BACKGROUND: Antimicrobial resistance to third-generation cephalosporins in gram-negative bacteria, especially Enterobacter, Citrobacter, and Serratia spp., is increasing. The resistance mechanism of these organisms are hyperproduction of AmpC beta-lactamase and plasmid-mediated extended-spectrum beta-lactamase (ESBL). This study was to determine the occurrence of AmpC hyperproduction and ESBLs in E. cloacae, C. freundii, and S. marcescens over a 3-month period in 2002. METHODS: We tested total of 619 consecutive, nonduplicate isolates (229 E. cloacae, 183 C. freundii, 207 S. marcescens) from 12 university hospitals and a commercial laboratory in Korea. Antimicrobial susceptibilities were tested using the disk diffusion method. AmpC hyperproduction was defined as nonsusceptible to cefotaxime or ceftazidime for E. cloacae and C. freundii and as nonsusceptible to cefotaxime for S. marcescens. ESBL production was determined by the double disk synergy test. RESULTS: Among the E. cloacae, C. freundii and S. marcescens derepressed strains were 20.5%, 30.1%, and 31.4% and ESBL producers were 23.6%, 10.9%, and 15.5%, respectively. The AmpC derepressed strains and ESBL producers revealed lower susceptibility rates for ciprofloxacin, piperacillin, piperacillin-tazobactam and aminoglycosides. CONCLUSIONS: These data reveal that the occurrence of AmpC derepressants and ESBL producers among E. cloacae, C. freundii and S. marcescens is relatively high. Continued nationwide surveillance is necessary to provide information on the spread of these important mechanisms of resistance to beta-lactams.
Aminoglycosides ; beta-Lactamases ; beta-Lactams ; Cefotaxime ; Ceftazidime ; Cephalosporins ; Ciprofloxacin ; Citrobacter ; Citrobacter freundii* ; Cloaca ; Diffusion ; Enterobacter ; Enterobacter cloacae* ; Gram-Negative Bacteria ; Hospitals, University ; Korea ; Piperacillin ; Serratia ; Serratia marcescens*

BACKGROUND: Inorganic arsenic trioxide (As2O3) has emerged as a new drug of choice for refractory acute promyelocytic leukemia (APL). But, the curable disease spectrum and the arsenic resistance in association with the expression of multidrug resistance (MDR) proteins are not yet to be established. METHODS: Five de novo APL and 20 refractory acute leukemia cases were selected. Leukemic cells were cultured for 24 hr in media with various As2O3 concentrations. Apoptotic cells or damaged cells were measured by a morphologic examination after Wright stain and flow cytometry using annexin V/propidium iodide (PI) stain. The lowest concentration of As2O3 at which greater than 90% of leukemic cells were damaged morphologically was defined as the morphologic arsenic sensitivity of leukemic cells. MDR protein markers including multidrug resistance associated protein (MRP), lung resistance protein (LRP), P-glycoprotein (PGP) and glutathinoe-S-transferase (GST) were analyzed by flow cytometry. RESULTS: The leukemic cells from de novo APLs (in 3 of 5) were sensitive to arsenic trioxide, compared to refractory acute leukemia (only 1 of 20). Of the five MDR proteins examined, only PGP was expressed more in the arsenic resistant cases (in 8 of 21) than in the sensitive cases (none of 4) (P=.032). CONCLUSIONS: Refractory acute leukemia had a variable arsenic sensitivity, but were more resistant than de novo APL. The arsenic resistance seems to be related to PGP expression.
Arsenic ; Drug Resistance, Multiple ; Flow Cytometry ; Leukemia* ; Leukemia, Promyelocytic, Acute* ; Lung ; Multidrug Resistance-Associated Proteins ; P-Glycoprotein

BACKGROUND: The aim of this study is to organize the maximum surgical blood order schedule (MSBOS) of red blood cells (RBCs) for elective surgeries according to the International Classification of Diseases, Ninth Revision, Clinical Modification guidelines (ICD-9-CM) and we compared the results with the previously reported MSBOSs. METHODS: From 1 March to 31 August 2007, the data of the transfused RBCs for elective surgeries in our hospital were analyzed. The MSBOS was organized as the average number of units of transfused RBCs for the type of surgery, according to the ICD-9-CM. The results were compared with the MSBOSs that were previously reportedfrom 1982 to 2004 in Korea. RESULTS: A total of 121 types of 3,375 surgeries were performed. Type & screen for 91 types (81.3%), 1 unit for 20 types (13.8%), 2 units for 7 types (3.8%), 3 units for 1 type (0.4%) and 4 units for 2 types (1.8%) were recommended. There was a minimal difference between these results and the range for the previously reported MSBOSs. CONCLUSION: It seems that the MSBOS showed minimal change since 2004. We organized the MSBOS according to the guidelines of the ICD-9-CM. Standardization of the surgery name should be considered to achieve more useful utilization of MSBOS.
Appointments and Schedules ; Erythrocytes ; International Classification of Diseases ; Korea

Streptococcus pneumoniae is the most common cause of community-acquired pneumonia in adults and an important agent in other infections, including meningitis, otitis media, and conjunctivitis, etc. The optochin susceptibility test is the most widely used method to discriminate S. pneumoniae from other streptococci. However, 0.8-1.5% of S. pneumoniae contain optochin resistant population. Recently, we experienced three cases of variants of S. pneumoniae with decreased susceptibility to optochin. Equivocal optochin disk test should be confirmed by bile solubility, agglutination test, or DNA probe test.
Adult ; Agglutination Tests ; Bile ; Conjunctivitis ; DNA ; Humans ; Meningitis ; Otitis Media ; Pneumonia ; Solubility ; Streptococcus pneumoniae* ; Streptococcus*

Stenotrophomonas maltophilia is a motile, non-fermentative, gram-negative rod. It is one of the important nosocomial pathogens associated with substantial morbidity and mortality such as pneumonia and bacteremia in immunocompromised patients. It should be carefully examined in the course of identification because it is frequently isolated together with other non-fermentative, gram-negative rods from clinical specimens. We report an isolate of S. maltophilia showing an oxidase-positive reaction, which is very rare for the species.
Bacteremia ; Humans ; Immunocompromised Host ; Indophenol ; Pneumonia ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Stenotrophomonas ; Stenotrophomonas maltophilia

Methods: The precision, linearity, limit of detection (LOD), correlation with the Abbott m2000 assay, and interference were evaluated. Results: The within-laboratory standard deviation ranged from 0.106 to 0.137 log IU/mL for HBV and from 0.073 to 0.097 log IU/mL for HCV, which was lower than the manufacturer’s specification of 0.25 log IU/mL, indicating good precision. Linearity was observed from 1.14 to 8.14 log IU/mL for the HBV assay and from 1.09 to 7.09 log IU/mL for the HCV assay. The LODs of HBV and HCV were 10 and 6.39 IU/mL, respectively, which were equivalent to or better than those claimed by the manufacturer. For comparative evaluation between Alinity m and m2000 assays, 142 HBV and 70 HCV samples were tested. The correlation test revealed a strong correlation for both markers, and the Passing–Bablok regression analysis did not reveal any significant deviation. Conclusions The Alinity m assay demonstrated excellent performance for HBV and HCV quantifications with reduced hands-on time and a randomaccess format.

Background: This study was conducted to evaluate the analytical performance of the SelexOnTM B-type natriuretic peptide (BNP) assay (Osang Healthcare Inc., Korea), a new rapid lateral flow immunoassay for point of care (POC) testing using whole blood. Methods: The imprecision, linearity, and method comparison of SelexOnTM BNP assay were evaluated. Two commercial BNP assays, the ADVIA Centaur® BNP (Siemens Health Care diagnostics Inc., USA) and the Triage® BNP assays (Alere, USA), were included for method comparison using 100 whole blood samples from patients. The reference interval was verified using 120 residual samples from health examination participants. Results: The SelexOn BNP had total CVs of 20.3%, 13.3%, and 10.3% in BNP concentrations of 89.44 pg/mL, 480.71 pg/mL, and 1,201.84 pg/mL of control materials, respectively. Linearity was observed from 56 pg/mL to 1544 pg/mL. The SelexOn BNP (y) regression equation was y=0.9706x-21.68 with Centaur BNP (x) (r=0.930) and y=0.7600x+0.0506 with Triage BNP (x) (r=0.845), respectively. The predicted mean difference (%) of the SelexOn BNP at the clinical decision levels (100 pg/mL) was up to 25% lower than the two comparative methods. The SelexOn BNP levels were below 50 pg/mL in 114 (95%) of the 120 samples. Conclusions The SelexOn BNP using EDTA was developed as a POC test for differential diagnosis or treatment monitoring for acute heart failure. However, clinical decision values must be improved to be compatible with other BNP methods.

BACKGROUND: We investigated the prevalence of various pathogens (13 enteric bacteria and 5 viruses) which cause diarrhea using multiplex PCR of stool specimens and compared two multiplex PCR methods for detecting diarrheagenic Escherichia coli. METHODS: A total of 405 stool specimens submitted between November 2010 to February 2011 for routine culture of enteric pathogens were included and screened for five viruses (astrovirus, Group A rotavirus, enteric adenovirus, norovirus G1/G2) and eight bacteria (Salmonella spp., Shigella spp., Campylobacter spp., Vibrio spp., C. difficile Toxin B, C. perfringens, Y. enterolytica, Aeromonas spp.) using the Seeplex(R) Diarrhea ACE detection kit (Seegene). In addition, virulence-associated genes of enteropathogenic E. coli, (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli, (EIEC), enterotoxigenic E. coli (ETEC), and enteroaggressive E. coli (EAEC) were detected using 16-plex PCR and a commercial diarrheagenic E. coli detection (DEC) PCR kit (SSI Diagnostica). RESULTS: Overall, 138 (34.1%) of 405 samples was positive for pathogen. The positive rate for virus was 18.5%. norovirus G2, Group A rotavirus, enteric adenovirus, astrovirus and norovirus G1 were detected in 40, 23, 8, 3 and 1 samples, respectively. The positive rate for bacteria was 24.4% (99/405). C. difficile toxin B was the most frequently detected, followed by C. perfringens, EPEC, and EAEC. The agreements of the two multiplex PCR methods for detecting EPEC and EHEC were 99.3% and 100%, respectively. CONCLUSION: The detection rate was high (34.1%) including various diarrheagenic E. coli (6.2%) and C. perfringens (5.2%). Multiplex PCR is thus useful for detecting various pathogens.
Adenoviridae ; Aeromonas ; Bacteria ; Campylobacter ; Diarrhea ; Enterobacteriaceae ; Enterohemorrhagic Escherichia coli ; Enteropathogenic Escherichia coli ; Enterotoxigenic Escherichia coli ; Escherichia ; Escherichia coli ; Multiplex Polymerase Chain Reaction ; Norovirus ; Polymerase Chain Reaction ; Prevalence ; Rotavirus ; Shigella ; Vibrio ; Viruses

No abstract available.
Disinfectants

BACKGROUND: An automated immunohematology analyzer, DAYMATE M (DAY Medical, Switzerland), has been recently developed. The potential of this analyzer to improve test results has been evaluated. METHODS: A total of 300 blood samples from Seoul St. Mary's hospital and Incheon St. Mary's hospital were tested for ABO and RhD typing. In addition, 336 antibody screening test (AST) samples and 82 patients treated with hematopoietic stem cell transplantation (HSCT) were included. AST results by DAYMATE M were compared with those obtained by a manual method using DS-Screening II (Bio-Rad Laboratories, Switzerland) and red blood cells from Selectogen (Ortho-Clinical diagnostics Inc., USA). RESULTS: Of the 300 patients enrolled, 87, 73, 79, and 61 had type A, B, O, and AB blood, respectively. The concordance rate was 99.9% for cell typing and 97.0% for serum typing. One discordant case was classified as type B instead of AB, and six discordant serum-typing cases were type A, but classified as type AB. Among the 336 AST samples, the concordance rate was 93.2%. From 136 positive cases, six were discordant. Within the 82 HSCT-treated patients, the concordance rate for ABO blood typing was 92.2%. Among the six discordant cases, DAYMATE M typed four cases as donor type where the standard method typed them as the recipient blood type. CONCLUSIONS: The DAYMATE M automated immunohematology analyzer performs reliably for ABO and RhD typing, as well as for ASTs and on samples from patients treated with HSCT.
Blood Grouping and Crossmatching ; Erythrocytes ; Hematopoietic Stem Cell Transplantation ; Humans ; Incheon ; Mass Screening ; Methods ; Seoul ; Tissue Donors