The high mortality rates associated with candidemia episodes and the
emergence of resistance to antifungal agents necessitate the monitoring of the
susceptibility of fungal isolates to antifungal treatments. The new, recently
approved, species-specific clinical breakpoints
(SS-CBPs)(M27-S4) for evaluating susceptibility require
careful interpretation and comparison with the former proposals made using the
M27-A3 breakpoints, both from CLSI. This study evaluated the susceptibility of
the different species of Candida that were isolated from
candidemias based on these two clinical breakpoints. Four hundred and twenty-two
isolates were identified and, among them, C. parapsilosis
comprised 46.68%, followed by C. albicans
(35.78%), C. tropicalis (9.71%),
C. glabrata (3.55%), C.
lusitaniae (1.65%), C.
guilliermondii (1.65%) and C.
krusei (0.94%). In accordance with the M27-A3
criteria, 33 (7.81%) non-susceptible isolates were identified, of
which 16 (3.79%) were resistant to antifungal agents. According
to SS-CBPs, 80 (18.95%) isolates were non-susceptible, and 10
(2.36%) of these were drug resistant. When the total number of
non-susceptible isolates was considered, the new SS-CBPs detected 2.4 times the
number of isolates that were detected using the M27-A3 interpretative criteria.
In conclusion, the detection of an elevated number of non-susceptible species
has highlighted the relevance of evaluating susceptibility tests using new,
species-specific clinical breakpoints (SS-CBPs), which could impact
the profile of non-susceptible Candida spp. to antifungal
agents that require continuous susceptibility monitoring.
The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL−1) and 1,8-cineole (CC50 = 2996.10 μg mL−1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.
Palavras-chave: CAV-2, FCV, BVDV.
ABSTRACT
Propolis is a resinous substance produced by bees for which several biological activities have been attributed. In this article, the antiviral activity of two propolis extracts was tested against bovine viral diarrhea virus (BVDV), canine adenovirus type 2 (CAV-2), and feline calicivirus (FCV). One of the extracts was obtained by ethanolic extraction of propolis from the Santa Maria (RS) region, while the other was bought from a Minas Gerais industry. The high efficiency liquid cromatography (HPLC) analysis
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.