Screening and estimation of antibacterial activity of bacteriocins produced by Enterococcus faecium LR isolated from raw horse milk samples.

This study focused on isolating and estimating the antibacterial properties of bacteriocins created by Lactic acid bacteria sourced from horse milk in Jeddah city, Saudi Arabia. Out of the 16 isolates tested, 12 demonstrated an ability to inhibit both Gram-positive and Gram-negative pathogenic bacteria, with one isolate (H6) matching Enterococcus faecium LR135401.1 completely and producing the highest bacteriocin.

About the Study

• This research focused on isolating, characterizing, and estimating the production of bacteriocins of Lactic Acid Bacteria (LAB). Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains. LAB are microorganisms found in meat, milk, fermented drinks, and vegetables. They have an ability to inhibit the growth of harmful, pathogenic, and decaying microorganisms.
• LAB samples were isolated from raw horse milk located in Jeddah city, Saudi Arabia. This provided a geographic context and a unique sample source.

Methodology and Findings

• LAB isolates were screened, cultured, and tested against pathogenic bacteria such as S. aureus, ST. Pneumonia, E. coli, and P. aeruginosa using the agar well diffusion method. This method is typically used to test the effectiveness of certain substances against bacteria.
• Out of 16 isolates that were observed, 12 of them—or, 75%—were successful in inhibiting all types of pathogenic bacteria which were used in the testing.
• The most effective isolate was identified and measured to be consistent with Enterococcus faecium LR135401.1. Enterococcus faecium is a high-level resistant bacterium that is often present in the human gut. This isolate was found to produce the highest amount of bacteriocin under specific conditions—35°C temperature, 24 hours, and at a pH of 6.5.

Conclusion

• The study resulted in significant findings, identifying 12 of 16 LAB isolates as having inhibitive properties against pathogenic bacteria which are significant to human health. This suggests that bacteriocins from these LAB farms could be utilized in the development of antibacterial components in both agricultural and clinical applications.
• The most successful isolate, identified as Enterococcus faecium LR135401.1, could offer potential benefits for the treating and preventing of infectious diseases, food production, and the development of probiotics. Further study in this area could lead to advancements in the ongoing battle against antibiotic resistance in medicine.