Molecular Identification and Amphotericin B Susceptibility Testing of Clinical Isolates of Aspergillus From 11 Hospitals in Korea

BACKGROUND: We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. METHODS: A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and beta-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. RESULTS: ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by beta-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of > or =2 microg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was < or =75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). CONCLUSIONS: Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.

Analysis of ABO Blood Discrepancies and Transfusion Experiences in Chonnam National University Hospital / 대한수혈학회지

BACKGROUND: ABO blood group discrepancy occurs when the results of red cell tests do not agree with those of the serum test. In order to select the proper blood units for transfusion, clarification of the cause of ABO discrepancies is essential. We analyzed the cases and recent actual transfusion experiences at Chonnam National University Hospital (CNUH). METHODS: In total, among pre-transfusion blood samples at CNUH between January 2012 and July 2013, 55 cases of ABO discrepancies were analyzed retrospectively. RESULTS: The discrepancy incidence was 0.14%. Problems with serum were the most common cause of ABO discrepancies, with 31 cases (56.4%), and extra serum reactivity due to cold allo-antibodies accounted for the highest frequency (n=7). There were three cases of non-specific aggregations caused by commercial RBC constituents and aggregation was not observed when a re-test was performed with other commercial RBCs or self-prepared human RBCs. Two of three cases with mix-field aggregations involved a pair of twins after in vitro fertilization - embryo transfer (IVF-ET). Among 55 patients, 20 were actually transfused, and all but four cases had weaker or identical RBC units and stronger or identical plasma units. CONCLUSION: There were newly revealed ABO discrepancies caused by non-specific aggregations of commercial RBCs and in twins after IVF-ET. In addition, investigation of actual transfusion experiences in patients with ABO blood group discrepancies would be helpful.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.

Morphological analysis of mandibular posterior edentulous bones using cross-sectional CT images / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to evaluate the morphologic features of posterior edentulous mandible for Korean patients using cross-sectional CT images. MATERIALS AND METHODS: Computed tomographic cross-sectional views taken in 2004 and 2005 at Seoul National University Dental Hospital were analyzed by an oral and maxillofacial radiologist. Four indices were measured to meet the purpose of this study: 1) the horizontal distance between the alveolar crest and mandibular canal (Type), 2) the angle of the mandibular long axis (Angle), 3) the bucco-lingual location of mandibular canal, and 4) the depth of the submandibular fossa. The averages and standard deviations of the measurements were compared according to the location (the first and second molar area) and sex of the patients. RESULTS: Statistically significant difference was found in Type, Angle, and submandibular fossa depth between the first and second molar area (p.0.05). However, there was no significant difference between men and women in any of the measured indices. Most of the mandibular canals were located in lingual side of posterior mandible. CONCLUSION: More care should be taken when an implant is installed on the mandibular second molar area.