Utility of an immunoglobulin gene rearrangement assay based on multiplex PCR in detecting bone marrow involvement in B-cell non-Hodgkin lymphoma

No abstract available.

Detection of Rotavirus from the Inner Surfaces of Domestic Refrigerators

BACKGROUND: Rotavirus is the leading cause of acute viral gastroenteritis, particularly in children, and is transmitted through the fecal-to-oral route by contaminated food or the environment. This study examined the contamination of the inner surfaces of domestic refrigerators with pathogens causing gastroenteritis. METHODS: Swab specimens from shelf surfaces of freezers and refrigerators were collected from 10 domestic refrigerators. Multiplex PCR for bacterial and viral pathogens causing acute gastroenteritis was performed. The VP7 and VP4 genes of rotavirus were amplified and then analyzed by DNA sequencing. RESULTS: Rotavirus was detected in five domestic refrigerators in the same apartment complex. All rotavirus samples showed the G1 genotype and the same DNA sequences. No pathogens causing acute gastroenteritis were identified in the other five domestic refrigerators. CONCLUSIONS: The inner surfaces of domestic refrigerators can be contaminated with pathogens causing acute gastroenteritis, such as rotavirus. Attention should be given to the hygiene of refrigerators. To estimate the contamination or hygienic status for food storage, testing for viral pathogens combined with ordinary bacterial cultures may be necessary.

Abnormalities in Chromosomes 1q and 13 Independently Correlate With Factors of Poor Prognosis in Multiple Myeloma

BACKGROUND: We comprehensively profiled cytogenetic abnormalities in multiple myeloma (MM) and analyzed the relationship between cytogenetic abnormalities of undetermined prognostic significance and established prognostic factors. METHODS: The karyotype of 333 newly diagnosed MM cases was analyzed in association with established prognostic factors. Survival analysis was also performed. RESULTS: MM with abnormal karyotypes (41.1%) exhibited high international scoring system (ISS) stage, frequent IgA type, elevated IgG or IgA levels, elevated calcium levels, elevated creatine (Cr) levels, elevated β2-microglobulin levels, and decreased Hb levels. Structural abnormalities in chromosomes 1q, 4, and 13 were independently associated with elevated levels of IgG or IgA, calcium, and Cr, respectively. Chromosome 13 abnormalities were associated with poor prognosis and decreased overall survival. CONCLUSIONS: This is the first study to demonstrate that abnormalities in chromosomes 1q, 4, and 13 are associated with established factors for poor prognosis, irrespective of the presence of other concurrent chromosomal abnormalities. Chromosome 13 abnormalities have a prognostic impact on overall survival in association with elevated Cr levels. Frequent centromeric breakpoints appear to be related to MM pathogenesis.

Intestinal Microflora and Atopy Development in Infants during the First Nine Months / 대한임상미생물학회지

BACKGROUND: The intestinal microflora varies according to the factors such as age, diet and environment. It is debated whether the changes of microbiota after birth are associated with atopic disease. The purpose of this study was to investigate colonization rates of some intestinal microflora during the initial 9 months after birth, and their association with the development of atopy. METHODS: Stool specimens were collected at 1, 3, 7 days and at 1, 2, 4, 6, 9 months after birth, and Escherichia coli, Lactobacillus, Bifidobacterium, Staphylococcus aureus were cultured with selective media. Diagnosis for atopy was accomplished via clinical history of atopy, serum total IgE, and skin prick test. RESULTS: By 12 months of age, among 48 infants, 36 (75.0%) were non-atopic while 12 (25.0%) had developed atopy. Although not statistically significant, the intestinal microflora of infants with atopy vs. non-atopy was characterized by being less often colonized with E. coli (12.5% vs. 52.4%; P=0.093) and S. aureus (0% vs. 38.1%; P=0.066) at three days after birth. Colonization rates of E. coli reached 50% after 3 days of birth in non-atopy group whereas this rate was not achieved until after 1 month in the atopy group. CONCLUSION: The intestinal colonization rates of bacteria in this study were not statistically different between atopy and non-atopy groups. Rapid colonization of E. coli and S. aureus was observed within 1 week after birth in the non-atopy group. The exact association between atopy and the bacterial colonization and/or diversity in the early days after birth has yet to be determined.

HMOX1 Gene Promoter Polymorphism is Not Associated with Coronary Artery Disease in Koreans

BACKGROUND: The heme oxygenase-1 gene (HMOX1) promoter polymorphisms modulate its transcription in response to oxidative stress. This study screened for HMOX1 polymorphisms and investigated the association between HMOX1 polymorphisms and coronary artery disease (CAD) in the Korean population. METHODS: The study population consisted of patients with CAD with obstructive lesions (n=110), CAD with minimal or no lesions (n=40), and controls (n=107). Thirty-nine patients with CAD with obstructive lesions underwent follow-up coronary angiography after six months for the presence of restenosis. The 5'-flanking region containing (GT)n repeats of the HMOX1 gene was analyzed by PCR. RESULTS: The numbers of (GT)n repeats in the HMOX1 promoter showed a bimodal distribution. The alleles were divided into two subclasses, S25 and L25, depending on whether there were less than or equal to and more than 25 (GT)n repeats, respectively. The allele and genotype frequencies among groups were statistically not different. More subjects in the S25-carrier group had the low risk levels of high sensitivity C-reactive protein (hsCRP) for the CAD than those in the non-S25 carrier group (P=0.034). Multivariate logistic regression analysis revealed that the genotypes of (GT)n repeats were not related to CAD status. The restenosis group in the coronary angiography follow-up did not show any significant difference in HMOX1 genotype frequency. CONCLUSIONS: The HMOX1 genotypes were not found to be associated with CAD, but the short allele carrier group contained more individuals with hsCRP values reflecting low risk of cardiovascular disease in the Korean population.

A Case of der(19)t(1;19) in Refractory Anemia with Ring Sideroblasts Associated with Marked Thrombocytosis

Translocation between chromosomes 1 and 19 is well documented in ALL. Here, we report a case of refractory anemia with ring sideroblasts associated with marked thrombocytosis with der(19)t(1;19). A 67-yr-old man was admitted to our hospital with anemia and thrombocytosis. The aspirated bone marrow showed erythroid and megakaryocytic hyperplasia and dyspoiesis. Iron staining showed that the ring sideroblasts increased in number. Bone-marrow cell karyotyping showed 46,XY,der(19)t(1;19)(q23;p13)[9]/46,XY,del(5)(q21)[2]/46,XY[9]. PCR analysis showed the absence of the TCF3-PBX1 rearrangement. The patient was treated with hydroxyurea and intermittent blood transfusion. It is known that t(1;19)(q23;p13) leads to a TCF3-PBX1 fusion gene, whose product is a powerful transcriptional activator that plays a key role in the development of ALL. However, t(1;19) has rarely been reported in myeloid neoplasms and the TCF3-PBX1 fusion gene has not been detected. This implies that other genes might be involved in the TCF3-PBX1 rearrangement, or an alternative TCF3-PBX1 fusion transcript with a different breakpoint has not been detected to date. Further research and case studies, including the use of molecular analysis techniques, are required to evaluate the clinical and prognostic significance of t(1;19) in the development of myeloid neoplasms.

Contamination of X-ray Cassettes with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus haemolyticus in a Radiology Department

BACKGROUND: We performed surveillance cultures of the surfaces of X-ray cassettes to assess contamination with methicillin-resistant Staphylococcus aureus (MRSA). METHODS: The surfaces of 37 X-ray cassettes stored in a radiology department were cultured using mannitol salt agar containing 6 microg/mL oxacillin. Suspected methicillin-resistant staphylococcal colonies were isolated and identified by biochemical testing. Pulsed-field gel electrophoresis (PFGE) analysis was performed to determine the clonal relationships of the contaminants. RESULTS: Six X-ray cassettes (16.2%) were contaminated with MRSA. During the isolation procedure, we also detected 19 X-ray cassettes (51.4%) contaminated with methicillin-resistant Staphylococcus haemolyticus (MRSH), identified as yellow colonies resembling MRSA on mannitol salt agar. PFGE analysis of the MRSA and MRSH isolates revealed that most isolates of each organism were identical or closely related to each other, suggesting a common source of contamination. CONCLUSIONS: X-ray cassettes, which are commonly in direct contact with patients, were contaminated with MRSA and MRSH. In hospital environments, contaminated X-ray cassettes may serve as fomites for methicillin-resistant staphylococci.

A Case of Therapy-related Myeloid Neoplasm after Successful Treatment of Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is considered as a curative disease after combined chemotherapy based on all-trans retinoic acid (ATRA) and anthracycline. However, as long-term survivors continue to increase, reports on sporadic cases of therapy-related myeloid neoplasm (t-MN) after successful APL treatment are also increasing. Recently, we have experienced one patient who developed t-MN 7 yr after APL diagnosis. Even though he had not been exposed to alkylating agents at all, he showed alkylating agents-associated features such as long latency period (>5 yr), first presentation as myelodysplatic phase (multilineage dysplasia with increased blasts), and complex karyotype including monosomy 5 and 7. He received only supportive care and expired 3 months after the diagnosis of t-MN (6 months of survival after the onset of cytopenias). t-MN after complete remission of APL is a rare but fatal complication, and patients with complex karyotypes show ominous prognosis in particular. For the early diagnosis of t-MN, long-term and close monitoring of the patient is needed. One should suspect this late complication whenever any unknown cytopenia develops, and should perform bone marrow biopsy and cytogenetic analysis.

A Serial Study of Hematologic Change in Burned Patients / 임상검사와정도관리

BACKGROUND: Hematologic changes in burned patients show unique patterns with time after burn injury. In this study, we analyzed the changes of leukocyte count, hemoglobin concentration, and platelet count according to elapsed time and burn size. METHODS: A total of 265 burned patients were included in this retrospective study. The changes in leukocyte count, hemoglobin, and platelet count according to elapsed time were analyzed every 6 hours from immediately after burn injury until day 2, and then every 24 hours from day 3 to day 14. The differences according to burn size were also analyzed. All the results were expressed as mean+/-standard deviation. RESULTS: Leukocyte count, hemoglobin, and platelet count began to increasing immediately after burn injury, reaching the peak within 12 hours after injury, and then decreased. WBC count was lowest at days 3 to 4 and then began increasing, reaching the second peak at day 7-8. Hemoglobin level continuously decreased and remained at the level of anemia from day 4 to day 14. Platelet count was lowest at days 3-4 and then continuously increased until day 14. The wider the burn sizes were, the greater the changes in leukocyte count, hemoglobin, and platelet count, with 11-40% of the patients showing the most remarkable increase in the number of platelets after day 4. CONCLUSIONS: The leukocyte count, hemoglobin concentration and platelet count were dramatically changed within the first 72 hours after burn injury and the wider the burn sizes were, the greater these changes were. These results could be used as reference data for interpreting the results of complete blood count in burned patients.

Isolation of Healthcare-Associated Pathogens from Cellular Phones Used by Medical Personnel / 병원감염관리

BACKGROUND: Cellular phone has become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. We investigated the bacterial contamination of cellular phones used by medical personnel in a tertiary hospital. METHODS: Culture swabs were obtained from 101 cellular phones and 99 anterior nasal cavities from medical personnel using cellular phones. The swabs were inoculated on blood agar, MacConkey agar, mannitol salt agar, and enterococcal broths containing 6microgram/mL vancomycin for 48 h at 37degrees C. The bacteria were identified on the basis of colony morphology, gram staining characteristics, catalase test, coagulase test, and DNase test; Microscan (Siemens, USA) was used for the identification of enterococci. RESULTS: Of the 101 cellular phones, 13 were contaminated with Staphylococcus aureus (including 4 methicillin-resistant S. aureus [MRSA]), 61 with coagulase-negative staphylococci (CoNS) (including 38 methicillin-resistant CoNS), 27 with Micrococcus spp., 11 with diphtheroids, 67 with Bacillus spp., and 4 with viridans streptococci. No gram-negative bacilli were isolated. Nasal swabs yielded 36 S. aureus, including 9 MRSA. Only 1 of 9 cellular phones used by the MRSA carriers was contaminated with MRSA. CONCLUSION: Cellular phones used by some medical personnel were contaminated with pathogens such as S. aureus or MRSA. Although, the clinical implications of pathogens isolated from cellular phones have not been fully investigated, pathogens could be transmitted by the hands of medical personnel who are cellular phone users.

Annual Report on External Quality Assessment in Diagnostic Genetics in Korea (2009) / 임상검사와정도관리

BACKGROUND: The quality control for genetic tests would be of great importance as the test volume and clinical demands increase dramatically. Diagnostic genetics subcommittee of KSQACL performed two trials for cytogenetics and molecular genetics surveys in 2009. METHODS: A total of 67 laboratories participated in the cytogenetic surveys, 30 laboratories participated in the FISH surveys, and 94 laboratories participated in the molsecular genetics surveys in 2009. RESULTS: Almost of them showed acceptable results. However, some laboratories showed unacceptable results for the karyotype nomenclature and detection of complex cytogenetic abnormalities in hematologic neoplasms, and most of them except one showed acceptable results in FISH surveys. The molecular genetics surveys included various tests: M. tuberculosis detection, hepatitis B (HBV) and C virus (HCV) detection and quantification, human papilloma virus (HPV) genotyping, Influenza A (H1N1) detection, gene rearrangement tests for leukemias and lymphomas, apolipoprotein E (APOE) genotyping, methylenetetrahydrofolate reductase (MTHFR) genotyping, hereditary breast and ovarian cancer genes (BRCA1 and BRCA2), and genetic tests for achondroplasia (FGFR3), FMS-like tyrosine kinase 3 (FLT3), JAK2, BRAF, hereditary disorders such as spinal muscular atrophy, Huntington disease (HD), spinocerebellar ataxia (SCA), Prader-Willi/Angelman syndrome (PWS/AS), mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), myoclonic epilepsy ragged red fiber (MERRF), wilson disease (ATP7B) and cancer-associated genes (KRAS). Molecular genetic surveys showed excellent results in most of the participants. CONCLUSIONS: External quality assessment program for genetic analysis in 2009 was proved to be helpful in continuous education and evaluation of quality improvement.

Comparison of Rapid Antigen Test and Real-Time Reverse Transcriptase PCR for Diagnosing Novel Swine Influenza A (H1N1) / 대한임상미생물학회지

BACKGROUND: Novel swine influenza (H1N1) was first identified in Mexico in April 2009. Because of its high infectivity and worldwide distribution, a rapid and efficient screening test is necessary. Here we evaluated the usefulness of a rapid antigen test currently in use, compared to real-time RT-PCR (rRT-PCR) as a screening test for detection of novel swine influenza (H1N1). METHODS: A total of 1,228 patients who visited Hallym University Kangdong Sacred Heart Hospital with influenza-like illness between 14 August 2009 and 30 September 2009, and were tested by both rapid antigen and rRT-PCR tests, were enrolled in this study. RESULTS: Sensitivity, specificity, predictive value of a positive test, and predictive value of a negative test for the rapid antigen test were 30.5%, 99.2%, 86.4% and 90.1%, respectively. Fifty-one (4.2%) patients were positive for both rapid antigen test and rRT-PCR, and 1,053 (85.7%) were negative for both rapid antigen test and rRT-PCR. A total of 124 (10.1%) patients showed a discrepancy between the two tests. Among them, 116 (9.4%) were only positive for rRT-PCR and 8 (0.7%) were only positive for the rapid antigen test. The latter 8 patients all showed negative H1/M2 results in rRT-PCR. There were significant differences in detection rates of the rapid antigen test between different H1 Ct (threshold cycle) interval groups and for different age groups (P<0.05). CONCLUSION: Although the rapid antigen test is easy to perform and provides fast results, its limits as a screening test for detection of novel swine influenza (H1N1) due to its low sensitivity compared to rRT-PCR need to be considered in practical situations.

Lot-to-lot Reagent Variation in Immunoassay: Retrospective Analysis of Daily Quality Control Results / 임상검사와정도관리

BACKGROUND: Lot-to-lot reagent reproducibility is an important issue in immunoassays. However, there have been no universal criteria for acceptable lot-to-lot reproducibility. We sought to evaluate the inter-lot reagent difference by analyzing the results of various quality control materials during a certain period of time. METHODS: The results of control materials using different reagent lots and same control lots for immunoassays of HBsAg, anti-HBs, alpha-fetoprotein (AFP), ferritin, and CA 19-9 were analyzed. The average value, standard deviation, and coefficient of variation obtained from each reagent lot were calculated and differences in mean control values between two different reagent lots were assessed. We also analyzed the difference between the last control result using one reagent and the first control result using a new reagent. RESULTS: There was no significant difference in control values among reagent lots during this study period in all immunoassays of HBsAg, anti-HBs, AFP, ferritin, and CA 19-9. Some of the reagents showed statistical differences in QC values, but the difference was not considered clinically different. Also, at the time of reagent lot change, there was no significant difference in reagent parallel tests. CONCLUSIONS: Lot-to-lot reagent variation was not significant in immunoassays evaluated in this study. However, this study has been performed during relatively short period by one to three reagent lot changes, parallel testing should be continuously checked at reagent lot changes in each laboratory for continuous quality assurance. These results can be used as basic data for setting the criteria of acceptance on inter-lot difference in reagent parallel tests.

A Case of Mosaic Ring Chromosome 4 with Subtelomeric 4p Deletion / 대한진단검사의학회지

Ring chromosome is a structural abnormality that is thought to be the result of fusion and breakage in the short and long arms of chromosome. Wolf-Hirschhorn syndrome (WHS) is a well-known congenital anomaly in the ring chromosome 4 with a partial deletion of the distal short arm. Here we report a 10-month-old male of mosaic ring chromosome 4 with the chief complaint of severe short stature. He showed the height of -4 standard deviation, subtle hypothyroidism and mild atrial septal defect/ventricular septal defect, and also a mild language developmental delay was suspected. Brain magnetic resonance imaging showed multifocal leukomalacia. Chromosomal analysis of the peripheral blood showed the mosaic karyotype with [46,XY,r(4)(p16q35)[84]/45,XY,-4[9]/91,XXYY, dic r(4;4)(p16q35;p16q35)[5]/46,XY,dic r(4;4)(p16q35;p16q35)[2]]. FISH study showed the deletion of the 4p subtelomeric region with the intact 4q subtelomeric and WHS region. Both paternal and maternal karyotypes were normal. We compared the phenotypic variation with the previously reported cases of ring chromosome 4. The ring chromosome 4 with the subtelomeric deletion of short arm seems to be related with the phenotype of short stature.

Annual Report on External Quality Assessment in Hematology in Korea (2008) / 임상검사와정도관리

Four trials of external quality assessment in diagnostic hematology were performed in 2008 with average 822 participating laboratories in Korea. We performed quality assessment for white blood cell count, hemoglobin, hematocrit, red blood cell count, platelet count, blood cell morphology, prothrombin time and activated partial thromboplastin time. The response rate was more than 96.5%. The coefficients of variation in hemoglobin, hematocrit and RBC was stable but variable in platelet count and WBC count according to measuring cell count. Test results of blood cell morphology showed variation among various cell morphologies.

Creatinine Interference dependent on Glucose and Creatinine Concentrations / 임상검사와정도관리

BACKGROUND: In peritoneal dialysis patients, measurement of creatinine is an important marker of kidney function and gives an information for assessment of dialytic adequacy. High glucose concentration in peritoneal dialysis fluid is known to interfere with creatinine measurement. Creatininine interference with kinetic Jaffe method for glucose and creatinine concentration must be considerated for giving accurate informations about the assessment of dialytic adequacy. METHODS: 10% dextrose fluid (Daihan Pharm Co., Korea) was diluted to prepare specimens with seven different glucose concentrations. Creatinine solutions with seven different concentrations were made with creatinine powder (Sigma-Aldrich Co., USA) and distilled water. The prepared specimens were mixed with equal volume to make total 49 specimens of different glucose and creatinine concentrations. The glucose concentrations of specimens were ranging from 200 mg/dL to 5,000 mg/dL and the creatinine concentrations of specimens were ranging from 0 mg/dL to 10 mg/dL. The specimens were assayed for creatinine with two automated chemistry analysers, Hitachi 7600-110 (Hitachi, Japan) and Unicel DXC 800 (Beckman Coulter Inc., USA). Creatinine HR reagent (Wako Pure Chemical Industries, Japan) and CREA reagent (Roche Diagnostics, Germany) were used in Hitachi 7600-110 analyser, and CREm reagent (Beckman Coulter Inc., Ireland) was used in Unicel DXC 800. RESULTS: Interference of creatinine measurement varied with both glucose and creatinine concentrations to different extent in different analytical systems and reagents. It was observed that creatinine interference increased with increasing glucose concentration in all the systems and reagents. At constant glucose concentration, creatinine interference showd a downward tendency with increasing creatinine concentration among the three reagents. CONCLUSIONS: High glucose concentration and creatinine concentrations provoked the interference of creatinine measurement and the aspect of creatinine interference varied according to the analytic systems and reagents. Each center performing creatinine assay should allow for the creatinine interference and give an accurate results to clinicians.

Nosocomial Infectious Bacterial Contamination onResidents' White Coats and Neckties / 대한임상미생물학회지

BACKGROUND: Doctors' white coats and neckties can become contaminated with potentially pathogenic bacteria and have a possibility of causing cross infections. Our objective was to determine the level of bacterial contamination and detect methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and Clostridium difficile present on the white coats and neckties of residents. METHODS: We sampled 28 long-sleeved white coats and 14 neckties worn by residents. The tested sites for white coats were the cuffs and lower front surfaces, and for neckties, the lower surfaces. Impressions of these sites were taken with the plates containing blood agar (BAP), mannitol salt agar supplemented with oxacillin (6microgram/mL), enterococcus screening agar supplemented with vancomycin (6microgram/mL) and phenyl ethanol agar. The colonies grown on each plate were Gram stained and identified by standard microbiological methods. RESULTS: Of the 28 white coats, 7 (25.0%) carried MRSA, and of the 14 neckties, 1 (7.1%) carried MRSA. The majority of white coats (96.4%) and all neckties (100.0%) carried methicillin-resistant coagulase negative staphylococci (MRCNS). None of the white coats and neckties carried VRE or C. difficile. CONCLUSION: Our results showed that white coats and neckties worn by residents were contaminated with MRSA and MRCNS. The preventive measures for clothing-borne cross contamination should be considered, especially when performing invasive procedures or having close contact with patients.

Erratum: Panton-Valentine Leukocidin Positive Staphylococcus aureus Isolated from Blood in Korea / 대한진단검사의학회지

This erratum is being published to correct the printing error on page 286 of the article entitled 'Panton-Valentine leukocidin positive Staphylococcus aureus isolated from blood in Korea' by Kim JS, Park JS, Song W, Kim HS, Cho HC, Lee KM, Kim EC in Korean J Lab Med 2007;27:286-91. DOI 10.3343/kjlm. 2007.27.4.286 as follows. The heading of the right column of the Table 1 was misprinted as methicillin-resistant, so it should be corrected to methicillin-susceptible.

Evaluation of the ABX Pentra DX 120 for the Detection of Immature Cells in Peripheral Blood / 임상검사와정도관리

INTRODUCTION: The ABX Pentra DX 120 (Pentra DX 120, ABX Diagnostics, Montpellier, France) adopted new technologies to perform differential leukocyte and erythroblast counts. The double matrix can discriminate Large Immature Cell (LIC), Immature Granulocyte (IMG), Immature Monocyte (IMM), Immature Lymphocyte (IML), and Atypical lymphocyte (ALY) in addition to a routine 5-differential count. For erythroblast (ERB), a fluorescence method is employed. In this study, we evaluated the performance of the Pentra DX 120 in the performance of differential leukocyte and erythroblast counts. METHODS: Precision was evaluated using 3-level control materials. Comparison analysis was performed on 200 samples: 100 normal and 100 abnormal samples. We evaluated the 5 part differential count, LIC, IMG, IMM, IML, ALY, and ERB. These parameters were analyzed in comparison with the results from the reference method, manual differential count. RESULTS: The coefficients of variation (CVs) of precision were 0.9 except monocytes and basophils. IMG, ALY and erythroblasts were also well correlated with manual count (r=0.8315, 0.5602, 0.8144, respectively). The efficiency of flagging system was 84% for LIC, 80% for ALY, and 78.0% for increased ERB (>2/100WBCs). CONCLUSIONS: The Pentra DX 120 performed reliable differential leukocyte and IMG, ALY, and ERB results demonstrated comparable performance to manual count. And, the flagging system was efficient for detecting each abnormal cell population. We expect the Pentra DX 120 double matrix and erythroblast count can reduce microscopic review rate in routine laboratory and promote laboratory efficiency.

Evaluation of MRSASelect for Discrimination of Methicillin-resistant Staphylococcus aureus from Other Staphylococci / 임상검사와정도관리

BACKGROUND: It is now recognized that screening for methicillin-resistant Staphylococcus aureus (MRSA) in hospital is an effective infection control measure, and selective media-based methods have been commonly used. MRSASelect (MRSAS; Bio-Rad, Hercules, CA, USA) is MRSA selective agar incorporating chromogenic enzymatic substrates, and have been found to be more sensitive and specific than other selective media. The aim of present study was to evaluate MRSAS for discrimination of MRSA from other staphylococci by comparison with mannitol-salt agar with oxacillin (MSO) which is widely used as a MRSA selective medium. METHODS: Ninety-eight staphylococcal strains which were isolated from blood culture specimen, representing 16 MRSA, 6 methicillin-susceptible S. aureus, 59 methicillin-resistant coagulase- negative staphylococci (MRCNS), and 17 methicillin-susceptible coagulase-negative staphylococci were tested. The isolated colonies from pure culture were directly inoculated onto MSO and MRSAS respectively. On MRSAS any growth appearing pink after 24 hours incubation, and on MSO any growth appearing yellow after 48 hours incubation was interpreted as positive for the presence of MRSA. RESULTS: Sensitivities of MRSAS and MSO for MRSA detection were equal (93.8%). Specificities for MRSA discrimination from other staphylococci were 98.8% and 89.0%, and especially from MRCNS were 100% and 84.7%, for MRSAS and MSO, respectively. CONCLUSIONS: The MRSAS showed equal sensitivity compared with MSO for the detection of MRSA. MRSAS showed higher specificity than MSO in discrimination MRSA from MRCNS. It was suggested that the implementation of MRSAS in MRSA screening could decrease the work needed for MRCNS identification.