Aquaculture has grown significantly, contributing to global food security and sustainability; however, intensified fish farming has increased disease susceptibility and antibiotic resistance. This study assessed the probiotic potential of Lactobacillus plantarum PSCPL13 (hereafter, PSCPL13), isolated from the intestines of Japanese eels, for enhancing the health of olive flounder. After screening 16 Lactobacillus isolates, PSCPL13 was selected because of its potential broad-spectrum antibacterial activity against many pathogens, such as Vibrio and Edwardsiella. This strain exhibited high acid and bile salt tolerance, which is crucial for intestinal survival. Molecular characterisation confirmed PSCPL13 to be L. plantarum. It was resistant to all tested antibiotics and exhibited significant enzyme activity. In vivo assays in olive flounder revealed that the body weight and length of the fish were significantly higher, while the prevalence of pathogens was lower in their gut microbiota. Regarding haematological parameters, the treated groups exhibited lower eosinophil counts and higher IgM levels, suggesting enhancement of the immune system. These findings indicate that PSCPL13 is a potential probiotic that can be used in aquaculture for naturally improving fish health, growth and immunity, in addition to combating antibiotic resistance and reducing environmental impacts. These findings not only highlight the potential of PSCPL13 in sustainable aquaculture but also provide a foundation for the development of future probiotics.

The growing challenge of antibiotic resistance and inflammation-related disorders calls for safe, multi-target therapeutic strategies. Morus alba (MOAL) and Pinus densiflora (PIDE) are known for their medicinal properties, yet their combined potential with methyl gallate (MG) has not been fully explored. In this study, the phytochemical composition of MOAL and PIDE was characterized using GC–MS, and their combined antimicrobial, antioxidant, and anti-inflammatory activities were evaluated. Hydroethanolic extracts were prepared and assessed for antioxidant activity (DPPH assay), antibacterial activity (disk diffusion, MIC, time kill), and nitric oxide (NO) suppression in Lipopolysaccharide (LPS)-stimulated macrophages, alongside MTT cytotoxicity screening. MOAL exhibited a higher extraction efficiency, reaching 500 mg/mL at 4 h, whereas Pinus achieved 450 mg/mL at the same time point. Both exhibited a diverse and abundant phytochemical profile. The optimized blend (MOAL:PIDE:MG, 1:1:0.1) demonstrated significantly enhanced bioactivity, with over 90% DPPH scavenging with the low IC₅₀ value (66.62 mg/mL), potent inhibition of both Gram-positive and Gram-negative bacteria, and the strongest effect against Staphylococcus aureus (264 μg/mL). Time-kill assays confirmed rapid bactericidal action, and NO production was reduced by approximately 75% without cytotoxicity. Molecular docking identified a lead multi-target compound exhibiting strong binding affinities to COX-2, TNF-α, and Keap1, supporting its observed anti-inflammatory and antioxidant potential. These findings highlight the promise of synergistic phytochemical formulations as broad-spectrum, multifunctional therapeutic candidates, supporting further in vivo and clinical validation.

The rising threat of antimicrobial resistance (AMR) is a global concern in both human and veterinary medicine, with multidrug-resistant (MDR) pathogens such as Staphylococcus aureus and Staphylococcus pseudintermedius presenting significant challenges. Background/Objectives: This study evaluates the effectiveness of amoxicillin against these MDR pathogens in canine isolates using pharmacokinetic and pharmacodynamic parameters. Methods: Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and mutation prevention concentration (MPC) were assessed. Additionally, time-kill assays and post-antibiotic effect (PAE) assessments were performed. Epidemiological cutoff (ECOFF) values were established for both species to guide therapy. Results: S. aureus had a higher resistance rate (35.89%) than S. pseudintermedius (15.27%), with MIC50 values of 0.50 μg/mL and 0.25 μg/mL, respectively. The MPC analysis revealed that S. pseudintermedius required higher antibiotic concentrations (16.11 μg/mL) to prevent mutations compared to S. aureus (2.20 μg/mL). Time-kill assays indicated that higher amoxicillin dosages caused faster bacterial reduction. The PAE analysis showed extended post-treatment bacterial suppression at elevated doses, particularly against S. aureus. Conclusions: Species-specific amoxicillin dosing strategies are necessary due to differing resistance and susceptibility profiles between S. aureus and S. pseudintermedius. High-dose amoxicillin therapy is recommended to achieve optimal therapeutic outcomes for resistant SA, while slightly adjusted dosing can manage S. pseudintermedius infections. These findings provide essential insights for veterinary antimicrobial stewardship, underscoring the need for tailored therapeutic approaches to minimize AMR development while ensuring effective infection control.

Background/Objectives: The growing number of households with companion dogs raises concerns. Co-living environments between companion dogs and their owners are linked to a heightened risk of cross-infections from strains such as Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Salmonella, and faecal coliforms. Therefore, this study aims to propose measures for healthy cohabitation by analysing the faecal microbiota of puppies and adult dogs. Methods: We isolated lactic acid bacteria (LAB) from their faeces and assessed their potential to inhibit E. coli, S. aureus, and Salmonella spp. Faecal samples from puppies (12 months old) were analysed and compared. Results: The analysis revealed that Lactobacillus dominated puppy faeces, while Bacteroidetes were more abundant in adult dogs. In total, 109 primary LAB candidates were isolated from faecal samples. These isolates underwent secondary screening for acid tolerance, bile salt resistance, acid production, heat resistance, protease activity, and antimicrobial activity against E. coli, S. aureus, and Salmonella spp. Five secondary LAB candidates with probiotic potential were further characterised via morphological and genetic analysis. All five strains were Lactobacillus reuteri, with L. reuteri JJ37, JJ68, JJ69, JJ71, and JJ77 emerging as the final probiotic candidates. Conclusions: They promote healthier cohabitation between dogs and their owners.

The global increase in livestock production has correspondingly intensified farm odors due to harmful bacteria, reduced immunity, and disease progression. In this study, we treated feces with Biomagic-Enzyme complex for 4 months to understand the relationship between farm odor, immunity against common viral diseases, immune cytokines, and changes in the microbiota. A gas meter (MultiRAE) was used to measure ammonia (NH3) and hydrogen sulfide (H2S) while odor intensity and offensiveness were characterized by the non-objective scaling method. A complete blood count was performed and plasma was obtained after blood centrifugation at 3,000 rpm for 20 minutes. The cytokine profile was evaluated using commercial kits. Microbial DNA was extracted and purified from fecal samples to analyze the microbiota. Microbial DNA and viral RNA/DNA were obtained from fecal samples and amplified to determine the expression of transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome (PRRS), and porcine circovirus type 2 (PCV2). Our results indicated that Biomagic reduced odor nuisance by decreasing ammonia levels, resulting in faint and fairly offensive odor intensity. After the enzyme treatment, Escherichia coli populations significantly reduced across all 3 farms. In contrast, beneficial Lactobacillus spp. levels remained stable, indicating the enzyme selectively targeted harmful bacteria while preserving beneficial ones. The beneficial Lachnospiraceae, Spirochaetaceae, and Bacteroidaceae were found to be higher in the third month of treatment. TGEV was not detected, while PRRS and non-pathogenic PCV2 showed a positive infection rate. In conclusion, Biomagic reduced ammonia, prevented viral infection from pig farms, and improved gut-beneficial bacteria and microbiota.

Employing affordable and uncomplicated sample preparation techniques to recommend the most efficient antibacterial therapy could help reduce antibiotic-resistant bacteria. This study evaluated the suitability of immunoassays and microbiological assays as alternatives for liquid chromatography/mass spectrometry (LC/MS) in determining plasma tylosin concentrations after intramuscular administration at a dose of 20 mg/kg to both healthy and diseased pigs in clinical veterinary practice. The diseased pigs were confirmed using the target genes Actinobacillus pleuropneumoniae (apxIVA) and Pasteurella multocida (kmt1). The methods showed good linearity, precision, and accuracy. In both healthy and diseased pigs, a significant correlation was observed between LC/MS and the microbiological assay (Pearson correlation coefficient: 0.930, p < 0.001 vs. Pearson correlation coefficient: 0.950, p < 0.001) and between LC/MS and the enzyme-linked immunosorbent assay (ELISA) (Pearson correlation coefficient: 0.933; p < 0.001 vs. Pearson correlation coefficient: 0.976, p < 0.001). A strong correlation was observed between the microbiological assay and the ELISA in both healthy and diseased pigs (Pearson correlation coefficient: 0.911; p < 0.001 vs. Pearson correlation coefficient: 0.908, p < 0.001). A Bland-Altman analysis revealed good agreement between the methods, i.e., 95% of the differences were within the limits of agreement. Therefore, the microbiological assay and the ELISA, which demonstrated sufficient precision and accuracy, can be viable alternatives to LC/MS when it is unavailable.