Annual Report on the External Quality Assessment Scheme for Clinical Microbiology in Korea (2015)

Annual proficiency surveys were conducted in March, June, and September in 2015 by the Clinical Microbiology Subcommittee of the Korean Association of External Quality Assessment Service. The program covers the sections of bacteriology, advanced bacteriology and mycology, mycobacteriology, and parasitology. Each trial was composed of three sets of different combinations of five bacteria and yeasts. These sets were distributed among laboratories for Gram staining, culture, identification, and antimicrobial susceptibility tests. Five slides with fixed sputum smears were provided as part of each trial for acid-fast bacilli detection. The survey material distribution was section-based. Two survey materials were provided in each trial, while five specimens for mycobacterial culture and identification, five specimens for anti-tuberculosis susceptibility testing and two Mycobacterium tuberculosis strains for rapid detection of rifampin and isoniazid resistance were distributed in the March and June trials. Five virtual microscopy files for stool parasite examination were availed by registered participants in the June trial. Out of the 334 enrolled laboratories, 328 (98.2%), 328 (98.2%), and 329 (98.5%) submitted responses in trials I, II, and III, respectively. Identification of bacteria, namely, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Vibrio fluvialis by more than 95% of participants was acceptable. Surveillance cultures for vancomycin-resistant enterococci and carbapenem-resistant Enterobacteriaceae were determined accurately by 75.8%–85.3% and 93.1% of the respondents, respectively. Species-level identification of Candida krusei, Candida lusitanae, and Candida guilliermondii was still low at 79.8%, 55.7%, and 42.7%, respectively. Disk diffusion method revealed an unacceptably high false-positive rate of resistance to glycopeptides in E. faecalis and to trimethoprim-sulfamethoxazole in S. pneumoniae. Advanced bacteriology trials revealed unsatisfactory results for species-level identification of moulds. Mycobacterial culture, identification and susceptibility testing, and molecular detection of rifampin and isoniazid resistance were performed exceedingly well by participants. Hymenolepsis diminuta could not be identified by participants, with a correct answer rate of only 46.5% and ‘no parasite seen’ answer rate of only 31.8% for negative specimens. Species-level identification of Candida and moulds was challenging for clinical microbiology laboratories. Disk diffusion method was found to be problematic in testing the susceptibility of microorganisms to glycopeptides and trimethoprim-sulfamethoxazole. Improvement is required in result interpretation of negative specimens in parasitology.

Annual Report on External Quality Assessment Scheme for Clinical Microbiology in Korea (2014)

Annual proficiency surveys were performed in March, June and September 2014 by clinical microbiology division of The Korean Association of Quality Assurance for Clinical Laboratory. Parasitology part has been newly incorporated in this survey. For each trial, three sets which were composed of different combinations of five bacteria and yeast were distributed for gram stain, culture, identification, and antimicrobial susceptibility tests of general bacteriology and five fixed sputum smear on slides were distributed for acid fast bacilli stain. Two advanced bacteriology survey materials for culture and identification of anaerobic bacteria and mold were distributed to the voluntary participants in every trial and five mycobacterial culture and identification specimens, five anti-tuberculosis susceptibility testing specimens, and two Mycobacterium tuberculosis strains for rapid detection of rifampin and isoniazid resistance were distributed to the voluntary participants in March and June trials. Five virtual microscopic slides for stool parasite examination were open for the registered participants in June trial. A total of 340 laboratories were enrolled and 330 (97.0%), 331 (97.4%), and 331 (97.4%) returned the results on trial I, II, and III, respectively. For bacterial identification, the percent acceptable identification of Burkholderia cepacia, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, Streptococcus agalactiae, Plesiomonas shigelloides, and Enterococcus faecalis were greater than 95%. Group C and group D Salmonella species challenged as the different sets of M1422 resulted in the acceptable rate lower than 95% because nine participants reported the identification of different sets. Surveillance cultures for methicillin-resistant S. aureus and vancomycin-resistant enterococci were correctly determined by 89.6% and 69.0% of the respondents, respectively. Correct identification to species level of Candida albicans, Candida auris, Candida glabrata, and Candida parapsilosis were 86.1%, 1.6%, 48.1%, and 83.8%. Vancomycin disk diffusion test in S. aureus, missing oxacillin screen or penicillin susceptibility test in S. pneumoniae and lack of reliable methods of quinolone resistance detection in Salmonella species caused unacceptable results in antimicrobial susceptibility testing. Advanced bacteriology trials revealed low performance in species identification of mold. Mycobacterial culture, identification and susceptibility test performance was kept in excellence. The performance of identification of stool parasites was acceptable >90% for detection of helminth eggs and amebic cysts but 28.6% false positive responses resulted from negative specimens. In conclusion, species-level identification of fungi of both candida species and mold were challenging to clinical microbiology laboratories. Vancomycin disk diffusion method for S. aureus and lack of proper penicillin susceptibility test for S. pneumoniae were still common cause of inaccurate results. Virtual microscopic survey has been successfully introduced in parasitology.

Annual Report on External Quality Assessment Scheme in Clinical Microbiology in Korea (2013) / 임상검사와정도관리

Annual external quality assessment was performed three times for clinical microbiology division of The Korean Association of Quality Assurance for Clinical Laboratory. For each trial, three sets composed of different combinations of four bacteria and one yeast were distributed for culture, identification, and antimicrobial susceptibility tests. A total of 340 laboratories were enrolled and 330 (97.0%), 331(97.4%), and 331(97.4%) returned the results on trial I, II, and III, respectively. For bacterial identification, the correct identification of gram-negative bacilli, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus capitis, Streptococcus agalactiae, Listeria monocytogenes, and Candida species was greater than 95%. However, correct identification of Staphylococcus lugdunensis, Corynebacterium striatum, Vibrio vulnificus, Aeromonas hydrophila, Cryptococcus neoformans, and Malassezia pachydermatis was relatively less accurate, with values of 95.4%, 89.9%, 50.7%, 91.3%, 93.6%, and 93.9%, respectively. Surveillance cultures for vancomycin-resistant enterococci and methicillin-resistant S. aureus were correctly determined by 95.4% and 93.9% of the respondents, respectively. False carbapenem-resistance due to AmpC beta-lactamase, disk diffusion testing for vancomycin in Staphylococcus species, oxacillin and penicillin susceptibility testing in S. lugdunensis and false imipenem-resistance in Proteus species were common sources of inaccurate results. The accuracy of species identification for Corynebacterium species and Vibrio species requires improvement. Consistent problems occurred with antimicrobial susceptibility testing of vancomycin for Staphylococcus species using the disk diffusion method.

Annual Report on External Quality Assessment Scheme in Clinical Microbiology in Korea (2013) / 임상검사와정도관리

Annual external quality assessment was performed three times for clinical microbiology division of The Korean Association of Quality Assurance for Clinical Laboratory. For each trial, three sets composed of different combinations of four bacteria and one yeast were distributed for culture, identification, and antimicrobial susceptibility tests. A total of 340 laboratories were enrolled and 330 (97.0%), 331(97.4%), and 331(97.4%) returned the results on trial I, II, and III, respectively. For bacterial identification, the correct identification of gram-negative bacilli, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus capitis, Streptococcus agalactiae, Listeria monocytogenes, and Candida species was greater than 95%. However, correct identification of Staphylococcus lugdunensis, Corynebacterium striatum, Vibrio vulnificus, Aeromonas hydrophila, Cryptococcus neoformans, and Malassezia pachydermatis was relatively less accurate, with values of 95.4%, 89.9%, 50.7%, 91.3%, 93.6%, and 93.9%, respectively. Surveillance cultures for vancomycin-resistant enterococci and methicillin-resistant S. aureus were correctly determined by 95.4% and 93.9% of the respondents, respectively. False carbapenem-resistance due to AmpC beta-lactamase, disk diffusion testing for vancomycin in Staphylococcus species, oxacillin and penicillin susceptibility testing in S. lugdunensis and false imipenem-resistance in Proteus species were common sources of inaccurate results. The accuracy of species identification for Corynebacterium species and Vibrio species requires improvement. Consistent problems occurred with antimicrobial susceptibility testing of vancomycin for Staphylococcus species using the disk diffusion method.

Risk Stratification-based Surveillance of Bacterial Contamination in Metropolitan Ambulances

We aimed to know the risk-stratification-based prevalence of bacterial contamination of ambulance vehicle surfaces, equipment, and materials. This study was performed in a metropolitan area with fire-based single-tiered Basic Life Support ambulances. Total 13 out of 117 ambulances (11.1%) were sampled and 33 sites per each ambulance were sampled using a soft rayon swab and aseptic containers. These samples were then plated onto a screening media of blood agar and MacConkey agar. Specific identification with antibiotic susceptibility was performed. We categorized sampling sites into risk stratification-based groups (Critical, Semi-critical, and Non-critical equipment) related to the likelihood of direct contact with patients' mucosa. Total 214 of 429 samples showed positive results (49.9%) for any bacteria. Four of these were pathogenic (0.9%) (MRSA, MRCoNS, and K. pneumoniae), and 210 of these were environmental flora (49.0%). However, the prevalence (positive/number of sample) of bacterial contamination in critical, semi-critical airway, semi-critical breathing apparatus group was as high as 15.4% (4/26), 30.7% (16/52), and 46.2% (48/104), respectively. Despite current formal guidelines, critical and semi-critical equipments were contaminated with pathogens and normal flora. This study suggests the need for strict infection control and prevention for ambulance services.

Annual Report on External Quality Assessment in Clinical Microbiology Laboratory in Korea (2009) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2009. A total of 16 specimens were distributed. Eight specimens were distributed to 339 laboratories with 322 (95.0%) returns in Trial I, and another eight specimens to 337 laboratories with 327 returns (97.0%) in Trial II. Two slide specimens for mycobacterium stain (AFB) were distributed in both Trial I and II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Sterotrophomonas maltophilia, Staphylococcus aureus, Streptococcus agalactiae, Micrococcus luteus, Vibrio parahemolyticus and Candida glabrata (Trial I) were 94.4%, 98.5%, 92.1%, 62.3%, 92.1% and 71.5%, respectively. The acceptable percentages of bacterial identification on Pseudomonas aeruginosa, Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, Moraxella catarrhalis and Enterobacter cloacae (Trial II) were 98.5%, 94.1%, 89.2%, 86.2%, 79.6% and 98.5%, respectively. The acceptable percentages for antimicrobial susceptibility tests on S. maltophilia and S. aureus (Trial I), and P. aeruginosa and E. faecalis(Trial II) were relatively good compared to data of the last year, except results using disk method for S. maltophilia. The acceptable percentages for AFB stain in Trial I and II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment in Clinical Microbiology Laboratory in Korea (2008) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2008. A total of 16 specimens were distributed. Eight specimens were distributed to 330 laboratories with 319 (96.7%) returns in Trial I, and 8 specimens to 335 laboratories with 319 returns (95.2%) in Trial II. Two slide specimens for mycobacterium stain (AFB) were distributed in Trial I and II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology except for Acinetobacter baumannii. The acceptable percentages of bacterial identification (correct answers to species level) on Klebsiella pneumoniae, Staphylococcus aureus, Neisseria meningitidis, Serratia marcescens, Erysipelothrix rhusiopathiae and Candida albicans (Trial I) were 97.4%, 99.2%, 55.6%, 97.0%, 79.2%, and 92.0%, respectively. The acceptable percentages of bacterial identification on A. baumannii, Enterococcus faecalis, Streptococcus pyogenes, Haemophilus parainfluenzae, Elizabethkingia meningoseptica, and Yersinia pseudotuberculosis (Trial II) were 92.0%, 90.8%, 4.5%, 53.1%, 74.8% and 94.3%, respectively. The acceptable percentages for antimicrobial susceptibility tests on K. pneumoniae and S. aureus (Trial I), and A. baumannii and E. faecalis, (Trial II) were relatively good compared to data of the last year. The acceptable percentages for AFB stain in Trial I and II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good except some cases with poor specimen quality. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2007) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2007) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2005) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratory were performed in 2005. A total of 12 specimens were distributed. Six specimens were distributed to 308 laboratories with 272 (88.3%) returns in Trial I and 276 (89.6%) returns in Trial II. The acceptable percentages of Gram-stain were relatively good. The acceptable percentages of bacterial identification on Acinetobacter baumannii, Staphylococcus aureus, Streptococcus pyogenes, Aeromonas hydrophila, Enterococcus casseliflavus, Brucella species (Trial I) were 80.1%, 98.3%, 87.6%, 81.3%, 55.5%, 38.1%, respectively. The acceptable percentages of bacterial identification on Klebsiella pneumoniae, Enterococcus faecalis, Brahamella catarrhalis, Burkholderia cepacia, Campylobacter fetus, Rhodoccus equi (Trial II) were 97.5%, 85.9%, 71.0%, 85.9%, 8.3%, 51.0%, respectively. The acceptable percentages for antimicrobial susceptibility tests on Acinetobacter baumannii, Staphylococcus aureus and Klebsiella pneumoniae were relatively high, but those on Klebsiella pneumoniae for ESBL and Enterococcus faecalis for vancomycin-resistance were not high. In conclusion, the acceptable percentages of bacterial stain and identification were relatively good except C. fetus. However, it is necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2004) / 임상검사와정도관리

Two trials of external quality assessment for clinical microbiology laboratory were performed in 2004. A total of 12 specimens were distributed. Six specimens were distributed to 293 laboratories with 277 returns in Trial I and six specimens to 293 laboratories with 274 returns in Trial II. The acceptable percentages of Gram-stain on Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus faecalis were 96.0%, 98.5%, 97.4% and 98.2%, respectively. The acceptable percentages of bacterial identification on Streptococcus pneumoniae, Escherichia coli, Enterococcus faecalis, Staphylococcus saprophyticus, Shigella flexneri, Gemella spp., Pseudomonas aeruginosa, Enterococcus faecalis (Trial II), Streptococcus agalactiae, Listeria monocytogenes, Erysipelothrix rhusiopathiae, and Eikenella corrodens were 97.5% (including 33.7% of no growth), 99.6%, 93.2%, 82.3%, 95.4%, 50.7%, 98.4%, 92.3%, 87.0%, 78.9%, 92.5% (including 53.4% of no growth), respectively. The acceptable percentages for antimicrobial susceptibility tests on Escherichia coli and Pseudomonas aeruginosa were relatively high, but those on Streptococcus pneumoniae and Enterococcus faecalis were not high. In conclusion, the acceptable percentages of bacterial stain and identification were relatively good. However, it is necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests on Streptococcus pneumoniae and Enterococcus faecalis, and the selection of the most appropriate antimicrobial agents to test should be also considered.

Annual Report on External Quality Assessment of Clinical Microbiology Laboratory in Korea (2003) / 임상검사와정도관리

Three trials of external quality assessment for clinical microbiology laboratory and two workshops were performed in 2003. A total of 19 specimens were distributed. Six specimens were distributed to 241 laboratories with 231 returns in Trial I, Five specimens to 241 laboratories with 225 returns in Trial II, and seven specimens to 245 laboratories with 220 returns in Trial III. The percentages of fully correct results of E. coli, E. faecalis, S. aureus, P. aeruginosa, K. pneumoniae, Candida albicans, P. aeruginosa, S. aureus, E. faecalis, K. pneumoniae, E. coli, and Candida tropicalis were 99%, 83%, 99%, 89%, 97%, 92%, 90%, 98%, 83%, 90%, 99%, and 63%, respectively. The standard deviation (SD) of inhibition zone diameter against each antibiotic was calculated. The within-one-SD percentages on disk diffusion test against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of E. coli (M0301) were 86%, 78%, 86%, 91%, and 76%, respectively. Those against vancomycin and teicoplanin of E. faecalis (M0302) were 77% and 95%, respectively. Those against vancomycin, oxacillin, penicillin G, clindamycin, erythromycin, ciprofloxacin, gentamicin and teicoplanin of S. aureus (M0303) were 82%, 80%, 81%, 81%, 79%, 80%, 88%, and 90%, respectively. Those against ciprofloxacin, gentamicin, imipenem, ceftazidime, and piperacillin of P. aeruginosa (M0304) were 73%, 88%, 85%, 83%, and 78%, respectively. Those against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of K. pneumoniae (M0305) were 89%, 89%, 87%, 81% and 86%, respectively. Thirty-five laboratories on Trial I and Trial II had reported the both results of disk diffusion and MIC methods. Seven laboratories use disk diffusion method or MIC method according to the bacterial species. The performance on the automated or E-test susceptibility tests was generally good. In conclusion, it is necessary that the quality assurance of the individual laboratories should be improved in the identification of Candida tropicalis and Enterococcus spp., and in susceptibility tests against oxacillin, erythromycin and ciprofloxacin of S. aureus, and cephalothin and imipenem of E. coli and vancomycin of E. faecalis in case of disk diffusion method.

Annual Report on External Quality Assessment in Clinical Microbiology Laboratory in Korea (2002) / 임상검사와정도관리

Three trials of external quality assessment for clinical microbiology laboratory were performed in 2002. A total of 19 specimens were distributed. Five specimens were distributed to 241 laboratories with 222 returns in Trial I, seven specimens to 241 laboratories with 232 returns in Trial II, and seven specimens to 245 laboratories with 220 returns in Trial III. The percentages of fully correct results of Plasmodium falciparum, P. malariae, P. vivax, gram-positive rods, group 5, S. aureus, E. faecium, Leuconostoc spp. Aeromonas hydrophila, Alternaria spp. S. aureus, E. coli, K. pneumoniae, E. faecalis, P. aeruginosa, E. coli, and K. pneumoniae were 38%, 66%, 68%, 85%, 68%, 94%, 76%, 51%, 86%, 76%, 100%, 99%, 93%, 79%, 86%, 95% and 96%, respectively. The acceptable percentages on disk-diffusion antibacterial susceptibility tests against oxacillin and vancomycin of S. aureus (M0206) were 99% and 94%, respectively. Those against vancomycin and teicoplanin of E. faecium (M0208) were 99% and 94%, respectively. Those against vancomycin, oxacillin, penicillin G, clindamycin, erythromycin, ciprofloxacin, gentamicin and teicoplanin of S. aureus (M0213) were 87%, 95%, 93%, 93%, 93%, 82%, 92%, 99%, and 95%, respectively. The acceptable percentages on disk diffusion test against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of E. coli (M0214) were 98%, 100%, 98%, 96%, and 87%, respectively. Those against ciprofloxacin, imipenem, ampicillin, cefotaxime, and cephalothin of K. pneumoniae (M0215) were 96%, 100%, 98%, 93% and 99%, respectively. Those against vancomycin, ciprofloxacin, ampicillin, penicillin G, erythromycin, and teicoplanin of E. faecalis (M0216) were 91%, 85%, 94%, 87%, 97%, and 100%, respectively. Those against ciprofloxacin, gentamicin, imipenem, ceftazidime, and piperacillin of P. aeruginosa (M0217) were 89%, 99%, 100%, 100%, and 100%, respectively. Those against amikacin, ciprofloxacin, gentamicin, imipenem, ampicillin, cefotaxime, and cephalothin of E. coli (M0218) were 98%, 98%, 98%, 100%, 98%, 100% and 90%, respectively. Those against amikacin, ciprofloxacin, gentamicin, imipenem, ampicillin, cefotaxime, and cephalothin of K. pneumoniae (M0219) were 97%, 97%, 98%, 100%, 99%, 99% and 99%, respectively. Twenty laboratories on Trial III had reported the both results of disk diffusion and MIC methods. The performance on the automated or E-test susceptibility tests was generally good, except in case of teicoplanin, showing the lower MIC in 63% of 51 participants. The susceptibility against teicoplanin should be confirmed by disk diffusion method in case of vancomycin-resistant Enterococcus in the laboratories using automated MIC methods. In conclusion, it is necessary that the quality assurance of the individual laboratories should be improved in the identification of malaria and Enterococcus spp., and in susceptibility tests against vancomycin, erythromycin and ciprofloxacin of S. aureus, and cephalothin of E. coli in case of disk diffusion method, and teicoplanin of Enterococcus in the laboratories using automated MIC methods.

Annual Report on External Quality Assessment in Diagnostic Genetics in Korea (2002) / 임상검사와정도관리

The importance of quality control for dramatically growing genetic tests continues to be emphasized with increasing clinical demands. Diagnostic genetics subcommitee of KSQACP performed two trials for cytogenetic study in 2002. Cytogenetic surveys were performed by 33 laboratories and answered correctly in most laboratories except some problems in nomenclature and analysis for mosaicism and cytogenetics of neoplasia. The molecular genetic test surveys include M. tuberculosis, HCV, HBV, leukemia/lymphoma, ABO genotyping, ApoE genotyping, spinocerebellar ataxia (SCA), spinal muscular atrophy (SMA), and mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes (MELAS). HBV, SCA, SMA, MELAS tests were the first challenge of the genetic survey. Molecular genetic survey showed excellent results in most participants, however, ABO genotyping tests should be improved by new methods in a few laboratories. External quality assessment program for diagnostic genetics could be helpful to give participants many chances of continuous education and of interesting case materials.

Detection of Shiga Toxin-Producing Escherichia coli by in Stitu hybridization and sequence Analysis of Stx2 / 대한임상미생물학회지

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) was found in several serotypes of E coli including 0157 serotype. Sorbitol-MacConkey agar: may be useful for the detection of E. coli 0157, but is not helpful for the detection of sorbitol-fermenting STEC other than 0157. Moreover, some strains of E. colt 0157 can ferment sorbitol. In this study, in situ hybridization using DNA probe of shiga toxin was used for the isolation of STEC from the PCR-positive stool and -Sequenbe analysis of a part of shiga toxin gene was performed. METHODS: The stool was incubated in LB broth overnight and DNA was extracted from the culture fluid. Multiplex PCR was performed with primers for stxl and stx2 genes. Specimen showed PCR-positive was incubated on MacConkey agar and colonies were blotted with nitrocellulose membrane. Digoxigenin-labelled DNA probe for shiga toxin was made by PCR and the positive colonies were detected with anti-digoxigenin-alkaline phosphatase conjugate and nitroblue tetrazolium. Agglutination test with antisera was performed for the serotying and VTEC-RPLA kit was used for the toxin production. Sequence analysis of PCR products was performed with automatic sequence analyser. RESULTS: An stxl-negative, but stx2-positive PCR was observed in a three-year-old girl, who visited Kumi Hospital on July 19, 1999 complaining of vomiting and diarrhea. The positive colonies were isolated by in situ hybridization using stx2-specific DNA probe. The titers of stxl and stx2 by VTEC-RPLA test were negative and 1:64, respectively. Agglutination for the serotyping was not observed with all of the 0 antisera. 160-nucleotide sequence of stx2 of this isolate was identical with bacteriophage 933W (GenBank X07865), except for the change (T-C) of 957th nucleotide and amino acid sequence was identical each other. CONCLUSIONS: For the sensitive detection of STEC from the stool of patients with diarrhea, multiplex PCR is recommended with stxl- and stx2-specific primers. And in situ hybridization should be performed in PCR-positive specimen for the isolation of STEC. This method may be helpful for the detection of STEC as the causative microorganisms in food-borne outbreak.

Detection of Shiga Toxin-Producing Escherichia coli by in Stitu hybridization and sequence Analysis of Stx2 / 대한임상미생물학회지

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) was found in several serotypes of E coli including 0157 serotype. Sorbitol-MacConkey agar: may be useful for the detection of E. coli 0157, but is not helpful for the detection of sorbitol-fermenting STEC other than 0157. Moreover, some strains of E. colt 0157 can ferment sorbitol. In this study, in situ hybridization using DNA probe of shiga toxin was used for the isolation of STEC from the PCR-positive stool and -Sequenbe analysis of a part of shiga toxin gene was performed. METHODS: The stool was incubated in LB broth overnight and DNA was extracted from the culture fluid. Multiplex PCR was performed with primers for stxl and stx2 genes. Specimen showed PCR-positive was incubated on MacConkey agar and colonies were blotted with nitrocellulose membrane. Digoxigenin-labelled DNA probe for shiga toxin was made by PCR and the positive colonies were detected with anti-digoxigenin-alkaline phosphatase conjugate and nitroblue tetrazolium. Agglutination test with antisera was performed for the serotying and VTEC-RPLA kit was used for the toxin production. Sequence analysis of PCR products was performed with automatic sequence analyser. RESULTS: An stxl-negative, but stx2-positive PCR was observed in a three-year-old girl, who visited Kumi Hospital on July 19, 1999 complaining of vomiting and diarrhea. The positive colonies were isolated by in situ hybridization using stx2-specific DNA probe. The titers of stxl and stx2 by VTEC-RPLA test were negative and 1:64, respectively. Agglutination for the serotyping was not observed with all of the 0 antisera. 160-nucleotide sequence of stx2 of this isolate was identical with bacteriophage 933W (GenBank X07865), except for the change (T-C) of 957th nucleotide and amino acid sequence was identical each other. CONCLUSIONS: For the sensitive detection of STEC from the stool of patients with diarrhea, multiplex PCR is recommended with stxl- and stx2-specific primers. And in situ hybridization should be performed in PCR-positive specimen for the isolation of STEC. This method may be helpful for the detection of STEC as the causative microorganisms in food-borne outbreak.

Bcr rearrangement analysis using digoxigenin-dUTP / 대한혈액학회지

No abstract available.