Antimicrobial behavior of phage endolysin PlyP100 and its synergy with nisin to control Listeria monocytogenes in Queso Fresco.

Hispanic-style fresh cheeses, such as Queso Fresco (QF), have been linked to numerous listeriosis outbreaks in the United States. In this work, we have studied the antilisterial behavior and effectiveness of the Listeria phage endolysin PlyP100 in QF, as well as the potential synergy between PlyP100 and nisin. PlyP100 showed similar bacterial reduction regardless of varying L.

Hot topic: Antilisterial activity by endolysin PlyP100 in fresh cheese.

Our objective was to assess the antimicrobial efficacy of a Listeria bacteriophage endolysin that may address limitations of current antilisterial processes for fresh cheeses. Listeria monocytogenes is highly problematic in the manufacture and processing of ready-to-eat foods due to its environmental persistence and its ability to grow under refrigerated storage. Special care must be taken to prevent listerial contamination during the production of fresh cheeses, as their delicate flavor and texture are incompatible with many of the antimicrobial processes and additives commonly used for other foods.

Creative lysins: Listeria and the engineering of antimicrobial enzymes.

Cell wall lytic enzymes have been of increasing interest as antimicrobials for targeting Gram-positive spoilage and pathogenic bacteria, largely due to the development of strains resistant to antibiotics and bacteriophage therapy. Such lysins show considerable promise against Listeria monocytogenes, a primary concern in food-processing environments, but there is room for improvement via protein engineering. Advances in antilisterial applications could benefit from recent developments in lysin biotechnology that have largely targeted other organisms.

Myrosinase-dependent and -independent formation and control of isothiocyanate products of glucosinolate hydrolysis.

Brassicales contain a myrosinase enzyme that hydrolyzes glucosinolates to form toxic isothiocyanates (ITC), as a defense against bacteria, fungi, insects and herbivores including man. Low levels of ITC trigger a host defense system in mammals that protects them against chronic diseases. Because humans typically cook their brassica vegetables, destroying myrosinase, there is a great interest in determining how human microbiota can hydrolyze glucosinolates and release them, to provide the health benefits of ITC.

Maternal fucosyltransferase 2 status affects the gut bifidobacterial communities of breastfed infants.

Background: Individuals with inactive alleles of the fucosyltransferase 2 gene (FUT2; termed the 'secretor' gene) are common in many populations. Some members of the genus Bifidobacterium, common infant gut commensals, are known to consume 2'-fucosylated glycans found in the breast milk of secretor mothers. We investigated the effects of maternal secretor status on the developing infant microbiota with a special emphasis on bifidobacterial species abundance.

Glycan-specific whole cell affinity chromatography: A versatile microbial adhesion platform.

We have sought a universal platform for elucidating and exploiting specificity of glycan-mediated adhesion by potentially uncharacterized microorganisms. Several techniques exist to explore microbial interactions with carbohydrate structures. Many are unsuitable for investigating specific mechanisms or uncharacterized organisms, requiring pure cultures, labeling techniques, expensive equipment, or other limitations such as questionable stability, stereospecificity, or scalability.

Lactobacillus adhesion to mucus.

Mucus provides protective functions in the gastrointestinal tract and plays an important role in the adhesion of microorganisms to host surfaces. Mucin glycoproteins polymerize, forming a framework to which certain microbial populations can adhere, including probiotic Lactobacillus species. Numerous mechanisms for adhesion to mucus have been discovered in lactobacilli, including partially characterized mucus binding proteins.

Sinorhizobium meliloti CheA complexed with CheS exhibits enhanced binding to CheY1, resulting in accelerated CheY1 dephosphorylation.

Retrophosphorylation of the histidine kinase CheA in the chemosensory transduction chain is a widespread mechanism for efficient dephosphorylation of the activated response regulator. First discovered in Sinorhizobium meliloti, the main response regulator CheY2-P shuttles its phosphoryl group back to CheA, while a second response regulator, CheY1, serves as a sink for surplus phosphoryl groups from CheA-P. We have identified a new component in this phospho-relay system, a small 97-amino-acid protein named CheS.