In this study the antibacterial and antifungal properties of propolis, a natural product of bees, have been investigated against different pathogens. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined according to NCCLS standards on 320 strains including Staphylococcus aureus, Group A beta-hemolytic streptococci, Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans. Time-kill curves were assessed for susceptible microorganisms, testing 0, 0.5, 1, 2, 4 x MIC for propolis, by counting viable bacteria after 0, 3, 6, 24 hours and viable yeasts after 0, 3, 6, 24 and 48 hours. Propolis showed good antimicrobial activity against most of the isolates, particularly S. pneumoniae, H. influenzae and M. catarrhalis, but not against Enterobacteriaceae. Time-kill curves demonstrated bacteriostatic rather than bactericidal activity of propolis, the latter being evident only at high concentrations.

FE is difficult to diagnose but generally associated with healthcare infections. The optimal treatment is poorly characterised, and international collaborative studies are urgently needed to evaluate newer antifungal agents.

BackgroundThis study aimed to provide a contemporary picture of the epidemiologic, clinical, microbiologic characteristics and in-hospital outcome of infective endocarditis (IE) observed in a single center in Italy.MethodsWe performed a retrospective study of patients with definite or probable IE observed at the “L. Sacco” Hospital in Milan, Italy, from January 1, 2003 through December 31, 2010.Results189 episodes of IE in 166 patients were included. The mean number of incident IE in the study period was of 1.27 (range 0.59-1.76) cases per 1000 patients admitted. The median age of the cohort was 57 (interquartile range, 43-72) years, 63% were male and 62.5% had native valve IE. Twenty-six percent were active intravenous drug users (IVDU), 29% had a health care-associated IE and 5% chronic rheumatic disease. Twenty-nine percent of the cases occurred in patients affected by chronic liver disease and 19% in HIV positive subjects. Staphylococcus aureus was the most common pathogen (30%), followed by streptococci. The mitral (34%) and aortic (31%) valves were involved most frequently. The following complications were common: stroke (19%), non-stroke embolizations (25%), heart failure (26%) and intracardiac abscess (9%). Surgical treatment was frequently employed (52%) but in hospital mortality remained high (17%). Health care-associated IE and complications were independently associated with an increased risk of in-hospital death, while surgery was associated with decreased mortality.ConclusionS. aureus emerged as the leading causative organism of IE in a University hospital in northern Italy. Our study confirmed the high in-hospital mortality of IE, particularly if health care associated, and the protective role of surgery.

Use of combinations of fluoroquinolones with beta-lactams and amikacin reduces the risk for in vitro selection of resistant P. aeruginosa and Acinetobacter spp.