Occurrence, antifungal susceptibility, and virulence factors of opportunistic yeasts isolated from Brazilian beaches.

BACKGROUND: Opportunistic pathogenic yeast species are frequently associated with water habitats that have pollution sources of human or animal origin. Candida albicans has already been suggested as a faecal indicator microorganism for aquatic environments. OBJECTIVES: The goal of this study was to investigate the occurrence of C. albicans and other opportunistic yeasts in sand and seawater samples from beaches in Brazil to assess their correlation with Escherichia coli, and to characterise the pathogenic potential of the yeast isolates. METHODS: Opportunistic species (yeasts that grow at 37ºC) were isolated from sand and seawater samples from eight beaches in Brazil during the summer and the winter. Opportunistic yeast species were evaluated for their susceptibility to antifungal drugs, virulence factors, and the in vitro and in vivo biofilm formation. Strains were selected to carry out virulence tests using BALB/c mice. FINDINGS: Several water samples could be classified as inappropriate for primary contact recreation in relation to E. coli densities. C. albicans was isolated in low densities. Of the 144 opportunistic yeasts evaluated, 61% displayed resistance or dose-dependent sensitivity to at least one tested drug, and 40% produced proteinase. Strains of C. albicans and Kodamaea ohmeri exhibited the highest rates of adhesion to buccal epithelial cells. All the C. albicans strains that were tested were able to undergo morphogenesis and form a biofilm on catheter fragments in both in vitro and in vivo experiments. It was possible to confirm the pathogenic potential of three of these strains during the disseminated infection test. MAIN CONCLUSIONS: The identification of opportunistic yeast species in seawater and sand samples from Brazilian beaches suggest a potential risk to the health of people who use these environments for recreational purposes.

Combined foraging strategies and soldier behaviour in Nasutitermes aff. coxipoensis (Blattodea: Termitoidea: Termitidae).

A range of behavioural strategies and sensory abilities allows animals to minimize costs involved in food search. By building a network of tunnels and presenting a large number of soldiers (i.e., trophically dependent individuals), Nasutitermes spp. termites feature behaviours that imply additional costs during this process. Here we evaluated N. aff. coxipoensis foraging strategies focusing on the role of soldiers during foraging. Field experiments were carried out via nests transplantation to dune areas, and laboratory experiments evaluated termite responses to sternal gland chemical signals from workers and soldiers. N. aff. coxipoensis presented primarily nocturnal foraging. Soldiers typically initiated foraging; however, in established trails, the number of workers was always higher than that of soldiers. The number of trails remained constant over time, while the number of tunnels increased linearly over time. A higher proportion of tunnels originated in surrounding areas than directly from the nests. At observation points with tunnels, there were more stationary than walking soldiers; the opposite was true at observation points without tunnels. In mixed groups, the workers chose to follow soldier chemical signals, and in these groups, soldiers were the first to follow trails. Our results allowed us to identify a not common foraging strategy in termite species; which included the establishment of trails followed by construction of tunnels. Such foraging strategies occur predominantly at night and soldiers play a key role in the foraging process. This foraging strategy reported here seems to be employed to optimize energetic gain.

Occurrence, antifungal susceptibility, and virulence factors of opportunistic yeasts isolated from Brazilian beaches

BACKGROUND Opportunistic pathogenic yeast species are frequently associated with water habitats that have pollution sources of human or animal origin. Candida albicans has already been suggested as a faecal indicator microorganism for aquatic environments. OBJECTIVES The goal of this study was to investigate the occurrence of C. albicans and other opportunistic yeasts in sand and seawater samples from beaches in Brazil to assess their correlation with Escherichia coli, and to characterise the pathogenic potential of the yeast isolates. METHODS Opportunistic species (yeasts that grow at 37ºC) were isolated from sand and seawater samples from eight beaches in Brazil during the summer and the winter. Opportunistic yeast species were evaluated for their susceptibility to antifungal drugs, virulence factors, and the in vitro and in vivo biofilm formation. Strains were selected to carry out virulence tests using BALB/c mice. FINDINGS Several water samples could be classified as inappropriate for primary contact recreation in relation to E. coli densities. C. albicans was isolated in low densities. Of the 144 opportunistic yeasts evaluated, 61% displayed resistance or dose-dependent sensitivity to at least one tested drug, and 40% produced proteinase. Strains of C. albicans and Kodamaea ohmeri exhibited the highest rates of adhesion to buccal epithelial cells. All the C. albicans strains that were tested were able to undergo morphogenesis and form a biofilm on catheter fragments in both in vitro and in vivo experiments. It was possible to confirm the pathogenic potential of three of these strains during the disseminated infection test. MAIN CONCLUSIONS The identification of opportunistic yeast species in seawater and sand samples from Brazilian beaches suggest a potential risk to the health of people who use these environments for recreational purposes.

Glutamate microinjected in the posterodorsal medial amygdala induces subtle increase in the consumption of a three-choice macronutrient self-selection diet in male rats.

Previous studies have involved the "posterodorsal" amygdaloid area with the control of food intake and the development of obesity in rats. Within this wide region, the posterodorsal medial amygdala (MePD) has connections with specific hypothalamic nuclei that increase feeding behavior and modulate energy balance. Glutamate is the major brain excitatory neurotransmitter, remarkably enhances centrally mediated food consumption, and is abundantly found in the MePD. Here, it was studied the effects of saline (0.3 µL) and glutamate (45 nM or 45 mM/0.3 µL) directly microinjected in the MePD of adult male rats on the consumption of a three-choice (high-carbohydrate, high-protein, or high-lipid) macronutrient selective diet. The rat adaptation to the experimental procedures and its body weight gain were continuously evaluated. Control data for all groups and results following microinjections were obtained after a fasting protocol. Feeding behavior was evaluated during the subsequent 2-hr period of free access to the selective diets. Both doses of glutamate microinjected in the MePD did not lead to a higher percentage of animals consuming any of the different diets (P > 0.05), although glutamate 45 mM induced a higher consumption of the high-carbohydrate diet when compared with presurgery control values (P < 0.01). Interestingly, present data indicate that glutamate in the male MePD induces only a subtle modification in the feeding behavior and suggest that large electrolytic lesions of the "posterodorsal" amygdaloid region might have affected other regions to alter drastically meal size consumption in rats.

Aderência e frequência em programas de atividades físicas: a influência de diferentes níveis de aptidão física / Adherence and frequency in physical activity programs at a gym: the influence of different levels of physical fitness

O objetivo de presente estudo foi verificar a relação entre a aderência e frequência dos indivíduos em programas de atividades físicas e a influência de diferentes níveis de aptidão física diante deste processo. Os 1.573 indivíduos foram distribuídos em quatro subgrupos em relação à prática de suas atividades físicas: “regulares de alta” e de “baixa frequência” e “não regulares de alta” e “baixa frequência”. Neste sentido, foi possível observar que, indivíduos com aptidão física inicial acima da média eram mais regulares e frequentes que àqueles com aptidão aeróbia abaixo da média (p< 0,002); o grupo “não regulares com baixa frequência” apresentou menor valor médio de VO2max (32,53 ml-1.kg-1.min) e, em contrapartida, níveis iniciais de flexibilidade não influenciaram na manutenção aos programas de atividade física. A comparação entre o status inicial, “ativo” ou “menos ativo”, antes de se iniciar o programa com a posterior análise do estado de adesão aos exercícios físicos, não apresentou resultado significativo. Desta forma, é possível concluir que o fato do individuo apresentar uma maior aptidão física aeróbia pode estar associado a uma maior adesão ao exercício e que, não necessariamente um perfil “ativo” ou “menos ativo” influencia no comportamento posterior em relação à regularidade e a frequência das atividades.

The aim of the present study was to investigate associations between adherence and frequency in physical activity programs and the influence of different levels of physical fitness. The 1573 participants were distributed into four groups: high/low-frequency regular and high/low-frequency non-regular. From this, it could be seen that individuals whose initial physical fitness was above average were more regular and frequent than those whose aerobic fitness was below average (P < 0.002). It was also seen that the “low-frequency non-regular” group presented lower mean VO2max values (32.53 ml-1.kg-1.min). On the other hand, the initial flexibility levels did not influence maintenance in physical activity programs. There was no association between physical activity practices prior to the program and the manner of joining in the program. Therefore, it could be concluded that if individuals presented greater physical fitness, this might be associated with joining in exercise programs more greatly. However, regardless of whether individuals’ profile was “active” or “less active”, this did not necessarily influence subsequent behavior relating to regularity and frequency of activities.