Pathogens Research Articles

Green Synthesis of Ganoderma Lucidum-Mediated Silver Nanoparticles and its Microbial Activity against Oral Pathogenic Microbes: An In Vitro Study

ABSTRACT Nanotechnology is developing into a fast-expanding discipline with applications in science and technology, and nanostructures are a crucial research tool in many fields. Due to their remarkable electrical, optical, magnetic, catalytic, and pharmacological capabilities, metal and metal oxide nanoparticles (NPs) have drawn study interest. Natural elements (plants, microorganisms, fungi, etc.) are utilized in a chemical-free, environmentally benign way to synthesize metals and metal oxides. The optical, electrical, and antimicrobial qualities of silver nanoparticle (AgNP) make them a popular choice. More than 200 active ingredients, including water-soluble, organic-soluble, and volatile chemicals, are found in Ganoderma. The main components are polysaccharides, adenosine, and terpenoids, each of which has exceptional therapeutic properties. This article explains the synthesis of Ag NPs by Ganoderma lucidum and tests the antibacterial effectiveness for use in biological applications.

Metagenomics for Pathogen Detection During a Mass Mortality Event in Songbirds.

Mass mortality events in wildlife can be indications of an emerging infectious disease. During the spring and summer of 2021, hundreds of dead passerines were reported across the eastern US. Birds exhibited a range of clinical signs including swollen conjunctiva, ocular discharge, ataxia, and nystagmus. As part of the diagnostic investigation, high-throughput metagenomic next-generation sequencing was performed across three molecular laboratories on samples from affected birds. Many potentially pathogenic microbes were detected, with bacteria forming the largest proportion; however, no singular agent was consistently identified, with many of the detected microbes also found in unaffected (control) birds and thus considered to be subclinical infections. Congruent results across laboratories have helped drive further investigation into alternative causes, including environmental contaminants and nutritional deficiencies. This work highlights the utility of metagenomic approaches in investigations of emerging diseases and provides a framework for future wildlife mortality events.

Perspective of Secondary Metabolites in Respect of Multidrug Resistance (MDR): A Review.

Aberrant and haphazard use of antibiotics has created the development of antimicrobial resistance which is a bizarre challenge for human civilization. This emerging crisis of antibiotic resistance for microbial pathogens is alarming all the nations posing a global threat to human health. It is difficult to treat bacterial infections as they develop resistance to all antimicrobial resistance. Currently used antibacterial agents inhibit a variety of essential metabolic pathways in bacteria, including macro-molecular synthesis (MMS) pathways (e.g. protein, DNA, RNA, cell wall) most often by targeting a specific enzyme or subcellular component e.g. DNA gyrase, RNA polymerase, ribosomes, transpeptidase. Despite the availability of diverse synthetic molecules, there are still many complications in managing progressive and severe antimicrobial resistance. Currently not even a single antimicrobial agent is available for which the microbes do not show resistance. Thus, the lack of efficient drug molecules for combating microbial resistance requires continuous research efforts to overcome the problem of multidrug-resistant bacteria. The phytochemicals from various plants have the potential to combat the microbial resistance produced by bacteria, fungi, protozoa and viruses without producing any side effects. This review is a concerted effort to identify some of the major active phytoconstituents from various medicinal plants which might have the potential to be used as an alternative and effective strategy to fight against microbial resistance and can promote research for the treatment of MDR.

370 Point-of-Service Salivary Microbiome Analysis in the Prevention and Detection of Oral Premalignant Lesions

OBJECTIVES/GOALS: Our aim is to establish soluble salivary biomarkers indicative of increased risk of oral premalignancy to be used in a point-of-service technology. Our goal is to non-invasively assess risk level for premalignancy by characterizing a molecular signature pattern that can be applied to such a diagnostic tool at routine dental or medical visits. METHODS/STUDY POPULATION: Adult patients 18 years of age and older who are non-smokers and patients of the University of Maryland School of Dentistry Oral Medicine Clinic and have been diagnosed with oral premalignancy (proliferative verrucous leukoplakia) are eligible. Exclusion criteria include history of immunosuppression or immune compromise; use of antifungal, antibiotic, and/or antiviral medications within the past three months; and gross dental disease. Serial unstimulated saliva samples will be collected at baseline or diagnosis of oral premalignancy, 6 months and 12 months. Solubility testing will be completed to determine whether malignant markers such as EGFR/mTOR/PI3K/p53 are soluble in saliva, and patient samples will be analyzed by ELISA and compared to appropriate controls. RESULTS/ANTICIPATED RESULTS: We anticipate demonstrating increased activity of molecular pathways known to be involved in malignant transformation, such as EGFR/mTOR/PI3K/p53, or increased burden of select microbial pathogens to be associated with increased risk of oral premalignancy in the form of proliferative verrucous leukoplakia. Preliminary sensitivity and specificity testing of the identified markers will provide additional insight to the utility of a diagnostic tool with salivary specimen. Therefore, the microbiome and/or molecular profile proposed from these results will serve as a translational application to development of future point-of-service test devices to be used in the prevention and detection of oral premalignant lesions. DISCUSSION/SIGNIFICANCE: Oral cancer is the sixth most common cancer worldwide, and presents challenges in its diagnosis and clinical management. Later diagnosis is associated with poorer patient outcomes—therefore, a molecular and microbiome profile that may be used in a noninvasive diagnostic test technology would prove beneficial to providers and patients.

Development of Zeolite‐Loaded Air‐Brushed Nanofibers for Oral Use and Its Characterization

AbstractZeolites are commercially available and naturally occurring minerals and synthetic materials, they are crystalline aluminosilicates with distinctive chemical and structural properties. Zeolites have a wide range of uses, including catalysis, gas separation, agronomy, animal feed additives, ecology, medicine, and cosmetics. The antibacterial activity of zeolite‐based nanofibers is fabricated and investigated in the current work utilizing a novel airbrushing method. Airbrushing is used to create zeolite‐loaded nanofibers with two groups of 5% and 10% zeolite, respectively. Scanning electron microscopy (SEM), Attenuation of Reflectance Fourier Transform Infrared Spectroscopy (ATR‐FT‐IR), contact angle measurement and an antibacterial test against Streptococcus mutans are used to characterize the fabricated zeolite‐loaded nanofibers. The SEM pictures demonstrate that the innovative strategy used in the study—air brushing—to effectively produce zeolite‐loaded nanofibers is a success. The morphology and diameter in nanometers is verified by SEM images for both groups. The ATR‐FT‐IR peaks confirm the blended compound and its chemical structure. The water contact angle measurement of the nanofibers of both groups show the hydrophobic qualities based on wettability. The findings of the zeolite nanofiber antibacterial test show a zone of inhibition (ZOI) of 19 mm compared to a positive control groups ZOI of 28 mm, indicating superior antibacterial activity against gram‐positive S. mutans. Based on the findings, it can be stated that zeolite nanofiber can be created by airbrushing and has antibacterial properties that can be utilized to stop dental caries, where S. mutans is the primary pathogenic organism.

Three-way junction structure-mediated reverse transcription-free exponential amplification reaction for pathogen RNA detection.

Since RNA is an important biomarker of many infectious pathogens, RNA detection of pathogenic organisms is crucial for disease diagnosis and environmental and food safety. By simulating the base mismatch during DNA replication, this study presents a novel three-way junction structure-mediated reverse transcription-free exponential amplification reaction (3WJ-RTF-EXPAR) for the rapid and sensitive detection of pathogen RNA. The target RNA served as a switch to initiate the reaction by forming a three-way junction (3WJ) structure with the ex-trigger strand and the ex-primer strand. The generated trigger strand could be significantly amplified through EXPAR to open the stem-loop structure of the molecular beacon to emit fluorescence signal. The proofreading activity of Vent DNA polymerase, in combination with the unique structure of 2+1 bases at the 3'-end of the ex-primer strand, could enhance the role of target RNA as a reaction switch to reduce non-specific amplification and ensure excellent specificity to differentiate target pathogen from those causing similar symptoms. Furthermore, detection of target RNA showed a detection limit of 1.0×104 copies/mL, while the time consumption was only 20 min, outperforming qRT-LAMP and qRT-PCR, the most commonly used RNA detection methods in clinical practice. All those indicates the great application prospects of this method in clinical diagnostic.

ADVANCES IN WATER QUALITY ASSESSMENT USING FUZZY APPROACH: RECENT TRENDS OF THEORY AND APPLICATIONS

Due to the rapid growth of economic development and population, the demand for water consumption and the levels of polluted water in Malaysia have constantly increased and are considered crucial issues in Malaysia. Urbanization has steadily produced great amounts of human wastes, such as domestic and industrial wastes which inevitably end up in the water bodies. The World Health Organization claimed that approximately 2.2 million people die annually from such illnesses caused by ingesting bacteria, viruses, protozoans, and other pathogenic microbes in untreated or poorly treated waters or wastewater. This paper intends to provide insight into the publication trends on water quality assessment using fuzzy approaches from 2015 to 2023. This study conducted a bibliometric analysis of 404 scholarly works on water quality assessment as recorded in the Scopus database in September 2023. The data was analysed using a variety of software which are VOSviewer, Harzing’s Publish and Perish, and Microsoft Excel. This paper highlights important contributions, publications, statistics, and current trends of theory and applications in the field. The finding also addresses essential information on present and future developments and critical information for increasing the inclusivity and global reach of water quality assessment which need further attention from the fuzzy research community.

Efficacy and Synergistic Potential of Cinnamon (Cinnamomum zeylanicum) and Clove (Syzygium aromaticum L. Merr. & Perry) Essential Oils to Control Food-Borne Pathogens in Fresh-Cut Fruits.

The presence of microbial pathogens in ready-to-eat produce represents a serious health problem. The antibacterial activity of cinnamon (Cinnamomum zeylanicum) and clove (Syzygium aromaticum L. Merr. & Perry) essential oils (EOs) was determined toward food-borne pathogens by agar disk diffusion and minimum inhibitory concentration (MIC) assays. The growth kinetics of all strains, both in a buffer suspension assay and "on food" in artificially contaminated samples, were also investigated. The two EOs demonstrated a good antibacterial effect both alone and in combination (EO/EO). The use of EO/EO led to a synergistic antibacterial effect, also confirmed by the growth kinetics studies, where the EOs were active after 10 h of incubation (p < 0.0001) at significantly lower concentrations than those when alone. In the "on food" studies performed on artificially contaminated fruit samples stored at 4 °C for 8 days, the greatest killing activity was observed at the end of the trial (8 days) with a reduction of up to 7 log CFU/g compared to the control. These results confirm the good antibacterial activity of the EOs, which were more effective when used in combination. Data from the "on food" studies suggest cinnamon and clove essential oils, traditionally used in the food industry, as a possible natural alternative to chemical additives.

New options in drug discovery: Endophyte technology

Antimicrobial discovery has traditionally focused on sources from plants, animals and microorganisms. However, with the reoccurring incidences of multidrug-resistant organisms (MDROs) towards the in-use antibiotics and the problem of over- exploration of plants that is heavily altering the ecosystem, the need for other sustainable means of acquiring novel drugs becomes imperative. In a bid to ameliorate these issues, researchegrs have resorted to the use of some endosymbiotic microorganisms, known as endophytes. These are microorganisms inhabiting the internal part of plants, which have been verified to possess great potentials to bioengineer novel products, for therapeutic purposes. The discovery of endophytic microorganisms has come with so many promises of alleviating the challenges of an increasingly daunting multidrug- resistant strain of pathogenic microbes, which have become a global issue in health care delivery. They can be harnessed and utilized in the generation of active ingredients for drug production, instead of the incessant cutting down or harvesting of plants or plant parts, which destroys nature, resulting in global warming and world climate problems. This systematic review is on endophytic technology as a new alternative in drug discovery.

Ebselen: A Promising Repurposing Drug to Treat Infections Caused by Multidrug-Resistant Microorganisms.

Bacterial multiresistance to drugs is a rapidly growing global phenomenon. New resistance mechanisms have been described in different bacterial pathogens, threatening the effective treatment of even common infectious diseases. The problem worsens in infections associated with biofilms because, in addition to the pathogen's multiresistance, the biofilm provides a barrier that prevents antimicrobial access. Several "non-antibiotic" drugs have antimicrobial activity, even though it is not their primary therapeutic purpose. However, due to the urgent need to develop effective antimicrobials to treat diseases caused by multidrug-resistant pathogens, there has been an increase in research into "non-antibiotic" drugs to offer an alternative therapy through the so-called drug repositioning or repurposing. The prospect of new uses for existing drugs has the advantage of reducing the time and effort required to develop new compounds. Moreover, many drugs are already well characterized regarding toxicity and pharmacokinetic/pharmacodynamic properties. Ebselen has shown promise for use as a repurposing drug for antimicrobial purposes. It is a synthetic organoselenium with anti-inflammatory, antioxidant, and cytoprotective activity. A very attractive factor for using ebselen is that, in addition to potent antimicrobial activity, its minimum inhibitory concentration is very low for microbial pathogens.

Enhanced antibacterial activity of porous chitosan-based hydrogels crosslinked with gelatin and metal ions

Addressing the increasing drug resistance in pathogenic microbes, a significant threat to public health, calls for the development of innovative antibacterial agents with versatile capabilities. To enhance the antimicrobial activity of non-toxic biomaterials in this regard, this study focuses on novel, cost-effective chitosan (CS)-based hydrogels, crosslinked using gelatin (GEL), formaldehyde, and metallic salts (Ag+, Cu2+, and Zn2+). These hydrogels are formed by mixing CS and GEL with formaldehyde, creating iminium ion crosslinks with metallic salts without hazardous crosslinkers. Characterization techniques like FTIR, XRD, FESEM, EDX, and rheological tests were employed. FTIR analysis showed metal ions binding to amino and hydroxyl groups on CS, enhancing hydrogelation. FESEM revealed that freeze-dried hydrogels possess a crosslinked, porous structure influenced by various metal ions. Antibacterial testing against gram-negative and gram-positive bacteria demonstrated significant bacterial growth inhibition. CS-based hydrogels containing metal ions showed reduced MIC and MBC values against Staphylococcus aureus (0.5, 8, 16 µg/mL) and Escherichia coli (1, 16, 8 µg/mL) for CS-g-GEL-Ag+, CS-g-GEL-Cu2+, and CS-g-GEL-Zn2+. MTT assay results confirmed high biocompatibility (84.27%, 85.24%, 84.96% viability at 10 µg/mL) for CS-based hydrogels towards HFF-1 cells over 48 h. Therefore, due to their non-toxic nature, these CS hydrogels are promising for antibacterial applications.

Dental Caries and Salivary Immunoglobulin A in Down Syndrome

Down syndrome (DS) is defined as trisomy chromosome 21, which is observed to be the most prevalent autosomal genetic anomaly. Salivary immunoglobulin A (sIgA) plays an important role in defence mechanism against the microbial pathogens that can invade the surface of mucosa. In children with DS, raised sIgA levels cause an increase in immune mechanism against dental caries. The evidence about the salivary IgA levels in children suffering from Down syndrome is contradictory and limited in the literature. Thus, there is a terrible requirement to conduct more longitudinal prospective studies on saliva of DS patients taking large sample sizes to assess the molecular interactions. The present review is aimed to evaluate the association of Dental caries and salivary immunoglobulin A in Down syndrome individuals. The sources were searched from a database of PubMed from 2004 to 2023 (last 19 years). The inclusion criteria included key words of microdontia, delayed eruption, dental anomalies, retained teeth, anodontia, fissured lip and tongue, macroglossia, hypodontia in Down syndrome. The 22 articles that met the selection criteria (most of them were review article and some observational studies) were included to this review, of which some of the studies have been conducted to assess the role of sIgA in relation to dental caries and observed that increased sIgA levels decrease the rate of incidence of dental caries. The present review revealed that patients suffering with Down syndrome are at an increased risk of dental caries because of impaired motor activities, malocclusion and affected quality of life.

Development of Molecular-Based Screening Test for Hepatitis B Virus in Human Plasma Samples.

Despite regular administration of hepatitis B virus (HBV) vaccine in several countries, the mortality rate associated with HBV remains significant. The antiviral medications available for the treatment of HBV infection do not suffice for the serious complications related to chronic HBV infection. Additionally, the serological tests fail to detect early viral replication preventing early treatment response. Recently, many studies have demonstrated the significant advantages of loop-mediated isothermal amplification (LAMP) over serological testing and polymerase chain reaction (PCR), for the rapid detection of microbial pathogens. Here we developed a rapid, sensitive, and portable system-integrative LAMP assay for the detection of HBV DNA in plasma samples. The final optimized assay was achieved with an amplification time of less than 45 min at 62°C. The assay showed 100% specificity, 92.20% sensitivity, and a detection limit of 10 copies/µL in 77 HBV-positive plasma samples with known Cq values. Our results showed that the colorimetric LAMP assay is sensitive, efficient, and supremely reliable for rapid detection of HBV, and may be potentially used as a screening test in areas with poor laboratory facilities and limited resource availability.

Decoding the Arsenal: Protist Effectors and Their Impact on Photosynthetic Hosts.

Interactions between various microbial pathogens including viruses, bacteria, fungi, oomycetes, and their plant hosts have traditionally been the focus of phytopathology. In recent years, a significant and growing interest in the study of eukaryotic microorganisms not classified among fungi or oomycetes has emerged. Many of these protists establish complex interactions with photosynthetic hosts, and understanding these interactions is crucial in understanding the dynamics of these parasites within traditional and emerging types of farming, including marine aquaculture. Many phytopathogenic protists are biotrophs with complex polyphasic life cycles, which makes them difficult or impossible to culture, a fact reflected in a wide gap in the availability of comprehensive genomic data when compared to fungal and oomycete plant pathogens. Furthermore, our ability to use available genomic resources for these protists is limited by the broad taxonomic distance that these organisms span, which makes comparisons with other genomic datasets difficult. The current rapid progress in genomics and computational tools for the prediction of protein functions and interactions is revolutionizing the landscape in plant pathology. This is also opening novel possibilities, specifically for a deeper understanding of protist effectors. Tools like AlphaFold2 enable structure-based function prediction of effector candidates with divergent protein sequences. In turn, this allows us to ask better biological questions and, coupled with innovative experimental strategies, will lead into a new era of effector research, especially for protists, to expand our knowledge on these elusive pathogens and their interactions with photosynthetic hosts. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Green Synthesis of Cobalt Oxide Nanoparticles with In-vitro Cytotoxicity Assessment Using Pomegranate (Punica granatum L.) Seed Oil: A Promising Approach for Antimicrobial and Anticancer Applications

Green synthesis of nanoparticles and their pharmacological implementation have gained importance in the field of nanotechnology. This study primarily aims to explore the use of Punica granatum L. seed oil as a reducing agent for the synthesis of cobalt nanoparticles, making it both economically and pharmacologically valuable. Gas chromatography-mass spectroscopy analysis was carried out to study the active metabolites present in P. granatum seed oil. The green synthesis of cobalt nanoparticles was established based on the color change of the reaction mixture from dark green to light green. These particles showed a ?max at 279.88 nm for UV-visible spectrometry analysis. Furthermore, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FE SEM) and Dynamic Light Scattering (DLS) were performed to confirm the nature of these nanoparticles. The pharmacological potential of these cobalt oxide nanoparticles was tested against microbial pathogens. The results suggest that these nanoparticles exhibited significant activity against various human bacterial and fungal pathogens. Additionally, in in vitro cytotoxicity analysis, demonstrated that CoONPs selectively targeted MCF-7 cancer cells with a significant IC50 value compared to non-cancerous cells (L929). In conclusion, this study demonstrated that green synthesized CoONPs using P. granatum show significant potential against eukaryotic cancer cells and microbial pathogens. Furthermore, this study has implications for medical research centers and pharmaceutical industries in addressing modern challenges such as increasing antibiotic resistance in communities.

SfREPAT38, a pathogen response gene (REPAT), is involved in immune response of Spodoptera frugiperda larvae through mediating Toll signalling pathway.

REPAT (response to pathogen) is an immune-associated gene family that plays important roles in insect immune response to pathogens. Although nine REPAT genes have been identified in Spodoptera frugiperda (Lepidoptera: Noctuidae) currently, their functions and mechanisms in the immune response to pathogens still remain unclear. Therefore, SfREPAT38, a pathogen response gene (REPAT) of S. frugiperda, was characterised and its function was analysed. The results showed that SfREPAT38 contains a signal peptide and a transcription activator MBF2 (multi-protein bridging factor 2) domain. Quantitative real-time polymerase chain reaction analysis showed that SfREPAT38 was highly expressed in the sixth-instar larvae (L6) and was the highest in expression in the midgut of L6. We found that the expression of SfREPAT38 could be activated by challenge with four microbial pathogens (Bacillus thuringiensis, Metarhizium anisopliae, Spodoptera exigua nuclearpolyhedrosis and Escherichia coli), except 12 h after E. coli infection. Furthermore, the SfREPAT38 expression levels significantly decreased at 24, 48 and 72 h after SfREPAT38 dsRNA injection or feeding. Feeding with SfREPAT38 dsRNA significantly decreased the weight gain of S. frugiperda, and continuous feeding led to the death of S. frugiperda larvae from the fourth day. Moreover, SfREPAT38 dsRNA injection resulted in a significant decrease of weight gain on the fifth day. Silencing SfREPAT38 gene down-regulated the expression levels of immune genes belonging to the Toll pathway, including SPZ, Myd88, DIF, Cactus, Pell and Toll18W. After treatment with SfREPAT38 dsRNA, S. frugiperda became extremely sensitive to the B. thuringiensis infection, and the survival rate dramatically increased, with 100% mortality by the eighth day. The weight of S. frugiperda larvae was also significantly lower than that of the control groups from the second day onwards. In addition, the genes involved in the Toll signalling pathway and a few antibacterial peptide related genes were down-regulated after treatment. These results showed that SfREPAT38 is involved in the immune response of S. frugiperda larvae through mediating Toll signalling pathway.

Isolation and identification of microorganisms associated with fairly used clothes (Okirika) sold in Eke Awka Market, Anambra State

The use of previously worn clothing poses a risk of transmitting infectious diseases as the history of previous users is unknown. Despite this, used clothes are commonly sold as they are cheaper compared to new ones. Research was carried out to investigate the presence of pathogenic microbes such as bacteria, fungi, and protozoa in used clothes bought at Eke Awka Market in Anambra State, Nigeria. A variety of clothing items, including trousers, shirts, caps, bras, panties, baby clothes, towels, socks, head ties, and bed sheets were purchased and analysed for the presence of contaminating microbes. Techniques such as culture and plate count methods were used for the isolation of these microorganisms, and further identification was done through morphological and biochemical methods. Additionally, protozoa were specifically isolated through a washing method, which involved centrifuging the samples at 500g for 10 minutes and then observing the sediments under a microscope. The study found microorganisms such as Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus spp, Rhodoborula spp, Candida glabrata and Entamoeba coli on the clothes examined. The highest number of bacteria isolates (2.00±0.000) were from caps and socks while the least (1.00±0.000) were from bras and bed sheets. The highest number of fungi isolates (2.50±0.707) were from trousers, bras, and baby cloths while shirts, socks, and bed sheets had the least number of fungi isolates (1.00±0.000). The only protozoan isolate was found in socks. In terms of colonies formed per unit, panties had the most colony-forming units (132.5±10.607) for fungi and (63.5±4.95) for bacteria organisms while caps had the least (16±1.414) for fungi and (8.5±2.121) for bacteria organisms, respectively. It is important to note that used clothes can act as a bearer of harmful bacteria for the epidermis and other diseases and should, whenever possible, be washed and sanitized thoroughly before use.

Study of the spectrum and antibiotic sensitivity of the respiratory tract microbiota of newborns with infectious complications during long-term mechanical lung ventilation

determining the structure of leading microbial colonizers of the respiratory tract as potential causative agents of ventilator-associated pneumonia and their sensitivity to antibacterial drugs plays an important role in choosing effective tactics for etiotropic therapy of newborns. According to the data of scientific publications, the etiological structure of infectious complications associated with long-term respiratory support in newborns is known to have certain features. The spectrum of nosocomial microbial pathogens and their sensitivity to antimicrobial drugs are among them. The patients of early age are characterized by a number of peculiarities of anatomical and physiological characteristics and the qualitative and quantitative composition of the microbiota of the respiratory tract. In order to form ideas about the determining causative agents of VAP in newborns, it was advisable to conduct a microbiological study of the species composition of microorganisms associated with this infectious complication, as well as to determine their sensitivity to antibiotics recommended by the management protocols of the corresponding pathology. To study and solve this problem, it is necessary to study the spectrum and antibiotic sensitivity of the causative agents of VAP. A prospective study was conducted in 69 newborns with VAP (2020 - 2023), who were treated in the Neonatal Intensive Care Unit (NICU) of the Vinnytsia Regional Children's Clinical Hospital (VRCCH) and consisted in studying the composition of the microbiota and antibiotic sensitivity. We took into account opportunistic microorganisms that are not characteristic of this biotope of the respiratory tract of newborns who were diagnosed with VAP during long-term mechanical ventilation. As a result of the prospective analysis of the microbiological study of the microbiota of 69 newborns, 82 microorganisms - etiologically significant pathogens of VAP - were isolated and identified. Thus, according to the data of our bacteriological studies, 17 Gram-positive and 65 Gram-negative pathogens of VAP were isolated and identified in NICU VRCCH for 2020-2023. As a result of the study of antibiotic sensitivity of VAP pathogens in newborns, the following trends were observed. Low sensitivity of Acinetobacter baumannii to ceftazidime, aztreonam, imipinem, meropenem, amoxicillin, piperacillin, levofloxacin, ciprofloxacin was established. And sensitive to amikacin, gentamicin and cefoperazone-sulbactam. High rates of resistance of Pseudomonas aeruginosa to ceftazidime, doxycycline, imipinem, meropenem, gentamicin, piperacillin, levofloxacin, ciprofloxacin, ofloxacin were established. The best indicators of sensitivity of P. aeruginosa to amikacin, cefoperazone-sulbactam and tobramycin were found. According to the results of the sensitivity of K. pneumoniae to antibiotics, resistance to all antibiotics was established. The development of resistance of Staphylococcus aureus to azithromycin, norfloxacin, cefotaxime, benzylpenicillin has been established. The indicators of S. aureus sensitivity to amikacin, tetracycline and vancomycin turned out to be the best. We took into account opportunistic microorganisms that are not typical for this biotype of the airways of newborns who were diagnosed with VAP during long-term mechanical ventilation. The results of the study indicate the need to take into account the data of a microbiological study with the mandatory identification of isolated pathogens, their microbial load at the site of infection, determining their antibiotic sensitivity is of crucial importance in the selection of etiotropic treatment tactics for newborns with VAP.

SOURCES OF POLLUTION OF SURFACE WATERS, DEVELOPMENT OF RECOMMENDATIONS FOR THEIR DETECTION AND DEVELOPMENT OF PREVENTION METHODS

The problem of water pollution is becoming more and more urgent for the whole world. Unfortunately, Georgia is not an exception, where water sources, despite their number, are small and a significant part of them is polluted. Unlike contamination of industrial wastewater treatment plants, which comes from multiple diffuse sources, biological contamination results from the movement of precipitation or snowmelt onto and into the soil. As runoff moves, it collects and transports natural and anthropogenic pollutants and deposits them in rivers, groundwater, or lakes. Special attention should be paid to the biological pollution of water sources, which occurs as a result of washing or flushing of sources of anthropogenic biological pollution with rain and melt water. After entering the water environment, under favorable conditions, pathogenic organisms can multiply rapidly, which poses a threat to the environment. Contamination of water sources is a major cause of water quality problems. The impact of source water contaminants on specific waters varies and cannot always be fully assessed. However, we know that these pollutants have harmful effects on drinking water supplies and wildlife. That is why it is necessary to find the source of biological pollution of water in order to develop an effective method of its elimination.

MbDecoda: a debiased approach to compositional data analysis for microbiome surveys.

Potentially pathogenic or probiotic microbes can be identified by comparing their abundance levels between healthy and diseased populations, or more broadly, by linking microbiome composition with clinical phenotypes or environmental factors. However, in microbiome studies, feature tables provide relative rather than absolute abundance of each feature in each sample, as the microbial loads of the samples and the ratios of sequencing depth to microbial load are both unknown and subject to considerable variation. Moreover, microbiome abundance data are count-valued, often over-dispersed and contain a substantial proportion of zeros. To carry out differential abundance analysis while addressing these challenges, we introduce mbDecoda, a model-based approach for debiased analysis of sparse compositions of microbiomes. mbDecoda employs a zero-inflated negative binomial model, linking mean abundance to the variable of interest through a log link function, and it accommodates the adjustment for confounding factors. To efficiently obtain maximum likelihood estimates of model parameters, an Expectation Maximization algorithm is developed. A minimum coverage interval approach is then proposed to rectify compositional bias, enabling accurate and reliable absolute abundance analysis. Through extensive simulation studies and analysis of real-world microbiome datasets, we demonstrate that mbDecoda compares favorably with state-of-the-art methods in terms of effectiveness, robustness and reproducibility.