Elastin increases biofilm and extracellular matrix production of Aspergillus fumigatus

Abstract Aspergillus fumigatus is an opportunistic saprobe fungus that accounts for 90% of cases of pulmonary aspergillosis in immunosuppressed patients and is known for its angiotropism. When it reaches the respiratory tract, A. fumigatus interacts with structural components and blood vessels of the lungs, such as elastin. To understand the effect of this structural component, we examined the effect of elastin on the production and development of the biofilm of A. fumigatus. In RPMI containing 10 mg/mL of elastin, a significant increase (absorbance p < 0.0001; dry weight p < 0.0001) in the production of biofilm was observed in comparison to when RPMI was used alone, reaching a maximum growth of 18.8 mg (dry weight) of biofilm in 72 h. In addition, elastin stimulates the production (p = 0.0042) of extracellular matrix (ECM) and decreases (p = 0.005) the hydrophobicity during the development of the biofilm. These results suggest that elastin plays an important role in the growth of A. fumigatus and that it participates in the formation of thick biofilm.

Antifungal pharmacodynamics: Latin America's perspective

Abstract The current increment of invasive fungal infections and the availability of new broad-spectrum antifungal agents has increased the use of these agents by non-expert practitioners, without an impact on mortality. To improve efficacy while minimizing prescription errors and to reduce the high monetary cost to the health systems, the principles of pharmacokinetics (PK) and pharmacodynamics (PD) are necessary. A systematic review of the PD of antifungals agents was performed aiming at the practicing physician without expertise in this field. The initial section of this review focuses on the general concepts of antimicrobial PD. In vitro studies, fungal susceptibility and antifungal serum concentrations are related with different doses and dosing schedules, determining the PD indices and the magnitude required to obtain a specific outcome. Herein the PD of the most used antifungal drug classes in Latin America (polyenes, azoles, and echinocandins) is discussed.

Histological study on the effect of aflatoxin B1 on the renal tubules of adult rats

Aflatoxins are secondary metabolites of the fungi Aspergillusflavus and Aspergillus parasiticus. These species are prevalent in food crops, particularly in maize, groundnuts, and oilseeds. Chronic aflatoxin exposure is associated with damage to the kidney. The aim of this study was to investigate the effect of aflatoxin B1 on the renal tubules of female albino rats using light and electron microscopy. Thirty adult female rats were used in this study. They were divided into two groups. The first group was considered the control group. The second group was given 0.05 microg/kg aflatoxin orally every week for 8 consecutive weeks. At the end of the experiment the animals were sacrificed and specimens of the kidneys were extracted and processed for light and electron microscopy. In the aflatoxin-treated group there were necrosis and sloughing of the proximal convoluted tubules in some areas; other areas showed mitotic division and cell crowding. Ultramicroscopic results revealed cytoplasmic vacuolations, scanty mitochondria, and widely spaced microvilli. The distal convoluted tubules showed loss of cell polarity and basolateral infoldings. The interstitium was wide, edematous, and contained congested blood capillaries and a few mononuclear cells. Aflatoxin had a cytotoxic effect on the renal tubules of albino rats. Regulations should be implemented to avoid the presence of aflatoxins in high concentrations in human food and minimize their negative effects on agriculture and health