• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.7-10
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• 2009

An analytical method for the determination of flumequine in meats was developed and validated using high-performance liquid chromatography with fluorescence detection. The samples were mixed with sodium sulfate and extracted with ethyl acetate. After clean-up, the residues were dissolved in mobile phase. The calibration curves showed high linearity ($r^2$=0.9979) within the concentration range of 0.1-1.0 mg/kg. The limit of detection and limit of quantification were validated at 0.005 and 0.017 mg/kg, respectively. The recoveries in fortified meats ranged from 90.8 to 101.1%. The method was then validated in correspondence with the CODEX guidelines for flumequine residue in meats. Herein we monitored 150 samples of meats that were purchased in Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju). Among the tested samples, flumequine was detected in 1 of beef and 1 of pork at levels in the range of 0.048-0.080 mg/kg. Overall, the flumequine residues in the tested samples were within the Maximun residue limit.

• Journal of fish pathology
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• v.12 no.2
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• pp.115-121
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• 1999

MIC test of 16 chemotherapeutic agents was performed on 24 isolates of Edwardsiella tarda collected from flounders. They revealed resistance against combinations of ampicillin, amoxicillin, erythromycin, flumequine, doxycycline(DOXY), nalidixic acid, novobiocin, oxolinic acid, oxytetracycline(OTC), thiamphenicol(TP) and sulfonamide. Two strains carried transferable R plasmid encoding Otc Kanamycin Tp and Otc chloramphenicol Doxy Tetracycline Tp, respectively. The R plasmids were not similar each other on the basis of their digestion pattern of restriction endonuclease, suggesting distribution of different transferable R plasmid among E. tarda from flounders.

• Journal of fish pathology
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• v.20 no.1
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• pp.25-31
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• 2007

Vibriosis is one of the most important diseases affecting marin fish. In this study, a bacterium belonging to the Vibrio were isolated from maroon clownfish (Premnas biaculeatus) larvae (3～7 days after hatching). The bacterium was identified as Vibrio ponticus KJS1 by 16S rRNA gene sequence analysis. The result of biochemical test using the GN2 microplate (BioLog Inc, USA) showed that it has the ability to use 35 substrates including dextrin and sucrose was detected, could not degrade 52 substrates including α-cyclodextrin, and showed the weak ability to use 7 substrates including glycogen. It was sensitive to oxolinic acid, flumequine, ciprofloxacine, ofloxacin, norfloxacin, nalidixic acid, pefloxacin, and doxycycline hydrochloride.

• Journal of fish pathology
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• v.17 no.2
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• pp.83-90
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• 2004

The outbreak of haemorrhagic specticemia and lesions in dermis, frequently associated with keratitis have occured on rock sea bream (Oplegnathus fasciatus) reared in Jeju island. A bacterium isolated from the diseased fish identified as Pseudomonas sp. by morphologic, cultural, and biochemical tests. The bacterium was identified Pseudomonas anguilliseptica according to 16S rDNA sequence analysis. The highest growth rate of this strain was obtained at 20 to $\25^circ{C}$ although the disease occurred mostly below $16^\circ{C}$. The challenge test by ip injection revealed that this bacterium was pathogenic to rock sea bream. All experimental fish in challenged by ip injection died within 21 days but there was no death in control group. The bacterium was sensitive to Doxycycline, Chloramphenicol, Ciprofloxacin, Erythromycin, Flumequine, Nalidixic acid, Norfloxacin, and Ofloxacin.

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.2002-2010
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• 2006

This study examined the quenching of ofloxacin (OFL) and flumequine (FLU) fluorescence by $Cuj^{2+}$, $Ni^{2+}$, $Co^{2+}$ and $Mn^{2+}$ in an aqueous solution. The change in the fluorescence intensity and lifetime was measured at various temperatures as a function of the quencher concentration. According to the Stern-Volmer plots, the fluorescence emission was quenched by both collisions (dynamic quenching) and complex formation (static quenching) with the same quencher but the effect of static quenching was larger than that of dynamic quenching. Large static and dynamic quenching constants for both OFL and FLU support significant ion-dipole and orbital-orbital interactions between fluorophore and quencher. For both molecules, the static and dynamic quenching constants by $Cu^{2+}$ were the largest among all the metal quenchers examined in this study. In addition, both the static and dynamic quenching mechanisms by $Cu^{2+}$ were somewhat different from the quenching caused by other metals. Between $Ni^{2+}$ and FLU, a different form of chemical interaction was observed compared with the interaction by other metals. The change in the absorption spectra as a result of the addition of a quencher provided information on static quenching. With all these metals, the static quenching constant of FLU was larger than those of OFL. The fluorescence of OFL was quite insensitive to both the dynamic and static quenching compared with FLU. This property of OFL can be explained by the twisted intramolecular charge transfer in the excited state.

• Journal of fish pathology
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• v.20 no.3
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• pp.221-227
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• 2007

In this study, one hundred strains of bacterial flora were isolated from the intestine of cultured and wild black rockfish Sebastes inermis collected in Yeosu and examined for drug resistance to 9 antibiotics. From cultrued fish, the isolated bacteria were Photobacterium group (26 strains) and Acinetobacter group (18 strains) of Gram-negative, and unidentified marine sediment bacterium (6 strains) of Gram-positive. From wild fish, Photobacterium group (18 strains), Acinetobacter group (12 strains) and Shewanella group (5 strains) of Gram-negative and Bacillus group (8 strains), Staphylococcus group (4 strains), and unidentified marine sediment bacterium (3 strains) of Gram-positive. Intestine flora of wild black rockfish was more diverse than that of one cultured. The drugs tested were tetracyclines (oxytetracycline), aminoglycosides (gentamicin), macrorides (erythromycin) and quinolones (flumequine, oxolinic acid, norfloxacin, ofloxacin, enrofloxacin and ciprofloxacin). Sensitivity to all seven antibiotics except oxytetracycline and oxolinic acid was higher in bacteria from wild fish than from cultured ones, although wild isolates were more resistant than control strain Escherichia coli ATCC9637. This suggests that use of antibiotics in the fish farm might have some resistance in intestinal flora of wild fish.

• Journal of fish pathology
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• v.19 no.3
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• pp.267-276
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• 2006

Seventy-five streptococci were isolated from diseased olive flounder, Paralichthys olivaceus in Jeju. Their drug susceptibility and transferable multiple drug resistance were characterized. All isolates were resistant to flumequine (AR) and oxolinic acid (OA) and 26 isolates (34.7%) showed 4～6 multiple resistance of ampicillin (ABPC), AR, doxycycline (DOXY), erythromycin (EM), norfloxacin(NOR), OA and oxytetracycline (OTC) in various combinations. pST9 of a transferable R plasmid was detected from a multiple drug resistance strain, Streptococcus sp., ST9 originated from diseased flounder in Jeju, previously. We performed DNA hybridization to know the distribution of plasmid with the same DNA structure as pST9 in streptococci. Thirteen out of 60 isolates analyzed were positive in colony DNA hybridization and the part of bacteria isolated from raw meal was also hybridized with pST9. It suggested that raw meal is one of the origin of the resistance plasmid and R plasmid with DNA structure differing from pST9 is also involving in multiple drug resistance of the streptococci. In conjugation experiment, we found transferable R plasmid carrying OTC, DOXY and/or EM resistance determinant in the 13 resistance strains. all of the streptococci carrying the transferable R plasmid were similar in RAPD patterns. However, pST -type R plasmid was rare in S. iniae most frequently appearing in flounder farm.

• Journal of fish pathology
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• v.20 no.1
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• pp.49-60
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• 2007

Non-hemolytic Streptococcus parauberis isolated from diseased olive flounder, Paralichthys olivaceus in the South coast of Korea were identified by physiological, biochemical and genetic analysis in order to define the different characteristics geographically. First, twelve strains of S. parauberis were isolated from catalase-negative gram-positive cocci by multiplex PCR assay. Phenotypic identifications were performed with commercially available kit (API 20 Strep and API ZYM system). Analysis of API profiles of the isolates showed that strains were identified as either of Lactococcus lactis, S. constellatus or S. uberis. Moreover, S. parauberis isolated from olive flounder differed from that of turbot (X89967) to the test of not Voges-Proskauer, arginine, hippurate, alkiline phosphatase and pyrroidonyl arylamidase but β-glucuronidase. All S. parauberis isolates were sensitive to florfenicol, ampicillin, ofloxacin and vancomycin but were resistant to oxolinic acid, flumequine, nalidixic acid and sulfisoxazol. However, the 16S rDNA sequences of the isolates showed 99% similarity to S. parauberis KCTC 3651 (AY584477) and a great homogenecity among the flounder isolates.

• Journal of Food Hygiene and Safety
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• v.23 no.4
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• pp.324-329
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• 2008

An analytical method for the simultaneous determination of nine quinolones (QNs) namely, marbofloxacin, norfloxacin(IS), ciprofloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, and flumequine in flatfish and egg was developed and validated using liquid chromatography with fluorescence detection (LC-FD). The samples were extracted using a traditional liquid-liquid extraction process; deproteinization was accomplished by the addition of trichloroacetic acid and acetonitrile (ACN), and defatting was performed with hexane. Chromatographic separation was achieved on a reverse phase C8 column with gradient elution using a mobile phase of 200 mM ammonium acetate buffer (pH 4.5) and ACN. The proposed method was validated according to the CODEX guideline. Mean recoveries of QNs from flatfish and egg were 89.6-106.5% with relative standard deviations (RSDs) below 15% at three different concentrations of 50, 100 and $500{\mu}g/kg$. Linearity was obtained with a correlation coefficient ($r^2$) of 0.9989-1.0000. The LOD for the investigated QNs was $1-16{\mu}g/kg$ depending on flatfish and egg. The present method can be applied simultaneously to determine QNs in muscle of flatfish and egg.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.23-27
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• 1999

The development and industrial application of intestinal anaerbic bacteria is highly important in the munufacture of foodstuffs and medical products. We have conducted studies, screening anaerobic intestinal bacteria for acid and bile tolerance and for pathogens suppression in the intestine of swine. One such study was taxonomic in nature and dealt with the isolate's biochemical responses. The results indicated that the BSA-131 strian ioslated. which suppressed various pathogens (13 typical strains), were identified as Lactobacillus reuterii. The strain, which named L. reuterii BSA-131, was able to tolerate acid condition down to pH2 and could also tolerate bile at 5%. The strain exhibited resistance to a range of antibiotics including, cephalexin, erythromycin, flumequine, furazolidine, gentamycin, penicillin G, norfloxacin, spectinomycin, tetracycline, tiamuline, neomycin, chloramphenicol, kanamycin etc.