Susceptibility to Nisin, Bactofencin, Pediocin and Reuterin of Multidrug Resistant Staphylococcus aureus, Streptococcus dysgalactiae and Streptococcus uberis Causing Bovine Mastitis

• Published in: Antibiotics (Basel) 2021-11, Vol.10 (11), p.1418
• Main Authors: Bennett, Samantha, Ben Said, Laila, Lacasse, Pierre, Malouin, François, Fliss, Ismail
• Format: Article
• Language: English
• Subjects: 3-Hydroxypropionaldehyde; alternative to antibiotics; Antibiotic resistance; Antibiotics; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Bacteria; Bacterial diseases; bacteriocin; Bacteriocins; Cattle; Clinical isolates; Dairy cattle; dairy cows; Dairy industry; Drug resistance; Gram-positive bacteria; Infections; Infectious diseases; intramammary infection; Mastitis; Microorganisms; Milk; Minimum inhibitory concentration; Multidrug resistance; Nisin; Pathogens; Pediocin; Penicillin; reuterin; Staphylococcus aureus; Staphylococcus infections; Strains (organisms); Streptococcus
• ISSN: 2079-6382; 2079-6382
• DOI: 10.3390/antibiotics10111418

Antibiotics are the most effective strategy to prevent and treat intramammary infections. However, their misuse has led to the dissemination of multidrug resistant bacteria (MDR) for both animals and humans. Efforts to develop new alternative strategies to control bacterial infections related to MDR are continuously on the rise. The objective of this study was to evaluate the antimicrobial activity of different bacteriocins and reuterin against MDR Staphylococcus and Streptococcus clinical isolates involved in bovine mastitis. A bacterial collection including S. aureus (n = 19), S. dysgalactiae (n = 17) and S. uberis (n = 19) was assembled for this study. Antibiotic resistance profiles were determined by the disk diffusion method. In addition, sensitivity to bacteriocins and reuterin was evaluated by determining minimum inhibitory concentrations (MIC). A total of 21 strains (37.5%) were MDR. MICs ranged from ≤1.0 μg/mL to ≥100 μg/mL for nisin and 2.0 to ≥250 μg/mL for bactofencin. Reuterin was active against all tested bacteria, and MICs vary between 70 and 560 μg/mL. Interestingly, 20 MDR strains were inhibited by bactofencin at a concentration of ≤250 μg/mL, while 14 were inhibited by nisin at an MIC of ≤100 μg/mL. Pediocin did not show an inhibitory effect.