Synergistic antimicrobial activity of lynronne-1 and EDTA against bovine mastitis pathogens.

Background: Bovine mastitis is the costliest disease in the dairy sector and the main cause of antibiotic use in dairy cattle, potentially contributing to the antimicrobial resistance crisis. Antimicrobial peptides (AMPs) offer promise as antibiotic alternatives for controlling mastitis pathogens.

Methods: The efficacy of five AMPs (Lynronne-1 [Lyn-1], Lynronne-2 [Lyn-2], Bovicin HC5, AMP 660, and AMP 1043) and two bioactive compounds (disodium ethylenediaminetetraacetic acid [EDTA] and glycerol monolaurate) was assessed against a range of 35 mastitis-causing pathogens.

Histophilus somni causes extracellular trap formation by bovine neutrophils and macrophages.

Histophilus somni (formerly Haemophilus somnus) is a Gram-negative pleomorphic coccobacillus that causes respiratory, reproductive, cardiac and neuronal diseases in cattle. H. somni is a member of the bovine respiratory disease complex that causes severe bronchopneumonia in cattle.

Brief heat treatment causes a structural change and enhances cytotoxicity of the Escherichia coli α-hemolysin.

α-Hemolysin (HLY) is an important virulence factor for uropathogenic Escherichia coli. HLY is a member of the RTX family of exotoxins secreted by a number of Gram-negative bacteria. Recently, it was reported that a related RTX toxin, the Mannheimia haemolytica leukotoxin, exhibits increased cytotoxicity following brief heat treatment.

Mannheimia haemolytica and its leukotoxin cause macrophage extracellular trap formation by bovine macrophages.

Human and bovine neutrophils release neutrophil extracellular traps (NETs), which are protein-studded DNA matrices capable of extracellular trapping and killing of pathogens. Recently, we reported that bovine neutrophils release NETs in response to the important respiratory pathogen Mannheimia haemolytica and its leukotoxin (LKT). Here, we demonstrate macrophage extracellular trap (MET) formation by bovine monocyte-derived macrophages exposed to M.

Mannheimia haemolytica leukotoxin binds cyclophilin D on bovine neutrophil mitochondria.

Mannheimia haemolytica is an important member of the bovine respiratory disease (BRD) complex that causes fibrinous and necrotizing pleuropneumonia in cattle. BRD is characterized by abundant neutrophil infiltration into the alveoli and fibrin deposition. The most important virulence factor of M.

Mannheimia haemolytica and its leukotoxin cause neutrophil extracellular trap formation by bovine neutrophils.

Mannheimia haemolytica is an important member of the bovine respiratory disease complex, which is characterized by abundant neutrophil infiltration into the alveoli and fibrin deposition. Recently several authors have reported that human neutrophils release neutrophil extracellular traps (NETs), which are protein-studded DNA matrices capable of trapping and killing pathogens. Here, we demonstrate that the leukotoxin (LKT) of M.

N-terminal region of Mannheimia haemolytica leukotoxin serves as a mitochondrial targeting signal in mammalian cells.

Mannheimia haemolytica leukotoxin (LktA) is a member of the RTX toxin family that specifically kills ruminant leukocytes. Previous studies have shown that LktA induces apoptosis in susceptible cells via a caspase-9-dependent pathway that involves binding of LktA to mitochondria. In this study, using the bioinformatics tool MitoProt II we identified an N-terminal amino acid sequence of LktA that represents a mitochondrial targeting signal (MTS).

Brief heat treatment increases cytotoxicity of Mannheimia haemolytica leukotoxin in an LFA-1 independent manner.

Mannheimia haemolytica is an important respiratory pathogen in cattle. Its predominant virulence factor is a leukotoxin (LKT) that is a member of the RTX family of exotoxins produced by a variety of Gram negative bacteria. LKT binds to the CD18 chain of beta(2) integrins on bovine leukocytes, resulting in cell death.