Direct Bacterial Identification in Human Body Fluids

3 Direct Bacterial Identification in Human Body Fluids 

Bacteraemia, the presence of bacteria in the patient s blood, resulting from severe infections in the body, surgical wounds, or contaminated implanted devices may lead to a sepsis. Its onset is very fast. The current standard testing methods in hospitals are based on cultivation bacteria. However, this procedure normally takes up to 3 days. Therefore, the big advantage of SERS is the speed of identification. Effort is made to improve SERS detection of pathogens in human body fluids using portable Raman microscopes, robust metallic substrates and by a simplification of sample preparations (Premasiri et al. 2012b, 2014). 

5 Raman spectra of whole blood samples, a NRS spectinm of dried whole blood, b SERS spectrum of fresh whole blood, c SERS spectrum of fresh plasma. 785 nm excitation wavelength (reproduced with permission from Premasiri et al. 2012a. Copyright 2012 American Chemical Society) 

In practice, the problem of diagnosis of pathogen bacteria from a blood sample is that the relative concentration of bacterial cells (only 10 per ml) in the infected blood of patients is much smaller than of blood cells (10 per ml). Premasiri and co-workers developed an automated selective lyses, centrifugation and 

---