The short time antibacterial effect of tetracaine hydrochloride was studied. S. aureus, Coagulase Negative Staphylococcus and P. aeruginosa were each incubated with tetracaine hydrochloride(preservative free) for 18 hours or for 2 minutes and then diluted and cultured on nutrient agar plate. Colony counts were done after 18 hours. In cases of 18 hours incubation, there was no growth of microbials in 0.5%, 0.1% tetracaine hydrochloride, but there was no inhibitory effect of 0.02% of tetracaine hydrochloride on growth of microbials, irrespective of inoculum amount. In cases of 2 minutes incubation with 0.5% tetracaine hydrochloride, there was no difference between the amount of microbial inoculum and colony count. Above in vitro study indicates that tetracaine hydrochloride has no inhibitory effect on bacterial growth in short time exposure less than 2 minutes.
Agar ; Coagulase ; Staphylococcus ; Tetracaine*

The short time antibacterial effect of tetracaine hydrochloride was studied. S. aureus, Coagulase Negative Staphylococcus and P. aeruginosa were each incubated with tetracaine hydrochloride(preservative free) for 18 hours or for 2 minutes and then diluted and cultured on nutrient agar plate. Colony counts were done after 18 hours. In cases of 18 hours incubation, there was no growth of microbials in 0.5%, 0.1% tetracaine hydrochloride, but there was no inhibitory effect of 0.02% of tetracaine hydrochloride on growth of microbials, irrespective of inoculum amount. In cases of 2 minutes incubation with 0.5% tetracaine hydrochloride, there was no difference between the amount of microbial inoculum and colony count. Above in vitro study indicates that tetracaine hydrochloride has no inhibitory effect on bacterial growth in short time exposure less than 2 minutes.
Agar ; Coagulase ; Staphylococcus ; Tetracaine*

KOH examination is a simple, rapid and diagnostic procedure to confirm dermatophytic infections. It is important to select a proper examination site of the lesion. To determinate the proper examination site of the lesion, mycologic studies were done with multiple specimens collected from the center, margin and out of margin of the ring-shaped dermatophytic skin lesion on the 58 patients. The results were as follows. Positive rate of KOH wet smear was 94.8% at the center and 100% at the margin of the lesions, 22.4% at the 1 cm and 5.2% at the 2 cm out of the lesions. The more hyphae were found in the lesion, the more hyphae were found out of the lesion. Culture was done on the Sabouraud's glucose agar from the highest KOH positive area and the positive culture was 48 strains (82.8%) of 58 patients. These findings suggested that the ring-shaped active margin was the best site to examine mycologic studies.
Agar ; Glucose ; Humans ; Hyphae ; Skin*

BACKGROUND: The aim of this study is to evaluate the effectiveness of automated ozonated water endoscopic reprocessing system (AORS). MATERIALS AND METHODS: Thirty cases were collected and randomly assigned to 3 groups according to the disinfection methods (Group A, AORS for 5 minutes; Group B, AORS for 10 minutes; Group C, automated disinfection with superoxidized water for 3 minutes 30 seconds). After disinfection was finished, samples were collected from the tip of scopes (Site 1, S1) and rinsing water through biopsy channel (Site 2, S2). Samples were inoculated in blood agar plate for 48 hrs, and then colony count was evaluated. RESULTS: Culture positive rate of S1 was 0% in all three groups. Culture positive rates of S2 were 70% (7/10), 70% (7/10) and 90% (9/10) in group A, group B and group C, respectively. High culture rate group (> or = 1 CFU/ml rinsing water) was 0% (0/10), 30% (3/10) and 70% (7/10) in group A, group B and group C, respectively. Disinfection efficacy between group A and C showed a significant difference in high culture rate (P<0.05). CONCLUSIONS: AORS for 5min was at least equally effective in endoscopic reprocessing compared with the conventional superoxidized water system.
Agar ; Biopsy ; Disinfection* ; Endoscopes ; Water*

BACKGROUND: The aim of this study is to evaluate the effectiveness of automated ozonated water endoscopic reprocessing system (AORS). MATERIALS AND METHODS: Thirty cases were collected and randomly assigned to 3 groups according to the disinfection methods (Group A, AORS for 5 minutes; Group B, AORS for 10 minutes; Group C, automated disinfection with superoxidized water for 3 minutes 30 seconds). After disinfection was finished, samples were collected from the tip of scopes (Site 1, S1) and rinsing water through biopsy channel (Site 2, S2). Samples were inoculated in blood agar plate for 48 hrs, and then colony count was evaluated. RESULTS: Culture positive rate of S1 was 0% in all three groups. Culture positive rates of S2 were 70% (7/10), 70% (7/10) and 90% (9/10) in group A, group B and group C, respectively. High culture rate group (> or = 1 CFU/ml rinsing water) was 0% (0/10), 30% (3/10) and 70% (7/10) in group A, group B and group C, respectively. Disinfection efficacy between group A and C showed a significant difference in high culture rate (P<0.05). CONCLUSIONS: AORS for 5min was at least equally effective in endoscopic reprocessing compared with the conventional superoxidized water system.
Agar ; Biopsy ; Disinfection* ; Endoscopes ; Water*

BACKGROUND: Early and appropriate antibiotic treatment improves the clinical outcome of patients with septicemia; therefore, reducing the turn-around time for identification (ID) and antimicrobial susceptibility test (AST) results is essential. We established a method for rapid ID and AST using short-term incubation of positive blood culture broth samples on solid media, and evaluated its performance relative to that of the conventional method using two rapid ID systems and a rapid AST method. METHODS: A total of 254 mono-microbial samples were included. Positive blood culture samples were incubated on blood agar plates for six hours and identified by the MicroFlex LT (Bruker Daltonics) and Vitek-MS (bioMeriéux) systems, followed by AST using the Vitek2 System (bioMeriéux). RESULTS: The correct species-level ID rates were 82.3% (209/254) and 78.3% (199/254) for the MicroFlex LT and Vitek-MS platforms, respectively. For the 1,174 microorganism/antimicrobial agent combinations tested, the rapid AST method showed total concordance of 97.8% (1,148/1,174) with the conventional method, with a very major error rate of 0.5%, major error rate of 0.7%, and minor error rate of 1.0%. CONCLUSIONS: Routine implementation of this short-term incubation method could provide ID results on the day of blood culture-positivity detection and one day earlier than the conventional AST method. This simple method will be very useful for rapid ID and AST of bacteria from positive blood culture bottles in routine clinical practice.
Agar ; Bacteria* ; Humans ; Methods ; Sepsis

OBJECTIVES: The purpose of this study was to provide photodynamic bactericidal effect against Enterococcus faecalis by erythrosine concentrations and LED irradiation times. METHODS: Erythrosine was used as a photosensitizer and green LED (3 Watt, 520-530 nm) was used as light source. E. faecalis ATCC 1943 and E. faecalis ATCC 29212 were used in this study. Approximately 10(5) CFU of bacteria were added in wells of a 96-well microtitration plate. For examining the effects of concentrations of erythrosine, 0, 0.625, 1.25, 2.5, 5, and 10 microM of erythrosine were added in wells containing bacteria. The irradiation time with LED was 30 sec. In another set of experiment, the effect of irradiation time for killing of bacteria was investigated by increasing irradiation time from 0 to 30 s with 10 microM of erythrosine final concentration. After irradiation, each sample was serially diluted with PBS and 50 microl of diluents was spread on duplicate blood agar plates. The plates were incubated for 72 h at 37degrees C under aerobic conditions and the number of CFU was determined. The experiments were repeated four times. The results were analyzed using one-way ANOVA, and Tukey's multiple comparison at a significance level of 0.05. RESULTS: When the erythrosine concentrations were more than 2.5 microM, E. faecalis ATCC 29212 was significantly decreased (P<0.05). The more erythrosine concentrations increased, the more E. faecalis ATCC 1943 decreased statistically significantly (P<0.05). In another set of experiment, when LED irradiation time was more than 20 s, E. faecalis ATCC 1943 decreased significantly (P<0.05), and if the irradiation times was more than 5 s, E. faecalis ATCC 29212 decreased significantly (P<0.05). CONCLUSIONS: PDT using erythrosine and green LED was found to be an effective method in killing E. faecalis.
Agar ; Bacteria ; Enterococcus faecalis* ; Erythrosine* ; Homicide ; Photochemotherapy

BACKGROUND: Clostridium difficile is the main etiologic agent of antibiotic-associated diarrhea and the most common cause of hospital-acquired diarrhea. Recently, the incidence of C. difficile infections (CDI) has increased and new highly virulent C. difficile strains have emerged. Therefore, accurate and rapid diagnosis is needed. We compared the results of using chromID C. difficile (chromID CD, bioMerieux, France) with the conventional C. difficile Selective Agar (CDSA; BD, USA) for the isolation of C. difficile. METHODS: A total of 738 stool specimens of suspected CDI patients at the Severance Hospital from July to August 2011 were inoculated onto CDSA. Among them, 104 stool specimens revealed colonies on CDSA that were then re-inoculated onto chromID CD. The stool samples were stored at -20degrees C until the time of the re-inoculation. Cultured agars were interpreted after 24 hrs and 48 hrs, respectively. Species identification was performed on the basis of colony characteristics on agar plates as well as the ATB 32A system (API System SA, France). RESULTS: The recovery rates of CDSA and chromID CD were 30.1% and 77.5% after 24 hrs, and 77.5% and 98.6% after 48 hrs, respectively. All of the C. difficile isolates were recovered as typical gray/black colonies on chromID CD. CONCLUSION: The performance of chromID CD for the isolation of C. difficile was better than that of conventional CDSA. The chromID CD could provide easy and sensitive detection of C. difficile even after 24hrs of incubation.
Agar ; Clostridium ; Clostridium difficile ; Diarrhea ; Humans ; Incidence

OBJECTIVE: We tried to investigate the activity of iron-uptake system (IUS) of Stap hylococcus aureus according to the isolation sites and thus the relatedness between IUS and virulence. METHODS: Seventy clinical isolates were classified into the isolates from patients (56), from doctors and nurses (7) and from hospital environments (7). The isolates from patients (56) were sub-classified into the isolates from hospitalized patients (40; HP) and from outpatients (16; OP). Siderophore activity was measured CAS agar diffusion assay and transferrin-binding protein (tbp) was detected by receptor-ligand binding assay. RESULTS: There was no difference of siderophore production among the isolates from patients, doctors and nurses, and hospital environments (P>0.05). However, the isolates from patients expressed more tbp than the isolates from doctors and nurses and hospital environments (P<0.05). The isolates from OP produced more siderophore and expressed more tbp than the isolates from HP (P<0.05). CONCLUSION: These results suggested that Staphylococcus aureus with more active IUS is more virulent and more easily causes infection even in patients with relatively good general condition.
Agar ; Diffusion ; Humans ; Outpatients ; Staphylococcus aureus ; Virulence

BACKGROUND: Currently fungal infections have been increasing in clinical aspect. Among them Candida albicans is considered as the most pathogenic. National Committee for Clinical Laboratory Standards(NCCLS) recommends broth macrodilution method for antifungal susceptibility test, but it is difficult to perform. E test is a relatively easy method to perform for the susceptibility testing. So in this study, antifungal susceptibility procedures were compared to determine MIC for fluconazole against 130 Candida strains isolated from clinical specimens. METHOD: The tests including were microdilution method, E test and disk diffusion method. The latter two tests were performed in casitone agar and the former test performed in RPMI 1640 media(Sigma Chemical co. St. Louis, USA). MIC was determined after 24 hrs of incubation. We used Candida albicans ATCC 90018 and Candida parapsilosis ATCC 90028 as controls. A total of 130 strains(93 C. albicans, 29 C. tropicalis, 5 C. parapsilosis and 3 C. glabrata) were tested. RESULTS: The MIC50 and MIC90 of broth microdilution test for C. albicans was > OR =64 microgram/mL equivalently. Agreement of > OR = +/-2 dilution between broth microdilution test and E test was 54 %, and the concordance rate was 55%. The concordance rate between E test and disk diffusion was 90%. CONCLUSIONS: From this study, we conclude that E test can be used as a alternative and convenient method to macrodilution method to determine MIC of fluconazole. But it is necessary for attention to microcolonies surrounding the E test strip. Disk diffusion method is rapid and also can be used as an alternative and convenient method.
Agar ; Candida albicans ; Candida* ; Diffusion* ; Fluconazole*