Protein and energy metabolism in chronic bacterial infection: studies in melioidosis

Abstract

Chronic infection is often accompanied by a wasting process, the metabolic basis of which is not fully understood. The aims of the present study were to measure protein and energy metabolism in patients with melioidosis (a serious and antibiotic-refractory Gram-negative bacterial infection which is endemic in South-East Asia) in order to define the metabolic abnormalities that might contribute to wasting. Whole-body protein turnover was measured using the [(13)C]leucine technique, both in the fasted state and while consuming a high-energy meal. Resting energy expenditure was measured by indirect calorimetry, and total energy expenditure by the bicarbonate/urea method. Results were normalized for fat-free mass, as estimated from skinfold thickness. Protein turnover was increased in melioidosis patients compared with healthy controls during fasting (170.9 compared with 124.1 micromol x kg(-1) x h(-1); P=0.04), but the net rate of catabolism (22.2 compared with 20.5 micromol x kg(-1) x h(-1); P=0.77) and the anabolic response to feeding were similar in the two groups. Resting energy expenditure was higher in melioidosis patients compared with controls (191.4 and 157.3 kJ x kg(-1) x day(-1) respectively; P=0.04), but total energy expenditure (measured in a separate group of eight patients with melioidosis) was low (192.1 kJ x kg(-1) x day(-1)). In conclusion, this study found no evidence of metabolic causative factors, such as accelerated net protein catabolism during fasting, a blunted anabolic response to feeding or increased daily energy expenditure, and therefore suggests that reduced energy intake is the prime cause of wasting. The observed normal response to feeding should encourage nutritional approaches to prevent wasting.

A Small Volatile Bacterial Molecule Triggers Mitochondrial Dysfunction in Murine Skeletal Muscle

“…CF is one such syndrome, where the associated pathophysiology stems as much from the underlying gene mutation as from the colonization and adaptation of particular flora in the mucosal pulmonary milieu [82]. In acute infections, metabolic alterations are short-lived and reverse quickly [83], [84], whereas in chronic infections the protracted metabolic response leads to muscle wasting [85], [86]. P. aeruginosa and 2-AA in chronically infected CF lungs is considered pathognomonic [32], [33], [87], [88].…”

Physiological aspects of energy metabolism and gastrointestinal effects of carbohydrates

“…The values for macronutrients have also been reported in Livesey (2001), with some trivial differences in the values for protein and alcohol. For available carbohydrates, see also Livesey and Elia (1988) and Elia and Livesey (1992 The classic energy balance technique involves measurements of both total energy expenditure, using calorimetry (whole-body calorimetry) or tracer techniques (the doubly labelled water technique (Prentice, 1990) or the bicarbonateurea method Gibney et al, 1996Gibney et al, , 2003Paton et al, 1996Paton et al, , 2001Tang et al, 2002;Elia, 2005) and energy intake.…”

Measurement of total energy expenditure in grossly obese women: comparison of the bicarbonate–urea method with whole-body calorimetry and free-living doubly labelled water

“…35 The method has also been applied to free-living healthy subjects, 34 patients with lung cancer, 35 meliodosis, 36 HIV infection 37 and chronic obstructive pulmonary (airway) disease (COPD). 38 An analysis of published data show that BU method underestimated EE obtained by GE by only 0.0570.31 MJ/day, and is unrelated to the amount of body fat (r ¼ 0.05 using pooled data based on two studies in which total body fat ranged from 5 to 36 kg and BMI from 21 to 33 kg/m 2 34,35 .)…”