title: Molecular characterization of microbial contaminants isolated from Umbilical Cord Blood Units for transplant.
abstract: Disposal of Umbilical Cord Blood Units due to microbial contamination is a major problem in Cord Blood Banks worldwide as it reduces the number of units available for transplantation. Additionally, economic losses are generated as result of resources and infrastructure used to obtain such units. Umbilical Cord Blood Units that showed initial microbial contamination were subject to strains isolation, identification, and characterization by sequencing the 16S rRNA gene and Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR). Moreover, tests of antimicrobial resistance/sensitivity and phenotypic activities that may play an important role in microbial infection were performed. Microbial contamination was detected in 120 Umbilical Cord Blood Units (2.31%) in the period from 2003 to 2013. The most frequently isolated strains were Enterococcus faecium, followed by Staphylococcus epidermidis, Escherichia coli, Enterococcus faecalis, Staphylococcus haemoliticus, Klebsiella pneumoniae, Enterococcus durans, Lactobacillus helveticus, Enterococcus hiriae and Roseomonas genomospecies 5. The ERIC-PCR assays revealed a wide genetic diversity in some strains although belonging to the same genus and specie, indicating different sources of contamination. Broad-spectrum penicillins, third generation cephalosporins, aminoglycosides, and fluoroquinolones showed lower inhibitory activity on the tested strains. All strains were proteolytic, 67.69% were amylase-positive, 27.6% hemolysis-positive, and 34.71% nuclease-positive. The most common sources of contamination were: vaginal flora, digestive tract, and skin flora, highlighting the need for staff training in good manufacturing practices in collection SCU since all contaminants identified are part of the microbial flora of the donors. Implications and consequences in the therapeutic use of Umbilical Cord Blood Units for transplantation contaminated by multiresistant bacteria in immunocompromised patients are discussed.
authors.affiliation: Centro Nacional de la Transfusión Sanguínea, México D.F., México. Electronic address: juanmanuelbello81@hotmail.com.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Bello-López
authors.affiliation: Centro Nacional de la Transfusión Sanguínea, México D.F., México.
authors.forename: Jorge
authors.initials: J
authors.lastname: Noguerón-Silva
authors.affiliation: Universidad Autónoma Metropolitana, unidad Xochimilco, México D.F., México.
authors.forename: Jorge Ismael
authors.initials: JI
authors.lastname: Castañeda-Sánchez
authors.affiliation: Centro Nacional de la Transfusión Sanguínea, México D.F., México.
authors.forename: Julieta
authors.initials: J
authors.lastname: Rojo-Medina
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001771:Blood Banks; D001793:Blood Preservation; D036101:Cord Blood Stem Cell Transplantation; D005312:Fetal Blood / Q000382:microbiology*; D005819:Genetic Markers; D005838:Genotype; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D006801:Humans; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010802:Phylogeny; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D005819:Genetic Markers
keywords: Microbial contamination; Molecular characterization; Umbilical Cord Blood Units