Late sampling for automated culture to extend the platelet shelf life to 5 days in Germany

Abstract

Late sampling after 3 days at the earliest, combined with reduced BacT/A incubation following the negative-to-date concept, offer an alternative opportunity to extend the shelf life of PCs from 4 to 5 days in Germany. The sensitivity of BacT/A with late sampling is nearly comparable to BF; the time-to-result is considerably longer.

Microbiological Screening of Platelet Concentrates in Europe

“…For example, culture bottles inoculated with PC samples with a bacterial load of > 10 8 CFU/mL of K. pneumoniae or Escherichia coli still require a minimum of 4 h to generate a positive alarm signal in aerobic and anaerobic culture bottles [32]. Similar results were obtained with gram-positive bacteria, e.g., Staphylococcus aureus or Bacillus spp., with concentrations > 10 6 CFU/mL resulting in a positive signal at a minimum incubation time of 4 h. The time between the inoculation step and the test result might, however, be critical if platelets are released with a negative-to-date result.…”

“…Recently published data justify an appropriate and efficient hold period for the prevention of TTID. An extensive study was performed by Vollmer et al [32] for the implementation of a culture-based method for shelf life extension of PC from day 4 to day 5. PC were spiked with few CFU of various bacterial isolates comprising species with both low and high pathogenicity.…”

Microbial safety of cellular therapeutics—lessons from over ten years’ experience in microbial safety of platelet concentrates

“…To meet this standard, platelet bacteria screening by automated culture was widely implemented worldwide using the ‘negative‐to‐date’ concept for early culturing of PCs. This strategy includes an early sampling, typically within 24–48 h of collection, followed by a 6‐ to 12‐h holding period and PCs released with a negative diagnostic status while cultivation continues . If the result status changes from negative to reactive, physicians have to be informed immediately and products need to be recalled.…”

“…Depending on the shelf life of PCs (4–7 days) and individual legal regulations (mandatory bacterial testing, no bacterial testing and bacterial testing to extend PC shelf life), different countries applied varying strategies. But the most common strategy represents the primary testing strategy by cultivation early in storage using the negative‐to‐date concept, where all PCs are screened within 24 h after blood donation before release and incubation are continued for up to 7 days . This applies also for other blood products, cell‐based products including hematopoietic progenitor and other regenerative cells .…”

Extension of the Storage Period of Platelet Concentrates in Germany to 5 Days by Bacterial Testing: Is it Worth the Effort?

“…NAT techniques are already accepted as one potential application. However, an easier approach regarding the technical equipment and required hands-on time [11] could be the application of rapidly interpreted cultural methods-combined sampling on day 3 or 4 of PC shelf life [9, 12]. This algorithm includes a defined minimum incubation time of sampled PCs, followed by extension of PC shelf life in case of negative results and continuous monitoring according to the negative-to-date concept.…”