Antimicrobial Resistance Of Microorganisms Research Articles

A preliminary study of fumaric acid, called allomaleic acid, as a pharmaceutical antimicrobial compound

The emergence of antimicrobial resistance in microorganisms and the adverse effects associated with antibiotic use have necessitated the exploration of new, natural substances for antimicrobial treatments. Fumaric acid, or allomaleic acid, is a natural bioactive compound primarily derived from plant-based products. Fumaric acid has potential analgesic, anti-inflammatory, antioxidant, anti-psoriatic, chemopreventive, immunomodulatory, and neuroprotective properties. So far, studies on the antimicrobial activity of fumaric acid have used a plant ingredient. The antimicrobial activity was attributed to fumaric acid because it was detected in large amounts in herbal products. In this preliminary study, the antibacterial and antifungal properties of pure fumaric acid (99+%) were determined by the microdilution method. As a result of the antimicrobial study, the Minimum Inhibitory Concentration (MIC) values of fumaric acid against Candida tropicalis, Candida krusei, Candida albicans, Candida glabrata, and Candida parapsilosis were 9.375, 37.5, 4.687, 4.687, and 1.172 mg/mL, respectively. Moreover, bacterial cells were found to be approximately one hundred times more sensitive to fumaric acid than Candida cells. The MIC values of fumaric acid against Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes were determined as 150 µg /mL, and against Staphylococcus aureus was 75 µg /mL. These results showed that pure fumaric acid has a potent inhibitory effect against pathogenic or opportunistic microorganisms. Its unique properties and potential as an antimicrobial agent make it a compelling study area. Therefore, the usability of fumaric acid in the pharmacotherapeutic field is promising for future advanced in vivo studies.

Dual Antifungal and Antiproliferative Activities of a Novel Protein Fraction from a Medicinally Important Herb Trillium govanianum Wall. ex. D. Don.

Antimicrobial resistance of microorganisms and the unwanted side effects of chemoradiation therapy in cancer are major issues in healthcare. In recent times, protein-based drugs have emerged as promising candidates due to their high specificity, less side effects, etc. In this context, the rhizome of Trillium govanianum was first explored for biologically active proteins/peptides. For this, three protein fractions namely Aqueous protein fraction (APF), Hexane-Methanol-treated aqueous protein fraction (HMAPF), and Methanol-treated aqueous protein fraction (MAPF) were prepared and evaluated for antimicrobial and antiproliferative activities. In antifungal activity, HMAPF showed the lowest MIC90 values of 1.56µg/ml against Candida parapsilosis and Candida glabrata and 3.12µg/ml against Candida albicans and Candida auris. The antifungal activity was further confirmed by a chitinase assay, a growth kinetics and a proteinase inhibitory assay. Surprisingly, none of the three protein fractions exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. Moreover, APF exhibited potent antiproliferative and antioxidant activities with IC50 values of 18µg/ml and 227µg /ml, respectively. For HMAPF, an IC50 value of 70µg/ml against the MDA-MB-231 cell line was observed. The present results demonstrate that the protein fractions, particularly HMAPF and APF, might serve as potential sources of a dual antifungal and antiproliferative protein-based drug.

Meropenem/Vaborbactam: β-Lactam/β-Lactamase Inhibitor Combination, the Future in Eradicating Multidrug Resistance.

Due to the fact that there is a steadily increasing trend in the area of antimicrobial resistance in microorganisms, there is a need to look for new treatment alternatives. One of them is the search for new β-lactamase inhibitors and combining them with β-lactam antibiotics, with the aim of increasing the low-dose efficacy, as well as lowering the resistance potential of bacterial strains. This review presents the positive effect of meropenem in combination with a vaborbactam (MER-VAB). This latest antibiotic-inhibitor combination has found particular use in the treatment of infections with the etiology of carbapenem-resistant Enterobacterales (CRE), Gram-negative bacteria, with a high degree of resistance to available antimicrobial drugs.

Evaluation of Enterotoxins and Antimicrobial Resistance in Microorganisms Isolated from Raw Sheep Milk and Cheese: Ensuring the Microbiological Safety of These Products in Southern Brazil.

This study emphasizes the importance of monitoring the microbiological quality of animal products, such as raw sheep's milk and cheese, to ensure food safety. In Brazil, there is currently no legislation governing the quality of sheep's milk and its derivatives. Therefore, this study aimed to evaluate: (i) the hygienic-sanitary quality of raw sheep's milk and cheese produced in southern Brazil; (ii) the presence of enterotoxins and Staphylococcus spp. in these products; and (iii) the susceptibility of the isolated Staphylococcus spp. to antimicrobial drugs and the presence of resistance genes. A total of 35 samples of sheep's milk and cheese were examined. The microbiological quality and presence of enterotoxins were accessed using Petrifilm and VIDAS SET2 methods, respectively. Antimicrobial susceptibility tests were conducted using VITEK 2 equipment and the disc diffusion method. The presence of resistance genes tet(L), sul1, sul2, ermB, tetM, AAC(6)', tetW, and strA were evaluated through PCR. In total, 39 Staphylococcus spp. were obtained. The resistance genes tetM, ermB, strA, tetL, sul1, AAC(6)', and sul2 were detected in 82%, 59%, 36%, 28%, 23%, 3%, and 3% of isolates, respectively. The findings revealed that both raw sheep's milk and cheese contained Staphylococcus spp. that exhibited resistance to antimicrobial drugs and harbored resistance genes. These results underscore the immediate need for specific legislation in Brazil to regulate the production and sale of these products.

Evaluation of the antimicrobial activity of a pyrimidine compound 2-methyl-3-(2-phenyl-2-oxoethyl) quinazolin-4(3H)-on against <i>Klebsiella pneumoniae</i> under <i>in vivo</i> conditions

The greatest danger is the development of multiple antimicrobial resistance in microorganisms, including Klebsiella pneumoniae, which actualizes the necessity of development and synthesis of new antimicrobial compounds. Considering the versatile pharmacological activity, pyrimidine compounds became a subject of interest for scientists in the aspect of their use as a basis for new antimicrobial agents.Aim: To assess the antimicrobial activity of the pyrimidine compound 2-Methyl-3-(2-phenyl-2-oxoethyl)quinazoline-4(3H)-on against Kl. pneumoniae under in vivo conditions.Material and Methods. The antimicrobial activity in vivo of the compound 2-Methyl-3-(2-phenyl-2-oxoethyl)quinazolin-4(3H)-on against Kl. pneumoniae was performed simulating generalized infection by intraperitoneal injection of the pathogen at a dose of 3 × 106. The experiment was conducted on CBA line mice (40 animals) divided into groups: control I – animals received intraperitoneal injection water; control II – infected animals received no treatment; experimental groups – mice with generalized infection treated with ceftriaxone at the dose 50 mg/kg intraperitoneally for 7 days, and the animals receiving the test compound at the dose 27 mg/kg against infection in the same mode. Antimicrobial activity was assessed by the following parameters: animal survival rate; internal organ and blood infestation index; total leukocyte count, C-reactive protein and procalcitonin.Results. It was found that pyrimidine derivative 2-Methyl-3-(2-phenyl-2-oxoethyl)quinazoline-4(3H)-on has a marked antimicrobial activity against Kl. pneumonia appeared in increase of animal survival in the conditions of generalized Klebsiella infection as well as in decrease of total leukocyte count, C-reactive protein and procalcitonin levels that confirms the reduction of the inflammatory reaction.Conclusion. Thus, the pyrimidine derivative 2-Methyl-3-(2-phenyl-2-oxoethyl)quinazoline-4(3H)-on exhibits antimicrobial activity, comparable with ceftriaxone, against Klebsiella pneumoniae in experimental generalized Klebsiella infection.

Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country.

Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

FEAMR: A Database for Surveillance of Food and Environment-Associated Antimicrobial Resistance.

The rapid dissemination of antimicrobial resistance (AMR) has emerged as a serious health problem on an unprecedented global scale. AMR is predicted to kill more than 10 million people annually by 2050 leading to huge economic losses worldwide. Therefore, urgent action is required at the national as well as international levels to avert this looming crisis. Effective surveillance can play an important role in the containment of AMR spread by providing data to help determine AMR hotspots, predict an outbreak, maintain proper stewardship and propose immediate and future plans of action in this respect. Although many existing databases provide genetic and molecular information on AMR in microorganisms, there is no dedicated database of AMR from non-clinical samples. The FEAMR database is a one-of-its-kind database to provide manually collated and curated information on the prevalence of AMR in food and the environment. For designing the FEAMR webpage, Microsoft Visual Studio with HTML, CSS, ASP.NET, Bootstrap for the front-end and C# for the back-end were used. The FEAMR database is a free access resource (https://feamrudbt-amrlab.mu.ac.in/), accepting verified food- and environment-related AMR submissions from across the globe. To the best of our knowledge, it is probably the first database providing AMR-related surveillance data from non-clinical samples. It is designed from the ‘One Health Approach’ perspective to help in the containment of global AMR spread.Graphical Flowsheet of steps for making FEAMR database 1. Research articles relating to Antimicrobial Resistance (AMR) were searched on the internet. 2. Data relating to AMR were retrieved from these articles and stored in an MS-Excel sheet. 3. The web pages of the FEAMR database (DB) were created using Microsoft Visual Studio (MVS) and its various tools. HTML, CSS, ASP.NET and Bootstrap were used for the front end and C# used for the back-end of the website. 4. The DB of FEAMR was created using MS SQL Server which was controlled by SQL Server Management Studio (SSMS). 5. The data from the MS-Excel sheet in step 2 was stored in the SQL server and displayed on the web page using GridView tool of MVS and C#. The database created was then uploaded on the University of Mumbai (UoM) website, where it can be accessed by all users having the link to the DB (https://feamrudbt-amrlab.mu.ac.in/).

Современные аспекты контроля антибиотикоустойчивости микробных загрязнителей пищи с учетом особенностей оценки связанного с ней риска здоровью. Часть 1

Antimicrobials are widely used in agriculture to prevent and treat diseases and to stimulate growth of food-producing animals. However, this induces developing antimicrobial resistance among animal bacteria, and this resistance is then transmitted along food chains and spreads in the environment. It is commonly accepted at the moment that effective measures should be taken to contain it in food production, to prevent it from spreading on the global scale and to minimize related negative health outcomes. This can be achieved, among other things, due to intensifying inter-branch interactions. This review aimed to consider contemporary aspects in preventing development of antimicrobial resistance in micro-organisms that contaminate raw materials and processed food products; to dwell on how the issue is controlled in food production both in Russia and abroad; to focus on trends and prospects of developing new effective measures in the sphere. The review involved analyzing domestic and foreign regulatory and legal documents concerning prevention of antimicrobial resistance and analysis of related risks; generalizing and analyzing latest scientific research works published in reference databases including Web of Science, Scopus, PubMed, Google scholar. As a result, we described the experience accumulated in organizing monitoring over prevalence of antimicrobial resistance in foreign countries, to generalize international recommendations as well as regional and national ones on monitoring over microorganisms that are resistant to antimicrobials, and to highlight practical activities aimed at preventing occurrence and spread of antimicrobial resistance in food production. We substantiated certain peculiarities of related health risk assessment, namely, occurrence of genetic determinants of antimicrobial resistance and antibiotic residues in food together with resistant microorganisms. We also formulated basic principles of organizing and conducting monitoring over antimicrobial resistance in food chains (with the focus on antimicrobial medications that are crucially important in medicine). These principles can be applied in the Russian Federation within programs aimed at preventing antimicrobial resistance.

Contemporary aspects in control over resistant to antibiotics microbial contaminants of food, taking into account peculiarities of related health risk assessment. Part 1

Antimicrobials are widely used in agriculture to prevent and treat diseases and to stimulate growth of food-producing animals. However, this induces developing antimicrobial resistance among animal bacteria, and this resistance is then transmitted along food chains and spreads in the environment. It is commonly accepted at the moment that effective measures should be taken to contain it in food production, to prevent it from spreading on the global scale and to minimize related negative health outcomes. This can be achieved, among other things, due to intensifying inter-branch interactions. This review aimed to consider contemporary aspects in preventing development of antimicrobial resistance in micro-organisms that contaminate raw materials and processed food products; to dwell on how the issue is controlled in food production both in Russia and abroad; to focus on trends and prospects of developing new effective measures in the sphere. The review involved analyzing domestic and foreign regulatory and legal documents concerning prevention of antimicrobial resistance and analysis of related risks; generalizing and analyzing latest scientific research works published in reference databases including Web of Science, Scopus, PubMed, Google scholar. As a result, we described the experience accumulated in organizing monitoring over prevalence of antimicrobial resistance in foreign countries, to generalize international recommendations as well as regional and national ones on monitoring over microorganisms that are resistant to antimicrobials, and to highlight practical activities aimed at preventing occurrence and spread of antimicrobial resistance in food production. We substantiated certain peculiarities of related health risk assessment, namely, occurrence of genetic determinants of antimicrobial resistance and antibiotic residues in food together with resistant microorganisms. We also formulated basic principles of organizing and conducting monitoring over antimicrobial resistance in food chains (with the focus on antimicrobial medications that are crucially important in medicine). These principles can be applied in the Russian Federation within programs aimed at preventing antimicrobial resistance.

Antimicrobial resistance in aquaculture and fisheries - Status and way forward

Fish is a rich source of high quality and cheap source of animal protein that is consumed by a significantly large population worldwide. With the increase in demand for consumption, there are efforts to increase fish production. The production in both the capture fisheries and aquaculture has increased tremendously over the past many years to meet the growing demand globally. One major drawback of intensive aquaculture is higher incidence of diseases, which can lead to the increased use of antimicrobial agents for their control. These antimicrobial agents are used directly into the aquaculture ponds that contaminate the environment as well. Indiscriminate use of antimicrobials in the environment is known to impact the microbial ecology as well as confer selection pressure which leads to the development of antimicrobial resistance (AMR) in microorganisms. In the present technical article, the authors discuss the current national and international status of the fisheries sector with respect to antibiotic use and antimicrobial resistance in microorganisms of aquatic origin. Further, few strategies that can be implemented in the fisheries sector to mitigate the burden of AMR are also listed.

Research Note: Antimicrobial resistance profile of Enterococcus spp. isolated from the eggshell of laying hens submitted to pharmacological treatment

The occurrence of antimicrobial resistance in microorganisms isolated from eggshells, especially Enterococcus, might serve as a parameter to assess the selection of bacteria due to the use of drugs in the diet of laying hens. In order to evaluate the frequency and the antimicrobial resistance profile of Enterococcus spp. isolated from the eggshells, 225 Hy-line laying hens were submitted to a 25-d long trial. The treatments were the following: hens fed ration without antimicrobials (control) and groups that received oxytetracycline (10 mg kg−1), doxycycline (20 mg kg−1), lincomycin (50 mg kg−1), and enrofloxacin (10 mg kg−1) in the ration for 5 d. Six replications were analyzed per treatment, composed of a pool of 5 eggs each. They were collected before treatment and on days 3, 6, 15, and 25, totaling 150 samples. Eggshells were submitted to counts of Enterococcus spp., which were identified by proteomic analyses. Antimicrobial resistance was determined by the disk-diffusion test. It was observed that 97.3% (n = 146) of the samples were contaminated with Enterococcus spp. There were no differences (P > 0.05) in the bacterial counts between treatments on the same day of evaluation. E. faecalis and E. faecium were the most frequent on the eggshells of all treatments. Multiresistance to the four classes of antimicrobials was also verified in the isolated bacteria. A total of 83% of the Enterococcus isolates showed resistance to neomycin, which was not administered to the hens, demonstrating an environmental problem. Thus, feeding laying hens with diets added with antimicrobials induces drug resistance in Enterococcus spp., isolated form the eggshells.

Bioinformatics approaches to the study of antimicrobial resistance.

Detection and monitoring of antimicrobial resistance are two pillars on which clinical microbiology will be based in the coming decades. The implementation of certain technologies such as whole genome sequencing (WGS) or mass spectrometry and the creation of national and international databases that include and gather data on antimicrobial resistance from around the world has allowed the application of bioinformatics in the study of antimicrobial resistance in microorganisms involved in human pathology.

Self-Assembly Pathways and Antimicrobial Properties of Lysozyme in Different Aggregation States.

Antimicrobial resistance in microorganisms will cause millions of deaths and pose a vast burden on health systems; therefore, alternatives to existing small-molecule antibiotics have to be developed. Lysozyme is an antimicrobial enzyme and has broad-spectrum antimicrobial activity in different aggregated forms. Here, we propose a reductive pathway to obtain colloidally stable amyloid-like worm-shaped lysozyme nanoparticles (worms) from hen egg white lysozyme (HEWL) and compare them to amyloid fibrils made in an acid hydrolysis pathway. The aggregation of HEWL into worms follows strongly pH-dependent kinetics and induces a structural transition from α-helices to β-sheets. Both HEWL worms and amyloid fibrils show broad-spectrum antimicrobial activity against the bacteria Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and the fungus Candida albicans. The colloidal stability of the worms allows the determination of minimum inhibitory concentrations, which are lower than that for native HEWL in the case of S. aureus. Overall, amyloid fibrils have the strongest antimicrobial effect, likely due to the increased positive charge compared to native HEWL. The structural and functional characterizations of HEWL worms and amyloids investigated herein are critical for understanding the detailed mechanisms of antimicrobial activity and opens up new avenues for the design of broad-spectrum antimicrobial materials for use in various applications.

Identification of bacteriological quality and antimicrobial resistance of microorganisms isolated from animal foods collected from the abattoir, butcher shops and local seafood market

The current study aimed to isolate bacteria that harbour various animal food products like meat, chicken and seafoods collected from the abattoir, butcher shops and local seafood market and to determine the antimicrobial resistance pattern of isolated pathogens which are responsible for various foodborne illnesses in human beings. A total of forty raw animal product samples were collected from the abattoir, butcher shops and local seafood market of Visakhapatnam. The samples selected for the study include raw chicken, meat, crab, prawns and different varieties of fish. A classic random sampling technique was employed to collect the study samples. All the samples were processed immediately using standard microbiological protocols. The bacteria isolation and characterization were done by studying morphological characteristics with staining methods, cultural characteristics by isolating and growing the pathogenic microorganisms in various selective and differential culture media. Antimicrobial susceptibility testing was performed by the Kirby -Bauer method by following Clinical and Laboratory Standards Institute (CLSI) guidelines. EDTA-Disc Potentiation Test and Imipenem-EDTA Double disc synergy test are used to detect the metallo beta-lactamase production of isolated pathogens. The highest number of isolates belong to Salmonella species (18), Pseudomonas aeruginosa (18) followed by Vibrio species (14) and few isolates belong to Enterobacter species (4). Majority of the microbial isolates obtained in the current study were multidrug resistant. The isolates from the abattoir environments, slaughterhouses, fish markets were found to exhibit variable resistance pattern to aminoglycosides, macrolides, β-lactams, cephalosporins, quinolone antibiotics used in the present study and at the same time most of them were sensitive to carbapenem antibiotic imipenem. Antimicrobial resistance (AMR) prevents the designing and assessment of effective interventions. If such a link can be established, then the tracking of antibiotic use and consumption data could be furthermore used as a surrogate indicator for the risk of potential antibiotic resistance (ABR) emergence.

Fatores de risco e perfil do uso de antimicrobianos entre pacientes com infecção no trato urinário em uma unidade de terapia intensiva

A Infecção no Trato Urinário (ITU) acometendo pacientes em Unidades de Terapia Intensiva (UTIs) é uma realidade preocupante, agravada pelo uso irracional de antimicrobianos e a alarmante multirresistência em microrganismos. Nós avaliamos o nível de assertividade quanto ao uso de antimicrobianos durante à antibioticoterapia empírica (ATE), em pacientes diagnosticados com ITU, comparando tal tratamento farmacológico empírico e o realizado após o antibiograma (antibioticoterapia direcionada), além disto, estimamos a prevalência dos agentes etiológicos e analisamos os fatores de risco associados. Este é um estudo observacional e transversal, realizado em 2015, no qual foram avaliados pacientes de ambos os sexos e todas as idades apresentando ITU e submetidos à antibioticoterapia, internados em uma UTI de um hospital no sul de Minas Gerais, Brasil. Dos 49 pacientes avaliados (28 mulheres [M] e 21 homens [H]), a média de idade foi 55±19 anos (IC(95) 49-61) e a faixa etária ≥70 anos foi a predominante. Quatorze diferentes microrganismos foram causadores de ITUs, sendo que 28,3% (IC(95%) 16,2-40,4) dos isolados clínicos tiveram Escherichia coli como o agente etiológico (33,3% H e 28,6% M); 18,9% (IC(95%) 8,3-29,4) Acinetobacter baumannii (33,3% H e 10,7% M); 15,1% (IC(95%) 5,5-24,7) Klebsiella pneumoniae (19% H e 14,3% M); 11,3% Pseudomonas aeruginosa (9,5% H e 14,3% M); 5,7% Enterobacter aerogenes (14,3% H); 3,8% Klebsiella oxytoca; 3,8% Staphylococcus aureus (7,1% M); e 1,9% para cada um dos seguintes microrganismos: Enterococcus faecalis (4,8% H); Proteus mirabilis (3,6% M); Enterobacter cloacae (3,6% M); Providencia rettgeri (4,8% H); Citrobacter koseri (3,6% M); Citrobacter freundii (3,6% M); e Fungos leveduriformes (4,8% H). As prevalências de ITUs causadas por A. baumannii e P. aeruginosa foram influenciadas pelo sexo (χ² com p<0,001). No sexo masculino, houve correlações positivas “substanciais” entre o aumento da idade (em anos) e a prevalência de ITU causada por E. coli (r = 0,69) ou entre idades menos avançadas e a prevalência de ITU causada por A. baumannii (r = -0,7). No sexo feminino, houve uma correlação positiva “extremamente forte” entre o aumento da idade e a prevalência de ITU causada por E. coli (r = 0,94; IC(95) 0,66-0,99; p<0,0014). Os antibióticos mais utilizados de forma empírica (ATE) foram: Ciprofloxacina (14,3% IC(95%) 4,7-24,1), Cefepima (14,3%) e Vancomicina (10%), e após o antibiograma (antibioticoterapia direcionada): Ceftazidima (16,3% IC(95%) 6-26,7), Ciprofloxacina (14,3% IC(95%) 4,5-24,1), Polimixina B (10,2%), Imipenem (10,2%) e Ampicilina + Sulbac. (8,2%). Em 20% dos casos, as terapias empíricas (ATE) foram consideradas “inapropriadas/não acertadas”. Contudo, também devemos ter ciência da necessidade clínica e quanto ao imediatismo para o tratamento de uma ITU em UTI, uma vez que a doença pode ser fatal se uma terapia não for instituída, portanto, nós aconselhamos avaliações mais minuciosas, tanto da racionalidade do uso de antibióticos, quanto dos fatores de risco para o desenvolvimento de ITUs em UTIs.

Polymeric Nanoparticles for Antimicrobial Therapies: An Up-To-Date Overview.

Despite the many advancements in the pharmaceutical and medical fields and the development of numerous antimicrobial drugs aimed to suppress and destroy pathogenic microorganisms, infectious diseases still represent a major health threat affecting millions of lives daily. In addition to the limitations of antimicrobial drugs associated with low transportation rate, water solubility, oral bioavailability and stability, inefficient drug targeting, considerable toxicity, and limited patient compliance, the major cause for their inefficiency is the antimicrobial resistance of microorganisms. In this context, the risk of a pre-antibiotic era is a real possibility. For this reason, the research focus has shifted toward the discovery and development of novel and alternative antimicrobial agents that could overcome the challenges associated with conventional drugs. Nanotechnology is a possible alternative, as there is significant evidence of the broad-spectrum antimicrobial activity of nanomaterials and nanoparticles in particular. Moreover, owing to their considerable advantages regarding their efficient cargo dissolving, entrapment, encapsulation, or surface attachment, the possibility of forming antimicrobial groups for specific targeting and destruction, biocompatibility and biodegradability, low toxicity, and synergistic therapy, polymeric nanoparticles have received considerable attention as potential antimicrobial drug delivery agents. In this context, the aim of this paper is to provide an up-to-date overview of the most recent studies investigating polymeric nanoparticles designed for antimicrobial therapies, describing both their targeting strategies and their effects.

ANTIMICROBIAL-RESISTANT MICROORGANISMS IN FOOD AS A HYGIENIC PROBLEM

The analysis of scientific data on the occurrence of the antimicrobial resistance in microorganisms from food sources is adduced. A presentation on the molecular mechanisms of its formation under the influence of veterinary medicinal products (VMPs) with an antimicrobial effect, taking into account the peculiarities of their use in the animal husbandry, is given. Ways of the contamination of food with VMPs, the potential of their residues in terms of direct and indirect risks for human health, the current situation with the contamination of food products, the principles of hygienic rationing and control are described. The role of sub-inhibitory doses of antibiotics in the formation of the antimicrobial resistance in microorganisms is described, and the importance of tetracyclines as the most important agents of activation of horizontal transfer of resistance in the environment is emphasized. The factors in food chain objects contributing to the realization of different types of horizontal gene transfer are highlighted, including examples of studies implemented by the author laboratory in a specific food industry establishment. The new data on the negative consequences of physical and chemical effects of non-antibiotic nature, sublethal for microflora in food, as well as products of microbial synthesis as inhibitory technological means, manifested by the enhancement of the gene transfer and the development of acquired antimicrobial resistance in food strains, is presented. The importance of extraneous (zoonotic pathogens, intestinal commensal flora representatives, HAIs agents) and the microflora of food products especially used (biotechnological, probiotic microorganisms, GMM) as vectors for transfer of resistant microorganisms to the human body have been disclosed. The modern data of international organizations and literary sources are summarized in terms of effective practical measures to counter the formation and occurrence of the resistance, including promising innovations in agriculture aimed at alternative technologies to antimicrobials for the growing and fattening of productive animals.

Антибиотикоустойчивые микроорганизмы в пище как гигиеническая проблема (Обзорная статья)

The analysis of scientific data on the occurrence of the antimicrobial resistance in microorganisms from food sources is adduced. A presentation on the molecular mechanisms of its formation under the influence of veterinary medicinal products (VMPs) with an antimicrobial effect, taking into account the peculiarities of their use in the animal husbandry, is given. Ways of the contamination of food with VMPs, the potential of their residues in terms of direct and indirect risks for human health, the current situation with the contamination of food products, the principles of hygienic rationing and control are described. The role of sub-inhibitory doses of antibiotics in the formation of the antimicrobial resistance in microorganisms is described, and the importance of tetracyclines as the most important agents of activation of horizontal transfer of resistance in the environment is emphasized. The factors in food chain objects contributing to the realization of different types of horizontal gene transfer are highlighted, including examples of studies implemented by the author laboratory in a specific food industry establishment. The new data on the negative consequences of physical and chemical effects of non-antibiotic nature, sublethal for microflora in food, as well as products of microbial synthesis as inhibitory technological means, manifested by the enhancement of the gene transfer and the development of acquired antimicrobial resistance in food strains, is presented. The importance of extraneous (zoonotic pathogens, intestinal commensal flora representatives, HAIs agents) and the microflora of food products especially used (biotechnological, probiotic microorganisms, GMM) as vectors for transfer of resistant microorganisms to the human body have been disclosed. The modern data of international organizations and literary sources are summarized in terms of effective practical measures to counter the formation and occurrence of the resistance, including promising innovations in agriculture aimed at alternative technologies to antimicrobials for the growing and fattening of productive animals.

Preliminary Phytochemical Analysis of the Crude extract of Marine Red and Brown Seaweeds

The seaweed is a large and diverse group of marine macro algae that can be found in intertidal and sub tidal coastal regions around the world. Seaweed are simpler in their structural composition because they take up the nutrients into their blades or fronds directly from the seawater, unlike more complex land plants which take up the nutrients through their roots. There are three different types of marine macro algae-red algae (Rhodophyta), brown algae (phaeophyta), green algae (chlorophyta). They are grouped according to their unique photosynthetic pigments, which give them their characteristics color and unique properties. Secondary metabolites from natural resources are a potential source that leads and drugs can exploited to combat antimicrobial resistance in microorganisms. The present study investigated to explore the preliminary phytochemical constituents of marine red and brown seaweed such as Gracilaria corticata, Gracilaria edulis, Saragussum wightii wherelse Methanol, Acetone and Aqueous were used as a solvent system for the preparation of the extract.

COMPARATIVE STUDY ON ANTIMICROBIAL ACTIVITY OF SEAWEEDS

Objective: Secondary metabolites from natural resources are a potential source of antimicrobial leads and drugs can exploited to combat antimicrobial resistance in microorganisms. Seaweeds are considered as a valuable source with a broad spectrum of biological activities. Hence, this study was undertaken to screen seaweeds from Mandapam coastal waters, East coast of India, for antimicrobial activity.Methods: Compounds were extracted using methanol from the seaweeds, namely, Halimeda gracilis, Caulerpa serrulata, Sargassum swartzii, Sargassum wightii, Jania rubens, Ulva lactuca, Ulva fasciata, Gracilaria corticata, Stoechospermum marginatum, Caulerpa scalpelliformis, Caulerpa taxifolia, Chaetomorpha crassa, Enteromorpha flexuosa, and Turbinaria ornate. The extracts were screened for their antimicrobial activity against selected bacterial and fungal pathogens.Results: In the present study, S. swartzii, J. rubens, and S. marginatum showed broad spectrum of antibacterial activity against all the test bacterial pathogens. Among these, the maximum activity was exhibited by S. swartzii against Enterococcus faecalis (27.00 ± 0.88) and Streptococcus pyogenes (23.00 ± 0.84), followed by J. rubens against E. faecalis (26.00 ± 0.56) and S. pyogenes (22.00 ± 0.75), and S. marginatum exhibited significant inhibition against Staphylococcus aureus (15.00 ± 0.22) and S. pyogenes (18.00 ± 1.16).Conclusion: These seaweeds with significant antibacterial activity will subjected to phytochemical screening to find out the potential active principle responsible for antimicrobial activity. It is followed by purification and characterization of the compounds for possible application in drug formulation, can take this to large-scale application in pharmaceutical industries.