• International Journal of Oral Biology
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• v.36 no.4
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• pp.163-166
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• 2011

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.114-118
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• 2014

A total of 122 ESBL-producing intestinal bacteria were collected from regional hospitals in the Chungcheong area. Combination disk test (CDT) was performed for antimaicrobial susceptability using cefotaxime and cefotaxime/clavulanate according to Clinical Laboratory Standard Institute (CLSI). Mutiplex PCR using specific primers was performed for a detection of ESBL-genotypes and enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out for the tracking of molecular epidemiology. In the confirmation test using CDT, 73 out of 76 (96.1%) ESBL-producing Escherichia coli and 43 out of 46 (93.4%) ESBL-producing Klebsiella pnemoniae were positive. In the multiplex PCR, 60.5% of E. coil were positive for CTX-M-2 type gene and 56.5% of K. pneumoniae were positive for VEB -1 type gene. In the ERIC-PCR, E. coil isolates formed 5 clusters and K. pneumoniae isolates were grouped into 4 clusters depending on region. Genotypes of clinical isolates are useful for detection and differentiation of ESBL producing intestinal bacteria. The ERIC-PCR method is thought to be helpful for establishing a regional surveillance system for infection due to its formation of different clusters depending on region.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1191-1196
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• 2013

Among Gram-negative pathogens in Korea, the incidence of resistance to third generation cephalosporins is becoming an ever-increasing problem. The production of extended-spectrum ${\beta}$-lactamase (ESBL) is the main mechanism of bacterial resistance to a third-generation cephalosporins and monobactams. Accurate identification of the ESBL genes are necessary for surveillance and epidemiological studies of the mode of transmission in the hospital. This study was conducted to detect the genes encoding ESBL of 46 K. penumoniae isolated from Daejeon, Chungnam and Chungbuk regional university hospitals from February to August in 2012. The phenotypes of the isolated specimens were examined according to the combination disc test (CDT) by the Clinical and Laboratory Standards Institute (CLSI). Forty two ESBL producing K. penumoniae isolates could be detected using ceftazidime (CAZ) discs with and without clavulanate (CLA). By CDT, 42 K. pneumoniae strains were confirmed to be ESBL strains. Genotyping was performed by multiplex PCR with type-specific primers. By PCR analysis, TEM gene in 46 strains, SHV gene in 37 strains and CTX-M genes in 14 strains were identified. Ten isolates did carry genes encoding ESBLs of all types TEM, SHV and CTX-M. The multiplex polymerase chain reaction (PCR) analysis was better to detect and differentiate ESBL producing K. penumoniae strains in clinical isolates.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.382-388
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• 2019

Streptococcosis caused by Streptococcus parauberis is a very important disease in farmed olive flounder Paralichthys olivaceus. For most fish pathogens, including S. parauberis, there are no analytical criteria to distinguish antibioticsusceptible strains from antibiotic-resistant strains. In this study, epidemiological cut-off ($CO_{WT}$) values were generated to classify 75 strains of S. parauberis isolated from 1999 to 2018 as wild type (WT) and non-wild type (NWT) using disc diffusion data and normalized resistance interpretation (NRI) analysis. The susceptibility of the isolates to 16 antibiotics was evaluated using CLSI guideline M42-A. The wild-type cut-off values for amoxicillin, erythromycin, oxytetracycline, and florfenicol for S. parauberis were ${\geq}35$, 31, 28, and 27 mm, respectively. The NWT ratios of S. parauberis strains to treatment with GEN, FFC, ENR, SXT, EFT, VAN, and CHL were 17% or less, indicating that these antibiotics may be used to treat streptococcosis caused by S. parauberis. For recent S. parauberis isolates, the NWT ratios for AMX, ERY, OTC and FFC are much higher than for strains isolated from 1999-2007. The $CO_{WT}$ data from this study will assist aquatic animal disease professionals in prescribing appropriate antibiotics for the treatment of streptococcosis caused by S. parauberis, which will help reduce the misuse and abuse of antibiotics in the aquaculture sector.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.19-31
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• 2021

This study aimed at comparing the performance of imported LX detergent cleaning solution (LX-CS) and the self-manufactured OC cleaning solution (OC-CS), based on functional and quantitative analysis. The functional analysis was carried out using apparent diffusion coefficient (ADC) values. For quantitative analysis, precision, linearity, and carry-over rates were measured with commercial control materials according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Using OC-Sensor PLEDIA (Eiken Chemical, Japan), the ADC value of all cuvettes satisfied the acceptance criteria. For quantitative analysis, precision was less than 5.0% for the two products, and carry-over rates were less than ±1.00%. The linearity slopes and r2 values were 1.0017 and 0.9982 in the LX-CS, and 0.9924 and 0.9996 in the OC-CS, respectively. The correlation coefficient (r) was found to be 0.9997. Also, the percent difference in correlation with 40 artificial-stool specimens was less than 10% and the p-value was less than 0.1. The result of standard deviation ratio (D: ±1 SD ratio) was similar for both products. In conclusion, the functional and quantitative analyses of the two products were compared and showed similar results. In the future, the self-manufactured OC-CS will be able to provide a much more stable and faster supply than the imported LX-CS.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.135-139
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• 2016

Scrophularia ningpoensis hemsl has been traditionally used in China and Vietnam for treatment of bacteria, atopy, pimple, tonsillitis, angina and encephalitis for a long time. The main objectives of this study were to evaluate the antibacterial activity of the Scrophularia ningpoensis hemsl extract on biofilm formation of Klebsiella pneumoniae. Antibacterial activity was conducted using disc diffusion assay and minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were determined using the broth micro dilution method in accordance to Clinical and Laboratory Standards Institute guidelines(CLSI). Furthermore, cytotoxicity on L929 were assessed using animal cell culture for the proliferation test(MTT cell assay) and the biofilm forming capacity of the K. pneumoniae were determined using the colony forming unit (CFU) assay. The extract exhibited considerable antibacterial activity. K. pneumoniae was susceptible to the extract with the MIC and MBC of 0.1875 and $1.5mg/m{\ell}$ respectively. Cytoxicity test in L929 showed no sign of toxicity at the concentration of $0.75mg/m{\ell}$ and at the same concentration the extract caused inhibition of bacterial biofilm formation. The extract of Scrophularia ningpoensis hemsl possesses an in vitro antibacterial antibiofilm activities against K. pneumoniae, with no sign of cytoxicity on L929.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.173-178
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• 2006

The production of extended-spectrum ${\beta}$-lactamases ($ESBL_S$) is the main mechanism of bacterial resistance to third-generation cephalosporins and monobactams, whose prevalence varies depending on the different geographical areas. In the last years it has increased notably to the point of being considered a health problem of great importance. The characterization of the ESBLs producing Klebsiella penumoniae strains present in clinical isolates is time-consuming. I describe here the development of a new system, which consists of a multiplex PCR. I found 51 K. pneumoniae strains to be presumptive strains ESBLs producers by clinical and laboratory standards institute (CLSI) guidelines. The double disc synergy test showed 47 positive K. pneumoniae, which were K. pneumoniae isolates. All ESBLs producing K. pneumoniae strains were resistant to antibiotic amikacin, gentamicin and ciprofloxacin. By multiplex PCR analysis, $bla_{TEM}$ gene in 17 strains 44 $bla_{SHV}$ genes and $bla_{CTX}$ genes in 33 strains were identified. In this study, the multiplex polymerase chain reaction (PCR) assay was a good method to detect and differentiate ESBLs producing K. penumoniae strains in clinical isolates.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.4
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• pp.153-157
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• 2009

The production of extended-spectrum ${\beta}$-lactamases ($ESBL_S$) of the TEM or SHV type by bacterial pathogens is a major threat to the use of the clinically important expanded-spectrum cephalosporins. The characterization of the SHV ESBLs producing Klebsiella pneumoniae strains present in clinical isolates is time-consuming processes. We describe here in the development of a novel system, which consists of a real time PCR. We found 11 K. pneumoniae strains to be presumptive strains ESBLs producers by clinical and laboratory standards institute (CLSI) guidelines. The double disk synergy test showed 8 ESBL positive and conventional PCR showed 10 SHV ESBL positive, which were K. pneumoniae strains isolates. By real time PCR analysis, SHV gene in 11 of 11 strains were identified. When sequencing analysis was compared with real time PCR, both analysis were presented 99% similarity. In this study, we used a rapid, sensitive, and specific real-time PCR (RT-PCR) method for detection of the assay SHV ESBL producing K. pneumoniae strains in clinical isolates.

• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.108-114
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• 2017

Background: The study was conducted to investigate the distributions of faecal bacteria in commercial oriental medicine herb products. Methods and Results: A survey was conducted on the microbial contamination levels and antimicrobial specificity of Bacillus cereus and other microbes using 106 oriental medicine herb products on sale in Seoul. Pouring and isolation methods such as standard plate counts were used to identify the bacteria. The isolated bacterias included coliforms, Bacillus spp., Enterococcus spp., Staphylococcus spp., Listeria spp.were identified by using gram staining and an API (analytical profile index) kit. Antimicrobial drugs discs were determined by CLSI (clinical and laboratory standards institute). Conclusions: The bacterial isolates present in the herbal medicines included 98 coliforms, 45 Bacillus spp., 29 Enterococcus spp., and 2 Listeria spp. Among these, there were nine Bacillus cereus strains, one Enterococcus faecium strain, and one Enterococcus faecalis strain present. The 9 Bacillus cereus strains were tested for susceptibility to 36 types of antibiotics products by the disc diffusion method. The strains showed resistance to 13 of these antibiotic products and semi-resistance to 5 antibiotic products. On the basis of these results, any oriental medicine herb product can be assumed to be contain resistant or semi-resistant bacterial strains. Therefore, we suggest prescribing guidelines and special management for the use of antibiotics in farms producing oriental medicine herb products.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.156-160
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• 2007

We evaluated the newly developed plastic sodium citrate tubes for routine coagulation test by direct comparison with glass citrate theophylline adenosine dipyridamole (CTAD) tubes. Blood was drawn from 100 patients into glass CTAD tubes and plastic sodium citrate tubes. After collection, samples were centrifuged at 1500 ${\times}$g for 15 min at $22^{\circ}C$. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen were measured by using the Coagrex-800 (IRC, Japan). We used comparison plot by linear regression model and difference plot graphs to compare the results of the independent measurements of PT, aPTT, fibrinogen between glass CTAD tubes and plastic sodium citrate tubes. On the comparison study between glass CTAD tubes and plastic sodium citrate tubes, the correlation coefficients (R) were 0.99 for PT, 0.97 for aPTT and 0.97 for fibrinogen. This results implicated good correlation of each parameter between two tubes. Although the difference plot graph analysis showed statistically significant differences between glass and plastic tubes for PT, aPTT and fibrinogen, the range of difference was acceptable according to the CLSI/NCCLS guideline. The plastic sodium citrate tubes showed good correlation with the glass CTAD tubes, so it can substitute glass citrate tube for routine coagulation tests.