Antimicrobial activity of cell-free supernatant derived from Ligilactobacillus animalis SWLA-1 in a novel ex vivo canine corneal infection model.

Introduction: Canine bacterial keratitis is a corneal infection that causes various symptoms, including visual impairment, and necessitates eye removal in severe cases. Staphylococcus pseudintermedius is a pathogen that causes significant bacterial keratitis in canine patients. Moreover, multi-drug resistant Staphylococcus pseudintermedius (MDRSP) has been reported in both humans and animals. Regarding treatment failure against multi-drug resistant (MDR) pathogens with classic antibiotics, antimicrobial compounds derived from probiotics have been suggested as an alternative approach. Methods: Ligilactobacillus animalis SWLA-1 strain and its cell-free supernatant (CFS) have previously demonstrated potent antimicrobial activity against various MDR pathogenic bacteria. Based on this finding, we evaluated the anti-staphylococcal activity of CFS derived from Ligilactobacillus animalis SWLA-1 against MDRSP in a newly established ex vivo canine corneal infection model using fresh canine corneoscleral rims. Additionally, an in vitro cytotoxicity test using human keratocytes was performed. Results and Discussion: CFS significantly inhibited the growth of MDRSP in the novel ex vivo model and did not exhibit any significant toxicity against keratocytes in vitro. Based on these results, the antimicrobial compounds in CFS show potential as a novel approach for MDR staphylococcal keratitis treatment.

Extracellular matrix-based sticky sealants for scar-free corneal tissue reconstruction.

Regenerative medicine requires both tissue restoration and ease of compliance for clinical application. Considering this, sticky tissue sealants have been shown to have great potentials over surgical suturing and wound treatment. However, tissue sealants currently used pose challenges such as uncontrollable adhesion formation, mechanical mismatch, and lack of tissue restoration. A new sticky sealant based on gelatinized cornea-derived extracellular matrix (GelCodE) with a visible light-activating system is firstly being introduced in this study. De novo tissue regeneration relies on the matrisome in charge of tissue-organization and development within GelCodE while visible light-based photopolymerization with ruthenium/sodium persulfate rapidly induces covalent bonds with the adjacent tissues. The ease of not only in vivo application, biocompatibility, and biointegration, but also exceptional de novo tissue formation is demonstrated in this study. Interestingly, newly regenerated tissues were shown to have normal tissue-like matrices with little scar formation. Hence, this work presents a promising strategy to meet clinical demands for scar-free tissue recovery with superior ease of clinical application.

Dacryoendoscopy for dacryocystitis management in a dog: A case report.

A castrated, mixed-breed, 10-year-old male dog developed a skin fistula from a ruptured periorbital swelling on the right eye; the patient was successfully treated with dacryoendoscope-guided cannulation using a nasolacrimal tube. On presentation, computed tomography with concurrent dacryocystography (CT-DCG) revealed obstruction of the right nasolacrimal duct and abnormal flow of contrast agents towards the root of tooth 109 at the right maxillary bone; however, the origin of the fistula remained unclear on CT-DCG. Dacryoendoscopy was used to confirm the physical association between the fistula and the nasolacrimal duct; the fistula end was found to be near the right upper gum mucosa around tooth 107. CT-DCG and dacryoendoscopy revealed that the periorbital swelling occurred owing to an infection or inflammation of the accessory nasolacrimal duct. The fistula end was connected to the oral cavity through a nasolacrimal tube installed in the oral mucosa. The tube was removed a week later, and the clinical symptoms completely resolved.