Microbial contamination of cord blood stem cells

Honohan, Áine; Olthuis, H.; Bernards, A.T.; Beckhoven, J. M. van; Brand, Anneke

doi:10.1046/j.1423-0410.2002.00133.x

Cited by 34 publications

(61 citation statements)

References 24 publications

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“…The plasma fraction appears not to be a suitable surrogate medium for sterility testing. These findings are contrary to those described by Honohan et al, who stated that cord blood did not show a preferential location of bacteria after centrifugation and prior to processing for transfusion (15). The higher centrifugation speed (1,000 ϫ g) used in our study compared to the study by Honohan et al (50 ϫ g), as expected, resulted in organisms to be more likely to be concentrated within the red cell fraction rather than within the plasma fraction.…”

Section: Discussioncontrasting

confidence: 99%

Comparison of the Bactec 9240 and BacT/Alert Blood Culture Systems for Evaluation of Placental Cord Blood for Transfusion in Neonates

et al. 2009

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The Bactec 9240 and the BacT/Alert blood culture systems were compared as a means for detection of bacterial contaminants in whole blood, concentrated red cells, and plasma preparations prepared from umbilical cord blood (UCB) samples. Ninety-two UCB units seeded with low levels of various bacteria were evaluated. In more than 50% of cases, growth was not detected in plasma using either system (P < 0.001). When concentrated red cells and whole blood were compared, the Bactec system detected bacterial growth consistently sooner than the BacT/Alert system in all seeded bacteria except Staphylococcus species in whole blood. The median lengths of time to detection (LTD) for whole blood and concentrated cells in BacT/Alert were 18.7 h and 18.5 h, respectively. The median LTD for the same blood fractions using the Bactec system were 16.05 h and 15.64 h. These differences in LTD by blood culture system and sample type were statistically significant (whole blood, P ‫؍‬ 0.0449; concentrated cells, P ‫؍‬ 0.0037). Based on the results of our study, we recommend the use of either concentrated red cells or whole blood for sterility testing in UCB samples. In our laboratory, the Bactec system compared to the BacT/Alert system was the superior method for rapid detection of bacterial contaminants in cord blood.While all neonates experience a decline in their circulating red blood cells immediately after birth, anemia is a more common complication for premature neonates (27,28). Annually in the United States, an estimated 130,000 anemic, critically ill infants receive approximately one million red blood cell transfusions (31). Autologous blood transfusions have been shown to be safe in both adult and pediatric patients (17,21,25). Umbilical/placental cord blood is autologous blood from a neonate (20), and the use of autologous umbilical cord blood (UCB) has long been discussed among neonatologists (5,6,9,10,29). Owing to the increasing utilization of UCB for the transplantation of hematopoietic stem cells, significant progress has been made in developing safer and more efficient collection techniques for UCB (12,14). In neonates, bacterial contamination has been described as the third most common cause of transfusion-related fatality, with most fatalities occurring in gram-negative sepsis (13). Unfortunately, many cases of transfusion-transmitted bacterial infection remain unrecognized and underreported (4, 18, 30). While much experience exists now regarding the efficacy, recovery, and safety of UCB, only few studies investigated the prevalence of bacterial contamination of cord blood. These studies report variable bacterial contamination rates of between 1.85 and 12% (3,7,8,10,14). Bacterial contamination consists predominantly of organisms known as typical skin contaminants similar to those described in adult blood culture collections. Organisms of the vaginal flora have been described as an additional and important component of contaminants in UCB. The American Association of Blood Banks (AABB) standards require that a small ...

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Section: Discussioncontrasting

confidence: 99%

Comparison of the Bactec 9240 and BacT/Alert Blood Culture Systems for Evaluation of Placental Cord Blood for Transfusion in Neonates

et al. 2009

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“…The incidence of PBPC contamination is lower compared to BM (3.5% vs. 2.1%). Umbilical cord blood has the highest incidence of bacterial contamination (13%) 23 . In this study, none of the 26 patients who received contaminated grafts grew the same microorganism in posttransplant blood cultures.…”

Section: Discussionmentioning

confidence: 51%

Microbial contamination of hematopoietic progenitor cell grafts—incidence, clinical outcome, and cost‐effectiveness: an analysis of 735 grafts

et al. 2005

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“…Five bacterial species known to be associated with contamination of CBUs were used in this study . These bacteria either were obtained from the American Type Culture Collection (ATCC) ( Escherichia coli [ATCC 25922] and Staphylococcus epidermidis [ATCC 49134]) or were isolated in‐house from contaminated blood products or CBUs ( Klebsiella pneumoniae [CLI‐UL‐01], Streptococcus agalactiae [CLI‐LSPQ‐37], and Bacteroides fragilis [CLI‐LSPQ‐19]).…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, inoculum volumes, culture bottles being used, as well as delays between CB processing, culture bottle inoculation, and culture launch vary substantially between CBBs. These operational discrepancies likely contribute to the wide variation, ranging from 0 to 48%, in the incidence of contaminated CB products among CBBs . In our organization, samples for sterility testing are prepared by diluting from 2 to 4 mL of the final CBU product in 25 mL RPMI‐1640 culture medium.…”

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confidence: 99%

Optimization of cord blood unit sterility testing: impact of dilution, analysis delay, and inhibitory substances

et al. 2017

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BACKGROUND: Different methods are used by cord blood banks to prepare samples for sterility testing. Suboptimal methods can result in the release of contaminated products. In our organization, samples are prepared by diluting the final product in RPMI-1640 medium. In this work, we have compared our method with different approaches to verify whether optimization should be sought. STUDY DESIGN AND METHODS:Cord blood units (n 5 6 units per bacterial strain) characterized to contain inhibitory substances or not were inoculated (10 colonyforming units/mL) with Streptococcus agalactiae, Staphylococcus epidermidis, Klebsiella pneumoniae, Escherichia coli, or Bacteroides fragilis. After plasma and red blood cell removal, stem cell concentrates were diluted in RPMI-1640, thioglycollate, or the unit's plasma. These products, as well as final product, plasma, and red blood cell fractions, were held from 0 to 72 hours at 20 to 248C before inoculation in culture bottles and detection using the BacT/ALERT 3D system. RESULTS: Dilution of cell concentrates in RPMI-1640allowed bacterial detection in 93.3% of noninhibitory cord blood samples after a 24-hour storage period. Thioglycollate medium better promoted bacterial growth in inhibitory cord blood samples that were held for 72 hours before testing (66.7%) compared with RPMI-1640 (45.0%). Less than 33% of all spiked plasma samples were detected by the BacT/ALERT 3D system. CONCLUSION:Diluting cord blood samples in culture medium containing bacterial growth promoting substances is a suitable option for sterility testing, whereas the use of plasma should be proscribed, because it might lead to false-negative results. Because inhibitory substances affect bacterial growth, inoculation of culture bottles should be done rapidly after sample preparation. U mbilical cord blood (CB) transplantation is indicated for severely immunocompromised patients. These patients have a high risk of contracting infections associated with the transplant. Given the nonsterile collection environment and the numerous procedures carried out before transplantation, microbial contamination of cord blood units (CBUs) is more frequent than for any other blood product.1-3 Consequently, the efficient microbial screening of CB donations remains a primary safety concern for cord blood banks (CBBs) while also being required by international accreditation organizations, such as the American Association of Blood Banks and the Foundation for the Accreditation of Cellular Therapy. 4,5 The development of standardized procedures for microbial screening of CBUs is still being awaited. The lack of consensus standards led to CBBs developing their own method for microbial screening. Generally, a sample of the final volume-reduced CB product is used for sterility testing; however, postprocessing plasma, red blood cell (RBC) fraction, a mixture of these by-products, or a small volume of the final stem cell concentrate (which includes the cryopreservation solution) are also used for microbial ABBREVIATIONS: ATCC 5 American Ty...

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Microbial contamination of cord blood stem cells

Cited by 34 publications

References 24 publications

Comparison of the Bactec 9240 and BacT/Alert Blood Culture Systems for Evaluation of Placental Cord Blood for Transfusion in Neonates

Comparison of the Bactec 9240 and BacT/Alert Blood Culture Systems for Evaluation of Placental Cord Blood for Transfusion in Neonates

Microbial contamination of hematopoietic progenitor cell grafts—incidence, clinical outcome, and cost‐effectiveness: an analysis of 735 grafts

Optimization of cord blood unit sterility testing: impact of dilution, analysis delay, and inhibitory substances

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