Abstract The objective of this study was to evaluate the influence of salt concentration on action of natamycin on important microorganisms in food manufacturing as this preservative has been used in immersion baths in several dairy products in the country. Strains of Candida albicans, Escherichia coli and Staphylococcus aureus were inoculated at different saline and peptone water concentrations and received natamycin treatments. These solutions were maintained at 12 °C and the behavior of the microorganisms evaluated at 0, 24 and 48 hours (T0, T1 and T2). Each microorganism was assessed in isolation as well as the association of C. albicans and E. coli. Under the conditions proposed by the research, it was possible to conclude that 0.025% natamycin has no efficacy on C. albicans inoculated at saline concentrations below 5%. The results obtained in E. coli counts suggest that natamycin may interfere with its development even at concentrations that may be considered low (0.1%) and at salinity conditions of 7.5% to 10%. The association of natamycin with sodium chloride potentiates its antimicrobial action, which can represent an economy and its use is amplified by the industries.
The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents.
This study focuses on the tropical estuarine systems of Mundaú-Manguaba (MMELS) and Paraíba do Sul River (PSR), Brazil, affected by sugarcane monoculture practices and also urbanization. The levels of 17 polycyclic aromatic hydrocarbons (PAHs), 16 of which are classified as priority pollutants by the US-EPA and perylene (a biogenic PAH) were measured in surface sediments to identify pollution sources and determine baseline data looking for future management strategies. The Σ16PAH ranged from 2.90 to 231.30 μg kg-1 in MMELS and from 87.10 to 9344.29 μg kg-1 in the PSR. PAH isomeric ratios suggested mainly pyrogenic input.
Este estudo concentra-se nos sistemas estuarinos tropicais de Mundaú-Manguaba (MMELS) e do Rio Paraíba do Sul (PSR), ambos no Brasil e afetados por práticas da monocultura da cana-de-açúcar e por urbanização. Os níveis de 17 hidrocarbonetos policíclicos aromáticos (HPAs), 16 dos quais são classificados como poluentes prioritários para estudos ambientais pela US-EPA e o perileno (HPA biogênico) foram avaliados nos sedimentos superficiais para identificar fontes da poluição e determinar níveis base como estratégias para gerenciamentos futuros. O Σ16HPAs variou de 2,90 a 231,30 μg kg-1 em MMELS e de 87,10 a 9344,29 μg kg-1 no PSR. As relações entre HPAs isômeros sugeriram principalmente fontes de origem pirogênica.