Sitafloxacin Expresses Potent Anti-Mycobacterium abscessus Activity

Therapeutic options for treating Mycobacterium abscessus infections are extremely limited; quinolones are important. The in vitro anti-M. abscessus activities of nine quinolones, emphasizing sitafloxacin, were investigated. Antimicrobial susceptibility testing was performed on 10 non-tuberculous mycobacterium reference strains and 194 clinical, M. abscessus isolates. The activity of sitafloxacin against intracellular M. abscessus residing within macrophages was also evaluated. A checkerboard assay was conducted to determine synergy between sitafloxacin and 10 clinically important antibiotics. Among the nine quinolones tested, sitafloxacin exhibited the greatest anti-M. abscessus activity with MIC50 and MIC90 of 1 and 2 mg/L, respectively. Sitafloxacin exerted a bacteriostatic effect on M. abscessus and inhibited the intracellular growth of M. abscessus at concentrations equivalent to clarithromycin. No antagonism between sitafloxacin and 10 clinically important anti-M. abscessus antibiotics was evident. In summary, sitafloxacin exhibited a significant advantage relative to other quinolones in inhibiting the growth of M. abscessus in vitro, suggesting the potential inclusion of sitafloxacin in new strategies to treat M. abscessus infections.

Modifications of Parylene by Microstructures and Selenium Nanoparticles: Evaluation of Bacterial and Mesenchymal Stem Cell Viability

Parylene-based implants or coatings introduce surfaces suffering from bacteria colonization. Here, we synthesized polyvinylpyrrolidone-stabilized selenium nanoparticles (SeNPs) as the antibacterial agent, and various approaches are studied for their reproducible adsorption, and thus the modification of parylene-C–coated glass substrate. The nanoparticle deposition process is optimized in the nanoparticle concentration to obtain evenly distributed NPs on the flat parylene-C surface. Moreover, the array of parylene-C micropillars is fabricated by the plasma etching of parylene-C on a silicon wafer, and the surface is modified with SeNPs. All designed surfaces are tested against two bacterial pathogens, Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The results show no antibacterial effect toward S. aureus, while some bacteriostatic effect is observed for E. coli on the flat and microstructured parylene. However, SeNPs did not enhance the antibacterial effect against both bacteria. Additionally, all designed surfaces show cytotoxic effects toward mesenchymal stem cells at high SeNP deposition. These results provide valuable information about the potential antibacterial treatment of widely used parylene-C in biomedicine.

Sulfonamide-salicylaldehyde imines active against methicillin- and trimethoprim/sulfonamide-resistant Staphylococci

Background: Increasing resistance has resulted in an urgent need for new antimicrobial drugs. A systematic me-too approach was chosen to modify clinically used sulfonamides to obtain their imines. Methods & results: Twenty-five compounds were synthesized and evaluated for their antibacterial activity. The most active compounds were also investigated against methicillin- and trimethoprim/sulfamethoxazole (SMX)-resistant Gram-positive species. Staphylococci shared the highest susceptibility including resistant strains with minimum inhibitory concentrations from 3.91 μM (≥2.39 μg ml-1). Crucially, the compounds inhibit MRSA and trimethoprim/SMX-resistant Staphylococci without any cross-resistance. Modification of parent sulfonamides turned a bacteriostatic effect into a bactericidal effect. Toxicity for HepG2 and hemolytic properties were also determined. Conclusions: The presence of a dihalogenated salicylidene moiety is required for optimal activity. Based on toxicity, promising derivatives for further investigation were identified.

STUDYING THE INFLUENCE OF PLASMA-CHEMICAL AND OZONE TREATMENT ON ARTIFICIALLY IMPLEMENTED MICROFLORA IN MODEL AQUEOUS SOLUTIONS

The pilot studies have been conducted to determine the biocidal effects of ozone and plasma chemical treatment for 1, 2, and 3 h on the strain “Moldavian” of infectious rhinotracheitis virus, reference strain of Escherichia coli ATCC 25922, atypical mycobacteria of the species Mycobacusleum phlei and archival strain of Aspergillus flavus artificially introduced into aqueous solution. It is shown that both treatments of aqueous solution contaminated with infectious rhinotracheitis virus have virucidal properties at the level of 95…100%. It was found that bactericidal (bacteriostatic) effect of ozone treatment for Escherichia coli fluid was 100% for all the time parameters. For plasma chemical treatment, the bacteriostatic effect (23%) was shown after the treatment within 3 h. The bactericidal (bacteriostatic) effect of ozone treatment for water samples contaminated with mycobacteria of the species M. phlei was only 65% at the treatment for 3 h. There was no bacteriostatic effect for plasma chemical treatment at any exposure. When studying the fungicidal (fungistatic) properties of ozone treatment for aqueous solution contaminated with a test culture of Aspergillus flavus, fungicidal properties were established (growth retardation by 95…98%). No fungicidal or fungistatic properties were shown for plasma chemical treatment.

STUDY OF THE DYNAMICS OF REPRODUCTION OF M. LEPRAE UNDER THE CONDITIONS OF APPLICATION OF ANISEED LOFANT EXTRACT OBTAINED FROM SUPERCRITICAL FLUID EXTRACTION METHOD

One of the ways to solve the problem of drug resistance in the therapy of infectious diseases is to develop herbal preparations with high antibacterial activity, which have a good drug safety profile, is extremely significant for long-term therapy, the use of which could complement and improve the used combination therapy regimens. The aim of our study was to study the anti-leprosy activity of lofant anise extract obtained by supercritical fluid extraction using CO2 containing phenolic compounds such as gallic acid, coumarin, umbelliferon, luteolin, quercetin, taxifolin, rutin. Materials and methods. The anti-leprosy activity had been studied on Shepard's model. Blood parameters were examined on a SYSMEX XT – 2000i hematological analyzer (Japan). Conclusion. Lofant anise extract, obtained by supercritical fluid extraction using CO2, has a bacteriostatic effect on M. leprae, which is not only comparable to the effect of dapsone, but also with a more prolonged course exceeding it. Unlike the drug of choice (dapsone), the extract, when administered for 30 days, does not cause changes in red blood parameters and does not cause neutropenia. The identified effects actualize further research of the extract for the development of dosage forms based on it for practical health care.

Veterinary and sanitary assessment and disinfection of refrigerator chambers of meat processing enterprises

The results of microbiological studies of air samples of refrigerating chambers of meat processing enterprises are presented. The quantitative composition of the air microbiota of the chambers of the refrigerating shop was studied. It has been established that the technological regimes for cooling meat in cooled chambers (t = +4 °C) and deep freezing chambers (t = -18 °C and -22 °C) have no bacteriostatic effect on the life activity of mold fungi. The developed disinfecting preparation (hydrogen peroxide (8.0 - 10%), acetic acid (10%), peracetic acid (5.0 - 7.0%), stabilizing additives, water) ensures the destruction of sanitary-indicative microorganisms in cold rooms meat processing plants when applied at a concentration of 0.05% - 60 minutes, 0.1% - 30 minutes, 0.15% - 10 minutes and does not have a toxic effect on meat raw materials that are stored in chambers of the refrigeration shop after disinfection.

Co@ag Core–Shell Nanomaterials: Preparation and Application in the Purification of Yellow River Water

In this study, we prepared a new type of recyclable Co@Ag core–shell nanomaterials with a very simple method named displacement reaction. Co@Ag core–shell nanomaterials were prepared in AgNO3 solution with cobalt nanomaterials as the core, while the surface was coated with silver nanomaterials. Co@Ag core–shell nanomaterials were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and oscillating sample magnetometer (VSM).We found that the diameter of the Co@Ag core–shell nanomaterials was about 100nm, which was exhibited in form of elemental elements andobvious magnetic properties.In order to evaluate the bacteriostatic effect of Co@Ag core–shell nanomaterials, we used qualitative and quantitative methods to assess the bacteriostatic effect of these materials on standard strains of Pseudomonas aeruginosa (ATCC27853, Gram - negative bacterium), Staphylococcus aureus (ATCC 25923, Gram-positive bacterium), Escherichia coli (ATCC 25922, Gram-negative bacterium) and Candida albicans (ATTC 90029, yeast) in Yellow River water in vitro. The results show that Co@Ag core–shell nanomaterials have a significant antibacterial effect. In addition, Co@Ag core–shell nanomaterials can be recycled through an external magnetic field to reduce environmental pollution. Interestingly, the reclaimed Co@Ag core–shell nanomaterials can still have antibacterial activity and can be reused. These results indicate that Co@Ag core–shell nanomaterials may have potential application as disinfectants for water.

Clindamycin as an Alternative Option in Optimizing Periodontal Therapy

Periodontal disease is an oral infectious and inflammatory disease caused by microorganisms that determine the host-mediated destruction of soft and hard periodontal tissues, which ultimately leads to tooth loss. Periodontitis affects a large part of the population, with various degrees of severity. Treatment consists of etiologic therapy: the removal of biofilm through mechanical debridement plus microbial elimination by supplementary measures. Antibiotic administration, either systemically or through local delivery, has been shown to improve clinical outcomes after mechanical periodontal treatment. Clindamycin is a lincosamide with a broad spectrum, being active against aerobic, anaerobic, and β-lactamase-producing bacteria. This antibiotic offers several advantages and some disadvantages and has been used in periodontal treatment both systemically and locally with various degrees of success. Among the properties that recommend it for periodontal treatment is the bacteriostatic effect, the inhibition of bacterial proteins synthesis, the enhancement of neutrophil chemotaxis, phagocytosis and the oxidative burst–oxidative stress storm. Furthermore, it is easily absorbed at the level of oral tissues in a considerable amount. This substantial tissue penetration, especially inside the bone, is synergistic with a stimulating effect on the host immune system. The aim of this review is to explore the applicability of this antibiotic agent and to evaluate its antimicrobial potential and limitations at the level of the oral biofilm associated with periodontal disease.