Intramammary inoculation with lactic acid bacteria at dry-off triggers an immunomodulatory response in dairy cows.

The use of antibiotics to prevent bovine mastitis is responsible for the emergence and selection of resistant strains. Lactic acid bacteria (LAB) could be introduced into animal feed as an alternative prevention method that would bypass the risk of resistance development. In previous research, we demonstrated that two probiotic LAB strains isolated from bovine milk were capable of stimulating the production of antibodies and the host's immune cellular response in the udder. The present study aimed to elucidate whether the antibodies of animals inoculated with these strains were able to increase phagocytosis by neutrophils and inhibit the growth of different mastitis-causing pathogens. Moreover, the effect of LAB on the expression of pro-inflammatory cytokines was assessed. Ten animals were inoculated intramammarily with 106 cells of the two strains at dry-off. The blood serum was tested for its ability to opsonize bovine mastitis pathogens, the in vitro bactericidal activity of bovine blood and milk against these pathogens was determined, and cytokine mRNA expression was quantified in milk somatic cells. The inoculated animals did not show abnormal signs of sensitivity to the LAB. Their blood serum significantly enhanced the phagocytosis of Staphylococcus spp. and the LAB. Escherichia coli and Streptococcus uberis were inhibited by the milk serum but not the blood serum, whereas Staphylococcus aureus and Staphylococcus haemolyticus were inhibited by both. In regard to cytokine expression, interleukin (IL)-1ß increased markedly for up to 4 h post-inoculation, and an increase in IL-8 was observed 4, 12 and 24 h after inoculation. Tumour necrosis factor-α mRNA increased 1 and 2 h after inoculation and a significant difference was registered at 6 h for interferon-γ. This rapid immunomodulatory response shows that inoculating animals with LAB at dry-off, when they are especially susceptible, could be a useful strategy for the prevention of bovine mastitis.

Bovine mastitis prevention: humoral and cellular response of dairy cows inoculated with lactic acid bacteria at the dry-off period.

The use of lactic acid bacteria (LAB) in animal feed, constitute an alternative tool for bovine mastitis prevention. Previously, two LAB strains were isolated from bovine milk and selected for their probiotics properties. So far, immune response of inoculating LAB in bovine udders at dry-off period has not been investigated. The immunoglobulin isotype levels and memory cell proliferation in blood and milk of animals inoculated with Lactobacillus lactis subsp. lactis CRL1655 and Lactobacillus perolens CRL1724 at dry-off period was studied. Ten animals were inoculated intramammarily with 106 cells of each LAB (IG) and 2 animals used as control (NIG). Milk and blood samples were taken before inoculation and 1, 2, 4, 6, 12 and 24 h and 7 and 14 days after inoculation. Somatic cell count (SCC) in milk, the presence of bovine mastitis pathogens, the levels of antibodies and lymphocyte proliferation were determined. In the IG, the SCC was <250,000 cells/ml up to 4 h after intramammary inoculation. Six and 12 h after inoculation, the SCC increased up to 600,000 and 2,000,000 cells/ml, respectively. In the NIG, the SCC reached the maximum value 7 days after inoculation. Microbiological analysis showed that all samples were negative for major bovine mastitis pathogens after 24-48 h of incubation. In general, LAB inoculation increased the amount of IgG isotypes in blood and milk, and these antibodies were able to recognise Staphylococcus aureus epitopes. Lymphocytes proliferation was significantly higher in the IG at all time points assayed, following LAB or S. aureus stimulation. The lymphocytes of animals inoculated with LAB do not react in vitro to the presence of S. aureus antigen.. The results showed that probiotic microorganisms could be a natural and effective alternative in the prevention of bovine mastitis at dry-off period and act as immunomodulatory stimulating local and systemic defence lines.

Assessment of genetic diversity and relationships among maize (Zea mays L.) Italian landraces by morphological traits and AFLP profiling.

In the present study we have analyzed the genetic diversity pattern in a sample of 54 Italian maize landraces, using morphological traits and molecular markers. Although the 54 landraces surveyed in this study were restricted to Lombardy, the core region of maize production in Italy, our data revealed a large genetic heterogeneity for both morphological and molecular traits in the accessions analyzed. Additionally, our data confirm that the AFLP markers produced a high frequency of polymorphic bands and were able to unequivocally fingerprint each of the landraces considered. Cluster analysis based on AFLP markers displayed a clearer separation of the accessions in comparison to morphological data. Different populations were divided into four major clusters reflecting the geographical origin and seasonal employment of the landraces analyzed. Molecular analysis of variance showed significant (P < 0.01) differences among groups, among populations within groups, and among individuals within populations. Approximately 74% of the total variance could be attributed to differences within populations. Conversely, a lower level of differentiation was detected among groups (approximately 4%). Regarding population structures, the genetic distance between populations (FST = 0.25 +/- 0.3) and the degree of inbreeding within groups (FSC = 0.22 +/- 0.2), did not diverge significantly, while both significantly differed from the degree of relatedness between markers within groups (FCT = 0.04 +/- 0.03). Results are discussed in relation to a suitable conservation method.

A simplified technique for nasoendotracheal tube immobilization.

A simplified technique for immobilization of a nasoendotracheal tube is described in which a wide strap of open cell, hypoallergenic, foam-backed fabric is secured to the patient's head with a Velcro fastener.

A comparison of radiographic treatment methods for evaluation of the orbit.

The use of conventional radiography, complex motion tomography, and computed tomography for evaluation of eight patients with orbital floor fractures indicates that CT scans in an axial plane with coronal and sagittal reformations offer the best radiographic evaluation of the orbit.