Microbiological contamination in stem cell cultures

Abstract

Cell therapy and regenerative medicine are potentially two of the most exciting aspects of the novel therapeutic methods currently under development. However, these treatments present a number of important biosafety issues, like the possible transmission of microorganisms to the recipients. The most common potential form of contamination in these cell products is by bacteria (including Mycoplasma), yeast and fungi. In our study, 32 stem cell lines and feeder cell lines were analysed. There were 19 contaminated cell passages (12%). The main contaminants were gram positive cocci and Mycoplasma species, followed by gram negative rods and gram positive rods. The Mycoplasma contamination rate was 4%. Stem cell banks and other research centres aim to screen all processed stem cell lines for these microorganisms, and to assure that no contaminants are introduced in the banking procedures. It is a standard part of current good practice in stem cell banks to carry out routine microbiological controls of the stem cell lines and to work in a controlled environment to reduce the probability of contamination in the final product.

Microbial and Viral Contamination of Animal and Stem Cell Cultures: Common Contaminants, Detection and Elimination

“…In an analysis of 32 stem cell lines and feeder cell lines, there were 19 contaminated cell passages (12%) -the main contaminants were gram positive cocci and Mycoplasma species, followed by gram negative rods and gram positive rods. 2 In this study, the Mycoplasma contamination rate was 4%. The microbial contamination of hematopoietic stem cell products may lead to potentially fatal complication of hematopoietic stem cell transplantation.…”

“…Lotto-lot variation in hormones and growth factors in sera, presence of endotoxins in water or sera or other culture additives (trypsin, amino acids etc), free radicals generated in media by the photo-activation of tryptophan, riboflavin or HEPES exposed to fluorescent light can all spoil a culture medium. 7 Residues from germicides used to disinfect incubators, equipments and labs, and impurities in gases used in CO 2 incubators have also been found to affect cell culture. 8 However, the major source of microbial contamination is documented to arise by contact with non-sterile supplies, media and solution, chemicals and equipments, and by the particulate matter and aerosols that fall out during transportation and incubation.…”

Conditions and Techniques for Mouse Embryonic Stem Cell Derivation and Culture

“…Therefore, they must be prepared continuously. Additionally, the traits of mEFs differ from batch to batch, and quality control of mEFs, especially for mycoplasma contamination, may be the problems [86,87]. Moreover, hFFs are more durable than mEFs in that they remain in healthy condition more than 2 weeks after inactivation by radiation.…”

Stem Cell Technology–Emerging Framework for Hazard Assessment and Biosafety Considerations

“…Blood borne pathogen standards are not limited to HIV and HBV; they also include the entire spectrum of adventitious agents in cell-based process and product development activities. For example, Cobo et al (2007) reported microbial contamination in stem cell cultures by bacteria (including Mycoplasma), yeast, and fungi. This study, based on an analysis of 32 stem cell and feeder cell lines, revealed contamination of nearly 12 percent of the cell lines mainly with gram-positive cocci and Mycoplasma species, followed by gram-negative rods.…”