Evaluation of Blood Culture System for Culture of Body Fluids / 임상검사와정도관리

BACKGROUND: Invasive and life-threatening infections such as meningitis, pericarditis, peritonitis, empyema, and septic arthritis are diagnosed via culture of relevant body fluids (BFs). The blood culture system (BCS) has been reported to be a useful alternative for BFs culture to enhance recovery of fastidious microorganisms and reduce detection time. The aim of this study was to evaluate the diagnostic performance of BCS as compared to conventional culture method (CCM) in terms of culture yield. METHODS: The samples collected between October 2011 and September 2012 were processed using CCM, while those collected between October 2012 and September 2013 were processed using BCS. The 2 processes were compared in terms of total number of requests, recovery rate, turnaround time (TAT), and detection time. RESULTS: The positive rate using CCM was 18.2% (575/3,151), where 845 isolates were recovered from 575 specimens. Using BCS, the positive rate was 28.3% (922/3,260), where 1,472 isolates were recovered from 922 specimens. While comparing the 2 methods on terms of yield of clinically significant isolates, a greater number of fungi (1.2%) and anaerobic bacteria (1.4%) were recovered using BCS as compared to using CCM. The difference in TAT for positive samples was 24 hours and 40 minutes, where BCS had a shorter TAT than CCM. The mean detection time of 951 positive samples by BCS was 19 hours and 56 minutes. Growth of clinically significant isolates was detected within 24 hours. CONCLUSIONS: BCS for culture of BFs showed an improvement in recovery rate, number of isolates, and TAT as compared to CCM. Thus, BCS is a suitable alternative for culture of BFs.

Prenatal Diagnosis of der(X)t(X;Y)(p22.31;q11.22) in a Male Fetus by Using Array Comparative Genomic Hybridization

Xp/Yq translocations are rare chromosomal rearrangements, and the phe-notype of male carriers varies according to the segment of the Xp region that is deleted. In this case report, we describe a der(X)t(X;Y)(p22.31;q11.22) translocation, detected by conventional cytogenetic analysis, in a male fetus at a gestational age of 16 weeks. Chromosomal analysis of parental blood confirmed that this chromosomal aberration had been maternally inherited. Array comparative genomic hybridization (CGH) analysis of fetal blood further indicated a nullisomy of Xp22.31-pter and a breakpoint between the STS and KAL1 genes. The STS, NLGN4, ARSE, CSF2RA, and SHOX genes are present in the region that was deleted, and are known to be related to conditions such as X-linked ichthyosis, chondrodysplasia punctata, mental retardation, and facial dysmorphism in humans. Prenatal ultrasonographic findings and autopsy results were consistent with Xp22.31-pter deletion phenotypes. Genetic counseling was provided for the mother. The observations from this case study indicate that advanced molecular techniques can provide a more precise prenatal diagnosis of chromosomal anomalies than conventional cytogenetics can.

Molecular Cytogenetic Characterization of Supernumerary Marker Chromosomes by Chromosomal Microarray

PURPOSE: Supernumerary marker chromosome (SMC) could be associated with various phenotypic abnormalities based on the chromosomal origin of SMCs. The present study aimed to determine the genomic contents of SMCs using chromosomal microarray and to analyze molecular cytogenetic characterizations and clinical phenotypes in patients with SMCs. MATERIALS AND METHODS: Among patients with SMCs detected in routine chromosomal analysis, SMCs originating from chromosome 15 were excluded from the present study. CGH-based oligonucleotide chromosomal microarray was performed in 4 patients. RESULTS: The chromosomal origins of SMCs were identified in 3 patients. Case 1 had a SMC of 16.1 Mb in 1q21.1-q23.3. Case 2 showed 21 Mb gain in 19p13.11-q13.12. Case 3 had a 4.5 Mb-sized SMC rearranged from 2 regions of 2.5 Mb in 22q11.1-q11.21 and 2.0 Mb in 22q11.22-q11.23. CONCLUSION: Case 1 presented a wide range of phenotypic abnormalities including the phenotype of 1q21.1 duplication syndrome. In case 2, Asperger-like symptoms are apparently related to 19p12-q13.11, hearing problems and strabismus to 19p13.11 and other features to 19q13.12. Compared with cat-eye syndrome type I and 22q11.2 microduplication syndrome, anal atresia in case 3 is likely related to 22q11.1-q11.21 while other features are related to 22q11.22-q11.23. Analyzing SMCs using high-resolution chromosomal microarray can help identify specific gene contents and to offer proper genetic counseling by determining genotype-phenotype correlations.