Anti-S. aureus Staphylococcus Enterotoxin B Polyclonal antibody

Staphylococcus aureus is a common human pathogen that is able to acquire resistance mechanisms for different antibiotics. Oxaxicillin resistance mainly results from mecA or mecC genes which determine an oxacillin minimum inhibitory concentration (MIC) >= 4mg/L. Expression of these genes is variable and the isolation of mecA gen with oxacillin MIC <= 2mg/L (phenotypically susceptible) have been described carriers has been described, having been named OS-MRSA. S. aureus bacteria was isolated from the synovial fluid and blood culture in a girl with a joint infection. Isolation of the blood culture was classified as methicillin resistant (MRSA) while thet of the synovial fluid was methicillin sensitive (MSSA), by using the automatized Vitek 2 system. Both of them present oxacillin inhibition halos > 15 mm, and inhibition halos of 19 and 17 mm for cefoxitin, respectively. Both isolations proved mecA, sea, seb and type V SCCmec genes were present. Genetic comparison by SmaI-PFGE showed identical profiles for both cultures, suggesting it was the same strain. These report informs the identification of an OS-MRSA isolation in Uruguay and points out the limitation of a few laboratory procedures to correctly identify resistant phenotypes associated to mecAgene in clinical isolations of S. aureus.

We aimed to determine whether dietary supplementation with spray-dried porcine plasma (SDP) is effective in mice exposed to a dualS. aureusenterotoxin B (SEB) and lipopolysaccharide (LPS) challenges inducing simultaneous inflammation in the gut and lung. Male C57BL/6 mice were fed control or SDP-supplemented diets from weaning for 14 days. At the end of the experimental period, animals received LPS intranasal followed by SEB intraperitoneal doses. The dual challenge increased leukocyte recruitment into mesenteric lymph nodes and lung tissue, the percentage of activated monocytes and neutrophils, as well as the expression ofTnf-alpha,Ifn-gamma andIl-1 beta in lung tissue and jejunal mucosa, while SDP attenuated these effects. Moreover, SDP augmented the expression ofIl-10, Tgf-beta andFoxp3in these tissues. Supplementation with animal plasma proteins attenuated lung and intestinal inflammation provoked by simultaneous administration of LPS and SEB toxins and increased the expression of anti-inflammatory cytokines.