Alfia Ibragimova

The use of glucocorticosteroids (GCS) in veterinary pharmacotherapy helps reduce inflammation and allergic reactions and has an immunosuppressive effect. Adaptive hormones increase the body’s resistance to stress. The widespread use of GCS in surgical interventions involving implantation is driven by a decreased reaction of surrounding tissues, reduced postoperative edema, and improved implant integration. However, oral administration of GCS is often associated with low bioavailability, and dose escalation carries the risk of severe adverse effects. The development of novel targeted delivery systems using biodegradable carriers makes it possible to increase the bioavailability of drugs, minimize side effects, and enhance the efficacy of pharmacotherapy. When choosing targeted delivery, it is important to assess the quantitative parameters of GCS concentration in blood plasma depending on the route of administration. The developed high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS) method enables the determination of very low drug concentrations within a range of 2 to 1000 ng/mL.

In developed countries, given the prevalence of methicillin‐resistant Staphylococcus aureus (MRSA), therapeutic options for treating such infections have become limited. In developing countries and Russia, little is known about resistance to antibiotics for St. aureus in veterinary medicine. Our research focused on (1) studying the clinical strain St. aureus from a sick horse for its ability to form a biofilm; (2) checking this clinical strain for resistance to antibiotics; (3) studying the effect of several farnesol (Far) concentrations on St. aureus biofilm; and (4) studying the effect of several Far concentrations on clinical strain resistance. The high phenotypic resistance of St. aureus isolates from a horse wound in our study highlights the importance of routine bacterial screening for inducible phenotypic resistance. This study describes for the first time the activity dynamic of the St. aureus strain in an environment containing antibacterial drugs and different concentrations of Far. Direct line revealed a correlation between strain resistance when assessed by the disk diffusion method and high ability of St. aureus strain to biofilm formation. We studied its ability to form biofilms and experimentally confirmed that Far perfectly inhibits their growth even at small concentrations from 1.6 μM/mL. St. aureus isolate showed resistance against three antibiotics out of seven. We have shown that combined treatment with antibiotics, especially in high concentrations 50–100–200 μM, increases St. aureus sensitivity to drugs.

Background and Aim: Fungal infections are a growing problem for both humans and animals due to the emergence of pathogenic strains resistant to modern antifungal treatments. To evaluate the efficacy of new antifungal drugs, it is essential to develop animal models that demonstrate typical responses to both the infection (pathogenesis and clinical course) and to the treatment, including adverse effects. In this study, we established a rabbit otitis model by infection of an aggressive multidrug-resistant strain from dogs, Malassezia pachydermatis C23, with no need for concomitant immunosuppression. Materials and Methods: Twenty healthy adult male gray giant rabbits (1 year old, 5.5 kg) were inoculated once with M. pachydermatis C23 at 108 colony-forming units/mL. We observed the clinical signs of the disease and collected ear smears and blood samples every 5 days. Results: The infection progressed rapidly and exhibited characteristic clinical signs without spontaneous recovery for at least 1 month. In fact, substantial deterioration was observed as evidenced by blood parameters. Conclusion: This rabbit otitis model established using an aggressive drug-resistant fungus strain without immunosuppression could prove valuable for testing novel antifungal agents. Keywords: in vivo model, Malassezia pachydermatis, otitis media, rabbit.

In this study, the data of the antagonistic action of the enzyme L-lysine-α-oxidase in relation to clinical isolates of multiresistant uropathogenic Escherichia coli isolated from patients aged 2 to 17 years of various genders with an established diagnosis of infectious urethritis and/or cystitis are presented. According to the results obtained, the top priority drugs for the treatment of infectious urethritis and/or cystitis are FO (Fosfomycin, 200 µg/disc), IMP (Imipenem, 10 mg/disc), and CIP (Ciprofloxacin, 30 µg/disc). It was found that out of 70 clinical isolates, only 36 of them formed biofilms using the plate method, which is equal to 51.4% of the total number of isolates studied. Despite polyresistance, clinical isolates of E. coli have moderate sensitivity to both the homogeneous enzyme and the culture fluid of the producer. The introduction of an enzyme or culture liquid at an early stage of strain cultivation significantly inhibits the formation of biofilms (91–100%). When introduced at later stages of the experiment—24 h and 48 h—inhibition is less pronounced—20–36% and 5–22%, respectively.

Background and Aim: The resistance of susceptible fish populations and the adaptive potential of heterogeneous biofilms, which cause multiple antibacterial resistance and long-term persistence of microorganisms, mediate the development and outcome of the infectious process. The study of the fish immunological parameters in interaction with biofilm-forming bacteria is of practical importance for assessing the stability of the homeostasis of the fish. This study aimed to determine the immunobiological parameters of Cyprinus carpio Linnaeus when interacting with biofilm-forming bacteria Aeromonas hydrophila. Materials and Methods: Clinically healthy fish C. carpio L. (Linnaeus, 1758) of both sexes, aged 4 years, and weighing 1.0–1.5 kg (n = 10), were used in this study. The fish were taken from the pond of the VNIIR experimental base in the period of 2020–2022. The standard method was employed to determine the phagocytic activity of blood cells, the total redox activity of neutrophils, and the bactericidal activity of blood serum. Results: After 24–48 h of cultivation in nutrient broth, the implementation of the processes of intercellular communication of bacteria had common patterns of formation of the heterogeneous structure of biofilms. Moreover, analyzing the optical density indices (density, D), it was observed that A. hydrophila was a strong producer of biofilms, as the optical density of the sample (density of sample, Ds) exceeded the optical density of the control (density of control, Dc) by more than 4 times (D = 0.464 ± 0.07). The ratio of the average number of microorganisms attached to the surface of one erythrocyte (average adhesion index) and the percentage (%) of erythrocytes having bacteria on their surface (adhesion coefficient [AC]) was 14.05 ± 0.72, and the adhesion index, AI was ≥4.00, indicating A. hydrophila to be highly adhesive. In addition, the AC of erythrocytes having bacteria on the surface was 14.05% ± 0.72%. A direct correlation was established (R2 = 0.94) between the AC (14.05% ± 0.11%–13.29% ± 0.08%) and the phagocytic index (11.3% ± 0.29%–32.0% ± 0.8%). The indicators of spontaneous nitro blue tetrazolium were 103.20 ± 11.70 when estimating the total redox activity of neutrophils. The optical density increased to 182.10 ± 21.12 with the addition of 20.0 μL of A. hydrophila bacteria (1 billion/mL) and the activity of neutrophils also increased. Conclusion: Among the markers of homeostasis stability, immunological indicators most fully reflect the mechanisms of initiation, development, and outcome of the infectious process mediated by the interaction of adhesive molecules of multicellular eukaryotes and adhesives of infectious disease pathogens. The research will contribute to further understanding the potential mechanism of quorum-sensing molecules and the search for new anti-adhesive drugs that reduce the formation of biofilms.

Background and Aim: Clinical strains of microorganisms, including pathogenic yeast-like fungi (YLF), are resistant to currently used antifungal agents. Thus, it is relevant to study the combinations of existing antimicrobial drugs and a medicinal extract of plant origin (farnesol). In previous studies, farnesol showed a relatively strong anti-biofilm effect against Candida albicans. This study aimed to determine how much the resistance profile of non-biofilm microorganisms can change. Materials and Methods: Six clinical isolates of C. albicans and one reference strain were used to study the interaction of farnesol with the most used antimycotics. To determine the sensitivity of YLF to antimycotic drugs, such as nystatin (50 μg), amphotericin B (10 μg), ketoconazole (10 μg), clotrimazole (10 μg), voriconazole (10 μg), fluconazole (25 μg), miconazole (10 μg), and intraconazole (10 μg), the classic disk diffusion method was used. In the second stage, one of the six strains was used to simulate candidiasis of the gastrointestinal tract in an in vivo quail model. As an unusual experimental design, this study investigated the effects of pretreated C. albicans in quails, not the in vivo pathogenicity of C. albicans, after treatment with farnesol. Results: The resistance profiles of Candida strains did not improve with farnesol in all strains. All concentrations of farnesol (100, 50, and 25 μM) demonstrated a fungistatic effect (i.e., an increase in drug sensitivity) in 23 of 56 (7×8) cases (41%). The remaining 54% demonstrated no changes in the resistance to antifungal drugs or deterioration of the indicators in rare cases (5%). At 100 μM farnesol, sensitivity improved in 33 of 56 cases (59%). Candidiasis or the severity of clinical disease of the quail digestive tract developed to a lesser extent if fungi were treated with farnesol. Conclusion: Farnesol does not always show a positive result on single cells without biofilm in the laboratory. However, in a biofilm or an in vivo model with biofilms, farnesol can be considered a new antimycotic drug or an additive to existing antimycotics.

Candida albicans was the first eukaryotic microorganism to exhibit quorum-sensing through the secretion of the sesquiterpene E, farnesol. This molecule is generated by dephosphorylation of farnesyl pyrophosphate in the mevalonate biosynthetic pathway in mammalian and yeast cells. Exogenous farnesol inhibits yeast-to-hyphal formation in a concentration- and time-dependent manner at the earliest stage of hyphal development. Much research has been devoted to studying the role of farnesol as an inhibitor of hyphal morphogenesis; however, little research has been published regarding the in vivo impacts of farnesol on fungal virulence and the development of Candida infection. While other studies have examined the impact of multiple doses of farnesol in addition to antimycotics, we hypothesize that C. albicans treated with a single dose of this quorum-sensing molecule could reduce fungal virulence in a quail model.

Заболеваниями опорно-двигательного аппарата (ОДА) страдают не только пожилые люди, но и молодые, которые относятся к экономически активному населению. Заболевания костно-мышечной системы практически всегда сопровождаются болевым синдромом, ограничением подвижности, что отрицательно влияет на качество и продолжительность жизни пациентов, в том числе и в арабских странах. Среди заболеваний ОДА ревматоидный артрит широко распространен среди групп населения с низким и средним уровнем дохода, особенно среди лиц с более низким социально-экономическим статусом. Основу терапии заболеваний ОДА в арабских странах составляют нестероидные противовоспалительные препараты (НПВП). Практически ежедневно принимают НПВП люди пожилого возраста (старше 65 лет). При этом многие пациенты не владеют полной информацией о препаратах, их побочных реакциях, взаимодействии с другими группами препаратов, а также не знают или не умеют рассчитывать правильную дозировку лекарственных средств (ЛС) и кратность их приема. Сегодня основные проблемы применения НПВП, связаны, с неосведомленностью пациентов о побочных реакциях ЛС, взаимодействии с другими препаратами и возможности дальнейшей фармакокоррекции. Выявленные проблемы применения НПВП в арабских странах свидетельствует о необходимости разработки селективных противовоспалительных препаратов системного применения. Они характеризуются как ЛС с наименьшим спектром побочных реакций, кратностью приема и, как следствие, могут быть рекомендованы пациентам с определенными сопутствующими заболеваниями, например со стороны ЖКТ, сердечно-сосудистой системы и...

Background and Aim: Candida albicans is a dimorphic fungus that has both yeast and filamentous forms. It is part of the normal flora in the oral and genital areas of mammals. One factor for the pathogenicity of C. albicans is its ability to switch from yeast to hyphae. The hyphal form adheres and penetrates tissues more readily than the yeast form and produces biofilms that are associated with chronic infection. Biofilms are protective niches that enable microorganisms to be more resistant to antibiotic treatment, thus allowing for persistent infection. The first stage in the transition from yeast to hyphae involves the formation of a germ tube, and this transition is triggered by interactions with host cells. Germ tube formation is dependent on serum, pH, temperature, and quorum-sensing molecules (QSMs). Farnesol, which is a QSM in C. albicans, can prevent yeast to hyphae conversion and inhibits the growth of fungal biofilm. Lyticase is a synergistic enzyme complex that catalyzes yeast cell lysis by β-1,3-glucanase and is a highly specific alkaline protease that produces protoplasts or spheroplasts. This study investigated the effect of farnesol and lyticase on the formation of C. albicans biofilms. Materials and Methods: C. albicans ATCC 2091 was cultivated on liquid and solid Sabouraud media. The presence of C. albicans was confirmed using HiCrome Candida Agar chromogenic medium. Enzyme activities were assayed using a HiCandida Identification Kit. The morphology and densitometry parameters of C. albicans biofilms were considered in the presence of farnesol (Sigma-Aldrich, Germany), lyticase (from Arthrobacter luteus; Sigma-Aldrich, Germany), and farnesol–lyticase. Results: This study shows that both farnesol and lyticase possess antifungal activity against C. albicans biofilms. A significant difference among treatment groups (p<0.05) was observed from strong biofilm production to medium and weak. Conclusion: Many studies have been devoted to the antimicrobial action of farnesol. Bacterial enzyme lyticase is also used to degrade fungal cell walls. Both molecules show substantial antifungal properties that are similar to the properties of modern antimycotics. The current study demonstrates that farnesol and lyticase can disrupt biofilm formation in C. albicans ATCC 2091, which is an effective biofilm producer.

Background and Aim: The study of biofilm-forming ability of Gram-negative microflora has great practical importance for assessing the effectiveness of antibiotic therapy and finding new ways to diagnose and inhibit the growth of biofilms. This is because poor penetration of antibacterial drugs into the biofilm can lead to the selection of resistant strains and has a consequence evident by the occurrence of relapse of infection in animals. This study aimed to evaluate morphological and densitometric indicators of biofilm formation as well as adhesive properties of Klebsiella pneumoniae. Materials and Methods: K. pneumoniae was cultured at 37°C for 2-144 h in vitro. The specimens for optical microscopy were prepared by fixation with a 1:1 alcohol-ether mixture for 10 min and stained with a 0.5% solution of gentian violet for 2 min, and the optical density index was evaluated at a wavelength of 490 nm. Further, the adhesive properties of the microorganisms were determined at a concentration of 1 billion/ml and a suspension of ram erythrocytes at a concentration of 100 million/ml when cultured at 37°C for 24 h. Blood smears were prepared and stained with 0.5% gentian violet. Results: K. pneumonia cultured at 37°C after 24 h on the meat peptone agar formed large, convex, mucous, and white colonies (d=3.0-6.0 mm). With the growth in the meat and peptone broth, uniform turbidity of the medium was observed. Analyzing the optical density indices (density, D), it was found that K. pneumoniae were good producers of biofilms (D=0.528±0.31). Data for indicators of adhesive properties of K. pneumoniae were as follows: Average adhesion index, 4.56±0.14; adhesion coefficient, 1.07±0.52; and adhesion index, 4.26±0.07. The studied bacteria had high adhesive activity. A direct correlation dependence (R=0.94) of the optical density of biofilms (D≥0.514-0.551) and AAI (4.15±0.28-4.76±0.75) was established. Conclusion: This study has demonstrated that K. pneumoniae had high adhesive activity, was strong producer of biofilms, and the optical density of the sample exceeded the optical density of the control by more than 4 times.