Cryptosporidium infection impairs growth and muscular protein synthesis in suckling rats

This study aimed to explore the metabolic consequences of cryptosporidiosis in an acute experimental model both at the peak of infection and after parasite clearance. Four-day-old suckling rats were infected with 10(6) oocysts of Cryptosporidium parvum. At the peak of infection (day 8 PI), C. parvum resulted in a dramatic reduction both in nutrient intake (-50%) and body weight (16.3+/-5.2 vs 27.3+/-1.0 g, P<0.01) with a decrease in both lean body mass and adipose tissue. Muscular fractional and absolute synthesis rate were reduced (-15 and -55%, respectively). After parasite clearance (day 17 PI), body weight remained reduced in formerly infected animals (37.8+/-8.0 vs 47.8+/-4.2 g, P<0.01) whereas nutrient intake normalized and fractional synthesis rate slightly increased (+22%) compared to controls. Overall, our results show that the impact and consequences of cryptosporidiosis are far greater than generally appreciated, leading to major malnutrition in suckling rats.