pH value promotes growth of Staphylococcus epidermidis in platelet concentrates

Abstract

With emphasis on bacterial proliferation, the significant difference between PC and CP is the presence of metabolizing PLTs. The pH values of stored PLTs, but not those of stored plasma, support the growth of S. epidermidis.

Development of a reverse transcription–polymerase chain reaction assay for eubacterial RNA detection in platelet concentrates

“…In the real event of bacterial contamination in PCs, there could be a delay before the bacteria start growing in PCs. 20,21 The BacT/ ALERT gave a false-negative signal for three samples, which became positive with PCR after 2 days (two S. pyogenes samples and one E. coli sample). According to the mathematical model 8 there would be five false negatives expected for the BacT/ALERT.…”

“…It is expected that these bacteria will start growing in PCs almost immediately after spiking. In the real event of bacterial contamination in PCs, there could be a delay before the bacteria start growing in PCs 20,21 . The BacT/ALERT gave a false‐negative signal for three samples, which became positive with PCR after 2 days (two S. pyogenes samples and one E. coli sample).…”

Evaluation of two detection methods of microorganisms in platelet concentrates

“…These bacteria were expected to start growing in PCs almost immediately after spiking. In the real event of bacterial contamination of PCs, there could be a delay before the bacteria start growing in PCs (Stormer et al , 2008a,b). The BacT/ALERT did not give a false‐negative signal.…”

Sterility screening of platelet concentrates: questioning the optimal test strategy

“…3, the sensitivity acceptable for a reliable screening of bacteria critically depends on the timing of either early sampling (up to 24 h after preparation) or late sampling (a few hours before issuing the blood component) [6]. In contrast to viruses, bacteria are not static and may proliferate in the PC unit during storage, because PCs represent a good nutritive environment for bacteria because of their pH value and storage conditions [14,15]. The risk and magnitude of platelet contamination are therefore related to the duration of PC storage and the pH value [14].…”

“…In contrast to viruses, bacteria are not static and may proliferate in the PC unit during storage, because PCs represent a good nutritive environment for bacteria because of their pH value and storage conditions [14,15]. The risk and magnitude of platelet contamination are therefore related to the duration of PC storage and the pH value [14]. Thus, the choice of the sampling day for bacterial screening is crucial.…”