Use of photodynamic therapy in the treatment of bovine subclinical mastitis.

Abstract

BACKGROUND:

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.

METHODS:

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.

RESULTS:

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.

CONCLUSION:

Photodynamic therapy was effective when applied in vivo for subclinical bovine mastitis. There was no need to separate the animal from production.

• Authors: Lívia Helena Moreira, José Carlos Pereira de Souza, Carlos José de Lima, Miguel Angel Castillo Salgado, Adriana Barrinha Fernandes, Dora Inés Kozusny Andreani, Antonio Balbin Villaverde, Renato Amaro Zângaro
• Journal: Photodiagnosis and photodynamic therapy (Photodiagnosis Photodyn Ther) Vol. 21 Pg. 246-251 (Mar 2018) ISSN: 1873-1597 [Electronic] Netherlands
• PMID: 29258951 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• Photosensitizing Agents
• Tolonium Chloride

Topics

• Animals
• Bacillus (drug effects)
• Cattle
• Cell Count
• Corynebacterium (drug effects)
• Escherichia coli (drug effects)
• Female
• Mastitis, Bovine (drug therapy, microbiology)
• Milk (microbiology)
• Photochemotherapy (methods)
• Photosensitizing Agents (therapeutic use)
• Staphylococcus
• Streptococcus (drug effects)
• Tolonium Chloride (therapeutic use)