Bacteremia in Hematopoietic Stem Cell Recipients Receiving Fluoroquinolone Prophylaxis: Incidence, Resistance, and Risk Factors

Eryilmaz-Eren Esma,Izci Feyza,Ture Zeynep,Sagiroglu Pinar,Kaynar Leylagul,Ulu-Kilic Aysegul 대한감염학회 2022 Infection and Chemotherapy Vol.54 No.3

Background Bacteremia is a common complication in hematopoietic stem cell transplant (HSCT) recipients. Prophylactic fluoroquinolone is recommended and used in these individuals. Breakthrough infections can occur with fluoroquinolone-resistant strains. We aimed to identify the incidence, resistance, and risk factors for bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis. Materials and Methods This retrospective study was performed on patients who received fluoroquinolone prophylaxis and underwent autologous and allogeneic HSCT between 2015 and 2019. The incidence of bacteremia, comorbidity, treatment, and invasive procedures was compared in these patients with and without bacteremia. Results There were 553 patients included in the study, 68 (12.3%) had bacteremia. The incidence of bacteremia is 8.2% of autologous HSCT recipients and 18.4% of allogeneic HSCT recipients. The significant risk factors associated with bacteremia were steroid-using (odds ratio [OR]:13.83, 95% confidence interval [CI]: 2.88 - 66.40), higher Charlson Comorbidity Index (CCI)-mean (OR: 1.57, 95% CI: 1.15 - 2.16), diabetes mellitus (OR: 4.29, 95% CI: 1.11 - 16.48) in autologous HSCT, steroid-using (OR: 6.84, 95% CI: 1.44 - 32.33), longer duration of neutropenia (OR: 1.05, 95% CI: 1.01 - 1.09) using central venous catheter (OR: 7.81, 95% CI: 1.00 - 61.23) in allogeneic HSCT. Seventy-three pathogens were isolated from a total of 68 bacteremia episodes. The most commonly occurring agents were Escherichia coli, Klebsiella pneumoniae and Enterococcus spp. Resistance to fluoroquinolones was 87.2%, 70.0% and 60.0% among these strains, respectively. Conclusion High CCI, diabetes mellitus, use of steroids and long-term neutropenia and use of central venous catheters were significantly associated with the breakthrough bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis. Fluoroquinolone prophylaxis may reduce the incidence of bacteremia but may select strains resistant to fluoroquinolone. Background Bacteremia is a common complication in hematopoietic stem cell transplant (HSCT) recipients. Prophylactic fluoroquinolone is recommended and used in these individuals. Breakthrough infections can occur with fluoroquinolone-resistant strains. We aimed to identify the incidence, resistance, and risk factors for bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis. Materials and Methods This retrospective study was performed on patients who received fluoroquinolone prophylaxis and underwent autologous and allogeneic HSCT between 2015 and 2019. The incidence of bacteremia, comorbidity, treatment, and invasive procedures was compared in these patients with and without bacteremia. Results There were 553 patients included in the study, 68 (12.3%) had bacteremia. The incidence of bacteremia is 8.2% of autologous HSCT recipients and 18.4% of allogeneic HSCT recipients. The significant risk factors associated with bacteremia were steroid-using (odds ratio [OR]:13.83, 95% confidence interval [CI]: 2.88 - 66.40), higher Charlson Comorbidity Index (CCI)-mean (OR: 1.57, 95% CI: 1.15 - 2.16), diabetes mellitus (OR: 4.29, 95% CI: 1.11 - 16.48) in autologous HSCT, steroid-using (OR: 6.84, 95% CI: 1.44 - 32.33), longer duration of neutropenia (OR: 1.05, 95% CI: 1.01 - 1.09) using central venous catheter (OR: 7.81, 95% CI: 1.00 - 61.23) in allogeneic HSCT. Seventy-three pathogens were isolated from a total of 68 bacteremia episodes. The most commonly occurring agents were Escherichia coli, Klebsiella pneumoniae and Enterococcus spp. Resistance to fluoroquinolones was 87.2%, 70.0% and 60.0% among these strains, respectively. Conclusion High CCI, diabetes mellitus, use of steroids and long-term neutropenia and use of central venous catheters were significantly associated with the breakthrough bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis. Fluoroquinolone prophylaxis may reduce the incidence of bacteremia but may select strains resistant to fluoroquinolone.

하천수로부터 분리한 Escherichia coli의 Fluoroquinolone 계 항생제에 대한 내성 현황

정다혜,이연희 서울여자대학교 자연과학연구소 2005 자연과학연구논문집 Vol.17 No.-

2004년 2월부터 2005년 1월까지 하천수으로부터 norfloxacin 내성 Escherichia coli 를 분리하였다. 분리된 E. coli 20 주에 대해 fluoroquinolone 항생제 (norfloxain, ciprofloxacin, nalidixic acid, moxifloxacin, levofloxacin, gemifloxacin, gatifloxacin)의 내성 실험을 실시하였다. Clinical and Laboratory Standards Institute (CLSI) 의 기준에 따라서 한천 희석법으로 항생제 최소 억제농도를 측정하였으며 E. coli 20주는 nalidixic acid 와 norfloxacin에서 모두 고도내성 (128 ㎍/ml)을 나타내었다. E. coli 20주에 대한 퀴놀론 내성 결정 부위인 GyrA 와 ParC 의 염기서열 분석결과, 20균주 모두에서 GyrA의 Ser83Leu, Asp87Asn 돌연변이와 ParC 의 Ser80Ile 돌연변이가 공통적으로 일어났으며, 3 균주에서는 ParC의 Glu84Gly 또는 Glu84Val 로의 돌연변이가 추가적으로 더 일어났다. 외막 단백질 감소 현상을 살펴본 결과, 막 투과성에 관여하는 OmpF 의 소실을 8균주(40%)에서 볼 수 있었다. 그러나, OmpF 소실량과 항생제 최소 억제농도와의 연관성은 찾을 수 없었다. 또한, 분리된 E. coli 20 주의 유사성을 비교해 보기위해서 pulsed field gel electrophoresis를 실시하여 총 6그룹으로 나뉘는 것이 관찰되었으며, fluoroquinolone 내성 기원의 다양함을 알 수 있었다. During one year period between 2004 and 2005, 310 norfloxacin-resistant (MIC≥16μg/ml) isolates of Escherichia coli were obtained from river water. Their resistance was tested with nalidixic acid, norfloxacin, ciprofloxacin, levofloxacin, moxifloxacin, gemifloxacin and gatifloxacin. MICs were determined by the agar dilution method according to the guideline suggested by the Clinical and Laboratory Standards Institute. Twenty isolates highly resistant to both nalidixic acid (MIC ≥128 μg/ml) and norfloxacin (MIC≥128 μg/ml) were further studied. When the quinolone resistance determining regions of GyrA and ParC were sequenced, every isolate had the same three mutations Ser83Leu, Asp87Asn in GyrA and Ser80Ile in ParC while three isolates had an additional mutation Glu84Gly or Glu84Val in ParC. Eight isolates (40%) showed decreased amount of OmpF which is responsible for quinolone uptake. However, relation between the amount of OmpF and resistance was not observed. Pulsed field gel electrophoresis using XbaI showed six profiles of these twenty isolates suggesting various origins of these fluoroquinolone resistant isolates.

Efficacy of Fluoroquinolone as a Substitute for Ethambutol or Rifampin in the Treatment of Mycobacterium Avium Complex Pulmonary Disease According to the Radiologic Type

( Jang Ho Lee ),( Yea Eun Park ),( Yong Pil Chong ),( Tae Sun Shim ),( Kyung-wook Jo ) 대한결핵 및 호흡기학회 2021 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.129 No.-

Objective During the treatment of Mycobacterium avium complex pulmonary disease (MAC-PD), ethambutol or rifampin is often discontinued due to adverse events. In this study we investigated the treatment outcomes when fluoroquinolone is substituted for ethambutol or rifampin in MAC-PD treatment according to radiologic type. Methods Between 2006 and 2019, 225 patients who initiated guideline-based therapy (GBT) and whose treatment duration was ≥1 year were enrolled at a tertiary referral centre in South Korea, including 178 patients with cavitary disease (fibrocavitary and cavitary nodular bronchiectatic types) and 47 patients with noncavitary nodular bronchiectatic (NC-NB) type. We compared microbiologic cure at 1 year between the patients maintaining GBT and those who replaced ethambutol or rifampin with fluoroquinolone (moxifloxacin or levofloxacin). Results The overall microbiologic cure rate of the 178 patients with cavitary disease was 71.3%. Among these, the microbiologic cure rate of the 16 patients who substituted fluoroquinolone for ethambutol was lower than that of the 156 patients who maintained GBT (37.5% vs. 74.4%, respectively; P = 0.007), which was also statistically significant in the multivariate analysis. The outcomes of the six patients in which fluoroquinolone was selected as an alternative to rifampin were similar to that of those receiving GBT. The microbiologic cure rate of the 47 patients with NC-NB was 83.0%; the treatment outcomes were similar whether the patients maintained GBT or replaced ethambutol or rifampin with fluoroquinolone. Conclusions In cavitary MAC-PD, substituting fluoroquinolone for ethambutol resulted in inferior patient outcomes. In other cases, treatment outcomes seemed to be similar.

Using <i>In Vitro</i> Dynamic Models To Evaluate Fluoroquinolone Activity against Emergence of Resistant <i>Salmonella enterica</i> Serovar Typhimurium

Lee, Seung-Jin,Awji, Elias Gebru,Park, Na-hye,Park, Seung-Chun American Society for Microbiology 2017 Antimicrobial Agents and Chemotherapy Vol.61 No.2

<P>The objectives of this study were to determine pharmacokinetic/pharmacodynamic (PK/PD) indices of fluoroquinolones that minimize the emergence of resistant Salmonella enterica serovar Typhimurium (S. Typhimurium) using in vitro dynamic models and to establish mechanisms of resistance. Three fluoroquinolones, difloxacin (DIF), enrofloxacin (ENR), and marbofloxacin (MAR), at five dose levels and 3 days of treatment were simulated. Bacterial killing-regrowth kinetics and emergence of resistant bacteria after antibacterial drug exposure were quantified. PK/PD indices associated with different levels of antibacterial activity were computed. Mechanisms of fluoroquinolone resistance were determined by analyzing target mutations in the quinolone resistance-determining regions (QRDRs) and by analyzing overexpression of efflux pumps. Maximum losses in susceptibility of fluoroquinolone-exposed S. Typhimurium occurred at a simulated AUC/MIC ratio (area under the concentration-time curve over 24 h in the steady state divided by the MIC) of 47 to 71. Target mutations in gyrA (S83F) and overexpression of acrAB-tolC contributed to decreased susceptibility in fluoroquinolone-exposed S. Typhimurium. The current data suggest AUC/MIC (AUC/mutant prevention concentration [MPC])-dependent selection of resistant mutants of S. Typhimurium, with AUC/MPC ratios of 69 (DIF), 62 (ENR), and 39 (MAR) being protective against selection of resistant mutants. These values could not be achieved in veterinary clinical areas under the current recommended therapeutic doses of the fluoroquinolones, suggesting the need to reassess the current dosing regimen to include both clinical efficacy and minimization of emergence of resistant bacteria.</P>

Chlamydia trachomatis에 대한 Fluoroquinolone CFC-222의 시험관내 약효시험

강정옥,박일규,최효선,안정열,최태열,김제학 대한감염학회 1996 감염 Vol.28 No.5

목 적 : Chlamydia trachomatis는 비임균성뇨도염, 영유아 폐염 등 여러 질환의 중요 원인균이다. 새고운 fluoroquinolone제제중의 하나인 CFC-222와 다른 quinolone제제와 함께 C. trachomatis에 대한 항균력을 측정하였다. 방 법 : 96-well microtiter cell culture plate에 McCoy을 키운 후 균접종을 하였고, 15개 표준균주 (A-L₃)와 36개 국내 분리 균주를 사용하였다. CFC-222, ciprofloxacin(CPFX), ofloxacin(OPLX), 및 minocycline(MC)을 2배수 희석하여 각 항균제의 최소억제 농도를 측정하였다. 결 과 : 표준균주의 MIC?는 CFC-22 0.15/ml, CPFX 2.5㎍/ml, OFLX 0.6㎍/ml 및 MC 0.08㎍/ml였다. 국내 분리 균주의 MIC?는 CFC-222 0.3㎍/ml, CPFX 1.2㎍/ml, OFLX 0.6㎍/ml 및 MC은 및 MC은 0.06㎍/ml였다. 결 론 : 새로운 fluoroquinolone CFC-222는 Chlamydia trachomatis에 탁월한 감수성을 나타내었다. Background : Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen. Our purpose is to investigate the antimicrobial activity of new fluoroquinolone CFC-222 (CFC-222)to C. trachomatis. Methods : In vitro antibacterial activity of CFC-222 against 15 control strains(A-L3) and 36 clinical strains of C. trachomatis were determined in 96-well microtiter cell culture plates, and compared with that of ciprofloxacin(CPFX), ofloxacin(OFLX) and minocycline(MC). The lowest concentration of antibiotic at which no inclusions could be observed was defined as the minimum inhibitory concentration(MIC). Results : The MIC? of CFC-222, CPFX, OFLX, and MC against control strains were 0.15㎍/ml, 2.5㎍/ml, 0.6㎍/ml, and 0.008㎍/ml respectively. The MIC? of CFC-222, CPEX, OFLX, and MC against isolates were 0.3㎍/ml, 1.2㎍/ml. 0.6㎍/ml, 0.04㎍/ml, and 0.06㎍/ml, respectively. Conclusion : The new fluoroquinolone CFC-222 was effective in vitro against C. trachomatis.

Correlation Between Virulence Genotype and Fluoroquinolone Resistance in Carbapenem-Resistant Pseudomonas aeruginosa

조혜현,권계철,김세미,구선회 대한진단검사의학회 2014 Annals of Laboratory Medicine Vol.34 No.4

Background: Pseudomonas aeruginosa is a clinically important pathogen that causes op- portunistic infections and nosocomial outbreaks. Recently, the type III secretion system (TTSS) has been shown to play an important role in the virulence of P. aeruginosa . ExoU, in particular, has the greatest impact on disease severity. We examined the relationship among the TTSS effector genotype ( exoS and exoU ), fluoroquinolone resistance, and tar- get site mutations in 66 carbapenem-resistant P. aeruginosa strains. Methods: Sixty-six carbapenem-resistant P. aeruginosa strains were collected from pa- tients in a university hospital in Daejeon, Korea, from January 2008 to May 2012. Mini- mum inhibitory concentrations (MICs) of fluoroquinolones (ciprofloxacin and levofloxacin) were determined by using the agar dilution method. We used PCR and sequencing to de- termine the TTSS effector genotype and quinolone resistance-determining regions (QR- DRs) of the respective target genes gyrA, gyrB, parC , and parE . Results: A higher proportion of exoU+ strains were fluoroquinolone-resistant than exoS+ strains (93.2%, 41/44 vs. 45.0%, 9/20; P ≤0.0001). Additionally, exoU + strains were more likely to carry combined mutations than exoS + strains (97.6%, 40/41 vs. 70%, 7/10; P =0.021), and MIC increased as the number of active mutations increased. Conclusions: The recent overuse of fluoroquinolone has led to both increased resistance and enhanced virulence of carbapenem-resistant P. aeruginosa . These data indicate a specific relationship among exoU genotype, fluoroquinolone resistance, and resistance- conferring mutations.

Levofloxacin과 흔히 사용되는 항균제의 호기성 세균에 대한 시험관내 항균력

이경원,정윤섭,권오헌 대한감염학회 1995 감염 Vol.27 No.1

목 적 : Levofloxacin 은 ofloxacin의 광학 이성체인데 그 항균력은 ofloxacin 보다 약 2배 강하며, 특히 그람양성 세균에 대한 항균력은 더 크다고 보고된 바 있다. 이 연구에서는 호기성 세균에 대한 levofloxacin의 항균력을 ofloxacin, ciprofloxacin 및 흔히 사용되는 수종 항균제의 항균력과 비교하고자 하였다. 방 법 : 시험 세균은 세브란스병원 환자에서 대부분 1994년에 분리하였고, NCCLS 한천희석법으로 감수성을 시험하였다. 결 과 : Fluoroquinolone 제제는 ampicillin, carbenicillin, cephalothin, doxycycline 및 gentamicin보다 ??치가 현저히 낮았다. Ciprofloxacin, levofloxacin 및 ofloxacin의 ??은 K. oxytoca, E. aerogenes, Proteus sp., M. morganii, Salmonella, s. flexneri 및 Y. enterocolitica에 대해 ≤1 ㎍/ml, C. freundii, E. cloacae, X. maltophilia에 대해 4-8㎍/ml, 다른 그람음성 간균에 대해 ≥8 ㎍/ml 이었고, methicillin 감수성 S. aureus, S. pyogenes, S. agalactiae, S. pneumoniae, M. (B.) catarrhalis에 대해 ≤0.25-4 ㎍/ml이었다. K oxytoca, E. aerogenes, Salmonella, S. flexneri 및 Y. enterocolitica는 시험균주 모두가 모든 fluoroquinolone 제제에 감수성이었다. P. aeruginosa는 ciprofloxacin과 levofloxacin에 대한 감수성율이 약간 높았고, E. cloacae와 X. maltophilia는 levofloxacin에 대한 감수성율이 현저히 높았다. 결 론 : 근래 분리되는 호기성 세균 중에는 흔히 사용되어 온 항균제에 내성인 균주가 많으나, fluoroquinolone 제제에 내성인 균주는 드물며, 시험된 fluoroquinolone 제제 중에서는 levofloxacin 에 대한 내성율이 가장 낮았음에 비추어 이 항균제는 여러부위의 감염증 치료에 유용할 것이라는 결론을 얻었다. Background : Levofloxacin (LVFX), an optical isomer of ofloxacin (OFLX), was reported to be approximately two-fold more active against aerobic bacteria than OFLX, but the antimicrobial activity against Korean isolates of bacteria has not been compared yet. The aim of this study was to compare the activity of LVFX to those of other commonly used antimicrobial agents, including OFLX and ciprofloxacin (CPFX) Methods : Aerobic bacteria, which were isolated from patients at Severance Hospital, during the years 1980 to 1994, were tested by the NCCLS agar dilution method. Results : Minimum inhibitory concentrations of CPFX, LVFX and OFLX for 90% of the strains were : ≤㎍/ml for Kiebsiella oxytoca (KOX), Enterobacter aerogenes (EAE), Proteus sp., Morganella morganii, salmonella serovars (SAL), Shigella flexneri (SFL) and Yersinia enterocolitica (YEN) ; 4-8 ㎍/ml for Citrobacter freundii, E. cloacae (ECL), Xanthomonas maltophilia (XMA) ;≥8 ㎍/ml for other gram-negative bacilli ; ≤0.25-4 ㎍/ml for Moraxella (Branhamella) catarrhalis and gram-positive cocci. All isolates of the KOX, EAE, SAL, SFL and YEN were susceptible to the fluoroquinolones. Pseudomonas aeruginosa were more often susceptible to CPFX and LVFX, and ECL and XMA more often to LVFX than to the other fluoroquinolones. Conclusion : The higher in vitro activity of fluoroquinolones against various aerobic bacteria, compared to the other commonly used antimicrobial agents and the slightly higher activity of LVFX against some species of bacteria strongly suggest that LVFX may be more useful in the treatment of various aerobic infections.

Impact of Anti-Tuberculosis Drug Use on Treatment Outcomes in Patients with Pulmonary Fluoroquinolone-Resistant Multidrug-Resistant Tuberculosis: A Nationwide Retrospective Cohort Study with Propensity Score Matching

( Hongjo Choi ),( Dawoon Jeong ),( Young Ae Kang ),( Doosoo Jeon ),( Hee-yeon Kang ),( Hee Jin Kim ),( Hee-sun Kim ),( Jeongha Mok ) 대한결핵 및 호흡기학회 2023 Tuberculosis and Respiratory Diseases Vol.86 No.3

Background: Effective treatment of fluoroquinolone-resistant multidrug-resistant tuberculosis (FQr-MDR-TB) is difficult because of the limited number of available core anti-TB drugs and high rates of resistance to anti-TB drugs other than FQs. However, few studies have examined anti-TB drugs that are effective in treating patients with FQr-MDR-TB in a real-world setting. Methods: The impact of anti-TB drug use on treatment outcomes in patients with pulmonary FQr-MDR-TB was retrospectively evaluated using a nationwide integrated TB database (Korean Tuberculosis and Post-Tuberculosis). Data from 2011 to 2017 were included. Results: The study population consisted of 1,082 patients with FQr-MDR-TB. The overall treatment outcomes were as follows: treatment success (69.7%), death (13.7%), lost to follow-up or not evaluated (12.8%), and treatment failure (3.9%). On a propensity- score-matched multivariate logistic regression analysis, the use of bedaquiline (BDQ), linezolid (LZD), levofloxacin (LFX), cycloserine (CS), ethambutol (EMB), pyrazinamide, kanamycin (KM), prothionamide (PTO), and para-aminosalicylic acid against susceptible strains increased the treatment success rate (vs. unfavorable outcomes). The use of LFX, CS, EMB, and PTO against susceptible strains decreased the mortality (vs. treatment success). Conclusion: A therapeutic regimen guided by drug-susceptibility testing can improve the treatment of patients with pulmonary FQr-MDR-TB. In addition to core anti-TB drugs, such as BDQ and LZD, treatment of susceptible strains with later-generation FQs and KM may be beneficial for FQr-MDR-TB patients with limited treatment options.

액체크로마토그래피-형광검출기를 이용한 닭고기 중 플루오로퀴놀론계 항균물질 정량분석 및 잔류조사

박은정,임지흔,이성모 한국식품위생안전성학회 2004 한국식품위생안전성학회지 Vol.19 No.1

1. 닭고기에서 4종의 플루오로퀴놀론계 합성항균제(ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin)를 액상추출법으로 추출하여 형광검출기와 HPLC를 이용하여 동시 정량분석하는 방법을 확립하였으며 분석조건으로서 컬럼은 Symmetry C18(250×4.6 mm id, 5 ㎛), 이동상은 0.4% triethylamine 및 0.4% phospholic acid 수용액, methanol 및 acetonitrile 혼합용액(800:100:100, v/v/v)을 사용하였으며, 형광검출기는 여기파장 278 nm, 측정파장 456 nm으로 그리고 유속은 1.0 ml/min., 주입량은 50 ㎕로 하였다. 확립된 분석조건으로 측정한 ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin 표준품의 표준곡선식에서 모두 상관계수 0.999이상의 양호한 직선성을 보였으며, 첨가한 닭고기의 크로마토그람에서도 각각의 nfwlfquf 분리시간대에 방해 피크 없이 양호한 분리도를 나타내었다. 0.05~0.2 ㎍/g 첨가한 시료에서 평균 회수율은 ofloxacin 92.0~95.4%, norfloxacin 84.2~87.3%, ciprofloxacin 78.3~82.2%, enrofloxacin 91.3~95.3%이었으며 변이계수(CV)는 2.7~9.4%이었다.4종의 동시분석법의 검출한계 및 정량한계는 각각 ofloxacin 23.5 ppb, 35.3 ppb, norfloxacin 3.4 ppb, 5.1 ppb, ciprofloxacin 3.0 ppb, 4.5 ppb, enrofloxacin 2.5 ppb, 3.8 ppb 수준이었다. 2. 인천 지역에서 돛구한 닭고기 총 1,523수를 EEC-4-plate법으로 검사한 결과 양성반응을 보인 닭고기는 15수(육계 10, 토종닭 5)였으며, HPLC를 이용한 정밀검사결과 육계 5수에서 ciprofloxacin이 불검출~0.04 ppm, enrofloxacin이 0.01~0.69 ppm수준으로 검출되었으며, 토종닭 5수에서는 ciprofloxacin이 0.02~0.12 ppm, enrofloxacin이 0.36~6.79 ppm수준으로 검출되었다. Ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin in chicken muscle were seperated by liquid extraction and determined with high performance liquid chromatography (HPLC) with fluorescence detector. Analysis was carried out using following cond itions; C18 column (250×4.6 mm i.d. 5 ㎛ particle size), mobile phase composed of D.W. (containing 0.4% triethylamine and phospholic acid): methanol : acetonitrile (800:100:100, v/v/v), isocratic pump at a flow rate of 1.0 ml/min and 50㎕ of injection volume, fluorescence detector with EX 278 nm/EM. 456 nm. The calibration curves of four fluoroquinolones showed linearity (r^2≥0.999) at concentration range of 0.025-0.6 ㎍/ml. The recoveries in fortified chicken muscle represented more than 80% with low coefficient of variation (<10%) for concentration range of four fluoroquinolones. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin were 23.5, 3.4, 3.0 and 2.5 ng/g in chicken muscle, respectively. We also monitored fluoroquinolones residue in muscle of chickens (broiler 1,227, Korean native chicken 219, laying chicken 77) using EEC-4-plate screening and HPLC confirmation methods. Ten(broiler 5, Korean native chicken 5) out of the fifteen samples which were positively detected by EEC-plate screening method from 1,523 chicken meat were confirmed with ciprofloxacin and enrofloxacin by HPLC. The ranges of residual concentration were 0-0.12 ppm for ciprofloxacin and 0.01-6.79 ppm for enrofloxacin. In conclusion, our method could be applied effectively to determine four fluoroquinolones residues in chicken meat, and further survey for fluoroquinolones residue in chicken meat are needed for more effective control of fluoroquinolones used in livestock.

새로운 퀴놀론 항균제 Dw286의 살균작용

윤희정,민유홍,심미자,최응칠 대한약학회 2003 약학회지 Vol.47 No.6

The bactericidal activities of DW286, a new fluoroquinolone were investigated by comparing the minimal bactericidal concentrations (MBCs) and the time-kill curve of it against some Gram-positive and Gram-negative bacterial strains. The MBCs of DW286 for the strains tested were either equal to or two-fold higher than the MICs, as were observed for the other fluoroquinolones. And DW286 exhibited rapid killing curves against the strains. Accordingly, it could be said that DW286 has bactericidal activity comparable to other fluoroquinolones.