VF Veterinarinės patobiologijos katedra (13.05)

Background: Early tumor-promoting events in skin carcinogenesis are characterized by increased keratinocyte proliferation, epidermal hyperplasia, and architectural alterations of the skin. Natural bioactive compounds with antiproliferative properties may represent promising chemopreventive strategies. C-phycocyanin (C-PC), a cyanobacteria - derived biliprotein, has demonstrated cytostatic and anti-inflammatory effects in experimental models (1-2). However, its topical delivery and influence on early tumor promotion require further investigation. Aim(s): To evaluate whether C-PC-loaded transfersomes modulate early proliferation- and dysplasiaassociated alterations in a mouse DMBA/TPA model of skin tumor promotion. Methods: Experimental skin carcinogenesis was induced using a classical DMBA/TPA initiation– promotion protocol. Animals were treated with C-PC-loaded transfersomes, empty transfersomes, or cancerogenic formulations. Histological assessment included epidermal thickness, rete ridge depth, and dysplasia grading. Immunohistochemical analysis of Ki-67 expression was performed separately in basal and suprabasal epidermal layers. Correlation analysis between suprabasal Ki-67 index and histopathological parameters was conducted. Statistical analysis included Welch’s ANOVA with Games–Howell post hoc test, Kruskal–Wallis analysis, and Spearman correlation (p < 0.05). Results: Tumor promotion induced marked epidermal hyperplasia, increased rete ridge formation, and elevated Ki-67 expression extending into suprabasal layers. Treatment with C-PC-loaded transfersomes significantly reduced epidermal thickness and suprabasal proliferative activity compared to untreated promoted skin. Suprabasal Ki-67 index positively correlated with epidermal thickness, rete ridge depth, and dysplasia grade, indicating its sensitivity as a marker of early pathological proliferation. Conclusion: Topical delivery of C-PC via transfersomes was associated with attenuation of early proliferative and structural alterations during skin tumor promotion in this experimental model. Further studies are required to clarify the underlying mechanisms and to determine their potential relevance in long-term chemopreventive strategies.

The main distinction between open and laparoscopic ovariectomy (OVE) is pneumoperitoneum (PNP) and anesthesia management. The objective of this study was to evaluate the effect of laparoscopic and open OVE on plasma cortisol, oxidative stress (OS), and cardiorespiratory parameters in dogs under the same anesthesia protocol. Twenty healthy female dogs were assigned to laparotomy OVE (LPTOVE, n = 10) and laparoscopic OVE (LAPOVE, n = 10) groups. OS was assessed using the total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI). Blood samples were collected prior to sedation (T0); prior to surgical incision (T1); prior to surgical closure in the LPTOVE group; and prior to the deflation of CO2 in the LAPOVE group (T2), 2 h after the surgery (T3). The monitored cardiorespiratory parameters were heart rate, respiratory rate, and end-tidal CO2 (EtCO2). Cortisol levels at T3 were markedly elevated in the LPTOVE group compared to the LAPOVE group. No substantial changes in TOS, TAS, or OSI between groups were detected. In the LAPOVE group, TOS diminished at T2, but TAS declined and OSI escalated at T3. EtCO2 levels were elevated in the LAPOVE group at the end of the procedure. These findings support laparoscopic OVE as a less traumatic alternative to open surgery, with careful management of PNP and anesthesia recommended to minimize postoperative stress.

Niukaslo liga - visame pasaulyje aktuali virusinė visų paukščių rūšių liga. Ji buvo primiršta ir nustelbta, kai maždaug 2000 m. pradėjo plisti labai patogeniškas paukščių gripo H5N1 potipis. Vis dėlto Niukaslo liga vėl priminė apie save, o 2026-ųjų pradžia nežada nieko gero.

Several studies have documented reverse zoonotic transmission of SARS-CoV-2, including in farmed mink which are susceptible to human respiratory viruses and are known for serving as a reservoir capable of generating new virus variants in densely populated farms. Here, we present the results of a genomic investigation launched in response to detected human infections with mink-origin SARS-CoV-2 lineages, and show evidence of at least 14 high-confidence introductions of SARS-CoV-2 from humans into farmed mink in Lithuania where sustained transmission in farmed mink lasted up to a year. We estimated the most likely timeframes for these introductions encompassing at least six SARS-CoV-2 lineages, some of which were already extinct in humans, with Bayesian phylogenetic and molecular clock analyses. This study highlights the public health risks posed by fur farms and underscores that passive genomic surveillance systems are ineffective without the active involvement and expertise of responsible institutions.

Continuing our work in the field of synthesis and research of amino acids, their derivatives, and cyclization products, in this work, we synthesized various 3-(6-bromo-2-oxo-1,3-benzoxazol-3(2H)-yl)propanoic acid derivatives and investigated their antimicrobial activity. A total of eighteen synthesized chemical compounds (No. 1–18), including several structural analogues (e.g., 3a, 3b, 4a–4e, 8a–8m, 9a–9d), were evaluated for their antibacterial properties. The antibacterial activity was assessed using the Kirby–Bauer disk diffusion method, and inhibition zone diameters (mm) were measured against five representative bacterial strains: S. aureus, MRSA, B. subtilis, E. coli, and P. aeruginosa. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the most active synthesized compounds were determined against representative Gram-positive and Gram-negative bacterial strains, including S. aureus, MRSA, B. subtilis, and E. coli. Overall, these results indicate that the tested compounds display selective antibacterial activity, mainly against Gram-positive bacteria, with compound 12 emerging as the most promising derivative in the series. The antibacterial activities of several synthesized compounds were systematically evaluated against S. aureus and MRSA over a 24 h incubation period, with optical density measured at ten time points. Bacterial growth was monitored spectrophotometrically at 600 nm (OD600) at 1, 2, 3, 4, 5, 6, 7, 8, 20, and 24 h, enabling a detailed assessment of growth kinetics and the temporal dynamics of inhibition. The effect of compound 11 on the growth kinetics of S. aureus was evaluated by quantifying viable bacterial counts (log10 CFU/mL) over a 6 h incubation period, and the results are presented in the time–kill curve. Compound 11 was selected for this experiment because it exhibited the most pronounced antibacterial activity against S. aureus in the disk diffusion assay. The cytotoxicity of compounds 9a, 11, 12, and 13 was evaluated at concentrations ranging from 125 to 1.95 µg/mL. The results showed a clear, concentration-dependent decrease in cytotoxicity for all tested compounds. The molecular structure of compound 3a was confirmed by a single-crystal X-ray diffraction.

Pathogens such as Toxoplasma gondii, lentiviruses (e.g., CAE), Hypoderma spp., Neospora caninum, Mycoplasma spp., and pestiviruses are important for goat farming in Lithuania; however, data on their prevalence remain limited. To address this gap, a multi-pathogen study was conducted between 2021 and 2024 using selected ELISA kits (ID.vet, Innovative Diagnostics, France). A total of 380 blood samples were collected from 30 goat herds across different regions of Lithuania; the sample size varied depending on the pathogen. Serum samples were tested for antibodies, and seroprevalence was calculated for each pathogen. The highest seroprevalence was detected for T. gondii (38.9%, 143/368) and CAE virus (19.5%, 74/380). Antibodies to Mycoplasma spp. (0.3%, 1/368), Hypoderma spp. (3.8%, 7/184), and N. caninum (0.5%, 2/368) were detected only sporadically, while no antibodies to Border disease virus or Q fever were identified. Mixed infections were found in 7.6% of samples. Chi-square analysis showed that co-infections with toxoplasmosis and CAE occurred more frequently than expected (χ2 = 19.05, p < 0.001). Herd size was significantly associated only with CAE seroprevalence (χ2 = 7.913, df = 1, p < 0.05). Overall, toxoplasmosis and CAE were identified as the most epidemiologically relevant infections in the Lithuanian goat population.

The anti-inflammatory scaffold 5-aminosalicylic acid, which is widely used in therapeutic applications, was chosen for the synthesis of N-[3-(hydrazinecarbonyl)-4-hydroxyphenyl]acetamide (1) to enhance its antibacterial properties. The condensation of hydrazide 1 with aromatic aldehydes provided hydrazone derivatives 2a–f, whereas cyclocondensation reactions and other related transformations afforded five-membered heterocycles, including pyrrole 3, pyrazole 4, pyrrolidinone 7, oxadiazoles 9, 10, thiadiazole 14, and triazole 15. Additional modifications yielded acetylhydrazine derivative 11, which was O-alkylated to analogue 12. Antibacterial evaluation showed stronger activity against Gram-positive bacteria such as S. aureus and MRSA than against Gram-negative strains of E. coli and S. Enteritidis, consistent with differences in cell membrane permeability. Notably, derivatives containing pyrrolidinone 7, thiosemicarbazide 13, and 1,3,4-thiadiazole 14 exhibited potent bactericidal activity against S. aureus and MRSA, while hydrazones 2b, 2c, 2f, pyrrole 3, and pyrrolidinone 7 exhibited activity against E. coli. These results provide a practical strategy for the discovery of heterocyclic compounds and emphasise the potential of functionalised 5-aminosalicylic acid derivatives as prime candidates for the development of broad-spectrum antibacterial agents.

Subclinical mastitis is a widespread condition in dairy cows, often treated with antibiotics. Due to rising antimicrobial resistance, natural alternatives like propolis are gaining interest.

Epilepsy is a common neurological disorder in cats, but its seizure types, etiologies, and clinical associations remain incompletely characterized compared to dogs. This retrospective study analyzed 118 feline epilepsy cases from two veterinary hospitals in Finland and Lithuania, aiming to evaluate the distribution of seizure types and their associations with demographic, clinical, neurological, diagnostic, and diagnostic test results. Seizures were classified as single generalized (SG), cluster seizures (CS), or status epilepticus (SE). SG and CS occurred with nearly equal frequency (44.9% and 45.8%, respectively), while SE was less common (9.3%). Median age at presentation was 72 months, and no significant differences were found in age, sex, reproductive status, or body weight between seizure types. Abnormal clinical findings (p = 0.009) and neurological abnormalities (p < 0.001) were significantly more frequent in cats with SE, indicating greater neurological compromise in severe seizure forms. MRI was performed in 74.6% of cases and revealed a significant difference in utilization among seizure types (p = 0.004), with lower imaging rates in SE, likely reflecting clinical instability at presentation. Etiology of seizure development was established in 89 cats: idiopathic epilepsy (IE) predominated (80.9%), followed by structural (15.7%) and metabolic/toxic (3.4%) causes. Seizure type and etiology were significantly associated (p = 0.006), with structural epilepsy most common in SE and idiopathic epilepsy prevailing in SG and CS. Among cats with known outcomes (n = 35), seizure control was achieved in 68.6%, while mortality and euthanasia were higher in SE. These findings provide new insight into feline epilepsy by linking seizure type to clinical and etiological profiles, emphasizing that severe presentations are more often associated with neurological abnormalities and structural causes, whereas demographic factors alone do not predict seizure severity.

Introduction

The increasing prevalence of viral diseases highlights the need for the destruction or inactivation of viruses on diverse material surfaces. While extensive research exists for human viruses, the interaction between metal surfaces and animal pathogens like BoHV-1 is not well understood. This study investigated the impact of copper (Cu), zinc (Zn), and iron (Fe) surfaces on the biological activity, virus, and viral DNA half-life time of BoHV-1.

Methods

MDBK-adapted BoHV-1 (strain 4016) was used to investigate the virucidal effect of copper, zinc, and iron surfaces. The virus was exposed for 1 and 24 hours under humid and dry conditions. Inactivation was evaluated by measuring the reduction in TCID50 log10, real-time PCR Ct values, and calculating half-lives for both the virus and its DNA.

Results

Herpesviruses were inactivated most rapidly on copper-coated surfaces in all cases. The virucidal effect after 1 hour of contact under humid and dry conditions was highly effective (3.25±0.29 log10 TCID50 and 4.5±0.1 log10 TCID50; p<0.01, p<0.05), with similar results after 24 hours under both conditions (4.5±0.25 log10 TCID50 and 4.5±0.1 log10 TCID50; p<0.05). Inactivation half-life time for the virus and viral DNA after 1 hour were shorter under dry conditions (4 minutes and 27 minutes) compared to humid conditions (6 minutes and 10 minutes). However, after 24 hours, inactivation half-life times were shorter under humid conditions (1 hour 31 minutes and 6 hours 20 minutes) compared to dry conditions (1 hour 36 minutes and 4 hours 7 minutes). Viral activity studies in cell culture correlated with real-time PCR, confirming copper’s strong effect on viral DNA under both conditions.

Conclusion

Copper surfaces demonstrated the highest virucidal activity against herpesviruses. The kinetics of inactivation were biphasic: while the immediate efficacy was higher after 1 hour under humid conditions, the long-term effect, considering both half-life measurements, proved to be superior in a dry environment.