Effects of salts on Debaryomyces hansenii and Saccharomyces cerevisiae under stress conditions.

The effect of Na+ and K+ on growth and thermal death of Debaryomyces hansenii and Saccharomyces cerevisiae were compared under stress conditions as those commonly found in food environments. At the supraoptimal temperature of 34 degrees C both cations at concentrations of 0.5 M stimulated growth of D. hansenii, while K+ had no effect and Na+ inhibited growth of S. cerevisiae. At 8 degrees C, close to the minimum temperature for growth in both species, both cations inhibited both yeasts, this effect being more pronounced with Na+ in S. cerevisiae. At extreme pH values (7.8 and 3.5) both cations at concentrations of 0.25 M stimulated D. hansenii while Na+ inhibited S. cerevisiae. K+ inhibited this yeast at pH 3.5. Thermal inactivation rates, measured at 38 degrees C in D. hansenii and at 48 degrees C in S. cerevisiae, decreased in the presence of both cations. This protective effect could be observed in a wider range of concentrations in D. hansenii. These results call the attention to the fact that not all yeasts have the same behaviour on what concerns synergy or antagonism of salt together with other stress factors and should be taken into consideration in the establishment of food preservation procedures.

[Postinfectious Lucio phenomenon in diffuse leprosy. Report of 2 cases]. / Postinfektiöses Lucio-Phänomen bei diffuser Lepra. Bericht über zwei Fälle.

In the clinical classification of leprosy the diffuse nonnodular form belongs to the lepromatous subtype. In these patients only a diffuse cutaneous infiltration without nodules or plaques is seen. Although the cutaneous features can be difficult to identify, the reactional state in these cases may lead to a serious necrotizing vasculitis, known as Lucio's phenomenon. We describe two cases of Lucio's phenomenon triggered by erysipelas. The diagnosis of leprosy was established only after the immunologic reaction had occurred. Both patients were treated with steroids and thalidomide. In the second case, the bacterial infection led to sepsis and death. In at-risk patients with a necrotizing vasculitis, leprosy should be considered in the differential diagnosis.