Use of photodynamic therapy in the treatment of bovine subclinical mastitis

• Published in: Photodiagnosis and photodynamic therapy Vol. 21; pp. 246 - 251
• Main Authors: Moreira, Lívia Helena, de Souza, José Carlos Pereira, de Lima, Carlos José, Salgado, Miguel Angel Castillo, Fernandes, Adriana Barrinha, Andreani, Dora Inés Kozusny, Villaverde, Antonio Balbin, Zângaro, Renato Amaro
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2018
• Subjects: Animals; Bacillus - drug effects; Cattle; Cell Count; Corynebacterium - drug effects; Dairy cows; Disease of cows; Escherichia coli - drug effects; Female; Mastitis, Bovine - drug therapy; Mastitis, Bovine - microbiology; Milk - microbiology; Photochemotherapy - methods; Photosensitizer; Photosensitizing Agents - therapeutic use; Phototherapy; Red LED; Staphylococcus; Streptococcus - drug effects; Tolonium Chloride - therapeutic use; Veterinary medicine; Dairy cows; Veterinary medicine; Red LED; Disease of cows; Photosensitizer; Phototherapy
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2017.12.009

•It was investigated the efficacy of the PDT in the treatment of bovine subclinical mastitis.•The PDT was efficient in reduction of the microorganisms present in bovine subclinical mastitis.•The PDT was used in dairy farm routine without interfering in farm management.•The PDT allows a rapid return of dairy cattle with subclinical mastitis to dairy production.•The PDT is a promising alternative for subclinical bovine mastitis treatment. Bovine mastitis is a disease that causes a severe drawback in dairy production. Conventional treatments with antibiotic could leave antibiotic residues in the milk. The aim of this study was to evaluate the effect of photodynamic therapy in the treatment of bovine subclinical mastitis to develop an in vivo therapeutic protocol that could be used in routine farm practice, favoring the early return to production. Forty cows with subclinical mastitis (n = 40) were divided into 4 groups (control, photodynamic therapy – PDT, light irradiation – LED, and photosensitizer – PS). Control group received no treatment, PDT group received application of 1.0 mL of 2.5% toluidine blue photosensitizer followed by LED irradiation at λ = 635 nm, the LED group was treated with LED irradiation alone, and the PS group received only 2.5% toluidine blue dye. LED irradiation was applied to the mammary gland by means of an acrylic light guide coupled to the LED equipment. The PDT and LED groups were irradiated with 200 J/cm2 at three different positions inside the mammary gland. Milk samples were collected at 0 h, 12 h, 24 h after treatment for microbial identification and total bacterial count. The treatment of the PDT group showed significant difference p < 0.05, characterizing the efficiency of this technique with the reduction of the microorganisms Streptococcus dysgalactiae and coagulase-negative Staphylococcus. Photodynamic therapy was effective when applied in vivo for subclinical bovine mastitis. There was no need to separate the animal from production.