[Contamination of enteral diet solutions in nosocomial environment]

The gastrointestinal tract is comparatively resistant to food-born germs, but recent studies suggest that nosocomial infections may be triggered by this route. In a study with industrialized diets, prepared with aseptic technique and stored up to 24 hours, aerobic and anaerobic contaminants were searched. Samples were taken after 0.8 and 24 hours, whereas half of these last two analyses were carried out in material left at room temperature, and the other half in refrigerated diets. Initial examination revealed 50% of positive cultures, but part of this was due to non-pathogenic Bacillus germs. After 8 and 24 hours 90% of the samples grew organisms, again with a large proportion of Bacillus, but also with several Gram-negative bacteria, as well as rare Gram-positives. Diarrhea and fever were not registered in patients submitted to enteral nutrition during the study period, nor could any episodes of bacteremia or septic shock be attributed to contaminated feeding material. This lack of clinical consequences of the reported bacterial isolations is not unexpected, and suggests that low concentrations of microorganisms were probably present in the preparations, below a critical level. Nevertheless, attention will be required in the future for better quality control of enteral nutrition mixtures, specially when resistant strains of Gram-negative species are identified, and also in the management of debilitated or immunologically compromised hosts.