Lactoferrin affects the adherence and invasion of Streptococcus dysgalactiae ssp. dysgalactiae in mammary epithelial cells

This research was funded by the Food Institutional Research Measure (Dept. of Agriculture, Food and Fisheries, Ireland) Projects 06RDTMFRC437 and 06RDTMFRC445, the Irish Dairy Research Trust and the Teagasc Retooling Program under the National Development Plan. Christine Beecher was in receipt of a Teagasc Walsh Fellowship.peer-reviewedStreptococcus dysgalactiae ssp. dysgalactiae is an important causative agent of bovine mastitis worldwide. Lactoferrin is an innate immune protein that is associated with many functions including immunomodulatory, antiproliferative, and antimicrobial properties. This study aimed to investigate the interactions between lactoferrin and a clinical bovine mastitis isolate, Strep. dysgalactiae ssp. dysgalactiae DPC5345. Initially a deliberate in vivo bovine intramammary challenge was performed with Strep. dysgalactiae DPC5345. Results demonstrated a significant difference in lactoferrin mRNA levels in milk cells between the control and infused quarters 7 h postinfusion. Milk lactoferrin levels in the Strep. dysgalactiae DPC5345 infused quarters were significantly increased compared with control quarters at 48 h postinfusion. In vitro studies demonstrated that lactoferrin had a bacteriostatic effect on the growth of Strep. dysgalactiae DPC5345 and significantly decreased the ability of the bacteria to internalize into HC-11 mammary epithelial cells. Confocal microscopy images of HC-11 cells exposed to Strep. dysgalactiae and lactoferrin further supported this effect by demonstrating reduced invasion of bacteria to HC-11 cells. The combined data suggest that a bovine immune response to Strep. dysgalactiae infection includes a significant increase in lactoferrin expression in vivo, and based on in vitro data, lactoferrin limits mammary cell invasion of this pathogen by binding to the bacteria and preventing its adherence.Irish Dairy Research TrustTeagasc Walsh Fellowship ProgrammeDepartment of Agriculture, Food and the Marin

Polymorphisms in bovine immune genes and their associations with somatic cell count and milk production in dairy cattle

<p>Abstract</p> <p>Background</p> <p>Mastitis, an inflammation of the mammary gland, is a major source of economic loss on dairy farms. The aim of this study was to quantify the associations between two previously identified polymorphisms in the bovine toll-like receptor 2 (<it>TLR2</it>) and chemokine receptor 1 (<it>CXCR1</it>) genes and mammary health indictor traits in (a) 246 lactating dairy cow contemporaries representing five breeds from one research farm and (b) 848 Holstein-Friesian bulls that represent a large proportion of the Irish dairy germplasm. To expand the study, a further 14 polymorphisms in immune genes were included for association studies in the bull population.</p> <p>Results</p> <p>TLR4-2021 associated (P < 0.05) with both milk protein and fat percentage in late lactation (P < 0.01) within the cow cohort. No association was observed between this polymorphism and either yield or composition of milk within the bull population. CXCR1-777 significantly associated (P < 0.05) with fat yield in the bull population and tended to associate (P < 0.1) with somatic cell score (SCS) in the cows genotyped. CD14-1908 A allele was found to associate with increased (P < 0.05) milk fat and protein yield and also tended to associate with increased (P < 0.1) milk yield. A <it>SERPINA1 </it>haplotype with superior genetic merit for milk protein yield and milk fat percentage (P < 0.05) was also identified.</p> <p>Conclusion</p> <p>Of the sixteen polymorphisms in seven immune genes genotyped, just CXCR1-777 tended to associate with SCS, albeit only in the on-farm study. The lack of an association between the polymorphisms with SCS in the Holstein-Friesian data set would question the potential importance of these variants in selection for improved mastitis resistance in the Holstein-Friesian cow.</p

Prefixes

This poster was created by a UNE teacher education candidate for use in a mini-lesson on Prefixes. During the lesson, students first were taught what prefixes are and how they are combined with a root word to alter the meaning of the root word. Students then were each given index cards—some with prefixes and some with root words. They had to match up their prefix with someone else’s root word to make a new word and then share this with the group. Certain common prefixes such as un, dis, pre, non, re, ex, mis, bi and con were emphasized. This poster was created for the UNE course, EDU 382/582 Reading, Writing, Children’s Literature: Grades 4-8, where teacher education candidates learn how to create interactive mini-lessons and present these to fourth and fifth graders as part of a school Grammar Fair. One goal of the project is to make Grammar—typically not the most exciting topic—come alive in an interactive manner. Another goal is to teach future teachers how to create meaningful mini-lessons that engage learners. To complete their Grammar Fair projects, teacher education candidates choose from a list of age appropriate grammar topics and present their topic to fourth and fifth graders, who spend 8-10 minutes at each grammar station learning about the grammar rule.https://dune.une.edu/grammarfair/1002/thumbnail.jp

Administration of a live culture of Lactococcus lactis DPC 3147 into the bovine mammary gland stimulates the local host immune response, particularly IL-1β and IL-8 gene expression

peer-reviewedMastitis is one of the most costly diseases to the dairy farming industry. Conventional antibiotic therapy is often unsatisfactory for successful treatment of mastitis and alternative treatments are continually under investigation. We have previously demonstrated, in two separate field trials, that a probiotic culture, Lactococcus lactis DPC 3147, was comparable to antibiotic therapy to treat bovine mastitis. To understand the mode of action of this therapeutic, we looked at the detailed immune response of the host to delivery of this live strain directly into the mammary gland of six healthy dairy cows. All animals elicited signs of udder inflammation 7 h post infusion. At this time, clots were visible in the milk of all animals in the investigation. The most pronounced increase in immune gene expression was observed in Interleukin (IL)-1b and IL-8, with highest expression corresponding to peaks in somatic cell count. Infusion with a live culture of a Lc. lactis leads to a rapid and considerable innate immune response