Impact of Environmental Factors on Bacteriocin Promoter Activity in Gut-Derived Lactobacillus salivarius.

Bacteriocin production is regarded as a desirable probiotic trait that aids in colonization and persistence in the gastrointestinal tract (GIT). Strains of Lactobacillus salivarius, a species associated with the GIT, are regarded as promising probiotic candidates and have a number of associated bacteriocins documented to date. These include multiple class IIb bacteriocins (salivaricin T, salivaricin P, and ABP-118) and the class IId bacteriocin bactofencin A, which show activity against medically important pathogens.

The Lantibiotic Lacticin 3147 Prevents Systemic Spread of Staphylococcus aureus in a Murine Infection Model.

The objective of this study was to investigate the in vivo activity of the lantibiotic lacticin 3147 against the luminescent Staphylococcus aureus strain Xen 29 using a murine model. Female BALB/c mice (7 weeks old, 17 g) were divided into groups (n = 5) and infected with the Xen 29 strain via the intraperitoneal route at a dose of 1 × 10(6) cfu/animal. After 1.

Bioengineering of a Nisin A-producing Lactococcus lactis to create isogenic strains producing the natural variants Nisin F, Q and Z.

Nisin is the prototypical example of the lantibiotic family of antimicrobial peptides and has been employed as a food preservative for over half a century. It has also attracted attention due to its potency against a number of multidrug-resistant clinical pathogens. Nisin A is the originally isolated form of Nisin and a further five natural variants have been described which differ by up to 10 amino acids (of 34 in total in Nisin A).

A comparison of the activities of lacticin 3147 and nisin against drug-resistant Staphylococcus aureus and Enterococcus species.

Objectives: Our goal was to compare the activities of lacticin 3147 and nisin, two of the most well characterized lantibiotics, against antibiotic-resistant staphylococci and enterococci.

Methods: We determined the MICs of lacticin 3147 and nisin for 20 strains of methicillin-resistant Staphylococcus aureus (MRSA), 20 strains of vancomycin-resistant enterococci (VRE), 6 strains of S. aureus with intermediate resistance to vancomycin (VISA), 5 strains of heterogeneous vancomycin-intermediate S.

Discovery of medically significant lantibiotics.

The emergence of drug-resistant pathogens such as staphylococci and enterococci in the hospital setting has long being recognized as a serious clinical problem. Staphylococcus aureus is the causative agent of many nosocomial infections from minor skin abscesses to serious, potentially life threatening diseases such as bone and soft tissue intra-surgical infections, sepsis and invasive endocarditis, while enterococci are responsible for nosocomial bacteraemia, surgical wound infections and endocarditis. The most infamous drug-resistant forms of these include MRSA (methicillin resistant S.

Isolation and analysis of bacteria with antimicrobial activities from the marine sponge Haliclona simulans collected from Irish waters.

Samples of the marine sponge Haliclona simulans were collected from Irish coastal waters, and bacteria were isolated from these samples. Phylogenetic analyses of the cultured isolates showed that four different bacterial phyla were represented; Bacteriodetes, Actinobacteria, Proteobacteria, and Firmicutes. The sponge bacterial isolates were assayed for the production of antimicrobial substances, and biological activities against Gram-positive and Gram-negative bacteria and fungi were demonstrated, with 50% of isolates showing antimicrobial activity against at least one of the test strains.