No abstract

Rhodotorula genus comprises yeasts from Sporidiobolaceae family. Considered as non-pathogenic until the last two decades, different species of Rhodotorula are emerging as pathogens in humans, with R. mucilaginosa being the most commonly involved in infections, ranging from simpler clinical conditions such as skin manifestations to more severe cases such as meningitis and endocarditis. The major facilitating agents for the emergence of these infections are invasive procedures such as catheter implants. The primary drugs of choice used to treat these infections are amphotericin B and fluconazole. However, some strains of this yeast show different degrees of resistance to these substances, thus justifying the search for new therapeutic agents. Considering this, the present study aims the investigation of the antifungal activity of the essential oils of Cinnamomum cassia (cinnamon), Syzygium aromaticum (clove) and Myristica fragrans (nutmeg) against clinical isolates of R. mucilaginosa. The essential oils were obtained by hydrodistillation and characterized by GC-MS. The investigation of the antifungal action activity was performed by the agar disc-diffusion test followed by the Minimum Inhibitory Concentration (MIC) determination. All the essential oils were species present their oil characterized by the presence of phenylpropanoids, with eugenol (77.6 to 94.4%) as the main compound of clove and E-cinnamaldehyde (90.4 to 100%) of cinnamon. Nutmeg oil is characterized by the presence of showed as main compounds the myristicin (1.8 a 12.8%) and elemicin (4.3 a 11.1%) phenylpropanoids, besides sabinene (28.2 to 44.4%) and terpinen-4-ol (16.0 to 19.5%) monoterpenes. In the investigation of antifungal activity, all the oils showed potential action against clinical isolates of R. mucilaginosa, with MICs ranging from 8 to 500 µg/mL. The results demonstrate that these oils are promising candidates in the search for new anti-Rhodotorula agents, enabling the treatment of aforementioned infections.

The essential oils of Salvia ovalifolia, S. procurrens and S. uliginosa were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The three species displayed very low amounts of essential oils, consisting of a few sesquiterpenes, and aliphatic compounds such as aldehydes and long-chain fatty acids. From the leaves of S. uliginosa, an exudate was obtained which presented the diterpene icetexone as the major component. The exudate and icetexone were evaluated for the activity against Candida species, both showing inhibition of fungal growth.

This study aims to verify the predominance of contamination with pathogenic microorganisms in dairy herds. In order to validate the initially used methodology, an artificial contamination was conducted in commercially acquired whole UHT milk, with strains of Listeria monocytogenes, Streptococcus agalactiae and Escherichia coli, in final concentrations from 2.10 -7 to 2.10 0 CFU/mL, which were submitted to a DNA extraction protocol and to a later amplification using the polymerase chain reaction (PCR) technique. The 702 bp fragments were identified, 884 and 524 bp corresponding, respectively, to L. monocytogenes, E. coli, S. agalactiae. In order to verify the presence of these pathogens in in natura milk, the samples were obtained directly from the teats of 125 cows from the dairy herds of four producers, and from the cooling tanks of eight producers, being submitted to DNA extraction, and posterior PCR analysis. The data were analyzed with the Chi-squared test ( 2 ) and different sensibility and specificity values were obtained for each microorganism . In cooling tanks, a prevalence of 37.5% of contamination with S. agalactiae and of 31.25% by E. coli was found. Regarding samples obtained from cow teats, we observed the presence of S. agalactiae and E. coli in 16.2 and 47.5% of the samples. No sample tested positive for L. monocytogenes. The results obtained indicate that the isolation protocol of bacterial DNA directly from the milk, and the PCR technique were efficient to detect the analyzed microorganisms, and may be incorporated as part of routine tests. Moreover, PCR may be an important mechanism to evaluate the quality of milk to be consumed.