In vitro and ex vivo antibacterial activity of levofloxacin against Pasteurella multocida and Escherichia coli isolated from rabbits (Oryctolagus cuniculus) – A preliminary study

Funding Information: This study was funded from the Riga Stradins University doctoral grant. Funding Information: The authors sincerely thank Dr. Aneliya Milanova (Trakia University, Bulgaria) and Dr. Cristina Vercelli (University of Turin, Italy) for their scientific advice and help. Publisher Copyright: © 2023 The Authors. Journal of Veterinary Pharmacology and Therapeutics published by John Wiley & Sons Ltd.Levofloxacin veterinary formulations are available in Argentina, China and India for the use in dogs, cattle, pig and sheep, but not currently in the rabbit. Only the extra-label use in rabbits is possible. Levofloxacin is not labelled for veterinary use in the EU or the USA. The activity of levofloxacin against rabbit pathogens Pasteurella multocida (P. multocida) and Escherichia coli (E. coli) was evaluated. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined in broth and serum for 10 P. multocida isolates and 5 E. coli isolates from rabbits. One isolate of each bacterial species was used for the time-killing curve study in vitro and ex vivo. In vitro AUC24/MIC ratios were used for building the inhibitory pharmacodynamic Imax model. The P. multocida MIC were 0.008–0.5 μg/mL, MBC – 0.015–0.5 μg/mL. Escherichia coli MIC was 0.008–0.03 μg/mL and MBC – 0.03–0.25 μg/mL. Bacterial counts were reduced to the limit of detection after 24 h with levofloxacin concentrations of 2 MIC and higher. All serum samples from rabbits treated with levofloxacin eliminated the bacteria within 24 h. AUC24/MIC ratios for bacteriostatic, bactericidal and bacterial elimination effects for P. multocida and E. coli isolates were 21, 29 and 75 h and 27, 32 and 60 h, respectively. Proposed daily doses against P. multocida (MIC = 0.015 μg/mL) and E. coli (MIC = 0.03 μg/mL) isolates were calculated as ≤0.91 and ≤1.43 mg/kg, respectively. Fluoroquinolones are categorized by WHO as ‘highest priority critically important antimicrobials’. Considering the increasing importance of antimicrobial stewardship, antimicrobials from a lower importance category that are active against the isolate of interest should be used in preference to fluoroquinolones. Fluoroquinolone use in veterinary medicine should be based on antimicrobial susceptibility testing in order to mitigate the risk to public health and prevent the spread of bacterial resistance.Peer reviewe

Antibacterial susceptibility testing of cutibacterium acnes in acne vulgaris patients

Publisher Copyright: © 2021 Skadins et al.Introduction: Combination therapy is widely used for the treatment of acne vulgaris (AV), including local anti-inflammatory drugs containing antimicrobials, such as clindamycin or erythromycin, to inhibit Cutibacterium acnes (C. acnes) growth and at the same time reduce the production of inflammatory mediators. The aim of the study is to compare the anti-bacterial susceptibility of C. acnes to clindamycin and erythromycin in AV patients compared with healthy patients in the control group (CG). Methods: The prospective study included 56 patients with clinically diagnosed AV symptoms and 12 patients were included in the CG who did not have AV. In the AV group, patient specimen was contents of pustules obtained by squeezing pustules, but in the CG, the specimen was content of sebaceous glands. All specimens were cultivated on a combined Mueller–Hinton solid medium. Identification was done by VITEK2 and followed by determination of antibacterial susceptibility of the isolated C. acnes strains by E-test. Results: C. acnes was isolated from samples of 28 (50%) in the AV group, whereas in the CG, C. acnes was isolated from 10 samples (80%). Resistance to clindamycin in both groups was similar, in 6 (21.4%) samples from patients in the AV group and in 2 (20.0%) samples in the CG, but resistance to erythromycin in the AV patients was higher compared to the CG, in 8 (28.6%) and 1 (10%) accordingly. Conclusion: Patients with AV have higher rates of resistance to erythromycin than the CG, while resistance to clindamycin is comparable. Resistance data showed no statistically significant association between use of erythromycin and clindamycin and the development of resistance. More C. acnes were identified in the CG than in the AV group.publishersversionPeer reviewe

Development of vancomycin delivery systems based on autologous 3d platelet-rich fibrin matrices for bone tissue engineering

Funding Information: Funding: This research was funded by the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 857287 and the Latvian Council of Science research project No. lzp-2020/1-0054 “Development of antibacterial autologous fibrin matrices in maxillofacial surgery (MATRI-X)”. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Autologous platelet-rich fibrin (PRF) is derived from the blood and its use in the bone tissue engineering has emerged as an effective strategy for novel drug and growth factor delivery systems. Studies have approved that combined therapy with PRF ensures higher biological outcomes, but patients still undergo additional treatment with antibiotic drugs before, during, and even after the implantation of biomaterials with PRF. These systematically used drugs spread throughout the blood and lead not only to positive effects but may also induce adverse side effects on healthy tissues. Vancomycin hydrochloride (VANKA) is used to treat severe Staphylococcal infections but its absorption in the target tissue after oral administration is low; therefore, in this study, we have developed and analyzed two kinds of VANKA carriers—liposomes and microparticles in 3D PRF matrices. The adjustment, characterization, and analysis of VANKA carriers in 3D PRF scaffolds is carried out in terms of encapsulation efficiency, drug release kinetics and antibacterial activity; furthermore, we have studied the micro-and macrostructure of the scaffolds with microtomography.Peer reviewe

Antibacterial Activity of Tanacetum vulgare L. Extracts against Clinical Isolates of Bovine Mastitis

Funding Information: This research was funded by the European Union’s Horizon 2020 research and innovation program under the grant agreement No 857287 and this research is supported by the Ministry of Agriculture and Rural Support Service Republic of Latvia with the European Agricultural Fund for Rural Development—Development of herbal plant containing medical extracts with anti-parasitic effect No 18-00-A01620-000028. Publisher Copyright: © 2023 by the authors.A bovine mastitis is an infectious disease, which is usually treated with antibiotics. Alternatively, herbal medicine has been proposed due to bacterial resistance. The aim of this study was to determine the antibacterial activity of the acetonic and ethanolic extracts of dried flowers and leaves of Tanacetum vulgare L. against bovine mastitis-inducing clinical isolates such as Escherichia coli, Streptococcus agalactiae, Streptococcus uberis, Serratia liquefaciens, Staphylococcus aureus, and reference cultures of S. aureus and E. coli. The extracts of T. vulgare showed partial antibacterial activity against tested strains of S. aureus. The MIC and MBC values of a 70% ethanol extract of flowers (MIC = 3.4 mg/mL, MBC = 3.4–6.8 mg/mL) were lower than for the 70% ethanol extract of leaves (MIC = 15.7–31.4 mg/mL, MBC = 62.9–125.9 mg/mL). The flower extracts showed low activity against E. coli (MIC = 53.9 mg/mL, MBC = 53.9–107.8 mg/mL) and S. agalactiae (MIC, MBC = 53.9 mg/mL). T. vulgare leaf extracts had minimal antibacterial effects against Streptococcus strains (MIC = 31.4–62.9 mg/mL, MBC = 53.9–125.9 mg/mL) and Serratia liquefaciens (MIC, MBC = 125.9 mg/mL). However, flower extracts had a higher phenolic content that did not correlate with antibacterial effects. T. vulgare flower and leaf extracts could be combined to obtain broader antibacterial effects.publishersversionPeer reviewe

Effect of Femtosecond Laser-Irradiated Titanium Plates on Enhanced Antibacterial Activity and Preservation of Bacteriophage Stability

Funding Information: This work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/4/20/638). Publisher Copyright: © 2023 by the authors.Titanium (Ti) is widely recognized for its exceptional properties and compatibility with medical applications. In our study, we successfully formed laser-induced periodic surface structures (LIPSS) on Ti plates with a periodicity of 520–740 nm and a height range of 150–250 nm. To investigate the morphology and chemical composition of these surfaces, we employed various techniques, including field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Additionally, we utilized a drop-shape analyzer to determine the wetting properties of the surfaces. To evaluate the antibacterial activity, we followed the ISO 22196:2011 standard, utilizing reference bacterial cultures of Gram-positive Staphylococcus aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922). The results revealed enhanced antibacterial properties against Staphylococcus aureus by more than 99% and Escherichia coli by more than 80% in comparison with non-irradiated Ti. Furthermore, we conducted experiments using the Escherichia coli bacteriophage T4 (ATCC 11303-B4) and the bacterial host Escherichia coli (ATCC 11303) to investigate the impact of Ti plates on the stability of the bacteriophage. Overall, our findings highlight the potential of LIPSS on Ti plates for achieving enhanced antibacterial activity against common bacterial strains while maintaining the stability of bacteriophages.Peer reviewe

Can Our Blood Help Ensure Antimicrobial and Anti-Inflammatory Properties in Oral and Maxillofacial Surgery?

In recent decades, the potential of PRF has been extensively studied. The number of studies about PRF has increased three times since the year 2012, but the full spectrum of its fundamental properties, such as antimicrobial and anti-inflammatory activity, is not clearly described. In oral and maxillofacial surgery, PRF is described in alveolar ridge preservation, orthognathic surgery, cleft lip and palate surgery, maxillary sinus augmentation, and dental implant placement as demonstrating favorable results and its clinical advantages. The structural complexity, inhomogeneous nature, and clotting ability of PRF make its antimicrobial effect evaluation complicated. Nevertheless, most of the used antimicrobial testing methods are based on antibacterial agent diffusion ability in culture media. Because the oral and maxillofacial region is the most frequent area of PRF application, its antimicrobial activity evaluation also prevails in the oral microbiome. PRF’s biological potential is highly dependent on the specific preparation protocol and methodology used; it should be carefully prepared and kept under proper conditions to keep cellular content alive. PRF’s influence on living cells demonstrates a stimulating effect on bone regeneration, and an angiogenetic effect, and it provides anti-inflammatory activity. According to analyzed studies, PRF demonstrated success in oral and maxillofacial surgery in various methods of application. Antibacterial and anti-inflammatory properties were proven by antibacterial activity against different bacterial species, sustained growth factor, sustained release, and cell activity on the material application. Accurately and correctly prepared PRF can ensure antibacterial and anti-inflammatory properties, and it can be a beneficial clinical tool in oral and maxillofacial surgery

Dentalni status i parodontološko zdravlje pacijenata s fenilketonurijom u Latviji

Objectives: Phenylketonuria (PKU) is an autosomal recessive inherited disorder of phenylalanine metabolism resulting from a deficiency of phenylalanine hydroxylase. The aim of this study was to evaluate the dental status and periodontal health of PKU patients in Latvia. Material and Methods: Fortyfive PKU patients and age/sex-matched controls were recruited for this cross-sectional study. Their anamnestic data, periodontal health and dental status were assessed by one experienced dentist. Results: Dental and periodontal clinical evaluation revealed that the median number of filled teeth was significantly smaller among PKU patients compared to the control group (p=0.021). PKU patients had a significantly larger median number of carious teeth than their healthy counterparts (p<0.001). Significant differences between the PKU and control groups were observed for several oral hygiene indices (p<0.001): Silness-Löe plaque index, OR=29.3 (95% CI: 3.7–232.4); CPITN index, OR=35.2 (95% CI: 4.5–278.3); Greene-Vermillion index, OR=10.2 (95% CI: 2.8–38.0); calculus removal necessity, OR=12.3 (95% CI: 3.3–45.4). Conclusion: Dental status and periodontal health of PKU patients was found to be significantly inferior compared to healthy controls. This is likely due to the regular consumption of PKU formula and the difficulties which mentally and/or physically disabled PKU patients experience with their oral hygiene. To prevent tooth decay and periodontal disease, PKU patients should visit a professional oral hygienist every three to six months. Furthermore, they should adopt the habit of rinsing their mouth with water immediately after consuming PKU formula to counteract the acidity in their oral cavity.Uvod: Fenilketonurija (PKU) je autosomno recesivni nasljedni poremećaj metabolizma fenilalanina koji nastaje zbog nedostatka fenilalanin hidroksilaze. Cilj ovog istraživanja bio je procijeniti dentalni status i parodontološko zdravlje pacijenata s PKU-om u Latviji. Materijal i metode: Za istraživanje poprečnoga presjeka odabrano je 45 pacijenata s PKU-om i kontrolna skupina podudarne dobi/spola. Njihove anamnestičke podatke, parodontološko zdravlje i dentalni status procijenio je iskusni stomatolog. Rezultati: Dentalna i parodontološka klinička procjena pokazala je da je medijan broja zuba s ispunima značajno manji među pacijentima s PKU-om u usporedbi s kontrolnom skupinom (p = 0,021). Pacijenti s PKU-om imali su značajno veći medijan broja zuba s karijesom od zdravih ispitanika (p < 0,001). Značajne razlike između pacijenata s PKU-om i kontrolne skupine uočene su za nekoliko indeksa oralne higijene (p < 0,001): Silness-Löeov indeks plaka, OR = 29,3 (95 % CI: 3,7 –2 32,4); CPITN indeks, OR = 35,2 (95% CI: 4,5 – 278,3); Greene-Vermillionov indeks, OR = 10,2 (95 % CI: 2,8 – 38,0), a tu je i potreba za uklanjanjem kamenca, OR = 12,3 (95 % CI: 3,3 – 45,4). Zaključak: Utvrđeno je da su dentalni status i parodontološko zdravlje pacijenata s PKU-om znatno lošiji u odnosu prema zdravim ispitanicima u kontrolnoj skupini. To je vjerojatno zbog redovite konzumacije formule za PKU i poteškoća koje imaju mentalno i/ili tjelesno invalidni pacijenti s PKU-om kada je riječ o održavanju oralne higijene. Kako bi spriječili karijes i parodontološke bolesti, profesionalna oralna higijena bila bi pacijentima s PKU-om potrebna svakih tri do šest mjeseci. Nadalje, trebali bi steći naviku ispiranja usta vodom odmah nakon konzumiranja formule za PKU kako bi smanjili kiselost u usnoj šupljini

Anatase or rutile TiO2 nanolayer formation on Ti substrates by laser radiation: Mechanical, photocatalytic and antibacterial properties

A laser-induced oxidation method for the formation of a TiO2 layer on a Ti substrate was used. The TiO2 phase can be controlled by an Nd:YAG laser with fundamental frequency at an intensity I = 52.8 MW/cm2 and three different doses. Dose D1 = 3.1x1020 phot/cm2 forms a TiO2 layer in the anatase phase, which possesses the highest photocatalytic, antibacterial and adhesion properties. As the laser dose increases, the TiO2 layer thickness increases from 40 nm to 100 nm, but the photocatalytic decomposition reaction constant decreases. The observed super-linear increase of the TiO2 layer thickness with the laser dose is explained by the presence of positive feedback during the irradiation process. The temperature rises with increasing of the thickness due to the interference-caused decrease of the reflection coefficient. As the thickness increases, TiO2 on Ti structure adhesion decreases from 800 mN to 400 mN due to the formation of a layer with a mixture of phases. The colonization intensities of P. aeruginosa and S. epidermidis bacteria decrease more than tenfold after TiO2 formation. These results are explained by the partial transformation of the TiO2 layer, formed in the anatase phase at dose D1, into the rutile one at doses D2 and D3 due to a deficit of O atoms caused by the low diffusion of O atoms in Ti. According to our experiments and calculations, using the Wagner oxide model, the laser technology can be used to form crystalline structures with a monolayer precisionLietuvos energetikos institutasVytauto Didžiojo universitetasŽemės ūkio akademij