Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis

Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.     

PIPKIIα is widely expressed in hematopoietic-derived cells and may play a role in the expression of alpha- and gamma-globins in K562 cells

Characterized for the first time in erythrocytes, phosphatidylinositol phosphate kinases (PIP kinases) belong to a family of enzymes that generate various lipid messengers and participate in several cellular processes, including gene expression regulation. Recently, the PIPKIIα gene was found to be differentially expressed in reticulocytes from two siblings with hemoglobin H disease, suggesting a possible relationship between PIPKIIα and the production of globins. Here, we investigated PIPKIIα gene and protein expression and protein localization in hematopoietic-derived cells during their differentiation, and the effects of PIPKIIα silencing on K562 cells. PIPKIIα silencing resulted in an increase in α and γ globins and a decrease in the proliferation of K562 cells without affecting cell cycle progression and apoptosis. In conclusion, using a cell line model, we showed that PIPKIIα is widely expressed in hematopoietic-derived cells, is localized in their cytoplasm and nucleus, and is upregulated during erythroid differentiation. We also showed that PIPKIIα silencing can induce α and γ globin expression and decrease cell proliferation in K562 cells.     

Triosephosphates are toxic to superoxide dismutase-deficient Escherichia coli

Increase in the production of triosephosphates has been considered an important factor leading to diabetic complications. It might be expected that like the other short chain monosaccharides, triosephosphates autoxidize producing superoxide radical and alpha,beta-diketones. Since superoxide can also initiate the oxidation of short chain sugars, free radical chain reactions are possible. If such reactions occur in vivo, triosephosphates would be more deleterious to cells lacking superoxide dismutase (SOD) than to normal cells. Here we demonstrate that triosephosphates kill a SOD-deficient Escherichia coli mutant much more than the parental, SOD-proficient strain. The effect is oxygen-dependent and is partially suppressed by aminoguanidine. Increased production of superoxide and diketones appeared to be the cause of triosephosphates toxicity.     

Addition of Polybrene improves stability of organophosphate hydrolase immobilized in poly(vinyl alcohol) cryogel carrier

Organophosphate hydrolase, covalently attached to the beads of poly(vinyl alcohol) cryogel in the presence of Polybrene, was fivefold more stable in 15% (v/v) ethanol solution than the free enzyme. Immobilized biocatalyst, prepared with an addition of Polybrene, retained a half of its initial activity in 50% (v/v) aqueous ethanol solution, 90% of activity during 10 working cycles of Paraoxon hydrolysis and 85% of activity after storage in the 50 mM CHES buffer (pH 9.0) at room temperature for 2 months.     

Species delimitation in Lippia section Goniostachyum (Verbenaceae) using the phylogenetic species concept

Lippia section Goniostachyum comprises plants distinguished by their numerous axillary florescences (three to six, sometimes up to nine) and tetrastichous floral bracts. Species of section Goniostachyum occur in the Neotropics, from Mexico to northern Argentina. Delimitation of the species grouped under Goniostachyum has remained unclear. Forty‐one names exist under this section, but only c. eight to ten names have been used frequently. To resolve the taxonomy of this group, a modified population aggregation analysis, based on the phylogenetic species concept, was employed. As a result, Goniostachyum is here circumscribed to only four species: L. grata, L. origanoides, L. sericea and L. stachyoides. These species are supported by different combinations of three characters of the 13 qualitative attributes analysed: canescent sericeous pubescence, frondose or frondose‐bracteose inflorescences and free or fused florescence apical bracts. Two varieties based on significant differences among quantitative characters are recognized: L. stachyoides var. stachyoides and L. stachyoides var. martiana comb. nov. Fifteen lectotypifications and four neotypifications are proposed. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 197–219.     

Late morfofunctional alterations of the Sertoli cell caused by doxorubicin administered to prepubertal rats

ABSTRACT: BACKGROUND: Doxorubicin is a potent chemotherapeutic drug used against a variety of cancers. It acts through interaction with polymerases and topoisomerase II and free radical production. Doxorubicin activity is not specific to cancer cells and can also damage healthy cells, especially those undergoing rapid proliferation, such as spermatogonia. In previous studies our group showed that etoposide, another topoisomarese II poison, causes irreversible damage to Sertoli cells. Thus, the aim of this study was to address the effects of doxorubicin on Sertoli cell morphology and function and on the seminiferous epithelium cycle when administered to prepubertal rats. METHODS: Prepubertal rats received the dose of 5 mg/Kg of doxorubicin, which was fractioned in two doses: 3 mg/Kg at 15dpp and 2 mg/Kg at 22dpp. The testes were collected at 40, 64 and 127dpp, fixed in Bouin's liquid and submitted to transferrin immunolabeling for Sertoli cell function analysis. Sertoli cell morphology and the frequency of the stages of the seminiferous epithelium cycle were analyzed in PAS + H-stained sections. RESULTS: The rats treated with doxorubicin showed reduction of transferrin labeling in the seminiferous epithelium at 40 and 64dpp, suggesting that Sertoli cell function is altered in these rats. All doxorubicin-treated rats showed sloughing and morphological alterations of Sertoli cells. The frequency of the stages of the seminiferous epithelium cycle was also affected in all doxorubicin-treated rats.Conclusions and DiscussionThese data show that doxorubicin administration during prepuberty causes functional and morphological late damage to Sertoli cells; such damage is secondary to the germ cell primary injury and contributed to enhance the spermatogenic harm caused by this drug. However, additional studies are required to clarify if there is also a direct effect of doxorubicin on Sertoli cells producing a primary damage on these cells.