• 대한임상검사과학회지
• /
• 제48권2호
• /
• pp.82-87
• /
• 2016

Enterotoxigenic Bacteroides fragilis (ETBF)는 병독소 인자로 알려진 장독소를 생성하는 균종이다. B. fragilis enterotoxin (BFT)은 bft-1, bft-2 및 bft-3 세 개의 유전자 아형들이 밝혀졌다. 본 연구에서는 임상 검체에서 분리된 B. fragilis에서 bft 유전자의 유무와 BFT 음성 및 양성 균주의 항균제 내성을 조사하였다. 국내의 한 대학병원에서 8년간(2006~2013년) 장외 검체에서 분리된 B. fragilis는 총 537주이었다. 다중중합연쇄반응으로 시험하여 bft 유전자 아형을 확인하였다. BFT 음성 74주와 양성 33주를 포함한 B. fragilis 107주의 항균제 감수성은 CLSI 한천희석법으로 시험하였다. 임상 검체에서 분리된 B. fragilis의 bft 유전자 검출율은 30% 이었고, 이 중 혈액과 혈액 외 장외 검체 분리주에서는 각각 33%, 29% 이었다. ETBF 중에서 가장 흔한 아형은 bft-1 이었고, 그 다음은 bft-2, bft-3 순이었다(bft-1: 77%, bft-2: 14%, bft-3: 9%). BFT-음성과 양성 균주의 내성률은 일부 항균제에 대해서 차이가 있었다(BFT-음성 균주: piperacillin-tazobactam 3%, cefoxitin 5%, imipenem 1%, clindamycin 38%; BFT-양성 균주: piperacillin-tazobactam 3%, cefoxitin 6%, imipenem 3%, clindamycin 42%). BFT-음성 및 BFT-양성 균주 모두는 chloramphenicol과 metronidazole에 대한 내성은 없었다. 결론적으로, 혈액 분리주에서의 ETBF 검출율은 혈액 외 장외 검체 분리주에서와 비슷하였고, 가장 흔한 유전자 아형은 bft-1 이었다. 항균제 내성은 BFT 양성 균주가 음성 균주보다 대체로 높았으나 통계학적으로 유의한 차이는 없었다.

• Pediatric Infection and Vaccine
• /
• 제18권2호
• /
• pp.109-116
• /
• 2011

목 적 : 폐구균은 소아의 비인두에 상재하면서 다양한 국소 및 침습성 감염을 일으키며, 특히 2세 이하의 소아에서 발병 빈도가 높다. 2008년 미국 CLSI의 기준이 개정되면서 국내 폐구균의 페니실린 감수성률이 증가하였고 이에 따라 국내 경증 폐구균 감염증의 경험적 치료로서 경구 페니실린 및 amoxicillin의 사용이 가능하다. 최근 약력동학적 모델을 이용하여 항생제의 치료 효과를 평가하는 연구들이 보고되고 있으며, 본 연구는 이러한 모델 분석을 통해 국내 소아에서의 폐구균 감염증 치료시, 경험적 항생제로서 amoxicillin의 적절한 용량 결정에 도움이 되는 기초 자료를 얻고자 한다. 방 법: 2008년 9월부터 10월까지 서울에 위치한 어린이집을 방문하여 건강한 무증상 소아로부터 분리한 폐구균 23균주를 대상으로, 베타락탐 및 마크로라이드 항생제에 대한 MIC 값을 측정하였다. 베타락탐 항생제의 경우 각 균주의 MIC 값에서 fT>MIC가 50% 이상 되는것을 목표치로 정하고 목표치 획득 확률(PTA)이 90% 이상일 경우 적절한 항생제 요법으로 간주하였다. 소아의 상기도내에 보균된 폐구균 균주가 중이염 등의 폐구균 감염증의 원인 균주가 될 가능성이 높다는 전제하에, 이러한 Monte Carlo simulation 모델에서 구해진 PTA값에 본 연구에 포함된 폐구균 균주의 MIC 값을 적용하여 분석하였다. 결 과:건강한 소아의 인후에서 분리된 23개 폐구균균주중 베타락탐 항생제인 정주용 penicillin, amoxicillin 및 cefotaxime에 대한 감수성 균주의 분율은 각각 78.3%, 82.6% 및 82.6%였고, 마크로라이드 항생제인 erythromycin에 대한 감수성 균주는 단 한 개였다. Fallon등19)이 제시한 Monte Carlo simulation 모델에서 약10 kg의 소아에게 amoxicillin을 40 mg/kg/일의 용량으로 투여 시 $MIC{\leq}1.0{\mu}g$/mL인 폐구균의 경우 PTA 값이 90%였으나, MIC 값이 2 ${\mu}g$/mL로 증가되면 PTA 값이 52%로 감소하였다. 그러나 amoxicillin을 90 mg/kg/일의 용량으로 투여 시 MIC 값이 2 ${\mu}g$/mL인 폐구균의 경우에도 PTA가 97%로 좋은 치료 반응이 예상된다. 이 모델에 국내의 건강한 소아의 인두에서 분리된 폐구균 균주의 MIC 값을 적용하여 약력동학적인 면을 고려한 적절한 항생제 용법을 판단하였다. 본 연구에서 분리된 23개의 폐구균 균주 중 amoxicillin에 대한 MIC 값이${\leq}1.0 {\mu}g$/mL인 경우는 7 균주(30.4%), ${\leq}2 {\mu}g$/mL인 경우는 19 균주(82.6%)로, 국내 소아의 급성 중이염과 같은 폐구균 감염증에서 경구용 amoxicillin을 90 mg/kg/일의 용량으로 투여시 80% 이상에서 좋은 치료 성적을 기대할 수 있었다. 결 론 : 국내 소아의 폐구균 감염증에서 경험적 항생제로 amoxicillin을 투여할 경우, 약력동학적 모델을 이용하면 90 mg/kg/day의 고용량이 더욱 효과적일 것으로 생각되며, 저용량의 amoxicillin 또는 마크로라이드 처방은 치료 실패의 확률이 높을 것으로 추정된다.

• Laboratory Medicine Online
• /
• 제2권1호
• /
• pp.10-14
• /
• 2012

배경: HbA_1c의 측정은 최근 6-8주간의 혈당조절을 평가하고 당뇨를 진단하기 위해 사용되고 있다. 최근 라텍스 면역비탁법을 사용하는 HbA_1c 측정법이 개발되어 분석 능력과 임상검사실에서의 유용성을 평가하였다. 방법: 2009년 4월부터 7월까지 TBA-200FR에 Autolab HbA_1c을 장착하여 CLSI guideline (EP5-A2, EP6-P, EP9-A2)에 따라 직선성, 정밀도, 상관성을 평가하였다. 결과: Autolab HbA_1c는 고농도(15.1%)와 저농도(3.1%)의 검체의 혼합에서 r²=0.9997의 높은 직선성을 보였다. 12.1%의 경우 검사 일내 정밀도와 검사 일간 정밀도의 표준편차는 각각 0.06, 0.12였고 변이계수는 0.5%, 1.0%였다. 5.1%의 경우 각각 표준편차는 0.04, 0.09이었고 변이계수는 0.8%, 1.6%이었다. 비교식은 Autolab HbA_1c=1.0859×HPLC-0.6957이었다. 결론: 본 연구에서 Autolab HbA_1c는 Tosoh G7과 비교하여 좋은 수행능력을 보였다. 문헌고찰에서 변이형 혈색소에 따른 간섭은 없는 것으로 알려졌다. Tosoh G7에 비해 결과획득시간은 지연되는 단점이 있지만 Autolab HbA_1c의 장점은 일반 화학분석기에 적용이 가능하고 검체의 전처리가 필요없으며 증류수를 사용하여 자동적으로 용혈과정이 이루어진다는 점이다.

• 한국식품위생안전성학회지
• /
• 제29권3호
• /
• pp.223-227
• /
• 2014

원유시료에서 분리한 methicillin 내성 황색포도알균의 분표율과 내성유전자의 분석을 분자수준에서의 실시하였다. 총 698종의 원유시료에서 286개의 포도알균속 세균을 Staphylococcus Medium 110을 이용하여 분리 후 Vitek 2 system을 이용하여 동정한 결과 94개의 황색포도알균을 확인하였다. 94개의 황색포도알균 중 총 7개의 균에서 methicillin 내성 mecA 유전자가 존재함을 확인하였다. Methicillin-resistant Staphylococcus aureus (MRSA)로 확인된 7 균주에 대해 수종의 항생제에 대한 감수성 시험, staphylococcal cassette chromosome mec (SCCmec) typing, 및 병독소유전자인 Panton-Valentine Leukocidin (pvl)유전자를 분석하였다. 그 결과 7종의 mecA 양성 MRSA 모두 ampicillin과 oxacillin에 내성이었으며 teicoplanin, vancomycin 및 ciprofloxacin에는 모두 감수성임을 확인하였다. 한편 SCCmec typing결과 7균 중 1균주는 SCCmec type II로 확인되었고 6균주는 SCCmec type IV로 확인되었으며 병독소 유전자인 pvl유전자는 검출되지 않았다.

• 대한의생명과학회지
• /
• 제22권4호
• /
• pp.174-183
• /
• 2016

In the present study, a serum-based minimum inhibitory concentration (MIC) testing to caspofungin was optimized and evaluated to solve the limitations of the conventional Clinical and Laboratory Standards Institute (CLSI) guideline-based antifungal agent MIC test and the usefulness of this testing for clinical application was determined. A total of 105 Candida albicans clinical isolates were used for measuring MIC to caspofungin. Results showed that growth characteristics were different according to types of serum and the mouse serum was the most suitable for this assay. In order to measure the optimal concentration of mouse serum, 0 to 100% mouse serum were added to the media during fungal culture. The optimal concentration of serum was 50% when consideration of antifungal agent administration and inoculum size, serum components and ease of hyphae separated, and the consideration of the degree of growth. In comparison of the usefulness between the conventional Alamar-modified broth microdilution MIC assay and 50% mouse serum-based MIC testing, the range of $MIC_{80}$ of the Alamar-modified broth microdilution MIC assay was $0.13{\sim}2.0{\mu}g/mL$ (SD ${\pm}0.42{\mu}g/mL$) and that of the 50% mouse serum-based MIC assay was $2.0{\sim}32.0{\mu}g/mL$ (SD ${\pm}9.01{\mu}g/mL$). The range of $MIC_{50}$ of the Alamar-modified broth microdilution MIC assay was $0.13{\sim}2.0{\mu}g/mL$ (SD ${\pm}0.40{\mu}g/mL$) and that of the 50% mouse serum-based MIC assay was $1.0{\sim}16.0{\mu}g/mL$ (SD ${\pm}2.36{\mu}g/mL$). The MICs of 50% mouse serum-based MIC testing was increased by up to 4 to 64 times than Alamar-modified broth microdilution MIC assay. In conclusion, a 50% mouse serum-based MIC assay was more useful for measuring MIC in Candida albicans clinical isolates than conventional colorimetric broth microdilution MIC testing.

• Journal of Microbiology and Biotechnology
• /
• 제21권12호
• /
• pp.1345-1351
• /
• 2011

Vancomycin therapy failure due to the emergence of tolerance in pneumococci is increasing. The molecular mechanism of tolerance is not clear, but lytA and $pep^{27}$ are known to be involved. Our aim was to evaluate the expression of both genes in vancomycin-tolerant Streptococcus pneumoniae (VTSP) strains. Eleven VTSP strains from a total of 309 clinical isolates of S. pneumoniae from 1997 to 2006 were classified according to the criteria of Liu and Tomasz. All VTSP strains were evaluated for susceptibility according to CLSI criteria, serotype by the Quellung test, and clonality by PFGE. The expressions of lytA and $pep^{27}$ were analyzed in different growth phases by RT-PCR with and without vancomycin. Eighty-two percent of VTSP strains showed resistance to penicillin, and 100% were sensitive to vancomycin and cefotaxime. The most frequent serotypes of VTSP strains were 23F (4/11) and 6B (3/11). Clonal relationship was observed in only two strains. No significant changes were observed in $pep^{27}$ expression in the three phases of growth in VTSP strains with and without vancomycin. Interestingly, $pep^{27}$ expression in the stationary phase in the non-tolerant reference strain R6 was significantly higher. However, no significant differences in lytA expression were observed between VTSP and R6 strains during the phases of growth analyzed. The absence of changes in $pep^{27}$ expression in VTSP strains in the stationary phase may be related to their ability to tolerate high antibiotic concentrations, and thus, they survive and remain in the host under the antibiotic selective pressure reflected in therapeutic failure.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6391-6395
• /
• 2012

Background: Ovarian cancer is ranked as the fifth most common cause of cancer death in women. In Malaysia, it is the fourth most common cancer in females. CA125 has been the tumor marker of choice in ovarian cancer but its diagnostic specificity in early stages is only 50%. Hence, there is a critical need to identify an alternative tumor marker that is capable of detecting detect ovarian cancer at an early stage. HE4 is a new tumor marker proposed for the early diagnosis of ovarian cancer and disease recurrence. Currently, none of the normal ranges of HE4 quoted in the literature are based on data for a multiethnic Asian population. Therefore, the aim of this study was to determine reference intervals for HE4 in an Asian population presenting in University Malaya Medical Centre, a tertiary reference hospital. Materials and Methods: 300 healthy women were recruited comprising 150 premenopausal and 150 postmenopausal women, aged from 20-76 years. All women were subjected to a pelvic ultrasonograph and were confirmed to be free from ovarian pathology on recruitment. Serum HE4 levels were determined by chemiluminescent microparticle immunoassay (CMIA, Abbott Architect). The reference intervals were determined following CLSI guidelines (C28-A2) using a non-parametric method. Results: The upper limits of the $95^{th}$ percentile reference interval (90%CI) for all the women collectively were 64.6 pmol/L, and 58.4 pmol/L for premenopausal) and 69.0 pmol/L for postmenopausal. The concentration of HE4 was noted to increase with age especially in women who were more than 50 years old. We also noted that our proposed reference limit was lower compared to the level given by manufacturer Abbott Architect HE4 kit insert (58.4 vs 70 pmol/L for premenopausal group and 69.0 vs 140 pmol/L in the postmenopausal group). The study also showed a significant difference in HE4 concentrations between ethnic groups (Malays and Indians). The levels of HE4 in Indians appeared higher than in Malays (p<0.05), while no significant differences were noted between the Malays and Chinese ethnic groups. Conclusions: More data are needed to establish a reference interval that will better represent the multiethnic Malaysian population. Probably a larger sampling size of equal representation of the Malay, Chinese, Indians as well as the other native ethnic communities will give us a greater confidence on whether genetics plays a role in reference interval determination.

• 한국수정란이식학회지
• /
• 제25권4호
• /
• pp.267-272
• /
• 2010

The present study was to investigate the source of contamination during semen processing for in vitro uses. In the present study, frozen semen was prepared from liquid semen in our laboratory for in vitro fertilization (IVF) experiments due to lack of fresh semen. Antibiotics were added in the frozen semen extender (kanamycin and gentamicin) and in vitro culture (IVC) medium (gentamicin) for further inhibiting growth of microorganisms. Nevertheless, proliferations of microorganisms were observed in IVC culture drop during culturing of IVF embryos using frozen semen. Randomly 3 samples were taken from the liquid semen, frozen semen and egg yolk. Contaminated IVC medium, frozen-thawed semen, liquid semen and egg yolk were cultured in de Man, Rogosa and Sharpe (MRS) agar medium. Whitish colonies were detected in contaminated IVC drop, frozen-thawed semen samples and egg yolk but no colonies were formed in liquid semen samples. Gram-negative and rod-shaped identical bacteria were found in both frozen-thawed semen sample and contaminated IVC drop and egg yolk samples. Enterobacter cloacae were confirmed by API 20E kit according to manufacturer's instruction with identification value (% ID) 94.3% and T index 0.88. Antibiotic susceptibility tests were done according to Clinical and Laboratory Standards Institute (CLSI) by using ampicillin, amikacin, cephalothin, gentamicin, kanamycin, tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin test. Among them Enterobacter cloacae were resistant to ampicillin, amikacin, cephalothin, gentamicin, kanamycin but susceptible to tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin. From these findings it could be suggested that this contamination sources might be from egg yolk.

• 대한임상검사과학회지
• /
• 제41권4호
• /
• pp.167-172
• /
• 2009

Methotrexate (MTX) in one of the antineoplastic drug and it is known to effective to management of acute lymphoblastic leukemia in children, management of choriocarcinoma and related trophoblastic tumors in women, management of carcinomas of the breast, tongue, pharynx, and tests, maintenance of remission in leukemia and treatment of serve, debilitating psoriasis. Intermediate to high-dose methotrexate administration followed by leucovorin rescue is effective in treatment of carcinoma of the lung and osteogenic sarcoma. Intrathecal administration is effective in treating meningeal leukemia or lymphoma. There are FPIA (Fluorescence polarization immunoassay) and EMIT (Enzyme multiplied immunotechique) methods that measure for MTX. We evaluated the FPIA and EMIT methods. MTX were measured by Hitachi-7600 P-module using EMIT and FPIA using TDX in the sera 60 patients. The performance characteristics evaluated were, light influence, linearity, comparison with FPIA. Also, precision evaluated were three level controls through put following CLSI evaluation protocols (EP10-A). When the MTX value of $4.16{\pm}5.78{\mu}{\mu}mol/L$ (mean, SD) by the Hitachi-7600 P-module was compared with that of $4.05{\pm}5.47{\mu}{\mu}mol/L$ by FPIA, coefficients of correlation of 0.988 was obtained. The regression equation was Y (Hitachi-7600 P-module) = 0.9408 x (FPIA) + 0.1316 (r=0.9885, n=60). CVs of MTX measured by Hitachi 7600 P-module was 6.78% at $0.33{\mu}{\mu}mol/L$, 0.96% at $1.16{\mu}{\mu}mol/L$, and 0.96% at $8.04{\mu}{\mu}mol/L$. The precision was excellent in each group. The linearity was acceptable. We evaluated that MTX is light-sensitive on prolonged exposure to direct sunlight. Comparing with the FPIA using TDX, the Hitachi-7600 P-module using EMIT showed good coefficient of correlation and precision. Therefore the Hitachi-7600 P-module can replace the FPIA for quantitative analysis of MTX.

• 한국환경보건학회지
• /
• 제47권5호
• /
• pp.479-485
• /
• 2021

Background: Vibrio vulnificus has been frequently detected in seawater, fish, and shellfish mainly in the coastal areas of Chungcheongnam-do Province. Objectives: This study was conducted to investigate the analyzed biochemical properties, genetic characteristics, and distribution of Vibrio vulnificus isolated from environmental sources in coastal areas of Chungcheongnam-do Province from 2019 to 2020. Methods: A total of 1,510 samples were obtained from six different sites in Chungcheongnam-do Province. Isolated strains from the samples were identified by a VITEK 2 system and MALDI-TOF. Antibiotic susceptibility testing for 85 isolates was done by microdilution minimum inhibitory concentration methods, and 11 isolates were analyzed for 16s rRNA sequences in multiple alignments. Results: Among the 1,510 samples taken during the investigation period, 306 strains were isolated and the detection rate of V. vulnificus was 20.3%. One hundred eighty-eight strains (24.6%) from seawater and 118 strains (15.8%) from mud flats were isolated. It was mainly detected in July (17.3%), August (36.5%), and September (28.8%), and the proportion was 82.0%. Based on the CLSI-recommended breakpoints, V. vulnificus isolates were all susceptible to amoxicillin/clavulanic acid, amikacin, gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole. However, nonsusceptible isolates to ampicillin, ampicillin/sulbactam, cefazolin, cefoxitin, imipenem, tetracycline and chloramphenicol were identified. In the analysis of the nucleotide sequences for 16s rRNA of V. vulnificus isolates, it was confirmed that mutations frequently occurred between nucleotide number 922 and 952, and 98.2% to 100% nucleotide identities between isolates was verified. Conclusions: The results of this study can be used as a basic data for infection control and prevention of Vibrio vulnificus infection by describing the distribution and characteristics of Vibrio vulnificus strains isolated in coastal areas of Chungcheongnam-do Province.