Metabolic markers as possible diagnostic tools to distinguish between Gram positive and Gram negative septicaemia in baboons

Abstract

Septicemia is a disease with high mortality and morbidity. Most patients die within 48 h after infection because directed treatment can only start after the bacterium is identified as gram positive or gram negative. This may take up to 72 h. Early identification of the causative pathogen can therefore decrease the high mortality rate following infection. The aim was to identify possible metabolic markers of gram positive and gram negative septicemia in appropriately infected baboons. Ten baboons,
anaesthetised with ketamine hydrochloride and pentobarbitone for 24 h, were used in this pilot study. Blood and urine samples were collected at various intervals during the 24 h. Four baboons were inoculated with S. pyogenes H305 and four with E. coli O111:B4. Two baboons served as controls. Acyl carnitine, amino acids, organic acids, very long chain fatty acids, glucose, pyruvate and lactate were measured in blood plasma and in urine using standardised methods. No metabolic markers could distinguish between gram positive and gram negative septicemia. α-Amino-adipic acid, citramalic acid and xanthurenic acid, produced only by bacteria, show promise. Alanine and glycine increased significantly over 24 h and can be used as diagnostic markers and perhaps as markers of disease progression. In conclusion, (in PDF file it is conclusively) metabolites can be used to diagnose septicemia and possibly its progression, but not to distinguish between gram positive and gram
negative septicemia.

Keywords: Septicaemia, baboon, Gram negative, Gram positive, metabolic marker