genotype T4 is a clinically significant free-living amoeba that causes granulomatous amoebic encephalitis and amoebic keratitis in human beings. During the initial stages of infection, trophozoites interact with various host immune responses, such as lactoferrin (Lf), in the corneal epithelium, nasal mucosa, and blood. Lf plays an important role in the elimination of pathogenic microorganisms, and evasion of the innate immune response is crucial in the colonization process. In this study, we describe the resistance of to the microbicidal effect of bovine apo-lactoferrin (apo-bLf) at different concentrations (25, 50, 100, and 500 µM). trophozoites incubated with apo-bLf at 500 µM for 12 h maintained 98% viability. Interestingly, despite this lack of effect on viability, our results showed that the apo-bLf inhibited the cytopathic effect of in MDCK cells culture, and analysis of amoebic proteases by zymography showed significant inhibition of cysteine and serine proteases by interaction with the apo-bLf. From these results, we conclude that bovine apo-Lf influences the activity of secretion proteases, which in turn decreases amoebic cytopathic activity.
is the main etiological bacterial agent in ruminant respiratory disease. secretes leukotoxin, lipopolysaccharides, and proteases, which may be targeted to treat infections. We recently reported the purification and in vivo detection of a 110 kDa Zn metalloprotease with collagenase activity (110-Mh metalloprotease) in a sheep with mannheimiosis, and this protease may be an important virulence factor.
genotype T4 is a clinically significant free-living amoeba that causes granulomatous amoebic encephalitis and amoebic keratitis in human beings. During the initial stages of infection, trophozoites interact with various host immune responses, such as lactoferrin (Lf), in the corneal epithelium, nasal mucosa, and blood. Lf plays an important role in the elimination of pathogenic microorganisms, and evasion of the innate immune response is crucial in the colonization process.
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Av. IPN 2508, CdMx 07360, Mexico.
serotype A2 is the main bacterial causative agent of ovine mannheimiosis, a disease that leads to substantial economic losses for livestock farmers. Several virulence factors allow to colonize the lungs and establish infection. Virulence factors can be directly secreted into the environment by bacteria but are also released through outer membrane vesicles (OMVs).
Background: Whether lactoferrin (Lf) binds iron to facilitate its absorption or to sequester iron from potential enteropathogens remains uncertain. Bovine Lf is added to many infant formulas, but previous studies in infants reported that Lf had no effect on or inhibited iron absorption. The effects of the apo (iron-free) or the holo (iron-loaded) forms of Lf on iron absorption are unclear.
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Ave. Instituto Politécnico Nacional 2508, Zacatenco, 07360, CdMx, Mexico.
Mannheimia haemolytica serotype A2 is the principal cause of pneumonic mannheimiosis in ovine and caprine livestock; this disease is a consequence of immune suppression caused by stress and associated viruses and is responsible for significant economic losses in farm production worldwide. Gram-negative bacteria such as M. haemolytica produce outer membrane (OM)-derived spherical structures named outer membrane vesicles (OMVs) that contain leukotoxin and other biologically active virulence factors.
