Distribution, origin and contamination risk of coagulase-negative staphylococci from platelet concentrates

Abstract

Transfusion-associated bacterial sepsis is the most common microbiological risk of transfusion and is caused mostly by platelet concentrates (PCs). The most frequently identified bacterial contaminants of PCs are coagulase-negative staphylococci (CNS). In order to learn more about the distribution, source and risk of the CNS that are involved in bacterial contamination of PCs, CNS strains isolated during platelet screening were collected and characterized to the species level with three different methods: 16S rRNA and sodA gene sequencing, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and amplified fragment length polymorphism (AFLP) analysis. AFLP analysis was also used for the typing of the CNS strains. A total of 83 CNS strains were analysed by sequencing and 8 different CNS species were identified, with Staphylococcus epidermidis being the predominant species. MALDI-TOF MS and AFLP analysis confirmed these results to a large extent. However, MALDI_TOF MS could not identify all strains to the species level and AFLP analysis revealed an additional, likely novel, CNS species. The species identified are mainly recognized as being part of the normal skin flora. Typing of the CNS strains by AFLP analysis showed that there was not a unique strain which is significantly more often present during bacterial contamination of PCs.

Platelet Transfusion in the Neonatal Intensive Care Unit: Benefits, Risks, Alternatives

“…Some such risks are at least partly defined, such as a risk of bacterial contamination of the donor platelets [35] . Other risks are poorly defined but still quantifiable.…”

Monitoring mitochondrial inner membrane potential for detecting early changes in viability of bacterium-infected human bone marrow-derived mesenchymal stem cells

“…The risk of microbial contamination is well recognized in the propagation of cells for therapeutic use, but little has been published to demonstrate and characterize possible effects of contamination and infection on stem cell properties and hence on the viability and ultimately on the safety monitoring of cell therapy products [10,12,14-16]. Accordingly, in the present study, we chose to focus on the quality control point of view of microbial risks during the in vitro manufacture of BMMSC-based cellular products.…”

“…Even though the incidents of microbial contamination of cell products seem to be rare, the risk of contamination is a critical issue since the consequences to patient health may be unpredictable and even devastating [10-16]. Currently, there is little or no evidence to predict the long-term outcomes of possible infections after cell implantation.…”

“…A variety of different pathogens have been isolated from cellular products, and the most common is coagulase-negative Staphylococcus spp . [10-16]. Moreover, a recent study has elucidated the ability of different pathogens, namely S. aureus , S. epidermidis , and Pseudomonas aeruginosa , to adhere to a biomaterial surface in the presence and absence of macrophages [20].…”

“…The bacteria included two strains of P. aeruginosa , three strains of Staphylococcus aureus , and three strains of Staphylococcus epidermidis . P. aeruginosa , which is a Gram-negative rod, and the Gram-positive cocci S. aureus and S. epidermidis have been shown to be common contaminants of cell products and in the hospital environment [10-16,34]. Two of the bacterial strains had previously been isolated from discarded, contaminated batches of blood products, making them biologically relevant models for studying the contamination process of stem cell cultures.…”