BACKGROUND: Microbial screening tests of umbilical cord blood (UCB) are essential for stem cell transplantation. We analyzed the microbial contamination rate and distribution of isolated microorganisms over 10 years of samples from the MEDIPOST Cord Blood Bank. In addition, we studied the influence of inoculum volume microorganism culture and compared the yield and speed of microorganism detection. METHODS: Microbial screening tests were performed using a manual method, which includes using an inoculum of 2 mL of plasma, a byproduct of UCB processing from pediatric culture bottles. When positive blood culture was detected, each set was once again inoculated with 2 mL and 4 mL of plasma. RESULTS: From 2004 to 2013, a total of 133,610 UCB units were screened, of which 1,311 (0.9%) tested positive for contamination. The most frequently identified microorganism was Escherichia coli (34.6%), followed by Bacillus spp. (12.8%), Enterococcus faecalis (5.3%) and Klebsiella pneumoniae (4.4%). The total yield rate increased by 0.2% over this time period, although the yield rate of Bacillus spp. increased by 8.3%. CONCLUSION: The results of this study could be used in many ways with both domestic and international data regarding cord blood contamination. Also, other microbiology laboratories using culture conditions similar to ours could refer this study when preparing guidelines. Finally, by detecting low levels of bacteria, we have contributed to cord blood safety.
Bacillus ; Bacteria ; Enterococcus faecalis ; Escherichia coli ; Fetal Blood* ; Klebsiella pneumoniae ; Mass Screening ; Plasma ; Stem Cell Transplantation ; Umbilical Cord*

In this study,we developed a simple screening procedure for the determination of 18 anthelmintics(including benzimidazoles,macrocyclic lactones,salicylanilides,substituted phenols,tetrahydropyr-imidines,and imidazothiazoles)in five animal-derived food matrices(chicken muscle,pork,beef,milk,and egg)using liquid chromatography-tandem mass spectrometry.Analytes were extracted using acetonitrile/1％acetic acid(milk and egg)and acetonitrile/1％acetic acid with 0.5 mL of distilled water(chicken muscle,pork,and beef),and purified using saturated n-hexane/acetonitrile.A reversed-phase analytical column and a mobile phase consisting of(A)10 mM ammonium formate in distilled water and(B)methanol were used to achieve optimal chromatographic separation.Matrix-matched standard calibration curves(R2≥0.9752)were obtained for concentration equivalent to ×1/2,×1,×2,×3,×4,and ×5 fold the maximum residue limit(MRL)stipulated by the Korean Ministry of Food and Drug Safety.Recoveries of 61.2-118.4％,with relative standard deviations(RSDs)of ≤19.9％(intraday and interday),were obtained for each sample at three spiking concentrations(×1/2,×1,and ×2 the MRL values).Limits of detection,limits of quantification,and matrix effects were 0.02-5.5 μg/kg,0.06-10 μg/kg,and-98.8 to 13.9％(at 20 μg/kg),respectively.In five samples of each food matrix(chicken muscle,pork,beef,milk,and egg)purchased from large retailers in Seoul that were tested,none of the target analytes were detected.It has therefore been shown that this protocol is adaptable,accurate,and precise for the quantification of anthelmintic residues in foods of animal origin.