Antibiotic Substances Research Articles

Discrepancy between antibiotic pack sizes and guideline recommendations: a real-world analysis based on claims data.

Antibiotics are often only available in predefined pack sizes, which may not align with guideline recommendations. This can result in leftover pills, leading to inappropriate self-medication or waste disposal, which can both foster the development of antibiotic resistance. The magnitude of inappropriate pack sizes is largely unknown. The objective of this study was to evaluate the potential non-conformity of prescribed antibiotic pack sizes. This retrospective observational study was based on claims data from a large Swiss health insurance company. The study analysed the prescriptions of eleven different antibiotic substances recommended for the five most common indications for antibiotics in Switzerland. All prescriptions for adult outpatients issued by general practitioners in 2022 were included and extrapolated to the entire Swiss population. Potential non-conformity was defined as a mismatch between the total dosage in a pack and the total dosage recommended. A total of n = 947,439 extrapolated prescriptions were analysed. In 10 of 23 of all analysed substance/indication combinations none of the prescribed packs aligned with the respective guideline recommendation. Considering pack sizes in which the total prescribed dosage of a substance did not correspond to any of the total dosages recommended in at least one of the guidelines, 31.6% of prescriptions were potentially non-conform and an estimated number of 2.7million tablets were overprescribed. We found a large discrepancy between prescribed pack sizes and guideline recommendations. Since inadequately prepacked antibiotics may lead to antibiotic resistance and unnecessary waste, efforts are needed to implement alternatives like exact pill dispensing.

ECONOMIC FEASIBILITY STUDY FOR THE IMPLEMENTATION OF A MICRO-INDUSTRY PRODUCING KOMBUCHA FLAVORED WITH PASSION FRUIT FROM THE CAATINGA.

Kombucha is a fermented beverage of Chinese origin produced from the infusion of black or green tea from the Camelia sinensis plant, sugar and a symbiotic culture known as SCOBY. After fermentation, the drink becomes rich in natural nutrients with functions that are beneficial to health such as organic acids, amino acids, vitamin C, polyphenols and antibiotic substances. The present work aims at carrying out a study of the economic feasibility of opening a micro-industry for the production of a black tea kombucha flavored with passion fruit from the caatinga. The caatinga passion fruit is a species native to the dry areas of northeastern Brazil. This fruit is rich in flavonoids, vitamin C and carotenoids, which have antimicrobial and antioxidant properties. For the development of the study, specifications of processes, equipment and analysis of financial and economic indicators were carried out. The evaluation of the investments was carried out using the internal rate of return (IRR), minimum attractiveness rate (TAM), net present value (NPV), simple payback and discounted payback methods. The initial investment for the production of 2,000 L of kombucha flavored with passion fruit from the caatinga was R$ 187,199.78. The economic indicators obtained resulted in NPV of R$ 253,154.68, IRR of 22%, TAM of 13.34% p.a. and simple payback of 3.9 years considering a useful life of 10 years. The positive IRR reflects that the enterprise is economically viable and profitable, making it possible to invest and generate income for cooperatives and family farmers.

The Ecological Strategy Determines the Response of Fungi to Stress: A Study of the 2,4-diacetylphloroglucinol Activity Against Aspergillus and Fusarium Species.

Aspergillus and Fusarium are two economically important genera of fungi. They cause significant yield losses and contamination of crops with mycotoxins. In this study we aimed to evaluate the impact of 2,4-diacetylphloroglucinol (2,4-DAPG) on Aspergillus and Fusarium fungi. It is hypothesized that two fungal genera, which have different ecological strategies, react differently to stress caused by a secondary metabolite produced by rhizosphere Pseudomonas species. We found that 2,4-DAPG was able to reduce biofilm formation of Aspergillus and Fusarium, as reflected in biomass and its chemical composition. Furthermore, subinhibitory concentrations of 2,4-DAPG increased the levels of ergosterol and polysaccharides (α- and β-glucans, chitin) in the cell membrane and cell wall of Aspergillus, while decreasing them in Fusarium. 2,4-DAPG altered the production of secondary metabolites, especially mycotoxins and extracellular proteases. The production of ochratoxin A was decreased in A. ochraceus, and T-2 toxin and zearalenone, on the contrary, were increased in F. culmorum and F. sporotrichioides, respectively. Thus, using 2,4-DAPG we demonstrated that the ecological role of fungi determines their reaction to antibiotic substances produced by the plant microbiome. Our data contributes to understanding the molecular mechanisms behind symbiotic relationships in natural communities, which are mediated by the biosynthesis of antibiotics.

Antimicrobial properties of the edible pink oyster mushroom, Pleurotus eous: In-vivo and in-vitro studies

In recent times, there has been a notable surge in the investigation of new antibiotic substances derived from natural origins. Pleurotus eous is an edible mushroom that has various useful bioactive substances and therapeutic properties, including antimicrobial activity. The present study aims to evaluate the antimicrobial efficacy of the methanolic extract of P. eous (MEPE) through in vitro method. Notably, S. aureus demonstrated the highest susceptibility to MEPE, prompting further investigation into its antibacterial mechanisms via scanning electron microscopy (SEM), membrane integrity, and permeability assays. The in-vivo antibacterial effect of MEPE against S. aureus was also assessed, including analysis of bacterial burden in organs, hematological profiles, and cytokine profiles. Detailed phytochemical analyses of MEPE were conducted using GC-MS. Results revealed MEPE's significant (p < 0.05) efficacy against Gram-positive bacteria, particularly S. aureus (77.56 ± 0.4 μg/mL and 34 ± 6.9 μg/ml in turbidometric and viable cell count assays, respectively). Moreover, membrane permeability significantly increased in 60.32 % of S. aureus isolates following treatment with MEPE. Additionally, mice receiving MEPE exhibited decreased levels of TNF-α, IL-1β, and IL-6, suggesting its potential in combating S. aureus infection in animal models.

Surgical Site Infections After Pediatric Liver Transplantation-Impact of a Change in Perioperative Prophylactic Antibiotic Protocol.

In spite of improved survival rates after pediatric liver transplantation, infections remain major contributors to perioperative morbidity and mortality. This study aimed to understand the impact of type and duration of perioperative antibiotic prophylaxis (PAP) on the occurrence of surgical site infections (SSIs). In total, 125 patients who underwent liver transplantation between 2014 and 2020 were retrospectively included. Patients were categorized into two periods based on changes in the standard PAP regimen. Risk factors for SSIs were investigated, including the influence of PAP duration, antibiotic substances used, and abdominal patch placement using multivariable regression models. SSIs occurred in 23 (19%) of 119 analyzed patients and were not impacted by changes in the PAP regimen. The placement of an abdominal patch was a relevant risk factor for SSIs (odds ratio 3.81; 95% confidence interval [CI] 1.15-12.68). Longer PAP duration reduced the occurrence of SSIs by up to 4.6 percentage points (95% CI 0.0-9.1) per day, with its effect diminishing with longer duration. The choice of antibiotic substances for PAP changed after implementation of the new protocol, with a decline in vancomycin usage from 14% to 3%. The results of this study emphasize the need for evidence-based PAP regimens tailored to the unique needs of pediatric liver transplant recipients. The occurrence of SSIs remains complex and is influenced by various factors beyond the PAP regimen. Multicentric efforts to develop effective prevention strategies against SSIs in this vulnerable population are warranted.

Periodate activation and pH regulation using ball-milled metal-oxide-mineral-biochar composite for removal of antibiotics from contaminated water

The inclusion of mineral salts in carbon activators are beneficial for advanced oxidation processes (AOPs). Herein, we present the application of ball-milled biochar with phosphate salt for periodate (IO4−) activation and degradation of antibiotics in contaminated water. Physical characterization results showed that the catalyst is infused with Mg3(PO4)2 and ball-milling increased the specific surface area to 216 m2 g−1 from 46 m2 g−1 while reducing the particle size to less than 1.0 μ. The optimized system successfully eliminated >99% of diclofenac while maintaining the pH of the reaction medium to circumneutral levels. Scavenger and ESR experiments revealed the degradation is triggered by O2•–, 1O2 and •OH species within the system. Electrochemical studies confirmed electron transfer during diclofenac degradation. The reported system demonstrated high degradation efficiency under both neutral and acidic pH conditions. Based on the by-product analysis, the degradation pathway of diclofenac was elucidated. Further, the toxicity assessment for the identified intermediates showed minimum toxicity of the degraded products. This mineral-biochar composite exhibited promising performance in eliminating other antibiotic substances. Therefore, the present finding highlights the importance of raw materials selection for producing mineral-biochar composite that provide new insights into IO4− activation for antibiotic removal by maintaining the natural pH.

Nano-Based Approaches in Surface Modifications of Dental Implants: A Literature Review.

Rehabilitation of fully or partially edentulous patients with dental implants represents one of the most frequently used surgical procedures. The work of Branemark, who observed that a piece of titanium embedded in rabbit bone became firmly attached and difficult to remove, introduced the concept of osseointegration and revolutionized modern dentistry. Since then, an ever-growing need for improved implant materials towards enhanced material-tissue integration has emerged. There is a strong belief that nanoscale materials will produce a superior generation of implants with high efficiency, low cost, and high volume. The aim of this review is to explore the contribution of nanomaterials in implantology. A variety of nanomaterials have been proposed as potential candidates for implant surface customization. They can have inherent antibacterial properties, provide enhanced conditions for osseointegration, or act as reservoirs for biomolecules and drugs. Titania nanotubes alone or in combination with biological agents or drugs are used for enhanced tissue integration in dental implants. Regarding immunomodulation and in order to avoid implant rejection, titania nanotubes, graphene, and biopolymers have successfully been utilized, sometimes loaded with anti-inflammatory agents and extracellular vesicles. Peri-implantitis prevention can be achieved through the inherent antibacterial properties of metal nanoparticles and chitosan or hybrid coatings bearing antibiotic substances. For improved corrosion resistance various materials have been explored. However, even though these modifications have shown promising results, future research is necessary to assess their clinical behavior in humans and proceed to widespread commercialization.

Adaptation of Ochrobactrum rhizosphaerae IMV B-7956 Bacteria to the Influence of Copper (II) Chloride

In technologically altered habitats, an increased content of organic compounds, nitrogen, phosphorus, sulfur compounds, antibiotic substances, etc. is found. Therefore, microorganisms that are systematically exposed to various stressors have developed adaptation mechanisms. The strain Ochrobactrum rhizosphaerae IMV B-7956, isolated from the infiltrate lakes of the Lviv solid waste landfill, is resistant to copper, chromium, manganese, and iron in concentrations exceeding the maximum permissible concentrations. The work aimed to study the response of O. rhizosphaerae IMV B-7956 cells to CuCl2 exposure by detecting changes in the content of lipid peroxidation products, products of the oxidative modification of proteins, activity of antioxidant defense system enzymes, and synthesis of extracellular polymers. Methods. To study the effect of CuCl2 on prooxidant indicators and the activity of enzymes of the antioxidant defense system, bacteria were pre-incubated in Tris-HCl buffer containing 2–10 mM CuCl2. After one hour of incubation, the bacterial cells were washed and cultured for 1, 12, 24, and 48 h in metal-free media. The copper content in the bacterial cells was determined by atomic absorption spectrometry. The content of lipid peroxidation indicators, carbonyl groups in proteins, total low-molecular-weight thiols, enzymatic activity, and the content of exopolysaccharides and extracellular proteins were determined photometrically. Results. Within an hour, O. rhizosphaerae IMV B-7956 bacteria accumulated 2.3–7.8 mg Cu/g of biomass. Under these conditions, an increased content of lipid peroxidation products was detected. During the first hour of growth in bacterial cells, enzymes with catalase and peroxidase activity were activated. During further cultivation, an increase in the activity of other antioxidant defense enzymes was detected. Carbonyl groups in proteins are probably formed due to an increase in the content of lipid peroxidation products, as they are formed later. Within 12–48 h of growth, the copper content in the bacterial cells decreases. This leads to the restoration of growth. Conclusions. The main damaging effect of CuCl2 on bacterial cells was detected during the first 24 h of growth. Activation of the enzymes of the antioxidant system and synthesis of exopolysaccharides are among the adaptations that ensure the survival of bacteria under these conditions.

Exploring the impact of biosecurity measures on somatic cell score in mountain dairy farms considering the CLASSYFARM system

Biosecurity plays a crucial role in preventing the introduction of infectious diseases to a herd as well as the spread of diseases within or between animals and herds. In particular, biosecurity measures are crucial for maintaining animal health and reducing the need for the application of antibiotic substances for fighting the rising antibiotic resistance. The object of this cross-sectional study was to investigate the presence of biosecurity measures and their association with milk quality parameters, with a special focus on somatic cell count (SCC) − an indicator for udder health −, in small-scale mountain dairy farms. Therefore, for the very first time, the CLASSYFARM system was considered, which is a computer platform integrated into the Italian national veterinary portal, that processes a significant amount of data from various sources collected in the field or from other information systems (e.g. animal welfare, health status, biosecurity, antimicrobial use, slaughterhouse information). A total of 169 dairy farms were included in the study. Biosecurity measures, based on 15 questions required in the CLASSYFARM welfare assessment protocol, as well as information about husbandry systems, milking systems and pasture practices were gathered and combined with milk yield data, provided by the South Tyrolean dairy association. Farms only scored 44.00 points on average in a scoring system from 0.00 to 100.00 points that was be able to summarize 15 different biosecurity measures in one index. Our results show a clear negative correlation (−0.713) between the biosecurity index and somatic cell score (SCS) indicating that a higher level of biosecurity, which reflects the presence of biosecurity measures within a farm, is associated with lower SCC levels. Furthermore, we found significant correlations between SCS and milk production (−0.629), confirming that udder health is linked to higher milk production. Fat, protein, and the fat-to-protein ratio showed a positive correlation with SCS (0.281, 0.146, 0.106), likely to be caused by a concentration shift effect (dilution effect). Husbandry system, breed, milking system, and pasture practices seem to have an impact as well, but the main factor was the biosecurity score. This study highlights the importance of implementing biosecurity measures for ensuring animal health and thus productivity and quality in milk production, even in small-scale farms, which are characterized by limited structure availability and smaller herds compared to big dairy enterprises in the lowlands.

Examination of the Bactericidal and Fungicidal Activity of Bacillus amyloliquefaciens M Isolated from Spring Waters in Bulgaria

In order for a strain to be considered a probiotic or suitable plant bioprotective agent, it must have proven antimicrobial activity against pathogenic bacteria and phytopathogenic fungi. Bacillus amyloliquefaciens M exhibited significantly high antifungal activity against pathogenic fungi of the genera Aspergillus, Penicillium, Fusarium, and Sclerotinia; yeasts of the genera Candida and Saccharomyces; as well as high antibacterial activity against pathogens of the genera Escherichia, Salmonella, Staphylococcus, Listeria, Pseudomonas, and Bacillus. The manifested antimicrobial activity was influenced by the composition of the growth medium. The antifungal activity of the strain was investigated at growth temperatures of 30 °C and 37 °C, and at different pH values in aerobic and anaerobic cultivation, under static and dynamic culturing conditions. High antifungal activity was observed at the 24th h on both growth media (LBG broth and MPB broth) at pH = 6 and pH = 7 in aerobic and anaerobic cultivation. Bacillus amyloliquefaciens M produced antibiotic substances at pH &gt; 5.0, and the antibiotic substances were either secreted into the medium or associated with the cell surface. Four compounds with different antifungal activity and different Rf values were registered through thin-layer chromatography (Rf1 = 0.47; Rf2 = 0.55; Rf3 = 0.67; and Rf4 = 0.75), two of the compounds were ninhydrin-positive. Bacillus amyloliquefaciens M was cultured in a bioreactor with stirring, and the parameters of the growth kinetics and the sporulation kinetics have been modeled. A spore concentrate of Bacillus amyloliquefaciens M has been obtained. In further research, the efficiency of the concentrate as a plant bioactive agent will be tested.

Quantitative determination of tetracyclines in medicated feed for food-producing animals by HPLC–DAD

Tetracyclines are a group of antibiotic substances largely administered through medicated feed to control diseases in food-producing animals. Fine dosing of antibiotics contained in medicated feed is crucial for the success of the treatment as well as minimising potential threats such as the spread of antimicrobial resistance and the transfer of antibiotic residues in food. A rapid analytical method based on HPLC with diode array detection (HPLC–DAD) was developed to quantify oxytetracycline, chlortetracycline and doxycycline in medicated feed. The reported method underwent in-house validation and was found to be suitable for the quantification of three target tetracyclines within the concentration range of 40–1000 mg kg−1 in official routine analysis. The method was applied to 103 official samples in the framework of the Italian National Plan on animal feed during the years 2021–2023 and nine non-compliant concentrations were identified in swine and fish feed samples.

Phytochemical Characterization and Antibacterial Activity of Albanian Juniperus communis and Juniperus oxycedrus Berries and Needle Leaves Extracts.

This paper aims to investigate the phytochemical profile and in vitro antibacterial activity of two juniper species collected in Albania, Juniperus communis and Juniperus oxycedrus. The berries and the needle leaves were subjected to solid-liquid solvent ultrasound-assisted extraction. The phytochemical characterization of the extracts was performed by spectrophotometric and chromatographic means. The extract of J. communis berries (JcB) showed a higher total phenolic and flavonoid content (3.04 ± 0.09 mg GAE/g DW, and 1.14 ± 0.36 mg QE/g DW, respectively), also a higher antioxidant activity from DPPH and ABTS radical screening assays, compared to J. oxycedrus berries (JoxB) extract. The extract of J. oxycedrus needle leaves (JoxL) prevailed in total flavonoid content (10.55 ± 0.24 mg QE/g DW), and ABTS assays (1.83 ± 0.01 mM TE/g DW), compared to the extract of J. communis needle leaves (JcL). The chromatographic analysis revealed the presence of ellagic acid and kaempferol in all the samples. Ellagic acid was the main identified compound with the highest quantity in the extracts of JoxB, JoxL, and JcB with an average of 445.69 ± 0.96 µg/g, 2890.05 ± 0.29 µg/g, and 8133.83 ± 4.03 µg/g, respectively. The antibacterial potential of the ethanolic extracts was evaluated on Bacillus spp., Escherichia coli, and Staphylococcus aureus. In the Agar Well Diffusion Assay, it was observed that all the tested bacterial strains were sensitive to the extracts, whereas selected extracts showed a similar inhibition activity rate compared with the antibiotic substance (Chloramphenicol), used as a positive control. The extracts showed a similar minimal inhibitory and bactericidal concentration for the individual bacterial strains, suggesting that J. communis and J. oxycedrus extracts have a similar potential in antibacterial activity.

A Novel Approach for Single-Step Analyte Fractionation of Raw Milk Prior to Antibiotic Residue Trace Analysis as an Alternative to QuEchERS-Based Extraction.

Antibiotic residues in milk are a well-known hazard in the dairy food chain. Detection methods for these residues, such as nonspecific microbiological inhibitor tests or group-specific receptor tests, are relatively inexpensive, easy to use, and widely applied to ensure food safety. In contrast, specific detection by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-although a critical, complimentary method to confirm the results of nonspecific testing-is relatively costly, time-consuming, and laborious. Furthermore, sample processing before LC-MS/MS analysis requires unique preparation procedures for different groups of antibiotic compounds. To simplify and speed up specific antibiotic residue detection, a low-cost, passive, and single-step method to fractionate analytes in raw milk was developed. Untreated raw milk was fractionated into its water and fat/protein phases using a Fractionation of Milk for Trace Analysis of Contaminants and Residues for Antibiotics (FraMiTrACR® AB) fractionation unit. The water fraction was then analyzed by LC-MS/MS. The analyte fractionation method was evaluated against a Quick Easy Cheap Effective Rugged and Safe (QuEChERS)-based method for sample preparation. Our method allows qualitative and quantitative detection of substances from the penicillin, cephalosporin, macrolide, lincosamide, sulfonamide, tetracycline, and fluoroquinolone groups of antibiotics. Detection limits are below the legally prescribed maximum residue levels, allowing reliable, specific, and rapid validation of a positive result in nonspecific microbiological inhibitor tests. Analyte fractionation by FraMiTrACR AB is a faster alternative to QuEChERS-based sample preparation for the detection of antibiotic substances in milk. This method describes a low-cost, environmentally friendly, passive, and single-step milk analyte fractionation. As an alternative to QuEChERS-based preparation, this fractionation method simplifies and speeds up the process for specific antibiotic residue detection.

Effect of a Bacillus subtilis plus Yeast Cell Wall Synbiotic on Salmonella Enteritidis Colonization in Ceca of Layer Pullets

Salmonella Enteritidis (SE) is a major contamination concern in eggs and risk for Salmonellosis in humans. Strains of Bacillus subtilis and yeast cell wall can be used as substitutes for antibiotic substances in feed against Salmonella in poultry. The objective of this study was to assess the effect of BacPack® (Quality Technology International, Inc., Elgin, IL, USA) Q1+1 (BPQ11), a feed additive combination of a Bacillus subtilis strain and Saccharomyces cerevisiae cell wall, on SE cecal colonization in Lohmann LSL pullets. A control group (CON) and a test group (BPQ) were each randomly assigned 100-day-old chicks. CON was fed a corn–soybean meal-based vegetarian mash diet, and BPQ was fed the control diet supplemented with BPQ11 for the duration of the study. At 8 days of age, chicks were orally challenged with a nalidixic acid-resistant SE strain at a dose of 6.3 × 107 colony forming units (CFUs) per bird. At 7, 11, 15, and 19 days post-challenge (DPC), 25 birds per group were euthanized, and their cecal contents were collected and analyzed for SE. SE counts were 6.88, 7.98, 7.79, and 7.50 in CON and 7.18, 7.31, 6.35, and 6.30 log10 CFU/g in BPQ at 7, 11, 15, and 19 DPC, respectively. SE did not differ between CON and BPQ at 7 DPC; however, BPQ had lower (p &lt; 0.0001) SE at 11 (−0.67), 15 (−1.45), and 19 (−1.20 log10 CFU/g) DPC. Results indicate that synbiotic BPQ11 may be a useful dietary pre-harvest tool for SE management in layer birds.

The Penicillin saga: a different tale

The Sumerians, but also the ancient Egyptians, as well as Greeks and Indians, used extracts of some plants and fungi for the treatment of infections. Henryk Adam Aleksander Pius Sienkiewicz (1846 - 1916), the author of Quo Vadis, Nobel Prize for Literature in 1905, in his novel “With iron and with fire” reports that during the 17th-century in Poland, wet bread was mixed with cobwebs (which often contained fungal spores) to heal wounds. In the same period, in England, in the book entitled Pharmacopoeia Londinensis, the apothecary and botanist John Parkinson (1567 - 1650) recommended the use of molds as a medical treatment for many infectious diseases that affect humans. These treatments often work since many organisms, including many species of mold, naturally produce antibiotic substances. However, ancient practitioners could not accurately identify or isolate the active components of these organisms. Similar experiences and evidence have been found in many other countries, including Italy. For example, Bartolomeo Bizio (1791 - 1862), found in 1821, that the red color assumed by “polenta” (a corn meal dish) was due to a bacterium that he named Serratia marcescens and that its development was inhibited by the presence of mold. After 1850, thanks to the progress of chemistry, the chemotherapy concept for the treatment of infectious diseases began to assert itself. Consequently, some effective chemical compounds were synthesized (for example sodium arsenylate by Antoine Béchamp in 1859 and used, at that time, against sleeping sickness and other trypanosomiasis. It was later abandoned due to its remarkable toxicity). However, thanks to Louis Pasteur (1822 - 1895), in the seventies and eighties of the nineteenth century, the interest in substances of natural origin returned. Pasteur in fact highlighted both the inhibiting action of molds on the development of some bacteria and the antagonism between different bacteria. These observations were taken up by Arnaldo Cantani (1837 - 1893), who tried, with poor results, to apply Pasteur’s concept, developing bacteriotherapy (fight against pathogenic bacteria with other harmless bacteria) to treat tuberculosis.

Mycolytic effect and underlying mechanism of Chaetomium subaffine LB‐1 on phytopathogenic fungi via morphological, physio‐biochemical and transcriptomic analysis

AbstractChaetomium subaffine LB‐1 is a biocontrol strain screened by our laboratory. Mycolytic effect and its action mechanism was researched in this study with Botrytis cinerea and Alternaria solani as test phytopathogenic fungi. Microscopic observation found that hyphae of the test fungi exhibited vacuolated and flocculent when cultured in LB‐1 culture filtrate for 48 h. Physio‐biochemical detection indicated that hyphae of the test fungi displayed red fluorescence with propidium iodide (PI) staining when cultured in LB‐1 culture filtrate 24 h later; conductivity and the leakage value of the extracellular fluid of the test fungi were significantly higher (p ≤ .05) than corresponding control fluid of test fungi cultured in potato dextrose broth (PDB), but the malondialdehyde (MDA) contents in hyphae of the test fungi have not significant difference (p ≤ .05) between treatment and control. Colorimetric determination showed that the activities of alkaline protease, neutral protease, acidic protease and β‐l,3‐glucanase in LB‐1 culture filtrate were significant. In RNA‐seq analysis, 3644 differentially expressed genes (DEGs) were found in 6 days shaking‐cultured LB‐1 as compared to that of 0 days shaking‐cultured, of which 1756 were up‐regulated and 1888 were down‐regulated. In significantly up‐regulated DEGs, 12 were annotated as cell wall hydrolase, 13 as enzyme of antibiotic substance production and 18 as membrane transporter. The above results indicated that C. subaffine LB‐1 might exert mycolytic effect through altering the permeability of cell membrane and the integrity of cell wall of phytopathogenic fungi, and this altering effect was closely related with cell wall hydrolase, antifungal substance and membrane transporter.

Most common diagnoses and antibiotics used in South American Camelid patients at a university clinic in Austria.

Knowledge of common diseases and their treatment in minor species, such as llamas and alpacas, is growing, but frequently drugs are not licensed in these species. Our aim was to evaluate frequent diagnoses and commonly applied antibiotics in patients of a university clinic with a particular focus on EMA Category B antibiotics, which are critically important for human health. We retrospectively analyzed anonymized patient records between 2005 and 2019 regarding the causes for antibiotic treatment and choice of antibiotic substance. The most frequent indications for antibiotic treatment were diseases of the digestive tract and perioperative prophylaxis for castrations. The number of applications of EMA Category B antibiotics initially increased with the number of patients treated, then remained stable, while the use of Category D drugs increased over time. Most Category B antibiotics were used for diseases of crias and diseases of the digestive tract, primarily dental disease. The use of EMA Category B antibiotics cannot be completely avoided based on the types of cases treated. However, antibiotic stewardship guidelines should be followed wherever possible.

Bacillus licheniformis: A Producer of Antimicrobial Substances, including Antimycobacterials, Which Are Feasible for Medical Applications.

Bacillus licheniformis produces several classes of antimicrobial substances, including bacteriocins, which are peptides or proteins with different structural composition and molecular mass: ribosomally synthesized by bacteria (1.4-20 kDa), non-ribosomally synthesized peptides and cyclic lipopeptides (0.8-42 kDa) and exopolysaccharides (>1000 kDa). Different bacteriocins act against Gram-positive or Gram-negative bacteria, fungal pathogens and amoeba cells. The main mechanisms of bacteriocin lytic activity include interaction of peptides with membranes of target cells resulting in structural alterations, pore-forming, and inhibition of cell wall biosynthesis. DNase and RNase activity for some bacteriocines are also postulated. Non-ribosomal peptides are synthesized by special non-ribosomal multimodular peptide synthetases and contain unnatural amino acids or fatty acids. Their harmful effect is due to their ability to form pores in biological membranes, destabilize lipid packaging, and disrupt the peptidoglycan layer. Lipopeptides, as biosurfactants, are able to destroy bacterial biofilms. Secreted polysaccharides are high molecular weight compounds, composed of repeated units of sugar moieties attached to a carrier lipid. Their antagonistic action was revealed in relation to bacteria, viruses, and fungi. Exopolysaccharides also inhibit the formation of biofilms by pathogenic bacteria and prevent their colonization on various surfaces. However, mechanism of the harmful effect for many secreted antibacterial substances remains unknown. The antimicrobial activity for most substances has been studied in vitro only, but some substances have been characterized in vivo and they have found practical applications in medicine and veterinary. The cyclic lipopeptides that have surfactant properties are used in some industries. In this review, special attention is paid to the antimycobacterials produced by B. licheniformis as a possible approach to combat multidrug-resistant and latent tuberculosis. In particular, licheniformins and bacitracins have shown strong antimycobacterial activity. However, the medical application of some antibacterials with promising in vitro antimycobacterial activity has been limited by their toxicity to animals and humans. As such, similar to the enhancement in the antimycobacterial activity of natural bacteriocins achieved using genetic engineering, the reduction in toxicity using the same approach appears feasible. The unique capability of B. licheniformis to synthesize and produce a range of different antibacterial compounds means that this organism can act as a natural universal vehicle for antibiotic substances in the form of probiotic cultures and strains to combat various types of pathogens, including mycobacteria.

Экологические особенности и биотехнологические возможности почвенных актинобактерий (обзор)

Actinobacteria are gram-positive aerobic and facultative anaerobic bacteria that tend to form branching hyphae capable of developing into mycelium. Their main role is in the decomposition of complex polymers in the soil: lignin, cellulose, chitin, humus substances; fertility formation; production of antibiotic substances; accumulation of biologically active compounds. Actinobacteria secrete into the environment a complex of secondary exometabolites of various compositions with aliphatic, carbocyclic, heterocyclic, nitrogenous, oxygen-containing and sulfur-containing compounds. Most of the isolated secondary metabolites have antibiotic, antimicrobial, antiviral, herbicidal, insecticidal properties. Biotechnological capabilities of soil actinobacteria producing biologically active substances with a wide range of environmental effects are used in the development of multifunctional biologics for various industries. Actinobacteria play a crucial role in optimizing the growing conditions of plants, and therefore there is a natural interest in studying the factors that influence the relationship between actinobacteria and various crops in specific soil conditions. The development of this issue is an important link in the ecological characterization of the soil microbial complex and it will help to develop the theoretical foundations for the targeted regulation of the interactions of actinobacteria with phytopathogenic microorganisms and insect pests. The purpose of this work is to analyze the ecological features and biotechnological capabilities of soil actinobacteria. The review describes the distribution of actinobacteria in various types of soils, including those with the presence of pollutant; the composition of the metabolites produced; relationships with other microorganisms, as well as biotechnological properties and the possibility of using actinobacteria for the development of biological products for agroecosystems.

O01 The consumption of human antibiotics in veterinary medicine, in Estonia, 2006–22

Abstract Objectives In the absence of authorized veterinary medicinal products, veterinarians can use authorized human medicines, if necessary. The number of registered veterinary medicinal products, including veterinary antibiotics, has increased, over the years. Reducing the use of medically important antimicrobials in veterinary medicine is increasingly important to avoid the development and spread of antimicrobial resistance. The aim of this study was to analyse 17 year trends in the use of human antibiotics in veterinary medicine, in Estonia. Methods The data of human antibiotics used in veterinary medicine are based on wholesaler’s reports collected by the Estonian State Agency of Medicines, in 2006–2022. The sales data include total sales of human antimicrobial medicinal products to veterinarians and are collected at package level per year, including the name of the medicinal product, identification number of the product, active substance, pharmaceutical form, strength, package size and number of sold packages. Results Between 2006 and 2022, the overall sales of human antibiotics to veterinarians increased from 40.6 kg in 2006 to 54.4 kg in 2022 (peak 71.6 kg in 2019). In Estonia, based on 17 years of data, 220 different human antimicrobial medicinal products were sold to veterinarians, an average 91 different products per year (range 79–101). The number of different human antibiotic substances used in veterinary medicine was 45 ± 2 per year, 60 in total. The most used antibiotics over the 17 years were orally administered amoxicillin, clindamycin, ciprofloxacin, sulfamethoxazole and doxycycline and injectable amoxicillin and cefazolin. The turnover of human antibiotics sold to veterinarians increased from 34 000 EUR in 2006 to 99 000 EUR in 2022. Over the years, analysed by the product form, the most sold human antibiotics for veterinary use were products for oral administration, accounted for 90% of total quantity of antibiotics (24 different substances), followed by injections (9%, 19 different substances) and dermatological and sensory preparations (0.6%, 7 and 9 different substances, respectively). From medically important antibiotics, meropenem, imipenem, piperacillin, ceftriaxone, vancomycin and mupirocin were used in small quantities throughout the years. Conclusions Despite the number of registered veterinary antibiotics having increased over the years, the consumption of human antibiotics used in veterinary medicine has increased by the total quantity and by the turnover. The number of human antibiotic substances and sold packages has no significant changes.