Microbial contamination survey of a large cohort human placentas and umbilical cords with development of a multiplex qPCR assay targeting E. coli, C. albicans, and E. faecium.

Microbial contamination during the collection of placental and umbilical cord tissues presents a significant challenge to the safety of stem cell-based therapies and the commercial storage. In this study, microbial contamination analysis of a large cohort placental and umbilical cord samples collected recent revealed with 38 distinct microbial species identified. Contaminated samples were predominantly from vaginal deliveries (82.7 %), and higher contamination rates were observed in mothers aged ≥30 years. For rapid monitoring, we developed a novel multiplex quantitative PCR assay for simultaneous detection of the most prevalent contaminants: Escherichia coli, Candida albicans, and Enterococcus faecalis. The assay demonstrated robust detection limits in pure cultures, with a lower limit of detection of 102 CFU/mL for E. coli and C. albicans, and 101 CFU/mL for E. faecalis. Based on the analytical performance described above, this multiplex qPCR assay establishes a robust framework for rapid, quantitative surveillance of microbial contaminants in placental-derived biologics. By enabling same-shift screening with sensitivity down to 10 CFU/mL, the method significantly enhances quality assurance protocols for stem cell banking a critical advancement toward safer clinical translation of placental-based therapeutics.