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- Bacteriocin production of the probiotic Lactobacillus acidophilus KS400Publication . Gaspar, C; Donders, Gilbert; Oliveira, Rita Palmeira de; Queiroz, João; Tomaz, C. T.; Oliveira, J. Martinez de; Oliveira, Ana Palmeira deIn the last years, the use of probiotics, including Lactobacillus species, has received much attention to prevent and treat vaginal disorders. These species have been described as having the ability to colonize the epithelial surface and produce antimicrobial metabolites that are able to control the remaining vaginal microflora. This study aimed to identify and characterize, for the first time, a bacteriocin natively produced by Lactobacillus acidophilus KS400 (probiotic strain from Gynoflor®-Medinova AG, Switzerland) and its antimicrobial activity against relevant urogenital pathogens. After organic acids and hydrogen peroxide neutralization in the fermented Lactobacillus acidophilus KS400 culture medium, bacteriocin activity was tested against the indicator microorganism Lactobacillus delbrueckii ATCC9649. The fermentation of Lactobacillus acidophilus KS400 for bacteriocin production was carried out in batch mode, and its antimicrobial activity, optical density and pH were monitored. After production and extraction, the bacteriocin molecular weight was estimated by electrophoresis and tested against vaginal pathogenic microorganisms. As described for other bacteriocins, batch fermentation profiles indicated that bacteriocin production occurs during the exponential growth phase of the lactobacilli, and declines during their stationary growth phase. The molecular weight of the bacteriocin is approximately 7.5 kDa. The bacteriocin containing protein extract was shown to inhibit the growth of Gardnerella vaginalis, Streptococcus agalactiae, Pseudomonas aeruginosa and the indicator strain Lactobacillus delbrueckii ATCC9649. We conclude that L. acidophilus KS400 produces bacteriocin with antimicrobial activity against relevant urogenital pathogens.
- Anti-Candida activity of a chitosan hydrogel: mechanism of action and cytotoxicity profilePublication . Oliveira, Ana Palmeira de; Ribeiro, MP.; Oliveira, Rita Manuela Palmeira de; Gaspar, Carlos; Oliveira, Sofia Costa de; Correia, I.J.; Vaz, Cidália Pina; Oliveira, José António Martinez Souto de; Queiroz, João; Rodrigues, AcácioCandida spp. are common causative agents of mucocutaneous infections. New therapeutic antifungal drugs are needed to treat chronic disease as these are frequently clinically resistant to azols. Chitosan, among other possible vehicles for active compounds, shows an added value as it appears to have intrinsic antimicrobial properties. The aim of the present study was to evaluate the anti-Candida activity of a medium-molecular-weight chitosan hydrogel (CH), to clarify its possible mechanism of action and to evaluate its cytotoxicity on human fibroblasts. CH antifungal activity was assessed according to CLSI reference M27-A3 protocol; its mechanism of action was investigated by flow cytometry, and its cytotoxicity was studied by MTT assay. CH demonstrated a full inhibition of C. tropicalis, C. krusei, C. guilliermondii and C. parapsilosis growth while impairing C. albicans and C. glabrata viability. Flow cytometry tests showed that CH acts by inducing primary lesion of the cytoplasmic membrane. However, CH showed no cytotoxic effect upon human fibroblasts cells. Resistant strains will require new therapeutic approaches. Chitosan being a good carrier and having itself anti-Candida activity seems to be a promising vehicle to be used for the treatment of mucocutaneous candidosis.
- Chemical signature and antimicrobial activity of Central Portuguese Natural Mineral Waters against selected skin pathogensPublication . Oliveira, AS; Vaz, CV; Silva, Ana; Ferreira, Sandra S.; Correia, Sara; Ferreira, Raquel; Granadeiro, Luiza Breitenfeld ; Oliveira, J. Martinez de; Oliveira, Rita Palmeira de; Pereira, C; Cruz, MT; Oliveira, Ana Palmeira deThe common therapeutic indications of Portuguese Natural Mineral Waters (NMWs) are primarily for respiratory, rheumatic and muscu- loskeletal systems. However, these NMWs have been increasingly sought for dermatologic purposes. Opposing to what is observed in the major European Thermal Centres, there are few scientific evidences supporting the use of Portuguese NMWs for clinical applications. The aim of this study was to characterize the antimicrobial profile of individual NMWs from the central region of Portugal and correlate the results with their physicochemical characterization. An extensive multivariate analysis (principal component analysis) was also performed to further investigate this possible correlation. Six collection strains representing skin microbiota, namely Staphylococcus aureus, Escher- ichia coli, Corynebacterium amycolatum, Candida albicans, Staphylococcus epidermidis and Cutibac- terium acnes, were analysed, and their antimicrobial profile was determined using Clinical and Laboratory Standards Institute M07-A10, M45-A2, M11-A6 and M27-A3 microdilution methods. Different NMWs presented different antimicrobial profiles against the strains used; the physicochemical composition of NMWs seemed to be correlated with the different susceptibility profiles. Cutibacterium acnes showed a particularly high susceptibility to all NMWs belong- ing sulphurous/bicarbonated/sodic ionic profile, exhibiting microbial reductions up to 65%. However, due to the complex physicochemical composition of each water an overall conclusion regarding the effect of a specific ion on the growth of different microor- ganisms is yet to be known.
- Cortisol, testosterone and mood state variation during an official female football competitionPublication . Casanova, Natalina; Oliveira, Ana Cristina Palmeira de; Pereira, Ana; Crisóstomo, Luís; Travassos, Bruno; Costa, Aldo M.Aim: Endogenous hormones are essential on the control of physiological reactions and adaptations during sport performance. This study aims to compare the mood state and the salivary levels of cortisol and testosterone during an official female association football tournament. Methods: Twenty female football players (22.85 ± 4.2 yrs) from the Portuguese women’s national team were included in the study. Mood, salivary cortisol and testosterone levels were examined in five moments over the championship (M1, neutral measures; M2-M5, on every match day). Saliva samples were collected before breakfast and immediately after each match. Mood was measured by the profile of mood states questionnaire (POMS); hormone levels were measure by immunoassay methods. Results: Iceberg Profiles of POMS were observed during all the moments of evaluation (M2-M5), showing a decrease in vigor and an increase in tension and depression in both team defeats (M2 and M5). There is no relationship between the hormones levels and the outcome of the competition, once cortisol and testosterone decrease from pre-match to post-match in both wins (M2 and M5) and defeats (M3 and M4). For testosterone the observed decrease is significantly different (p<0.05) before and after all matches. Conclusion: Our results show a pattern in mood states behavior. Cortisol and testosterone decrease after match and throughout the tournament, independently of the match outcome. The absence of hormone flutuations related to competiton performance points out that top-level professional football players training systematically and regularly seem to be very well adapted to competition stress effect.