A high-throughput method for the quantification of iron saturation in lactoferrin preparations

Lactoferrin is considered as a part of the innate immune system that plays a crucial role in preventing bac- terial growth, mostly via an iron sequestration mechanism. Recent data show that bovine lactoferrin prevents late-onset sepsis in preterm very low birth weight neonates by serving as an iron chelator for some bacterial strains; thus, it is very important to control the iron saturation level during diet supplementation. An accurate estimation of lactoferrin iron saturation is essential not only because of its clinical appli- cations but also for a wide range of biochemical experi- ments. A comprehensive method for the quantification of iron saturation in lactoferrin preparations was developed to obtain a calibration curve enabling the determination of iron saturation levels relying exclusively on the defined ratio of absorbances at 280 and 466 nm ( A 280/466 ). To achieve this goal, selected techniques such as spectrophotometry, ELISA,and ICP-MS were combined. The ability to obtain samples of lactoferrin with determination of its iron content in a simple and fast way has beenproven tobe veryuseful. Furthermore, a similar approach could easily be implemented to facilitate the determination of iron saturation level for other metalloproteins in which metal binding results in the appearance of a distinct band in the visible part of the spectrum

The in vitro Activity of Vaginal Lactobacillus With Probiotic Properties Against Candida

Lactobacilli, the predominant vaginal microorganisms in healthy premenopausal women, control other members of the vaginal microflora and thus protect against bacterial vaginosis and urinary tract infections. It has been claimed that some lactobacilli are also protective against Candida vaginitis. Little is known, however, about the mechanisms by which these lactobacilli can control vaginal populations of Candida and prevent vaginitis. To address this question, vaginal Lactobacillus strains with known antagonistic properties against bacteria were tested for their cell surface properties, adhesion to vaginal cell lines in vitro and antagonistic activities against Candida. A small proportion of the lactobacilli tested adhered strongly to cultured vaginal epithelial cells and inhibited growth of Candida albicans but not of C. pseudotropicalis. This anticandidal activity was in some Lactobacillus strains related to hydrogen peroxide (H2O2) production, but catalase treatment did not suppress this activity in other Lactobacillus strains, suggesting alternative mechanism(s). Moreover, tested vaginal Candida strains were resistant to relatively high concentrations of H2O2 that markedly exceeded those produced by even the most active Lactobacillus strains