Гентамицин является одним из компонентов комбинированной терапии инфекционных эндокардитов, вызванных Staphylococcus aureus, включая метициллинорезистентные штаммы (methicillin-resistant S.aureus, MRSA). Цель исследования — анализ влияния десяти 6-часовых циклов воздействия высоких концентраций (16 мкг/мл) гентамицина in vitro на изменение фенотипа и генотипа аминогликозидочувствительных штаммов S.aureus, относящихся к четырём сиквенс-типам: ST5 (ATCC 29213), ST8, ST97 и ST22 (MRSA). Для всех штаммов, кроме ATCC 29213, после селекции отмечалось увеличение МПК гентамицина до 8–64 мкг/мл. Один штамм (SA0937) диссоциировал на три морфотипа, включая мелкоколониевый вариант (small colony variant, SCV). Вариант производного штамма SA0937 с колониями нормального размера характеризовался ассоциированной устойчивостью к даптомицину за счёт мутации P314L в MprF. Формирование устойчивости не сопровождалось изменением скорости роста, кроме морфотипа SCV. Для штамма ATCC 29213 после селекции отмечалось появление толерантности, проявляющейся в увеличении эффективного киллинга до 14 ч в 24-часовом time-killing эксперименте с концентрацией антибиотика 16 мкг/мл. У штамма ATCC 29213 выявлены мутации в пептидил т-РНК гидролазе (Pth). У трёх штаммов были обнаружены делеции в гене atpG, входящим в состав АТФ-синтазного комплекса. У остальных производных штаммов были выявлены делеции и мутации в генах метаболизма менахинона hepS, menA и трансляционном факторе элонгации G (fusA). Таким образом, использование гентамицина сопряжено с возможным быстрым формированием устойчивости и толерантности, не связанными с приобретением генов аминогликозид-модифицирующих ферментов. Выявление SCV ассоциировано с неблагоприятными клиническими исходами. При использовании комбинированной терапии необходимо учитывать, что существует возможность формирования устойчивости к даптомицину на фоне селекции гентамицином.
The created cell line of human proximal renal tubules RPTEC/TERT1 showed maximum compliance with primary human RPTEC, which makes it optimal for use in studies of the nephrotoxic properties of xenobiotics. Transepithelial resistance measurement (TEER) is a valuable non-invasive method that can be used to quantify the integrity of the cell barrier at various stages of cell growth and differentiation, as well as to predict the toxicity and permeability of drugs. The aim of the study was to examine the dynamics of changes in transepithelial resistance in the model of the RPTEC/TERT1 cell line during incubation with drugs with nephrotoxic effects. Material and methods. The human proximal renal tubule cell line RPTEC/TERT was obtained from the ATCC cell culture bank. Cells at passage 14 were used in the experiment. The following drugs were studied: cisplatin: 2.5 mcg/ml; vancomycin: 50 mcg/ml; doripenem — 20mcg/ml; cefepim — 150mcg/ml. 4–5 repetitions were performed for each concentration of the drug in the experiment. THEER measurements were carried out 4–5 times for each well. Results. Cisplatin, vancomycin, doripenem, and cefepim in the concentrations used do not show a cytotoxic effect on the RPTEC cell line according to TEER dynamics.
Background. The modern healthcare system is constantly improving and introducing new measures to protect the population from viral diseases, but the experience of the COVID-19 pandemic has shown that infections cannot always be controlled on global scale. In this regard, the development of new broad-spectrum antiviral drugs is more relevant than ever.The aim of the study was to investigate the antiviral activity and cytotoxicity of copolymers of sodium styrene sulfonate and vinyl monomers of various chemical structures, as well as to identify promising polymers for the development of new antiviral agents.Materials and methods. 14 copolymers of sodium styrene sulfonate (NaSS) with various functional comonomers were synthesized. Three viruses with different reproduction strategies and transmission methods — respiratory syncytial virus, influenza virus, and herpes virus — were selected for the assessment of antiviral activity.Results. The screening identified copolymers that showed high activity against all three viruses. It was found that the introduction of various functional groups into the structure of NaSS did not decrease antiviral activity, but significantly reduced cytotoxicity. The molecular weight has also shown a noticeable effect on the activity. Different sensitivity of viruses and cells to the studied polymers was revealed, likely due to the structural features of the virus shell and cell wall.Conclusions. The results demonstrate the potential of sodium styrene sulfonate copolymers as a model for developing a broad-spectrum antiviral drug.
A significant increase in sales of antibacterial drugs in pharmacies and their purchases by medical institutions of the Russian Healthcare System was observed against the background of the past pandemic of a novel coronavirus infection in Russia. Microbiological monitoring that was carried out at City Clinical Hospital No. 67 named after. L. A. Vorokhobov (Moscow) in 2020–2021, revealed a pressing problem — primarily gram-negative bacteria, with a predominance of multidrug-resistant (MDR) strains, were isolated from patients with healthcare-associated infections (HAIs). As shown by pharmacoeconomic studies conducted by the authors, the cost of one course of targeted antibacterial therapy for HAI in this case could increase by 6–12 times compared to a similar course of therapy in the absence of both MDR strains and XDR strains of hospital pathogens. In order to achieve a reduction in the cost of antibacterial therapy developed and used by the authors, in addition to the development of effective antibacterial therapy regimens for HAIs caused by MDR/XDR pathogens, another study was carried out as a continuation of the work on creating and improving biotherapy regimens for HAIs, namely the development of personalized phage therapy regimens for patients with hospital-acquired pneumonia caused by MDR bacterial strains. Based on the data obtained, the concept of a personalized approach to phage therapy of various nosological forms of HAIs caused by hospital-acquired MDR pathogens in patients of a multidisciplinary hospital was proposed and tested. As a result of this approach, the effectiveness of phage therapy for various nosological forms of HAIs caused by MDR and XDR strains of hospital pathogens in City Clinical Hospital No. 67 named after. L. A. Vorokhobov increased by 30%, and the effectiveness of the initial antibiotic regimen was 70%. The economic effect of the combination of antibiotic therapy and phage therapy («booster therapy») amounted to 3,000,000 rubles, compared with the use of antibiotics alone in the treatment of patients with HAIs caused by MDR/XDR strains of hospital pathogens.
Aim. To study the efficacy and safety of Riamilovir in patients diagnosed with acute respiratory viral infection using several dosage regimens of the drug.Material and Methods. The clinical efficacy and safety of Riamilovir were evaluated based on the results of a study, that included 150 patients in three comparative groups, 50 patients each. The research groups received etiotropic antiviral therapy with 1 capsule (250 mg) of Riamilovir 3 times per day for 5 days in the first group; in the second group, patients received Riamilovir off-label — 1 capsule (250 mg) 5 times per day for 5 days; and the third group included 50 patients who received only pathogenetic treatment.Results. As a result of the study, Riamilovir demonstrated a high safety profile regardless of the dosage regimen; no adverse events were registered. It was shown that Riamilovir use, regardless of the dosage regimen, led to a statistically significant reduction in the duration of inpatient treatment. It should be noted that the shortest periods of hospitalization were observed in patients who received the studied drug at increased daily dosages. Riamilovir was found to reduce the duration and severity of general infectious signs of the disease, while complete elimination of ARVI pathogens occurred by the 6th day of hospitalization; the shortest total duration of fever and a number of respiratory tract syndromes was registered among patients receiving Riamilovir at a daily dose of 1250 mg for 5 days.Conclusion. The etiotropic antiviral drug Riamilovir has shown clinical efficacy when used in both treatment regimens in patients with acute respiratory viral infections, as well as a good safety profile.
