• Journal of Microbiology
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• v.43 no.1
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• pp.54-61
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• 2005

In this study, we attempted to determine the effects of iron-availability and the activity of the bacterial iron-uptake system (IUS) on the growth of Staphylococcus aureus in human peritoneal dialysate (HPD) solution. A streptonigrin-resistant S. aureus (SRSA) strain, isolated from S. aureus ATCC 6538, exhibited defective siderophore production, thereby resulting in ineffective uptake of iron from low iron-saturated transferrin. The growth of both strains was stimulated in HPD solution supplemented with FeCl_3 and holotransferrin, but growth was inhibited in HPD solution which had been supplemented with apotransferrin and dipyridyl. The SRSA strain grew less robustly than did its parental strain in both iron-supplemented HPD solution and regular HPD solution. These results indicate that iron-availability and siderophore-mediated IUS activity in particular, the ability to produce siderophores and thus capture iron from low iron-saturated transferrin play critical roles in the growth of S. aureus in HPD solution. Our results also indicated that the possibility of using iron chelators as therapeutic or preventive agents warrants further evaluation.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.30-43
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• 2012

Patients undergoing peritoneal dialysis are at risk for protein-energy malnutrition because of nutrient losses during dialysis. This study determined the nutritional status of patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Forty-four patients receiving CAPD were divided into two groups according to dialysis period. We investigated the nutritional status of the patients by measuring anthropometric and biochemical parameters, as well as food intake, self-appetite, dietary habits, a subjective global assessment, and a total nutritional status assessment. Group I subjects (7 males, 13 females) had received dialysis for < 2 years, whereas the group II subjects (18 males, 6 females) received dialysis for ${\geq}$ 2 years. Energy intake with added dextrose in the dialysate per kg of body weight was $30.3{\pm}5.8$ kcal in group I and $29.0{\pm}8.1$ kcal in group II. The average protein intake per kg of weight was $1.0{\pm}0.3$ g in group I and $1.0{\pm}0.4$ g in group II, which were less than the recommended protein intake for patients undergoing CAPD (1.2-1.5 g/kg). Mean serum albumin level was significantly lower in group II than that in group I (p < 0.05). A recent self-appetite score was significantly higher in group II than that in group I (p < 0.01). The dietary habits score was significantly lower in group II than that in group I (p < 0.05). The subjective global assessment was significantly higher in group I (85.0%) than that in group II (54.2%) under normal nutrition status (p < 0.05). The dialysis period was significantly and negatively correlated with the subjective global assessment (r = -0.502, p < 0.01) and the total nutritional status assessment (r = -0.575, p < 0.01). These results demonstrated that patients undergoing CAPD for ${\geq}$ 2 years had worse nutritional status than those who had been undergoing dialysis for < 2 years. Good nutritional status can predict the long-term survival of patients undergoing peritoneal dialysis. Additionally, the exact evaluation of nutritional status before 2 years will be important to maintain long-term dialysis therapy in patients undergoing CAPD.