Occurrence of bacteriocin production among environmental enterococci

Area of Science:

• Microbiology
• Environmental Science
• Food Safety

Background:

• Enterococci are common bacteria found in animal feces.
• Their presence in agricultural environments can have implications for public health and food safety.
• Bacteriocin production by enterococci is of interest for antimicrobial applications.

Purpose of the Study:

• To investigate the occurrence and species distribution of enterococci in cattle dung water in northeastern Slovakia.
• To screen enterococcal isolates for bacteriocin production and characterize their antimicrobial activity.
• To identify potential sources of antimicrobial compounds from enterococci.

Main Methods:

• Sampling of cattle dung water from 25 farms in 15 districts of northeastern Slovakia.
• Cultivation and identification of enterococcal species using standard microbiological techniques.
• Assay of bacteriocin production and characterization of antimicrobial activity against indicator bacteria, including Gram-negative species.
• Determination of optimal production conditions (pH) and substance properties (heat stability, hydrophobicity).

Main Results:

• Enterococci were detected in cattle dung water with an average count of 5.0 x 10^3 cfu/ml.
• Enterococcus faecium was the predominant species (25%), followed by Ent. casseliflavus (19.2%) and Ent. faecalis (9.6%).
• Many isolates exhibited antagonistic activity, primarily against Listeria species.
• A specific Enterococcus faecalis V24 strain produced a heat-stable, hydrophobic antimicrobial substance effective against Gram-negative bacteria within a pH range of 4-7.

Conclusions:

• Cattle dung water serves as a reservoir for various enterococcal species.
• Enterococcal isolates possess antimicrobial properties, with potential applications in controlling Gram-negative pathogens.
• The Enterococcus faecalis V24 strain is a promising source of novel antimicrobial agents.