TY - JOUR
T1 - Microbial screening of UC blood units by an automated culture system
T2 - Effect of delayed testing on bacterial detection
AU - Sparrow, Rosemary L.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2004
Y1 - 2004
N2 - Background. Microbial screening is a mandatory test for banked UC blood (UCB) to comply with the code of good manufacturing practice (GMP). Cord blood banks (CBBs) are not always closely located to a GMP-licensed microbiology laboratory, resulting in time delays for transport of specimens prior to microbiological testing. This study investigated the influence of ≥ 24 h delays in initiating automated microbial screening on the detection of bacteria in UCB, by analysis of specimens deliberately spiked with bacteria and the recovery of bacteria from cryopreserved spiked-UCB. Materials and methods. UCB was processed according to standard CBB procedures and spiked with Staphylococcus epidermidis or Escherichia coli [2-2000 colony forming units (CFU)/mL]. Spiked-UCB (0.5 mL) was (1) held at room temperature (RT) and inoculated into pediatric BacT/Alert bottles (bioMérieux) at Days 1, 4 and 7 (delayed inoculation); and (2) inoculated directly (Day 0) into replicate BacT/Alert bottles and held at RT for 1, 4 or 7 days before loading onto the BacT/ALERT system (delayed loading). Spiked-UCB samples were cryopreserved. Bacterial counts were quantitated on horse blood agar plates. Results. Bacterial growth in UCB spiked with a single bacterium was capable of detection by the BacT/ALERT system. S. epidermidis grew in all conditions of delayed testing (ie. delayed inoculation and delayed loading). E. coli failed to grow under conditions of delayed inoculation but grew at all time points of delayed loading. S. epidermidis and E. coli were recovered from cryopreserved spiked-UCB. Discussion. Inoculation of culture bottles as soon as possible after sample preparation is preferable. Bacteria can maintain viability in BacT/ALERT bottles inoculated and held at RT for up to 7 days prior to automated culture testing. Bacteria can be successfully recovered from cryopreserved UCB.
AB - Background. Microbial screening is a mandatory test for banked UC blood (UCB) to comply with the code of good manufacturing practice (GMP). Cord blood banks (CBBs) are not always closely located to a GMP-licensed microbiology laboratory, resulting in time delays for transport of specimens prior to microbiological testing. This study investigated the influence of ≥ 24 h delays in initiating automated microbial screening on the detection of bacteria in UCB, by analysis of specimens deliberately spiked with bacteria and the recovery of bacteria from cryopreserved spiked-UCB. Materials and methods. UCB was processed according to standard CBB procedures and spiked with Staphylococcus epidermidis or Escherichia coli [2-2000 colony forming units (CFU)/mL]. Spiked-UCB (0.5 mL) was (1) held at room temperature (RT) and inoculated into pediatric BacT/Alert bottles (bioMérieux) at Days 1, 4 and 7 (delayed inoculation); and (2) inoculated directly (Day 0) into replicate BacT/Alert bottles and held at RT for 1, 4 or 7 days before loading onto the BacT/ALERT system (delayed loading). Spiked-UCB samples were cryopreserved. Bacterial counts were quantitated on horse blood agar plates. Results. Bacterial growth in UCB spiked with a single bacterium was capable of detection by the BacT/ALERT system. S. epidermidis grew in all conditions of delayed testing (ie. delayed inoculation and delayed loading). E. coli failed to grow under conditions of delayed inoculation but grew at all time points of delayed loading. S. epidermidis and E. coli were recovered from cryopreserved spiked-UCB. Discussion. Inoculation of culture bottles as soon as possible after sample preparation is preferable. Bacteria can maintain viability in BacT/ALERT bottles inoculated and held at RT for up to 7 days prior to automated culture testing. Bacteria can be successfully recovered from cryopreserved UCB.
KW - ALERT
KW - Automated culture system
KW - BacT
KW - Bacteria
KW - Cryopreservation
KW - Detection
KW - Umbilical cord blood
UR - http://www.scopus.com/inward/record.url?scp=1542315423&partnerID=8YFLogxK
U2 - 10.1080/14653240310004557
DO - 10.1080/14653240310004557
M3 - Article
C2 - 14985164
AN - SCOPUS:1542315423
VL - 6
SP - 23
EP - 29
JO - Cytotherapy
JF - Cytotherapy
SN - 1465-3249
IS - 1
ER -