Gloria Soria

Microbiological testing protocols are key components of human milk bank operations, yet the lack of consensus on screening schedules and microbiological criteria leads to variability in discard rates and uncertainty about safety standards. This study provides a large-scale characterization of pre-pasteurization donor human milk microbiota and evaluates the impact of testing protocols on operational outcomes. Over 59 months, 7,921 donor human milk batches were analysed. Pre-pasteurization analyses were dominated by skin staphylococci, with environmental Gram-negative bacilli and enteric genera detected at lower prevalence. Among pathogens of concern, only Staphylococcus aureus , Escherichia coli and Bacillus cereus sensu lato were identified. A selective 24-h workflow, incorporating BACARA® plates with a detection limit of 1 CFU/mL, was validated and implemented to target these organisms within the pre-pasteurization 24-h storage interval. This protocol significantly increased B. cereus s.l. detection (2.2% vs. 8.8%), without affecting S. aureus or Enterobacteriaceae detection, indicating improved analytical sensitivity. B. cereus s.l. exhibited a reproducible warm-season excess (5.5% vs. 2.4%) and accounted for 72% of post-pasteurization positives. In a sub-study of 491 batches, agreement between pre- and post-pasteurization B. cereus s.l. results was good ( κ ≈ 0.61) with a high negative predictive value (95%), supporting the predictive value of early screening. Protocol design was a major determinant of discard rates, and using higher microbiological thresholds (2 × 10 ⁵ CFU/mL) reduced avoidable losses without compromising safety. These findings hightlight the importance of integrating rapid, selective methods and advancing towards harmonized, risk-based microbiological criteria in human milk banking to improve both operational efficiency and microbiological safety.

Fungal contamination of donor corneas, although rare, constitutes a serious infection risk to recipients. Therefore, microbiological quality control with methods optimized for fungal detection is crucial in eye banks to detect and discard contaminated corneas. This study aimed to compare the performance of different BACT/ALERT^® bottles (iFA Plus and iLYM) incubated at different temperatures (32 °C and 37 °C) when corneal preservation media, with or without amphotericin B, were cultured. A total of 6 culture conditions were compared by inoculation of fewer than 100 colony-forming units of 18 fungi (10 yeasts and 8 filamentous fungi). iFA Plus bottles incubated at 32 °C reliably detected 94.4% of fungi, regardless of amphotericin B presence, while iLYM bottles detected 77.8% in the absence of amphotericin B and 72.2% in its presence. At 37 °C, iFA Plus fungal detection decreased to 61.1%. iFA Plus bottles incubated at 32 °C provided the highest detection rates, effectively neutralizing the effect of amphotericin B and enabling recovery of both yeasts and filamentous fungi, except for Cladosporium. Our findings support that the optimal strategy for cornea sterility testing is incubating iFA Plus bottles at 32 °C for optimal fungal recovery, while maintaining iFN Plus at 37 °C to allow timely detection of anaerobic bacteria.

Donor human milk (DHM) can harbor microbial contaminants that cause serious infections in premature infants. Bacillus cereus is a pathogen frequently found in DHM, capable of forming spores that can resist Holder pasteurization (62.5 °C, 30 min). Since no microbial growth is acceptable in post-pasteurized DHM, microbiological testing of pre-pasteurized DHM provides information about its contamination level to determine if it should be accepted for pasteurization. Culture is the gold standard in microbiological control but it requires 24–48 h to provide results. In this study we developed and validated a non-commercial real-time PCR assay for the detection of Bacillus cereus (BC test) in DHM specimens on a fully automated high-throughput platform, the cobas^® 6800 system. The BC test showed excellent sensitivity and specificity, repeatability and linearity over an 8-log range and a low limit of detection in milk specimens, as well as good agreement with selective culture methods. BC test was then used to systematically control all milk donations (3439) over a 24-month period. Bacillus cereus was detected in 14.2% of DHM, with monthly rates ranging from 6 to 29% and a significantly higher incidence in warmer months. Incorporating this assay into our laboratory workflow improved efficiency and reduced turnaround time.

Background: Umbilical cord blood (CB) units stored in banks are an important source of hematopoietic stem cells for transplantation and other cell therapies. New applications, such as their use in transfusions, require rapid quality release as cord blood red blood cells (CB‐RBC) have a shorter shelf life.Study Design and Methods: This project aims to investigate the most prevalent microbial contaminants in CB preparations and validate a rapid sterility testing strategy for CB‐RBC based on an automated system (BACT/ALERT®) in tandem with a molecular assay (real‐time PCR) capable of detecting at least 100 CFU/mL of Cutibacterium acnes in CB‐RBC to accelerate the detection of the most common slow‐growing bacteria.Results: Microbial contamination incidence was assessed by reviewing 4696 CB sterility tests, revealing a positivity rate of 3.4%, with C. acnes being the most common slow‐growing pathogen. The BACT/ALERT® system, which was validated according to European Pharmacopeia guidelines, was an appropriate method for sterility testing of CB‐RBC, although it required up to 14 days of culture to detect C. acnes when iFAPlus and iFNPlus bottles were used to neutralize antimicrobials. Interestingly, the BACT/ALERT® method detected C. acnes at 30 CFU/mL within 14 days, while real‐time PCR identified concentrations ≥65 CFU/mL by Day 4.Discussion: In conclusion, we developed a rapid sterility testing strategy that combines automated culture systems and real‐time PCR for early microbial contamination, enhancing CB‐RBC shelf life for transfusion and emphasizing the importance of combining detection methods.

Prematurity is a significant health issue due to its incidence and associated complications. Anemia is common in extremely preterm infants (EPI) and often requires transfusions. Red blood cells (RBC) from adult blood (AB) donors have been linked to oxygen-related complications in EPI, leading to the exploration of cord blood (CB) as an alternative source. However, standardization of CB-RBC manufacturing and comparison with AB-RBC characteristics are necessary before clinical studies can be conducted. This study investigated the quality and characteristics of leukoreduced, gamma-irradiated CB-RBC obtained using a commercial closed system from CB donations not meeting hematopoietic transplantation criteria. CB-RBC units were compared with AB-RBC units, both stored in saline-adenine-glucose-mannitol (SAGM). Various parameters, including hematological and biochemical characteristics, pH, 2,3-DPG levels, blood gases and potential toxicants, were evaluated during storage. CB-RBC units had acceptable initial quality parameters and a hematocrit (55±2%) comparable to AB-RBC. The main finding during storage was a faster rise in hemolysis compared to AB-RBC. Potassium (K+) significantly increased during storage in both sources. As expected, glucose levels decreased, and conversely, lactate levels increased, indicating similar patterns of anaerobic glycolysis during storage. pH decreased, affecting the oxygen dissociation curve due to reduced 2,3-DPG levels. After irradiation at 14 days of storage, CB-RBC were less stable as hemolysis and K+ significantly increased compared to AB-RBC at 24 hours. Phthalate concentrations, indicative of plasticizers, increased during storage, but significantly less in CB compared to AB-RBC. Most metals measured were within acceptable ranges. The quality of CB-RBC during storage is primarily influenced by levels of hemolysis and extracellular K+ content. Based on the analyzed parameters, we suggest that the expiration date for CB-RBC stored with SAGM should be set at 14 days, with transfusion occurring within <24 hours after irradiation.

Cell therapies are required to meet with compulsory regulations that co-exist with other optional standards and guidelines that together compose a complex quality management system. Indeed, reliable insights on the mechanisms of action and safety of novel cell-based therapies require adherence to solid quality management structures in all steps of the value chain, from early research and tissue procurement to clinical trials and biovigilance, thus guaranteeing reproducibility and solid foundations for better science and improved clinical practice. Herein we present the concept of the quality ecosystem as a tool to understand and assist all stakeholders involved in developing and structuring the integration of standards as novel developments are taking place. We conclude that the various quality management initiatives can all be thought about under the umbrella of an ecosystem.

Background - The COVID-19 pandemic is placing blood and tissue establishments under unprecedented stress, putting its capacity to provide the adequate care needed at risk. Here we reflect on how our integrated organisational model has faced the first impact of the pandemic and describe what challenges, opportunities and lessons have emerged. Materials and methods -The organisational model of the Catalan Blood and Tissue Bank (Banc de Sang i Teixits, BST) is described. The new scenario was managed by following international recommendations and considering the pandemic in a context of volatility, uncertainty, complexity, and ambiguity (VUCA), allowing rapid measures to be taken. These aimed to: ensure donor safety, promote proper responses to patients' needs, ensure the health and well-being of personnel, and prepare for future scenarios. Results - The BST has adapted its activities to the changes in demand. No shortage of any product or service occurred. Donor acceptance, safety and wellbeing were maintained except for tissue donation, which almost completely stopped. To support the health system, several activities have been promoted: large-scale convalescent plasma (CP) production, clinical trials with CP and mesenchymal stromal cells, massive COVID-19 diagnoses, and participation in co-operative research and publications. Haemovigilance is running smoothly and no adverse effects have been detected among donors or patients. Discussion - Several elements have proven to be critical when addressing the pandemic scenario: a) the early creation of a crisis committee in combination with technical recommendations and the recognition of a VUCA scenario; b) identification of the strategies described; c) the integrated donor-to-patient organisational model; d) active Research and Development (R & D); and e) the flexibility of the staff. It is essential to underline the importance of the need for centralised management, effective contingency strategies, and early collaboration with peers.

Introduction: Pre‐analytical and analytical errors can threaten the reliability of flow cytometry (FC) results. A potential solution to some of these is the use of dry, pre‐mixed antibodies, such as the ClearLLab 10C system. The purpose of the present study was to compare the diagnostic performance of the ClearLLab 10C B cell tube with that of our standard laboratory practice.Methods: We compared the diagnoses made with the ClearLLab 10C B cell tube (experimental strategy) with those made with standard laboratory practice (standard strategy). Samples were selected aiming for representation of the full spectrum of B cell disorders, with an emphasis on mature B cell malignancies, as well as healthy controls.Results: We included 116 samples (34 normal controls, 4 acute lymphoblastic leukemias, 54 mature lymphoproliferative disorders in peripheral blood and bone marrow, 3 myelomas, 6 bone marrow samples with involvement by lymphoma and 1 with elevated hematogone count, 14 lymph node samples, 1 cerebrospinal fluid, and 1 pleural effusion). There were two diagnostic errors (1.7%). The agreement between the two strategies in the percentage of CD19 cells and fluorescence intensity of CD5, CD19, CD20, CD200, and CD10 was very good.Conclusions: In this study, the ClearLLab 10C B cell tube performed similarly to our standard laboratory practice to diagnose and classify mature B cell malignancies.