Ozone preparations on microorganisms responsible for endometritis in mares

I find this exciting because ozone-enriched air is currently commercially available, low-cost, and has a very wide spectrum of activity. Throw in the lack of antibiotics and all the downsides associated with them, and the probable tolerability of the procedure, and this looks like a winner. We need some in vivo studies to check the feasibility, proper in-vivo dosages, and tolerance of the endometrium to ozone.
DrO

In vitro effects of different ozone preparations on microorganisms responsible for endometritis in the mare
Theriogenology. 2024 Apr 15:219:132-137. doi: 10.1016/j.theriogenology.2024.02.011. Epub 2024 Feb 15.
Authors
Gian Guido Donato 1 , Patrizia Nebbia 1 , Maria Cristina Stella 1 , Daniela Scalas 1 , Denis Necchi 2 , Alessia Bertero 3 , Giovanna Romano 4 , Lara Bergamini 5 , Mariagrazia Lucia Poletto 1 , Andrea Peano 1 , Patrizia Robino 1 , Tiziana Nervo 1
Affiliations

1 Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, 10095, Grugliasco, Italy.
2 Keros Embryo Transfer Center, Westrozebekestraat 23A, 8980, Passendale, Belgium.
3 Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, 10095, Grugliasco, Italy. Electronic address: alessia.bertero@unito.it.
4 Centro Equino Arcadia, Frazione Mottura 106, 10068, Villafranca Piemonte, Italy.
5 Allevamento Le Fontanette, Via Fontanette 12, 10067, Vigone, Italy.

PMID: 38430797
DOI: 10.1016/j.theriogenology.2024.02.011

Free article
Abstract

Infectious endometritis is considered one of the major causes of infertility and it can affect up to 60% of barren mares. It is characterized by the presence of one or more microorganisms in the reproductive tract and it is treated with the administration of antibiotics, ecbolic agents and uterine lavages. Ozone, thanks to its antimicrobial properties that are based on its high oxidative potential, could represent an effective alternative treatment for endometritis. The aim of this study was to test in vitro the bactericidal and fungicidal properties of different ozone formulations, either as gas (experiment 1) or dissolved in two liquid matrices (experiment 2), specifically distilled water or oil (Neozone 4000, Cosmoproject, Parma, Italy), onto 6 different species of microorganisms isolated from mares with clinical endometritis, namely Escherichia coli, Staphylococcus aureus, Streptococcus equi subsp. Zooepidemicus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. In the first experiment, 3 clinical antibiotic-resistant strains per each species were exposed to different conditions: to O2O3 gas mixtures (15 and 40 μg/ml for 1, 3 and 5 min), to 100 % O2 or left untreated. The results showed a reduction of the microbial count of over 99,9% for every pathogen, time and concentration of O2O3 gas mixtures tested. Furthermore, gaseous ozone showed both a time-dependant effect (5 vs 3 vs 1 min of exposure) and a concentration-dependant effect (40 vs 15 μg/ml) at 1 and 3 min, while after 5 min no differences were observed. In the second experiment, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC, MFC) of ozonated distilled water and ozonated oil were evaluated. Ozonated oil showed a bactericidal/fungicidal activity against all the strains tested (MIC range 12.5-25 % v/v, MBC/MFC range 12.5-50 % v/v) while ozonated distilled water didn’t show an observable antimicrobial effect, discouraging its use as an antimicrobial agent for the treatment of endometritis. The results of this in vitro study indicate that both gaseous ozone and ozonated oil exerted remarkable antimicrobial activities and are promising alternative treatments for infectious endometritis, even when caused by antibiotic-resistant bacteria, and encourage further experiments in an effort to scale down or even prevent the use of antibiotics in equine reproduction.

Keywords: Antimicrobial activity; Endometritis; In vitro; Infertility; Mare; Ozone.

Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.