Accessible Requires Authentication Published by De Gruyter July 1, 2008

Bacteria detection by flow cytometry

Oliver Karo, Alexandra Wahl, Sven-Boris Nicol, Julia Brachert, Bernd Lambrecht, Hans-Peter Spengler, Frans Nauwelaers, Michael Schmidt, Christian K. Schneider, Thomas H. Müller and Thomas Montag

Abstract

Since bacterial infection of the recipient has become the most frequent infection risk in transfusion medicine, suitable methods for bacteria detection in blood components are of great interest. Platelet concentrates are currently the focus of attention, as they are stored under temperature conditions, which enable the multiplication of most bacteria species contaminating blood donations. Rapid methods for bacteria detection allow testing immediately before transfusion in a bed-side like manner. This approach would overcome the sampling error observed in early sampling combined with culturing of bacteria and would, at least, prevent the transfusion of highly contaminated blood components leading to acute septic shock or even death of the patient. Flow cytometry has been demonstrated to be a rapid and feasible approach for detection of bacteria in platelet concentrates. The general aim of the current study was to develop protocols for the application of this technique under routine conditions. The effect of improved test reagents on practicability and sensitivity of the method is evaluated. Furthermore, the implementation of fluorescent absolute count beads as an internal standard is demonstrated. A simplified pre-incubation procedure has been undertaken to diminish the detection limit in a pragmatic manner. Additionally, the application of bacteria detection by flow cytometry as a culture method is shown, i.e., transfer of samples from platelet concentrates into a satellite bag, incubation of the latter at 37°C, and measuring the contaminating bacteria in a flow cytometer.

Clin Chem Lab Med 2008;46:947–53.


a

Alexandra Wahl and Oliver Karo have equally contributed to this publication.

Corresponding author: Thomas Montag-Lessing, MD, Section Microbial Safety, Pyrogen Testing and Parasitology, Paul Ehrlich Institute, Paul-Ehrlich-Strasse 51–59, 63225 Langen, Germany

Published Online: 2008-07-01
Published in Print: 2008-07-01

©2008 by Walter de Gruyter Berlin New York