No abstract availble.
Anti-Bacterial Agents/therapeutic use ; Disk Diffusion Antimicrobial Tests ; *Drug Resistance, Bacterial ; Drug Therapy, Combination ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori/drug effects/isolation & purification ; Humans ; Microbial Sensitivity Tests ; Peptic Ulcer/*drug therapy

BACKGROUND: The aim of this study was to compare the BD Phoenix (Beckton Dickinson Diagnostic Systems, USA) extended-spectrum beta-lactamase (ESBL) test with the Clinical and Laboratory Standards Institute (CLSI) ESBL phenotypic confirmatory test by disk diffusion (CLSI ESBL test) in Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and Proteus mirabilis. METHODS: We tested 224 clinical isolates of E. coli, K. pneumoniae, K. oxytoca and P. mirabilis during May 2006 to March 2007. These isolates were examined by the Phoenix and the CLSI ESBL tests simultaneously. For the isolates showing discordant results between the two tests, boronic acid disk test was performed to differentiate AmpC beta-lactamase and ESBL. RESULTS: Among the 224 clinical isolates, 75 and 79 isolates were positive for ESBL by CLSI ESBL test and Phoenix test, respectively. Having detected 4 more isolates as ESBL-producers, Phoenix test showed a 98.2% agreement with a 100% sensitivity and 97.3% specificity compared with CLSI ESBL test. Among the four false positive isolates, three were AmpC-positive but ESBL-negative. CONCLUSIONS: The BD Phoenix ESBL test was sensitive and specific, and can be used as a rapid and reliable method to detect ESBL production in E. coli, Klebsiella species, and P. mirabilis.
Automation ; Bacterial Proteins/classification/*metabolism ; Disk Diffusion Antimicrobial Tests ; Escherichia coli/drug effects/*enzymology/isolation & purification ; Humans ; Klebsiella/*enzymology ; Klebsiella oxytoca/drug effects/enzymology/isolation & purification ; Klebsiella pneumoniae/drug effects/enzymology/isolation & purification ; *Microbial Sensitivity Tests ; Proteus mirabilis/drug effects/*enzymology/isolation & purification ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; beta-Lactamases/classification/*metabolism

BACKGROUND/AIMS: Antibiotic resistance of Helicobacter pylori (H. pylori) is a significant clinical problem because it reduces the efficacy of eradication therapy. The aims of this study were to assess the changing patterns of antibiotic resistance of H. pylori in patients with peptic ulcer diseases and to evaluate the eradication rate in antibiotic resistant H. pylori strains. METHODS: One hundred forty four H. pylori isolates obtained from 466 patients with peptic ulcer disease between June 2001 and December 2005 were examined for antimicrobial resistance. The minimum inhibitory concentration (MIC) of metronidazole was determined by modified broth microdilution method (mBMD) and E test. MICs of clarithromycin and amoxicillin were determined by mBMD, E test, and disc diffusion test. The breakpoints for metronidazole, clarithromycin, and amoxicillin resistance were defined as >8microgram/mL, >1microgram/mL, and > or =1microgram/mL, respectively. RESULTS: Resistance to metronidazole and clarithromycin was detected in 34.7% and 16.7% of H. pylori isolates, respectively. During the recent 5-year study period, amoxicillin-resistant rate of H. pylori was 11.8%, and multi-drug resistance rate of H. pylori was 16.7%. The eradication rate of clarithromycin containing triple therapies was low (7.8%) in clarithromycin-resistant H. pylori strains. CONCLUSIONS: The proportions of clarithromycin-resistant H. pylori strains have increased significantly over the last 5-years. There is an increasing tendency for the emergence of strains with multi-drug resistance. The increase in clarithromycin-resistant strains results in a decrease in eradication rate for H. pylori. In areas with high clarithromycin resistance, new alternative first-line treatment combination should be considered.
Adult ; Aged ; Amoxicillin/therapeutic use ; Anti-Bacterial Agents/therapeutic use ; Clarithromycin/adverse effects/therapeutic use ; Disk Diffusion Antimicrobial Tests ; *Drug Resistance, Bacterial ; Drug Therapy, Combination ; Female ; Helicobacter Infections/*drug therapy/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/therapeutic use ; Microbial Sensitivity Tests ; Middle Aged ; Peptic Ulcer/*drug therapy ; Retrospective Studies

Production of extended-spectrum beta-lactamase (ESBL) is one of the most important resistance mechanisms that hamper the antimicrobial treatment of infections caused by Enterobacteriaceae. ESBLs are classified into several groups according to their amino-acid sequence homology. While TEM and SHV enzymes were the most common ESBLs in the 1990s, CTX-M enzymes have spread rapidly among Enterobacteriaceae in the past decade. In addition, some epidemiological studies showed that organisms producing CTX-M enzymes had become increasingly prevalent in the community setting in certain areas in the world. Several novel enzymes with hydrolyzing activity against oxyimino-cephalosporins, albeit with additional enzymatic characteristics different from those of original TEM and SHV ESBLs (e.g., inhibitor-resistance), have been discovered and pose a problem on the definition of ESBLs. Although several methods to detect the production of ESBL are available in clinical laboratories, existence of other factors contributing resistance against beta-lactams, e.g., inducible production of Amp-C beta-lactamase by some species of Enterobacteriaceae, or inhibitor-resistance in some ESBLs may hinder the detection of ESBLs with these methods. Carbapenems are stable against hydrolyzing activity of ESBLs and are regarded as the drug of choice for the treatment of infections caused by ESBL-producing Enterobacteriaceae. Although several other antimicrobial agents, such as fluoroquinolones and cephamycins, may have some role in the treatment of mild infections due to those organisms, clinical data that warrant the use of antimicrobial agents other than carbapenems in the treatment of serious infections due to those organisms are scarce for now.
Anti-Bacterial Agents/*pharmacology/therapeutic use ; Carbapenems/pharmacology/therapeutic use ; Disk Diffusion Antimicrobial Tests ; Enterobacteriaceae/drug effects/*enzymology/genetics ; Enterobacteriaceae Infections/*drug therapy/microbiology ; Fluoroquinolones/pharmacology/therapeutic use ; Humans ; Microbial Sensitivity Tests/methods ; beta-Lactamases/*biosynthesis/metabolism ; beta-Lactams/*pharmacology/therapeutic use

Mycobacterium abscessus is the second most common etiology of pulmonary disease caused by nontuberculous mycobacteria in Korea. Although antimicrobial susceptibility tests are important for appropriate patient management in M. abscessus lung disease, the tests have never been investigated in Korea. Seventy-four isolates of M. abscessus recovered from patient respiratory samples were tested against eight antimicrobial agents following the guidelines set forth by the National Committee for Clinical Laboratory Standards. Of the parenteral antibiotics, amikacin (99%, 73/74) and cefoxitin (99%, 73/74) were active against most isolates. Imipenem (55%, 36/66) and tobramycin (36%, 27/74) had activity against moderate number of isolates. Of the oral antibiotics, clarithromycin (91%, 67/74) was active against the majority of isolates. Moxifloxacin (73%, 54/74) and ciprofloxacin (57%, 42/74) had activity against a moderate number of isolates. Doxycycline was the least active, inhibiting only 7% (5/74) of isolates. In conclusion, the variations in susceptibility within M. abscessus isolates to currently available antimicrobials suggest that the antimicrobial susceptibilities of any clinically significant M. abscessus isolate be needed individually.
Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests

BACKGROUND: A spectrophotometric approach to minimum inhibitory concentration (MIC) determination for filamentous fungi may provide an objective and rapid MIC reading, and quantify the hyphal growth of molds. In this study, we evaluated two spectrophotometric broth microdilution methods (SBM) to determine amphotericin B and itraconazole MICs for Aspergillus species isolated from clinical specimens. METHODS: A total of 80 clinical isolates (20 A. fumigatus, 20 A. flavus, 18 A. niger, 20 A. terreus, and 2 A. nidulans) were tested for amphotericin B and itraconazole susceptibility by the broth microdilution method. The MIC endpoint was calculated by the spectrophotometer with microplate reader (SBM-Spec method) or colorimetric XTT (tetrazolium dye) method (SBM-XTT method). The results of the SBM method were compared with those of NCCLS M38-A broth microdilution method. RESULTS: The MICs of amphotericin B by the NCCLS M38-A method ranged from 0.125 to 8 g/mL, and those of itraconazole ranged from 0.25 to 2micrograms/mL. The agreement of SBM-Spec and SBM-XTT methods within one dilution of the NCCLS M38 reference were 98.8% and 96.3% for the ampho-tericin B, and 98.8% and 100% for itraconazole, respectively. The agreements between SBM-Spec and SBM-XTT methods were 97.5% for amphotericin B and 98.8% for itraconazole. CONCLUSIONS: In antifungal susceptibility testing of Aspergillus species, the SBM method includ-ing SBM-Spec and SBM-XTT methods showed high levels of agreements with the NCCLS M38-A method. The SBM methods can be useful in the clinical laboratory.
Amphotericin B ; Aspergillus* ; Fungi ; Itraconazole ; Microbial Sensitivity Tests ; Niger

BACKGROUND: Malassezia is considered as major factor in dandruff of human scalp. OBJECTIVE: In order to develop an antimicrobial agent, bamboo oil was extracted by high temperture suction from dried bamboo truk abd then antimicrobial activities against Malassezia are investigated. METHODS: Minimum inhibitory concentration and antimicrobial activity were measured in Malassezia species. RESULTS: 1. Minimum inhibitory concentration of the Bamboo (Phyllosrachys bambusoides) Essential Oil Malassezia furfur standard, Malassezia furfur patient, Malassezia sympodialis standard, Malassezia sympodialis patient, Malassezia dermatis standard, Malassezia dermatis patient were 10 microliter/ml, 5 microliter/ml, 5 microliter/ml, 10 microliter/ml, 5 microliter/ml and 10 microliter/ml respectively. 2. Minimum inhibitory concentration of the Itraconazole Malassezia furfur standard, Malassezia furfur patient, Malassezia sympodialis standard, Malassezia sympodialis patient, Malassezia dermatis standardntia, Malassezia dermatis patient were 10 microgram/ml, 10 microgram/ml, 10 microgram/ml, 0.1 microgram/ml, 1 microgram/ml, and 0.01 microgram/ml, respectively. 3. Minimum inhibitory concentration of the ketoconazole Malassezia furfur standard, Malassezia furfur patient, Malassezia sympodialis standard, Malassezia sympodialis patient, Malassezia dermatis standard, Malassezia dermatis patient were 0.01 microgram/ml, 10 microgram/ml, 10 microgram/ml, 0.1 microgram/ml, 0.01 microgram/ml, and 0.01 microgram/ml, respectively. 4. Malassezia furfur standard, Malassezia furfur patient, Malassezia sympodialis patient and Malassezia dermatis patient showed the strongest antimicrobial effect on bamboo oil > ketoconazole > itraconazole. 5. Malassezia sympodialis standard, Malassezia sympodialis patient and Malassezia dermatis standard strongest antimicrobial effect on ketoconazole > bamboo oil > itraconazole. CONCLUSION: Bamboo oil might be applied as antidandruff treatment modality by its anti-malassezial effect.
Humans ; Itraconazole ; Ketoconazole ; Malassezia ; Microbial Sensitivity Tests ; Scalp ; Suction

BACKGROUND: With a growing number of people using a variety of medications, and suffering from systemic diseases, such as AIDS, Candida infection is also on the rise. This brings the issue of antifungal resistance into the spotlight. OBJECTIVE: This study sought to evaluate the detection of oral Candida and the change of minimum inhibitory concentration (MIC) in patients on oral fluconazole for treatment of onychomycosis. METHODS: We studied 25 patients who are on fluconazole for treatment of onychomycosis. We evaluated the MIC and detection of oral Candida at the time of the first visit, at the point of initial dosing, and subsequently, 12 and 24 weeks thereafter, and 12 weeks after the point of final dosing. RESULTS: At the first visit, we collected strains from the oral cavity. At 12 and 24 weeks thereafter, and 12 weeks after final dosing, C. albicans were detected in all cases. MIC measured at the corresponding time points revealed sensitivity in all cases with MIC under 8.0 microg/ml. After 12 and 24 weeks of administration, we identified the same strains at the oral cavity, and MIC of the two regions was elevated. At 12 weeks after the point of final dosing, MIC was decreased or remained the same at the three sites, and the result was the same at 12 and 24 weeks thereafter. CONCLUSION: The purpose of this study was to ascertain that the acquisition of resistance to fluconazole by oral Canadida is not as serious as we had anticipated; however, further studies based on larger patient pools would provide greater assurance.
Candida ; Fluconazole ; Humans ; Microbial Sensitivity Tests ; Mouth ; Onychomycosis ; Stress, Psychological

PURPOSE: The purpose of this study is to investigate the feasibility of bone cement as a vehicle of methotrexate, and potent chemotherapeutical drugs for osteosarcoma, and to evaluate the cytotoxic effect of the eluted methotrexate on osteosarcoma cells. MATERIALS AND METHODS: Various amounts of methotrexate were mixed with bone cement to make pellets containing corresponding dosages of methotrexate. The elution experiment was performed. The amount and the rate of elution, the duration of elution, and the elution pattern were checked daily by measuring the absorbance for four weeks. The cytotoxic effect of the eluted methotrexate on SaOS2 and MG63 osteosarcoma cells was examined by MTT assay, and the results were analyzed according to the concentration of the methotrexate and time. RESULTS: The amount of eluted methotrexate was the greatest during the first day, then the amount decreased rapidly until the end of the first week, reaching its plateau in the third week. The amount of eluted methotrexate from the pellets averaged 6.1% during the first week, and 9.6% during the four weeks. The concentration of eluted methotrexate was 130 to 10,000 times higher than the minimum inhibitory concentration throughout the experimental period. As a result of the cytotoxic effect of the eluted methotrexate, the number of viable tumor cells decreased significantly after 72 hours of exposure, and the viable cells were hardly seen after one week. CONCLUSIONS: In conclusion, the methotrexate eluted from the bone cement has sufficient cytotoxic effect on osteosarcoma cells in vitro, and the results suggest that local chemotherapy using a methotrexate loaded cement may be applicable in the management of osteosarcoma after evaluation of its long-term effect.
Cell Line* ; Drug Therapy ; Methotrexate* ; Microbial Sensitivity Tests ; Osteosarcoma*

BACKGROUND: Voriconazole is a potent new triazole antifungal agent expected to be particularly useful for the treatment of invasive aspergillosis. However, in vitro susceptibility of voriconazole for clinical strains of Aspergillus species isolated in Korea has not been fully surveyed. OBJECTIVE: We determined minimum inhibitory concentrations (MICs) of voriconazole for clinical Aspergillus isolates. METHODS: A total of 100 clinical isolates of Aspergillus species (40 A. fumigatus, 24 A. flavus, 17 A. niger, 17 A. terreus and 2 A. nidulans) was tested. In vitro voriconazole susceptibility testing was accomplished utilizing the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method M38-A. MIC of voriconazole was determined using RPMI medium at 48 h of incubation. RESULTS: Among the 100 isolates of Aspergillus species tested, 98% were inhibited by < or = 1 microgram/mL of voriconazole. The MICs of voriconazole ranged from 0.125 to 2 microgram/mL (geometric mean MIC, 0.52 microgram/mL). The MIC50 (MIC at which 50% of the isolates tested were inhibited) and MIC90 were 0.5 and 1.0 microgram/mL for all Aspergillus species, respectively. The strains showing MIC> or =2 microgram/mL were 0/40 (0%) in A. fumigatus, 1/24 (4%) in A. flavus, 1/17 (6%) in A. niger, 0/17 (0%) in A. terreus, and 0/2 (0%) in A. nidulans. CONCLUSION: These data demonstrate promising in-vitro activity of voriconazole against clinical strains of Aspergillus species isolated from Korean patients.
Aspergillosis ; Aspergillus* ; Humans ; Korea ; Microbial Sensitivity Tests ; Niger