Appearance Of Bacteria Research Articles

Bacteriophages and Bacterial Resistance: The Link

Bacterial resistance is a public health problem that has caused the most deaths in the world; Various international organizations have launched an emergency call for attention to this problem. One of the main factors that contribute to its appearance is the inappropriate use of antibiotics, which generates the appearance of bacteria with specific genes that shield them from exposure to these drugs. In nature there are elements such as bacteriophages that have the ability to "steal" these genes from inside bacteria and transport them to other bacteria in different environments; In addition, due to their propagation, they are considered one of the links that contribute the most to the dissemination of genes, causing public and veterinary health problems as well as economic losses in different sectors such as agriculture and agriculture.

VIBRATORY DRYERS AS AN EFFECTIVE TOOL FOR REDUCING ENERGY CONSUMPTION IN PRODUCTION

Drying of materials is a complex technological process used in various industries and often is one of the main stages of production. This process, in particular for bulk materials, depends on humidity, particle size, hydrodynamic conditions of the particles flowing through the drying agent and environmental parameters. Grain dryers expose grain to more stringent conditions than natural drying, which can potentially lead to a deterioration in grain quality. The combination of these factors determines the nature of the entire process. In agricultural production, the drying stage is one of the most important for grain preservation. Currently, the convective drying method is widely used for this process. However, along with its advantages, this method also has a number of significant disadvantages, one of the most significant of which is its high energy consumption. In this regard, scientific research is being intensively conducted to develop ways and methods to reduce the energy intensity of the convective drying method. The effects of vibration on raw materials are being rapidly introduced in various industries. The use of vibration technologies during drying intensifies the process of processing grain raw materials due to the rapid renewal of its surface in contact with the drying agent. Fast and efficient drying with vibration technology reduces moisture content and the risk of the appearance of bacteria and mold in the grain. The construction of the dryer using vibration technology helps to avoid overheating of the grain, providing optimal temperature conditions, which contributes to the preservation of nutrients and other useful properties of bulk agricultural materials.

The influence of various sample storage conditions and sample bacterial contamination on concentrations of routine biochemical parameters.

The pre-analytical (PA) phase is the most vulnerable phase of the laboratory testing procedure, with critical procedures-collection, handling, sample transport, and time and temperature of sample storage. This study aimed to examine the stability of basic biochemical parameters depending on the samples' storage conditions and the number of freeze-thaw cycles (FTCs). In parallel, the presence of sample bacterial contamination during routine laboratory work was examined. Two plasma pools (ethylenediaminetetraacetic acid (EDTA), and sodium-fluoride/potassium oxalate plasma (NaF)) were stored at +4 ˚C/-20 ˚C. Total chole - sterol (TC), glucose, triglycerides (TG), urea, and albumin concentrations were measured using BioSystems reagents (cholesterol oxidase/peroxidase, glucose oxidase/per - oxidase, glycerol phosphate oxidase/peroxidase, urease/ salicylate, and bromcresol green method, respectively) on Ilab 300+. Sample bacterial contamination was determined by 16S rRNA sequence analysis. The expe - riment encompassed a 5 day-period: Day 1-fresh sample, Day 2-1st FTC, Day 3-2nd FTC, Day 4-3rd FTC, Day 5-4th FTC. The appearance of bacteria in two consecutive samples was the experiment's endpoint.

Studi Eksperimen Pengaruh Ekstrak Kulit Nanas terhadap Laju Pertumbuhan Mikrofouling

Biofouling often sticks to the ship's hull, even to the propeller parts and pipes that are submerged in water. The existence of this biofouling has an impact on the ship's performance, reducing it and requiring more fuel, which ultimately contributes significantly to increased costs. Microfouling is one of the stages of biofouling growth that appears in a matter of days to weeks with a size of up to 1 mm which can be characterized by the appearance of a slippery layer on the surface of the specimen. Until now, many antifouling paints, as a means of preventing the occurrence of biofouling, still contain TBT, which has serious side effects as a chemical pollutant. Pineapple peel is a waste that is often found in Indonesia and contains bromelain and tannin which are anti-bacterial. The appearance of bacteria is the first phase in the growth of biofouling which is usually called biofilm, so it is hoped that pineapple peel extract will be able to prevent the emergence of biofilm. To determine the effectiveness of pineapple peel extract, this experimental study was carried out. The method used was a Randomized Block Design on ASTM 36 steel plate which is a certified ship material with 3 variations and 1 control of specimen as follows, 3 specimens as controls, 3 specimens with a ratio of 30% pineapple peel extract, 3 specimens with a ratio of pineapple peel extract. 50%, and 3 specimens with a pineapple peel extract ratio of 70%. Immersion for 7 weeks was carried out at Boom Beach, Banyuwangi by calculating the DGR (Daily Growth Rate) once a week. The DGR results obtained were respectively 0.095 g/day at an extract ratio of 30%, 0.0727 g/day at an extract ratio of 50%, and 0.0730 g/day at an extract ratio of 70%.

Handwashing Training for Hotel Employees to Reduce the Incidence f Traveler Diarrhea Disease in Tourists

Traveler diarrhea is known as Bali's belly and is often suffered by foreign tourists who visit Bali Island. These activities aimed to see the diarrhea status and knowledge level of hotel employees of the hand washing method. We held this community devotion at a hotel in the Kalibukbuk District, Buleleng – Bali Province, in April 2023. The objective of these activities was for all the hotel employees, a number 44 people. The subjects were chosen by the total sampling method. The inclusion criteria are the hotel employees were registered and willing to participate. The inclusion criteria are sick and on duty. The data collected are the results of a complete fecal laboratory and the level of knowledge about excellent and correct hand washing. Complete fecal data was collected by observation, while knowledge level data was collected by the self-administered questionnaire method. Furthermore, the data were analyzed in a univariate descriptive. Of the forty-four service participants, twenty-one were willing to collect fecal samples. The results of laboratory tests were obtained 100% of the hotel staff had complete fecal results within normal limits based on indicators of color, texture, fecal consistency, the appearance of bacteria, fungi, parasites, viruses, blood, lenders, pus, meat fiber, sugar and fat in feces and potential fecal, hydrogen (pH). The staff's knowledge level score about handwashing increased from 75.7 before counseling to 99.2 after counseling. Hotel employees are free from traveler's diarrheal disease and their level of knowledge increases after being given a campaign on proper and correct handwashing methods. So, it is advisable to routinely conduct fecal examinations once every one year and keep. Updating the knowledge and skills of staff in washing hands appropriately and correctly as an effort to prevent disease, especially travelers' diarrhea.

Controlled Experimental Infection in Pigs with a Strain of Yersinia enterocolitica Harboring Genetic Markers for Human Pathogenicity: Colonization and Stability.

Yersinia enterocolitica (Ye) is one of the major causes of foodborne zoonosis. The BT4/O:3 bioserotype is most commonly isolated in human infections. Pigs are considered the main reservoir of Ye, and hence, understanding the dynamics of infection by this pathogen at the individual and group levels is crucial. In the present study, an experimental model was validated in Large White pigs infected with a BT4/O:3 strain. This study showed that Ye contamination in pigs may occur via the introduction of the bacteria not only by mouth but also by snout, with a colonization process consisting of three periods corresponding to three contamination statuses of pigs: P1, corresponding to the 24 h following ingestion or inhalation of Ye with the appearance of bacteria in tonsils or in feces; P2, from 2 days postinoculation (dpi), corresponding to expansion of Ye and colonization of the digestive system and extraintestinal organs associated with an IgG serological response; and P3, after 21 dpi, corresponding to regression of colonization with intermittent Ye detection in tonsils and feces. Although the inoculated strain persisted up to 56 dpi in all pigs, genetic variations with the loss of the gene yadA (a gene involved in human infection) and the emergence of two new multilocus variable-number tandem-repeat analysis (MLVA) profiles were observed in 33% of the 30 isolates studied. This experimental infection model of pigs by Ye provides new insights into the colonization steps in pigs in terms of bacterial distribution over time and bacterial genetic stability.

Analysis of the Bacterial Biocenosis of Activated Sludge Treated with Leachate from Municipal Landfills.

The influx of toxic pollutants into wastewater treatment plants can negatively affect the quality of the activated sludge (AS). One source is landfill leachate. The identification of microorganisms present in AS is very important, e.g., while improving wastewater treatment technology. Therefore, the aim of the study was to investigate the effect of raw leachate and after purification of Phragmites australis and Ceratophyllum demersum on the composition of the AS bacterial biocenosis. In addition, AS status was assessed by LIVE/DEAD BacLight ™ fluorescent staining. The obtained results showed that the leachate did not significantly affect the cell membranes of AS bacteria, and even a slight improvement was noted. The research carried out using the next-generation sequencing method shows that the origin of the samples (active and closed storage) and the method of processing do not significantly affect the composition of the AS bacterial biocenosis at higher taxonomic levels. However, at the species level, the appearance of bacteria not previously present in AS was observed, namely: Flavobacterium luticocti, Candidimonas nitroreducens and Nitrobacter hamburgensis. The obtained results suggest that the leachate may be a source of microorganisms positively influencing the condition of AS bacteria.

The studies on the membrane activity of triester of phosphatidylcholine in artificial membrane systems.

Due to the increasing number of infections together with the appearance of bacteria exhibiting multi-drug resistance, new antibiotics are being sought. In this context the interest of the cationic lipoids increases because of their amphiphilic structure and positive charge that can stimulates the antibacterial action of these compounds. Thus, in this work we have performed the studies on the effect of one selected triesters of phosphatidylcholine, namely 1,2-dipalmitoyl-sn-glycero-3-ethylphosphocholine (EDPPC), on the model lipid membranes. The investigations included the analysis of the impact of EDPPC on multicomponent monolayers and bilayers consisting of the lipids naturally occurring in bacterial membranes (phosphatidylethanolamines (PE), phosphatidylglycerols (PG) and cardiolipin (CL)), mixed in proportions reflecting the lipid composition of these biomembranes. In the study, the Langmuir monolayers (registered on water and PBS buffer) and liposomes as model bacterial biomembranes were applied. The obtained results demonstrate that the presence of cationic lipoid in PE/PG and PE/PG/CL systems significantly modifies their properties and molecular organization. The incorporation of EDPPC into model bacterial membranes primarily impact on the intermolecular interactions. It was shown that the strength of the interaction between the cationic lipid and the components of the model membranes depends both on the composition of the membrane as well as on the type of subphase. Furthermore, the investigated cationic lipoid leads to the decrease of the ordering of acyl chains and thus to the increase of fluidity of membranes. The obtained results allow one to propose that EDPPC may behave as antibiotic active at the level of membrane.

Obesity and diabetes as comorbidities for COVID-19: Underlying mechanisms and the role of viral-bacterial interactions.

Obesity and diabetes are established comorbidities for COVID-19. Adipose tissue demonstrates high expression of ACE2 which SARS- CoV-2 exploits to enter host cells. This makes adipose tissue a reservoir for SARS-CoV-2 viruses and thus increases the integral viral load. Acute viral infection results in ACE2 downregulation. This relative deficiency can lead to disturbances in other systems controlled by ACE2, including the renin-angiotensin system. This will be further increased in the case of pre-conditions with already compromised functioning of these systems, such as in patients with obesity and diabetes. Here, we propose that interactions of virally-induced ACE2 deficiency with obesity and/or diabetes leads to a synergistic further impairment of endothelial and gut barrier function. The appearance of bacteria and/or their products in the lungs of obese and diabetic patients promotes interactions between viral and bacterial pathogens, resulting in a more severe lung injury in COVID-19.

Early changes.

The findings of this study suggest a biochemical shift in the infant samples associated with the appearance of bacteria.

Bacterial colonization reprograms the neonatal gut metabolome.

Introductory ParagraphInitial microbial colonization and later succession in the gut of human infants are linked to health and disease later in life. The timing of the appearance of the first gut microbiome, and the consequences for the early life metabolome, are just starting to be defined. Here we evaluated the gut microbiome, proteome, and metabolome in 88 African American newborns using fecal samples collected in the first few days of life. Gut bacteria became detectable using molecular methods by 16 hours after birth. Detailed analysis of the three most common species, Escherichia coli, Enterococcus faecalis, and Bacteroides vulgatus, did not suggest a genomic signature for neonatal gut colonization. The appearance of bacteria was associated with reduced abundance of approximately 50 human proteins, decreased levels of free amino acids, and an increase in products of bacterial fermentation, including acetate and succinate. Using flux balance modeling and in vitro experiments, we provide evidence that fermentation of amino acids provides a mechanism for the initial growth of Escherichia coli, the most common early colonizer, under anaerobic conditions. These results provide a deep characterization of the first microbes in the human gut and show how the biochemical environment is altered by their appearance.

Influence of In-Situ Electrochemical Oxidation on Implant Surface and Colonizing Microorganisms Evaluated by Scanning Electron Microscopy.

Peri-implantitis is a worldwide increasing health problem, caused by infection of tissue and bone around an implant by biofilm-forming microorganisms. Effects of peri-implantitis treatment using mechanical debridement, air particle abrasion and electrochemical disinfection on implant surface integrity were compared. Dental implants covered with bacterial biofilm were cleaned using mechanical debridement and air particle abrasion. In addition, implants were disinfected using a novel electrochemical technique based on an array of boron-doped diamond (BDD) coated electrodes. Following treatment and preparation, the implants were inspected by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical debridement led to changes in surface topography destroying the manufacturer’s medium-rough surface by scratch formation. Air particle abrasion led to accumulation of the abrasive used on the implant surface. With both treatment options, appearance of bacteria and yeasts was not affected. In contrast, electrochemical disinfection did not cause alterations of the implant surface but resulted in distorted microbial cells. Electrochemical disinfection of implant surfaces using BDD electrodes may constitute a promising treatment option for cleaning dental implant surfaces without negatively affecting materials and surface properties.

Current paradigms and new perspectives on fetal hypoxia: implications for fetal brain development in late gestation.

The availability of oxygen to the fetus is limited by the route taken by oxygen from the atmosphere to fetal tissues, aided or diminished by pregnancy-associated changes in maternal physiology and, ultimately, a function of atmospheric pressure and composition of the mother's inspired gas. Much of our understanding of the fetal physiological response to hypoxia comes from experiments designed to elucidate the cardiovascular and endocrine responses to transient hypoxia. Complementing this work is equally impactful research into the origins of intrauterine growth restriction in which animal models designed to restrict the transfer of oxygen from the maternal to the fetal circulation were used. A common assumption has been that outcomes measured after a period of hypoxia are related to cellular deprivation of oxygen and reoxygenation: an assumption based on a focus on what we can see "under the streetlights." Recent studies demonstrate that availability of oxygen may not tell the whole story. Transient hypoxia in the fetal sheep stimulates transcriptomics responses that mirror inflammation. This response is accompanied by the appearance of bacteria in the fetal brain and other tissues, likely resulting from a hypoxia-stimulated release of bacteria from the placenta. The appearance of bacteria in the fetus after transient hypoxia complements the recent discovery of bacterial DNA in the normal human placenta and in the tissues of fetal sheep. An understanding of the mechanism of the physiological, cellular, and molecular responses to hypoxia requires an appreciation of stimuli other than cellular oxygen deprivation: stimuli that we would have never known about without looking "between the streetlights," illuminating direct responses to the manipulated variables.

Proof of Principle: Transfer of Small Numbers of Bacteria from Mother to Fetus

The fetus is thought to develop in a sterile environment in utero. Long standing dogma that “the uterus and the feto‐placental unit is “sterile” is based primarily on microbiological culture‐based techniques that were unsuccessful in growing “culture resistant” bacteria or intracellular bacteria. We have reported the presence of low numbers of bacteria in tissues from normal sheep fetuses in pregnancies not complicated by infection. The exposure of the fetus to bacteria might aid neonatal survival by informing fetal immune development. We propose that the fetus is not sterile and that bacteria or fragments of bacteria can be transferred from mother to fetus. We hypothesize that inoculation in the maternal mouth results in the appearance of bacteria in the fetus. We used S. aureus containing green (GFP), red (RFP), or far‐red (FRFP) fluorescent protein‐expressing plasmids to inoculate late‐gestation pregnant sheep (gestational age= 130–135 days, n=7) intravenously (GFP, 104 cfu), into maternal mouth (RFP, 104 cfu) and vagina (FRFP, 104 cfu). These were small doses of bacteria which did not cause physiological (no fever) or psychological (no anorexia) signs of infection. Five to seven days post maternal inoculation, animals were humanely sacrificed, and fetal tissues were collected, and DNA was extracted from placenta and fetal liver, spleen, and cerebral cortex. We probed for GFP plasmid using several primer pairs for endpoint PCR. While detection of whole‐length plasmids was not successful, PCR reactions probing for smaller fragments of plasmid were successful. We found GFP plasmid DNA in all tissues in 10/10 fetal livers and RFP in 10/10 livers. The appearance of GFP and RFP‐labelled bacteria in fetal liver (p=7.497e‐06) was statistically significant as tested by Chi‐Square analysis. We did not detect significant FRFP plasmid DNA in liver. Analysis of tissues by immunohistochemistry revealed GFP and RFP‐expressing bacteria in fetal tissues, although most appeared to be in aggregates. We conclude that S. aureus, introduced in small numbers in maternal mouth and bloodstream, appear in the fetus and placenta. We were unable to determine whether these bacteria were alive in the fetus.Support or Funding InformationThis work was supported by HD033053, AI120195, and HL083810This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of ketamine on the fetal transcriptomic response to umbilical cord occlusion: comparison with hypoxic hypoxia in the cerebral cortex.

The cerebral response to fetal asphyxia is characterized by an upregulation of nucleic acid and chromatin modification processes, as well as a downregulation of metabolic processes at 1h post-umbilical cord occlusion (UCO). Twenty-four hours post UCO, there was an upregulation of metabolic processes and protein modifications. UCO did not alter bacterial gene expression levels, nor did it produce a robust inflammatory response compared to maternal hypoxia. The administration of ketamine produced minimal effects on the fetal response to UCO in the cerebral cortex. Umbilical cord occlusion (UCO) is known to cause neurological disorders in the neonate. Previously, we have reported that hypoxic hypoxia (HH) stimulates the appearance of bacteria in the fetal brain and upregulates the expression of inflammatory markers in fetal cerebral cortex (CTX) and also that ketamine attenuates these responses. In the present study, we aimed to test the hypothesis that UCO, similar to HH, produces an inflammatory response in the fetal CTX and also that treatment with ketamine reduces these effects. In chronically instrumented fetal sheep (∼125days), 30min of partial UCO decreased fetal levels by ∼50%. Half of the fetuses received ketamine (3mgkg-1 ) 10min prior to UCO (n=4 per group). Fetal brains were collected 1 and 24h after the experiment and mRNA was extracted and hybridized for microarray analyses. Differentially-expressed genes were analysed for significant association with gene ontologies and pathways. After 1h, UCO upregulated nucleic acid processing and chromatin modification and downregulated metabolic processes compared to control. After 24h, UCO upregulated metabolic and protein modification processes. Ketamine produced minimal effects. UCO did not alter the abundance of bacterial DNA in fetal brain, nor did it upregulate inflammation pathways compared to HH. We conclude that UCO produced time-dependent responses that did not include bacterial invasion or upregulation of inflammation pathways in fetal CTX. This contrasts with the response to HH, which resulted in the appearance of bacteria in the CTX and upregulated inflammation pathways. These responses in fetal CTX to oxygen deprivation are therefore modified by the maternal or placental response to the stimulus.

Bacterial DNA detected on pathologically changed heart valves using 16S rRNA gene amplification.

Nowadays, dental diseases are one of the most common illnesses in the world. Some of them can lead to translocation of oral bacteria to the bloodstream causing intermittent bacteraemia. Therefore, a potential association between oral infection and cardiovascular diseases has been discussed in recent years as a result of adhesion of oral microbes to the heart valves. The aim of this study was to detect oral bacteria on pathologically changed heart valves not caused by infective endocarditis. In the study, patients with pathologically changed heart valves were involved. Samples of heart valves removed during heart valve replacement surgery were cut into two parts. One aliquot was cultivated aerobically and anaerobically. Bacterial DNA was extracted using Ultra-Deep Microbiome Prep (Molzym GmbH, Bremen, Germany) followed by a 16S rRNA gene PCR amplification using Mastermix 16S Complete kit (Molzym GmbH, Bremen, Germany). Positive PCR products were sequenced and the sequences were analyzed using BLAST database ( http://www.ncbi.nlm.nih/BLAST ). During the study period, 41 samples were processed. Bacterial DNA of the following bacteria was detected in 21 samples: Cutibacterium acnes (formerly Propionibacterium acnes) (n = 11; 52.38% of patients with positive bacterial DNA detection), Staphylococcus sp. (n = 9; 42.86%), Streptococcus sp. (n = 1; 4.76%), Streptococcus sanguinis (n = 4; 19.05%), Streptococcus oralis (n = 1; 4.76%), Carnobacterium sp. (n = 1; 4.76%), Bacillus sp. (n = 2; 9.52%), and Bergeyella sp. (n = 1; 4.76%). In nine samples, multiple bacteria were found. Our results showed significant appearance of bacteria on pathologically changed heart valves in patients with no symptoms of infective endocarditis.

Expression of Genes Involved in Bacteriocin Production and Self-Resistance in Lactobacillus brevis 174A Is Mediated by Two Regulatory Proteins.

We have previously shown that the lactic acid bacterium Lactobacillus brevis 174A, isolated from Citrus iyo fruit, produces a bacteriocin designated brevicin 174A, which is comprised of two antibacterial polypeptides (designated brevicins 174A-β and 174A-γ). We have also found a gene cluster, composed of eight open reading frames (ORFs), that contains genes for the biosynthesis of brevicin 174A, self-resistance to its own bacteriocin, and two transcriptional regulatory proteins. Some lactic acid bacterial strains have a system to start the production of bacteriocin at an adequate stage of growth. Generally, the system consists of a membrane-bound histidine protein kinase (HPK) that senses a specific environmental stimulus and a corresponding response regulator (RR) that mediates the cellular response. We have previously shown that although the HPK- and RR-encoding genes are not found on the brevicin 174A biosynthetic gene cluster in the 174A strain, two putative regulatory genes, designated breD and breG, are in the gene cluster. In the present study, we demonstrate that the expression of brevicin 174A production and self-resistance is positively controlled by two transcriptional regulatory proteins, designated BreD and BreG. BreD is expressed together with BreE as the self-resistance determinant of L. brevis 174A. DNase I footprinting analysis and a promoter assay demonstrated that BreD binds to the breED promoter as a positive autoregulator. The present study also demonstrates that BreG, carrying a transmembrane domain, binds to the common promoter of breB and breC, encoding brevicins 174A-β and 174A-γ, respectively, for positive regulation.IMPORTANCE The problem of the appearance of bacteria that are resistant to practical antibiotics and the increasing demand for safe foods have increased interest in replacing conventional antibiotics with bacteriocin produced by the lactic acid bacteria. This antibacterial substance can inhibit the growth of pathogenic bacteria without side effects on the human body. The bacteriocin that is produced by a Citrus iyo-derived Lactobacillus brevis strain inhibits the growth of pathogenic bacteria such as Listeria monocytogenes, Staphylococcus aureus, and Streptococcus mutans In general, lactic acid bacterial strains have a system to start the production of bacteriocin at an adequate stage of growth, which is called a quorum-sensing system. The system consists of a membrane-bound histidine protein kinase that senses a specific environmental stimulus and a corresponding response regulator that mediates the cellular response. The present study demonstrates that the expression of the genes encoding bacteriocin biosynthesis and the self-resistance determinant is positively controlled by two transcriptional regulatory proteins.

Hiện trạng hệ vi sinh vật phân giải lân trên một số loại đất phù sa trồng lúa nước vùng đồng bằng sông Hồng

The aim of this study was to assess phosphorus solubilizing microorganisms in eutric fluvisols (Gia Lam district, Hanoi) and gleyic fluvisols (Tien Lu district, Hung Yen province) for cultivating rice in the Red River Delta (2 crops per year). The results of isolation showed the appearance of bacteria, actinomycetes in the samples, but absence of fungi. Overall, density of phosphorus solubilizing microorganisms in eutric fluvisols was much more than that in gleyic fluvisols; however, the amount of strains was less diverse. It was not the same between the 2 types of soil, even between different samples of the same soil type. There were 4 common strains of bacteria in eutric fluvisols; the density ranged from 15.5 to 22.9 x104 CFU/g soil. Meanwhile, the gleyic fluvisols had 4 strains of popular bacteria and 1 strains of actinomycetes, ranged from 2.3 to 17.3 x104 CFU/g soil. In these 2 soil types, the density of inorganic-phosphate solubilizing microorganism was higher than that of organic- phosphate solubilizing microorganism. However, compared to the total of microorganisms, both microbial groups were very low in density, less than 1% of each. Besides, ability of phosphorus solubilization of them are not high, phosphate PO43- released ranging from 0.70 to 5.66 ppm (Tricalcium phosphate form) and from 0.0 to 1.83 ppm (Lecithine form).

Detection of single bacteria – causative agents of meningitis using raman microscopy

Early diagnostics of meningitis is a very topical problem as it is a fulminant disease with a high level of mortality. The progress of this disease is, as a rule, accompanied by the appearance of bacteria in the cerebrospinal fluid (CSF) composition. The examination of the CSF is well known to be the only reliable approach to the identification of meningitis. However, the traditional biochemical analyses are time consuming and not always reliable, simple, and inexpensive, whereas the optical methods are poorly developed. This work is devoted to the study of Raman spectra of several bacterial cultures which are mainly present during meningitis. Raman microscopy is a prompt and noninvasive technique capable of providing reliable information about molecular-level alterations of biological objects at their minimal quantity and size. It was shown that there are characteristic lines in Raman spectra which can be the reliable markers for determination of bacterial form of meningitis at a level of a single bacterium.

In vivo monitoring of Staphylococcus aureus biofilm infections and antimicrobial therapy by [18F]fluoro-deoxyglucose-MicroPET in a mouse model.

A mouse model was developed for in vivo monitoring of infection and the effect of antimicrobial treatment against Staphylococcus aureus biofilms, using the [(18)F]fluoro-deoxyglucose-MicroPET ([(18)F]FDG-MicroPET) image technique. In the model, sealed Vialon catheters were briefly precolonized with S. aureus strains ATCC 15981 or V329, which differ in cytotoxic properties and biofilm matrix composition. After subcutaneous implantation of catheters in mice, the S. aureus strain differences found in bacterial counts and the inflammatory reaction triggered were detected by the regular bacteriological and histological procedures and also by [(18)F]FDG-MicroPET image signal intensity determinations in the infection area and regional lymph node. Moreover, [(18)F]FDG-MicroPET imaging allowed the monitoring of the rifampin treatment effect, identifying the periods of controlled infection and those of reactivated infection due to the appearance of bacteria naturally resistant to rifampin. Overall, the mouse model developed may be useful for noninvasive in vivo determinations in studies on S. aureus biofilm infections and assessment of new therapeutic approaches.