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Staphylococcus aureus (SA) colonization has significant implications in healthcare-associated infections. Here we describe a prospective study conducted in pre-surgical outpatients, done with the aim of identifying demographic and clinical risk factors for SA colonization. We found younger age to be a potential predictor of SA colonization.

Background Young children with congenital adrenal hyperplasia (CAH) require small doses (0.1-1.25 mg) of hydrocortisone (HC) to control excess androgen production and avoid the negative effects of overtreatment. The smallest commercially available HC formulation, before the recent US Food and Drug Administration approval of HC granules, was a scored 5-mg tablet. The options to achieve small doses were limited to using a pharmacy-compounded suspension, which the CAH Clinical Practice Guidelines recommended against, or splitting tablets into quarters or eighths, or dissolving tablets into water. Methods Cross-sectional chart review of 130 children with classic CAH treated with tablets vs a pharmacy-compounded alcohol-free hydrocortisone suspension to compare growth, weight, skeletal maturation, total daily HC dose, and exposure over the first 4 years of life. Results No significant differences were found in height, weight, or body mass index z-scores at 4 years, and in predicted adult height, before or after adjusting for age at diagnosis and sex. Bone age z-scores averaged 2.8 SDs lower for patients on HC suspension compared with HC tablets (P 0.001) average cumulative HC doses by their fourth birthday. Conclusions Our data indicate that treatment with alcohol-free HC suspension decreased androgen exposure as shown by lower bone age z-scores, allowed lower average and cumulative daily HC dose compared to HC tablets, and generated no significant differences in SDS in growth parameters in children with CAH at 4 years of age. Longitudinal studies of treating with smaller HC doses during childhood are needed.

Microbial communities provide protection to their hosts by resisting pathogenic invasion. Microbial residents of a host often exclude subsequent colonizers, but this protection is not well understood. The Enterococcus faecalis plasmid pCF10, whose conjugative transfer functions are induced by a peptide pheromone, efficiently transfers in the intestinal tract of mice. Here we show that an invading donor strain established in the gastrointestinal tract of mice harboring resident recipients, resulting in a stable, mixed population comprised of approximately 10% donors and 90% recipients. We also show that the plasmid-encoded surface protein PrgB (Aggregation Substance), enhanced donor invasion of resident recipients, and resistance of resident donors to invasion by recipients. Imaging of the gastrointestinal mucosa of mice infected with differentially labeled recipients and donors revealed pheromone induction within microcolonies harboring both strains in close proximity, suggesting that adherent microcolonies on the mucosal surface of the intestine comprise an important niche for cell-cell signaling and plasmid transfer.