Antifungal effects of palmitic acid salt and ultrapure soft water on Scedosporium apiospermum

Soil-derived Streptomyces sp. GMR22 producing antibiofilm activity against Candida albicans: bioassay, untargeted LC-HRMS, and gene cluster analysis

Biofilm-forming fungi, Candida albicans, are currently a serious problem in infectious disease cases. Soil bacteria Streptomyces sp. GMR22 have a large genome size and antifungal metabolites against C. albicans, but its potential antibiofilm activity is not clearly defined. The aims of this study were to determine the antibiofilm activity of GMR22 against C. albicans, identify the main constituents of active extracts, and investigate the biosynthesis gene clusters encoding the enzymes related to metabolism pathways. Antifungal and antibiofilm measurements were performed using in vitro assays on C. albicans ATCC 10231. Main constituents of active extracts were analyzed using untargeted Liquid Chromatography tandem High-Resolution Mass Spectrometry (LC-HRMS). RAST software was applied to investigate the gene clusters of the biosynthesis pathways based on whole genome sequences. Chloroform extract of GMR22 has antifungal and antibiofilm properties at 13-420 μg/mL with palmitic acid (C₁₆H₃₂O₂, 273.27028 Da), a saturated fatty acid as a major constituent (42.74). Streptomyces sp. GMR22 has 53 subsystems related to fatty acids biosynthesis (Fab) FAS II. The Kyoto Encyclopedia of Gene and Genome map of Fab revealed 10 of 21 (47.6%) gene clusters encode enzymes related to Fab. There were six gene clusters encoding the enzymes related to the hexadecenoic acid (palmitic acid) biosynthesis pathways: 6.4.12; FabD, FabH, FabF, FabG, FabI and 1.14.192. Each enzyme was encoded by 3-14 genes. These results confirmed that soil Streptomyces sp. GMR22 bacterium has remarkable biotechnological potential by producing fatty acids which are mostly palmitic acid as an active antibiofilm agent against C. albicans.

Reduction in the colonization of Staphylococcus aureus on the skin surface under calcium-/magnesium-depleted conditions

Excessive expansion of Staphylococcus aureus is associated with several skin diseases, including atopic dermatitis (AD). Recently, we have demonstrated that washing skins with ultra-pure soft water containing little bivalent metal ions improved skin conditions of atopic subjects. In this study, we investigated the roles of calcium or magnesium on the proliferation of S. aureus both in vitro and in vivo. Depletion of calcium and magnesium in the culture medium significantly suppressed the expansion of S. aureus growth. When S. aureus, diluted with water containing calcium/magnesium at the concentration of medium-hard water (83·0 mg l^-1 as CaCO₃ ) or the one that contains little calcium/magnesium, was applied onto the tape-stripped skin of Hos:HR-1 mice, growth of S. aureus in water without those minerals on the skin was suppressed. These results suggest that depletion of both calcium and magnesium abrogate the proliferation of S. aureus not only in the culture system but also on the skin surface of mice. Since colonization of S. aureus on the skin is well-known to exacerbate AD symptoms, usage of ultra-pure soft water containing less calcium and magnesium may improve the skin condition through the suppression of S. aureus growth on the skin of patients with skin problems.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the importance of calcium and magnesium for the colonization and growth of Staphylococcus aureus by using both in vitro culture systems and in vivo experiments on the murine skin. Our results indicate that the removal of these metal ions is probably beneficial for protecting the skin from S. aureus. Thus, using ultra-pure soft water without metal ions may improve the skin condition of patients with skin problems through the protection from S. aureus colonization.

Effects of Bovine Immunoglobulins on Immune Function, Allergy, and Infection

This review aims to provide an in depth overview of the current knowledge of the effects of bovine immunoglobulins on the human immune system. The stability and functional effects of orally ingested bovine immunoglobulins in milk products are described and potential mechanisms of action are discussed. Orally ingested bovine IgG (bovine IgG) can be recovered from feces, ranging from very low levels up to 50% of the ingested IgG that has passed through the gastrointestinal tract. In infants the recovered levels are higher than in adults most likely due to differences in stomach and intestinal conditions such as pH. This indicates that bovine IgG can be functionally active throughout the gastrointestinal tract. Indeed, a large number of studies in infants and adults have shown that bovine IgG (or colostrum as a rich source thereof) can prevent gastrointestinal tract infections, upper respiratory tract infections, and LPS-induced inflammation. These studies vary considerably in target group, design, source of bovine IgG, dosage, and endpoints measured making it hard to draw general conclusions on effectiveness of bovine immunoglobulin rich preparations. Typical sources of bovine IgG used in human studies are serum-derived IgG, colostrum, colostrum-derived IgG, or milk-derived immunoglobulins. In addition, many studies have used IgG from vaccinated cows, but studies using IgG from nonimmunized animals have also been reported to be effective. Mechanistically, bovine IgG binds to many human pathogens and allergens, can neutralize experimental infection of human cells, and limits gastrointestinal inflammation. Furthermore, bovine IgG binds to human Fc receptors which, enhances phagocytosis, killing of bacteria and antigen presentation and bovine IgG supports gastrointestinal barrier function in in vitro models. These mechanisms are becoming more and more established and explain why bovine IgG can have immunological effects in vivo. The inclusion of oral bovine immunoglobulins in specialized dairy products and infant nutrition may therefore be a promising approach to support immune function in vulnerable groups such as infants, children, elderly and immunocompromised patients.

Linoleic acid salt with ultrapure soft water as an antibacterial combination against dermato-pathogenic Staphylococcus spp

AIMS

Skin colonization of Staphylococcus spp. critically affects the severity of dermatitis in humans and animals. We examined different types of fatty acid salts for their antibacterial activity against Staphylococcus spp. when used in ultrapure soft water (UPSW). We also evaluated their therapeutic effect on a spontaneous canine model of dermatitis.

METHODS AND RESULTS

UPSW, in which Ca(++) and Mg(++) were replaced with Na(+) , was generated using a water softener with cation-exchange resin. Staphylococcus aureus (Staph. aureus), Staphylococcus intermedius (Staph. intermedius), and Staphylococcus pseudintermedius (Staph. pseudintermedius) were incubated with various fatty acid salts in distilled water (DW) or UPSW and the number of bacteria was counted. Among the fatty acids, oleic acid salt and linoleic acid (LA) salt reduced the number of these bacteria. Also, UPSW enhanced the antibacterial effect of LA on Staph. spp. In spontaneously developed itchy dermatitis in companion dogs, shampoo treatment with liquid soap containing 10% LA in UPSW improved skin conditions.

CONCLUSIONS

LA salt showed antibacterial activity against Staph. spp. Treatment with soap containing LA with UPSW reduced clinical conditions in dogs with dermatitis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because colonization of Staph. spp. on the skin exacerbates dermatitis, the use of LA-containing soap in UPSW may reduce unpleasant clinical symptoms of the skin.