacillus spp. Saliva was collected always at the same time of day, between 10.00 a.m. and 1.00 p.m. Patients were 2 h after a meal.Results. There was a higher incidence of tooth caries, worse gum condition and worse oral hygiene status in obese patients compared with those of normal weight. It has been demonstrated significantly lower amount of rest and stimulated saliva in patients with obesity compared to those of normal weight. There was a statistically significant correlation between the levels of Streptococcus mutans and Lactobacillus spp. and the groups of patients.Conclusion. Obesity may contribute to the clinical deterioration of oral cavity, reduced salivary flow, and increased titer of bacteria.