The emergence of drug-resistant bacteria has impacted the outcome of current therapeutics as a threat to global healthcare; novel medicines are urgently needed. Thirteen medicinal plants were collected in Northeastern Thailand, and their crude ethanolic extracts were evaluated for antibacterial activities against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922 using the broth micro-dilution method. Piper betle leaf ethanolic extract showed optimal activity against both representative bacterial strains. Activity was also observed against clinical isolates of methicillin-resistant S. aureus (MRSA) and E. coli, with minimal inhibitory concentration (MIC) ranging from 0.31 mg/mL to 2.5 mg/mL and minimal bactericidal concentration (MBC) ranging from 0.62 mg/mL to 2.5 mg/mL. A time-kill study revealed that the extract activity was time- and dose-dependent, and also bactericidal on the tested bacteria. P. betle extract inhibited biofilm formation and promoted biofilm eradication in both S. aureus and E. coli. 4-Allyl-1,2-diacetoxybenzene and eugenol were identified as the most abundant compounds in the extract and may play major roles in the anti-bacterial and anti-biofilm activity. Results suggest that ethanolic P. betle leaf extract shows promise as an alternative method for the prevention of bacterial diseases.

Sericin, a natural protein from silk cocoon, has been reported for various biological properties in the biomaterials field. Modified forms of sericin have been studied for bone tissue engineering, while its unmodified form has been scarcely reported. Therefore, the purpose of this study was to evaluate physical and biological properties of unmodified sericin for potential use in bone surgery. Sericin was extracted from silk cocoons using a chemical-free boiling method. Sericin extract showed distinct bands with molecular weight ranging from 25 to 42 kDa including smear bands. Fourier transform infrared spectra presented characteristic peaks of amide I, II, and III, confirming the chemical composition of sericin. Based on biological activity, sericin extract at a concentration of 40 μg/mL increased the proliferation of osteoblast cells up to 135%, compared with the untreated control. Moreover, increase in antibacterial activity against Staphylococcus aureus, both clinical isolates and the reference strain ATCC 29213, was demonstrated for sericin extract with normal saline, while no antibacterial activity was observed for sericin with broth. It was found that sericin with normal saline showed higher zeta potential than sericin without normal saline, indicating higher system stability. This was confirmed by the average particle size of sericin extract with NaCl (3,249.3±226.1 nm) showing approximately 10 times smaller than sericin solution (29,015.9 ± 8,085.6 nm). Furthermore, sericin extract at the minimal inhibitory concentration significantly reduced the biofilm formation of S. aureus up to 95%. The study indicates biological activities of sericin, which could be applied as a dual-functional bioactive material to support bone regeneration and treat bone infections.

Staphylococcus pseudintermedius is a zoonotic pathogen that can cause life-threatening infections in animals and humans. The study of methicillin-resistant S. pseudintermedius (MRSP) and its ability to produce biofilms is important to select the most suitable treatment. The prevalence and characteristics of S. pseudintermedius isolated from dogs admitted at the Veterinary Teaching Hospital, Prince of Songkla University, Thailand were assessed. Results showed that 28.30% (15/53) of the isolates were MRSP. Amplification of the mecA gene was observed in 93.33% (14/15) MRSP. Methicillin-resistant strains revealed co-resistant patterns against other antibiotics, including chloramphenicol, clindamycin, tetracycline, clarithromycin, ciprofloxacin, and trimethoprim. In this study, all bacterial isolates produced biofilms, while 90.55% of S. pseudintermedius isolates were strong or moderate biofilm producers. Most (45–60%) of the resistant strains were strong biofilm producers, while the correlation between biofilm production and antibiotic resistance was not statistically significant. This is the first study in southern Thailand to investigate the drug-resistant profile of S. pseudintermedius and its ability to form biofilm. The results will contribute to a better understanding of the emergence and prevalence of antimicrobial resistance in S. pseudintermedius.

The development of effective wound dressings remains a critical challenge in medical treatments, requiring materials that promote healing, minimize infection, and enhance tissue regeneration. This study evaluated the wound-healing potential of sericin-based film-forming gels. Six formulations were developed by combining varying concentrations of sericin, a protein derived from silk cocoons, with polyvinyl alcohol (PVA). These formulations were evaluated for physical properties including drying time, pH, spreadability, stability, swelling ratio, flexibility, and adhesion. Film-forming gel is an attractive option for wound dressing due to its flexibility, adhesion, and infrequent reapplication. The F4 formulation (1% sericin) demonstrated superior performances in drying time, spreadability, stability, swelling ratio, flexibility, and skin adhesion, was easy to apply, and formed a stable film on drying. Biological evaluations showed that F4 exhibited excellent compatibility with skin fibroblast cells, maintained a suitable pH, and significantly promoted cell proliferation and migration. The F4 formulation also demonstrated anti-inflammatory effects by inhibiting iNOS expression and nitric oxide production, offering mechanical stability, biological activity, and ease of use with significant potential for treating acute and chronic wounds.