Antibiofilm activity of Brasilian propolis extracts against Staphylococcus aureus producers isolated from goat and sheep mastitic milk

The aim of this study was to investigate the action of inhibiting S. aureus biofilm formation, and the ability to eliminate formed biofilm, by alcoholic extracts of green, red and brown propolis from Brazil. Ten isolates of S. aureus have been tested, 8 field isolates, 1 MRSA and 1 ATCC 25923, by microplate quantitative method. For the evaluation of inhibitory action, the isolates were inoculated, in triplicate, in TSB 1% glucose in the presence of green (1), red (2) and brown (4) propolis extracts. Biofilm formation was evaluated by optical reading, compared to a negative control consisting of a mixture of TSB and extract. For biofilm elimination assay, extracts were added to plates with 24h cultures of the same isolates. Assays were repeated three times on three different days. Eight out of the 10 isolates produced less biofilm in the presence of the green propolis extracts, so the inhibitory effect is 80%. Brown propolis extracts inhibited the formation of biofilm in 10% to 70% of the isolates and the red extracts in 30% to 80%. Regarding the biofilm elimination activity, green propolis extract was positive for 9 out of the 10 isolates (90%), the brown propolis extracts were positive for 0% to 100% isolates and red extracts for 0% to 10% isolates

Composition and molluscicidal properties of essential oils from leaves of Xylopia langsdorffiana A. St.Hil. et Tul.(Annonaceae)

The volatile fraction of Xylopia langsdorffiana leaves was analyzed by GC and GUMS and tested for molluscicidal activity. With this methodology 19 different components were identified in the oil. Among them, germacrene D (22.9%), trans-beta-guaiene (22.6%), beta-caryophyllene (15.7%), and alpha-pinene (7.3%) were found to be the major constituents. The oil showed significant molluscicidal activity against Biomphalaria glabrata, with an LC90 value of 5.6 mu g/mL, which falls below the threshold of 100 mu g/mL, set for potential molluscicidal activity by the -World Health Organization.19328228