BACKGROUND: Polymerase chain reacation (PCR)-based methods have been described for rapid detection and identification of Candida spp. Multiplex PCR assay was developed using internal transcribed spacers and topoisomerase II gene for the accurate identification of Candida species. METHODS: We designed Dual Specificity Oligo (DSO) primers for multiplex PCR. Multiplex PCR was followed by agarose gel electrophoresis to test 8 type strains (C. albicans, C. parapsilosis, C. glabrata, C. tropicalis, C. krusei, C. guilliermondii, C. lusitaniae, C. dubliniensis) and 96 clinical isolates (C. albicans 51 isolates, C. parapsilosis 10 isolates, C. glabrata 10 isolates, C. tropicalis 9 isolates, C. krusei 6 isolates, C. guilliermondii 5 isolates, C. lusitaniae 5 isolates) of Candida spp. RESULTS: With multiplex PCR using DSO primers, the eight Candida type strains each could be easily differentiated and all 96 clinical isolates were identified as the same species as were identified by the conventional method. CONCLUSION: Multiplex PCR followed by electrophoresis can be useful for the simple and rapid identification of Candida species in routine laboratories.
Candida* ; DNA Topoisomerases, Type II ; Electrophoresis ; Electrophoresis, Agar Gel ; Multiplex Polymerase Chain Reaction* ; Sensitivity and Specificity

BACKGROUND: Sputum smear microscopy is rapid, economic, and useful to detect patients with transmittable tuberculosis, albeit laborious. We aimed to evaluate the usefulness of an automated acid-fast bacilli stainer, which had been developed for lowering the labor and maintaining or increasing the staining quality. METHODS: One hundred sputum samples including some known positive smear specimens which were selected from clinical specimens requested for smear and culture for mycobacteria at Pusan National University Hospital, were used for evaluation. Auramine/rhodamine fluorescent acid-fast stainings were performed manually or by using the automated stainer, AT-2000F (Dagatron, Ilsan, Korea). Ziehl-Neelsen stain was also performed simultaneously. RESULTS: Concordance rate between automated and manual fluorescent stains was 98.0% and that between automated fluorescent and manual Ziehl-Neelsen stains was 88.0%. In all discordant cases, the automated stains showed one-grade higher results compared to the respective manual fluorescent or Ziehl-Neelsen stains. With the automatic stainer, all staining procedures were processed automatically except for slide loading and unloading. The process time was reduced by a half, and the slide-to-slide or day-to-day variations of staining quality were reduced compared with the manual fluorescent stain. CONCLUSION: Acid-fast bacilli stain using automated stainer AF-2000F can reduce the processing time, labor, and variations of staining quality, and enhance or maintain the detection of positive smears.
Busan ; Coloring Agents ; Humans ; Microscopy ; Sputum ; Tuberculosis

BACKGROUND: Silver has extensive and powerful antimicrobial activities and silver-containing materials have been widely used in many medical fields. Recently nanoparticulate silver was developed and it is superior to other types of silver in the antimicrobial activity and cytotoxicity. There have been no data from Korea on its antimicrobial activity, and we evaluated the antimicrobial activity of NANOVER against common clinical isolates. METHODS: Minimum inhibitory concentrations (MICs) of NANOVER for clinical isolates were determined using the agar dilution method of Clinical and Laboratory Standard Institute. A total of 45 isolates were tested including 4 reference strains (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Enterococcus faecalis ATCC 29212), 5 strains of methicillin-resistant S.aureus (MRSA), 7 strains of methicillin-sensitive S. aureus (MSSA), 14 strains of E.coli,and 15 strains of P. aeruginosa. RESULTS: The MICs of S.aureus to NANOVER were under 12.5 microgram/mL regardless of the methicillin sensitivity or resistance. The other isolates showed the MICs under 12.5 to 6.25 microgram/mL. CONCLUSION: NANOVER has strong and extensive antimicrobial activities to common clinical isolates including those resistant to other antimicrobials.
Agar ; Enterococcus faecalis ; Escherichia coli ; Korea ; Methicillin ; Methicillin Resistance ; Microbial Sensitivity Tests ; Nanoparticles* ; Pseudomonas aeruginosa ; Silver*

BACKGROUND: The aim of this study was to determine a nation-wide prevalence of Ambler class A and D extended-spectrum-lactamases (ESBL) in Klebsiella pneumoniae isolates in Korea. METHODS: During the period of April to May 2005, 189 isolates of K.pneumoniae were collected from 11 Korean hospitals. Antimicrobial susceptibilities to ceftazidime and cefotaxime were tested by the disk diffusion method, and ESBL production was determined by double-disk synergy test. Determinants of ceftazidime or cefotaxime-resistance were transferred to Escherichia coli J53 (azide-resistant) by transconjugation. Genotypes of class A and D ESBL genes were determined by PCR amplification and sequencing. RESULTS: One hundred-sixty isolates of K.pneumoniae showed positive results in double-disk synergy test. The most prevalent ESBL was SHV-12 (n=148). Also detected were genes encoding ESBLs including TEM-52 (n=1), SHV-2a (n=2), CTX-M-3 (n=15), CTX-M-9 (n=6), CTX-M-12 (n=2), CTX-M-14 (n=9), CTX-M-15 (n=1), PER-1 (n=1), GES-5 (n=3), and OXA-30 (n=2) beta-lactamases. CONCLUSION: With the emergence of CTX-M-12, PER-1, and OXA-30 beta-lactamases, the ESBLs in K.pneumoniae isolates are becoming more diverse in Korea.
beta-Lactamases ; Cefotaxime ; Ceftazidime ; Diffusion ; Escherichia coli ; Genotype ; Klebsiella pneumoniae* ; Klebsiella* ; Korea ; Polymerase Chain Reaction ; Prevalence

BACKGROUND: Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in transplant recipients and immunocompromised patients. We compared the results of a dual polymerase chain reaction (dual-PCR) and an antigenemia (Ag) test for detection of CMV from blood samples. METHODS: Between February 2002 and May 2005, we analyzed 175 blood samples submitted for CMV tests at Hanyang University Hospital. The late antigen (LA) and major immediate early (MIE) genes of CMV were concurrently amplified in the dual-PCR. The lower matrix protein pp65 of CMV was detected for the Ag test (Chemicon, Temecula, CA, USA). RESULTS: The positive rate of the dual-PCR was 14.3% (25/175) and that of the Ag test was 13.1% (23/175). The concordance rate of the dual-PCR and Ag test was 85.1% (149/175), while the discordance rate was 14.9% (26/175). CONCLUSION: The dual-PCR is a useful method for the early detection of CMV, but we recommend using both the dual-PCR and Ag test for detection of CMV due to a high discordance rate of the two methods.
Cytomegalovirus* ; Immunocompromised Host ; Mortality ; Polymerase Chain Reaction ; Transplantation

BACKGROUND: To estimate the influence of a change in the hospital environment on a hospital-acquired urinary tract infection (HAUTI), we analyzed and compared the rates of HAUTI and the associated risk factors between an old hospital (Phil-dong) and a new hospital (Heucksuck-dong) of Chung-Ang University. METHODS: Retrospective studies of patients with urinary tract infection were conducted at the old and new hospital during the period from July 2003 to June 2004 and from January to December 2005, respectively. HAUTI was defined as the isolation of one or two microorganisms at greater than 10(5)CFUs/mL from urine at 48 hours or more after admission. The risk factors of HAUTI included sex, age, duration of hospitalization, as well as malignancy, chronic disease, diabetes mellitus, intensive care unit care, immune deficiency, renal function, Foley catheterization, and immobility. RESULTS: The rates of HAUTI at the old and new hospital were 2.9% (206 cases per 7,088 patients) and 2.0% (289 per 14,704), respectively (P<0.05), but there were no statistical differences in the associated risk factors between the two hospitals (P>0.05). CONCLUSION: Although both the old and new hospitals were served by the same health-care staff and inspectors using the same methods, the rate of HAUTI was significantly lower at the new hospital. This suggests that a change of the hospital environment, including new instruments and equipment, has an influence on the rate of HAUTI.
Chronic Disease ; Diabetes Mellitus ; Hospitalization ; Humans ; Intensive Care Units ; Retrospective Studies ; Risk Factors ; Urinary Catheterization ; Urinary Tract Infections* ; Urinary Tract*

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) accounts for more than 70% of S. aureus isolates from tertiary-care hospitals in Korea. Recently, a multilocus sequence typing (MLST) scheme has been used to study the local and global epidemiologies of MRSA. The aim of this study is to compare the genetic background of MRSA strains isolated in the same ward during two different periods. METHODS: To investigate clonal changes of endemic MRSA isolates between 1996 and 2004, we studied a total of 33 MRSA strains (16 from 1996 and 17 from 2004) isolated in the intensive care units of a tertiary-care hospital in Korea. The isolates were analyzed for their sequence types by MLST and for their antimicrobial susceptibilities by the disk diffusion method. RESULTS: ST5 was the most frequent type (n=11, 68.7%) in 1996, followed by ST254 (n=3, 18.8%) and ST1 (n=2, 12.5%). In 2004, ST239 was the most frequent type (n=10, 58.8%), followed by ST5 (n=6, 35.3%). CONCLUSION: The major clone type of MRSA isolates from intensive care unit patients changed from ST5 in 1996 to ST239 in 2004.
Clone Cells ; Diffusion ; Humans ; Intensive Care Units* ; Critical Care* ; Korea ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Multilocus Sequence Typing*

BACKGROUND: Enterococci have become increasingly predominant as causative agents of nosocomial infections. Infections due to multi-drug resistant enterococci have drawn increasing attention during the past two decades. The purpose of the present study was to evaluate the occurrence of virulence factors and antimicrobial resistance in enterococci isolated from patients with bacteremia or urinary tract infection. METHODS: A total of 209 strains of enterococi (102 Enterococcus faecalis and 107 E. facium) isolated during 8 months of 2005 were collected from 10 university hospitals in Korea. Disk diffusion susceptibility tests were performed using Mueller-Hinton agar. The antimicrobial resistance genes and virulence factors were determined using PCR. RESULTS: In E. faecalis, the rate of resistance to ciprofloxacin, tetracycline, and quinupristindalfopristin was 27.4%, 83.3%, and 85.2%, respectively; no isolates were resistant to ampicillin, vancomycin, teicoplanin, or linezolid. In E. faecium, the rate of resistance to ampicillin, ciprofloxacin, tetracycline, vancomycin, and teicoplanin was 86.9%, 87.9%, 8.4%, 19.6%, and 6.5%, respectively; no strains were resistant to quinupristin-dalfopristin or linezolid. All the E. faecalis strains tested were found to harbor multiple virulence factors, but E. faecium strains were generally without virulence factors except esp. The prevalence of the esp gene was significantly higher in enterococci isolated from urinary tract infection than in those from bacteremia. CONCLUSION: A similar pattern of resistance to antimicrobial agents and prevalence of virulence factors was observed in both the enterococci isolated from bacteremia and urinary tract infection. Our study indicates that host factors are more likely than bacterial properties to influence the development of bacteremia.
Agar ; Ampicillin ; Anti-Infective Agents ; Bacteremia* ; Ciprofloxacin ; Cross Infection ; Diffusion ; Enterococcus faecalis ; Hospitals, University ; Humans ; Korea ; Polymerase Chain Reaction ; Prevalence ; Teicoplanin ; Tetracycline ; Urinary Tract Infections* ; Urinary Tract* ; Vancomycin ; Virulence Factors* ; Virulence* ; Linezolid

BACKGROUND: There is growing evidence linking infection with Chlamydophila pneumoniae with vascular diseases, such as atherosclerosis and myocardial infarction. However, the data remain inconclusive and the clinical importance of C. pneumoniae as vasculopathic is unclear. So, we intend to detect C. pneumoniae in acute myocardial infarction patients by microimmunofluorescence (mIF) and polymerase chain reaction (PCR). METHODS: Blood and peripheral mononuclear cells (PMNCs) of 24 myocardial infarction patients and 100 normal controls were collected. Serum were used in mIF and PMNCs in PCR. PMNC sample were tested for C. pneumoniae by 'touchdown 'nested PCR. The first round PCR amplified DNA from both C. pneumoniae and Chlamydophila psittaci, while the second round specially targeted C. pneumoniae allowing the two species to be differentiated. RESULTS: Seropositivity of IgG and IgM anti-Chlamydophila pneumoniae antibody titers were 95.8% and 25% in myocardial infarction patients and 61% and 16% in control group, respectively. Positive rates of PCR of PMNCs were 8.3% in the patients and 15% in control group. CONCLUSION: The results of mIF show that mIF positive rate in myocardial infarction was much higher than control group. So an association between C. pneumoniae and myocardial infarction can be concluded. But the opposite results of PCR of PMNCs needed further studies.
Atherosclerosis ; Chlamydial Pneumonia* ; Chlamydophila pneumoniae* ; Chlamydophila psittaci ; Chlamydophila* ; DNA ; Humans ; Immunoglobulin G ; Immunoglobulin M ; Myocardial Infarction* ; Pneumonia ; Polymerase Chain Reaction ; Vascular Diseases

BACKGROUND: The associations between preterm labor or premature rupture of membrane (PROM) and urogenital infections of pregnant women are reported. Ureaplasma urealyticum and Mycoplasma hominis are well known as important pathogens of urogenital infections in pregnant women. In routine clinical laboratory, conventional culture for these microorganisms has not been made generally because of the requirements for strict growth condition. MYCOFAST(R) Evolution 2 is an easy and rapid liquid microculture method using metabolism of these microorganisms. Author investigated the relationship between U. urealyticum or M. hominis infections and preterm labor or PROM by MYCOFAST Evolution 2 and PCR. Also it was reviewed that the possibility of substitution of MYCOFAST Evolution 2 for conventional culture method by comparing with PCR methods. METHODS: This study was done on 91 pregnant women. They were composed of two groups; group I(n=48) had full-term delivery and group II(n=43) had preterm labor or PROM before the 37th week.Two cervical swabs were made each time. One was used for MYCOFAST(R) Evolution 2 and the other for PCR. RESULTS: The positivity of U. urealyticum was 39.6% in group Iand 58.1% in group IIby MYCOFAST Evolution 2 and 39.6% and 58.1% by PCR method, respectively. The positivity of M. hominis was 4.2% in group Iand 11.6% in group IIby MYCOFAST Evolution 2 and 4.2% and 7.0% by PCR method, respectively. The positivity of U. urealyticum and M. hominis in group IIwas higher than that in group Ibut was not significant statistically. The concordance rates between two methods were 86.8% for U. urealyticum and 97.8% for M. hominis. It showed good correlation between two methods (U. urealyticum, r=0.736; M. hominis, r=0.835). CONCLUSIONS: The infections of U. urealyticum and M. hominis were related to preterm labor or PROM. Considering vertical transmission to fetus or neonates resulting in perinatal morbidity or mortality, the detection of these microorganisms is important. MYCOFAST(R) Evolution 2 was an easy, rapid and reliable method substituting conventional culture method.
Female ; Fetus ; Humans ; Infant, Newborn ; Membranes ; Metabolism ; Mortality ; Mycoplasma hominis* ; Mycoplasma* ; Obstetric Labor, Premature ; Polymerase Chain Reaction* ; Pregnancy ; Pregnant Women* ; Rupture ; Ureaplasma urealyticum* ; Ureaplasma*