• Korean Journal of Clinical Pharmacy
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• v.13 no.2
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• pp.55-58
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• 2003

Astromicin is an aminoglycoside antiviotic that is structually different from conventional aminoglycosides. Astromicin has been shown to be active against aerobic Gram-negative bacilli. The pharmacokinetics of astromicin were determined in 12 healthy volunteers ($65.5\pm5.23\;kg$ of body weight) following a 30-min continuous intravenous infusion at a dose of 200 mg. The plasma and urine samples were collected up to 24 h and drug concentrations were measured by a bioassay using Bacillus subtilis. Pharmacokinetic parameters were calculated by fitting individual concentration-time curve to a one-exponential decay model. The plasma levels were $16.9\pm1.68\;and\;1.05\pm0.346\l{\mu}g/ml$ at 0 h and 8 h after the infusion, respectively. The elimination half-life of astromicin was $1.86\pm0.360\;h$ The volume of distribution was $0.182\pm0.0164\;L/kg$, and the total body clearance was $5.25\pm1.74\;L/h$. These pharmacokinetic parameters were similar to these of gentamicin, tobramycin, and amikacin. Therefore, it is recommended that therapeutic drug monitoring of astromicin could be conducted in a similar fashion as the other aminoglycosides.

• BMB Reports
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• v.44 no.4
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• pp.262-266
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• 2011

The aac(6')-Ib gene is the most prevalent gene that encodes aminoglycoside-modifying enzymes and confers resistance to tobramycin, kanamycin, and amikacin. The aac(6')-Ib-cr variant gene can induce resistance against aminoglycoside and fluoroquinolone simultaneously. Two main methods, sequence analysis and the restriction enzyme method, can detect the aac(6')-Ib-cr variant in clinical strains. We collected the 85 strains that were believed to be aac(6')-Ib positive from clinical isolates. Among them, 38 strains were the wild-type; the remaining 47 strains were the aac(6')-Ib-cr variant. Of these 47 strains, 19 simultaneously harbored aac(6')-Ib and aac(6')-Ib-cr. Our study aims to report the characteristics of the 19 strains that simultaneously harbored both genes. This study is the first investigation published in Korea of strains that included both aac(6')-Ib and aac(6')-Ib-cr variant.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.201-206
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• 2010

Nontuberculous mycobacterial (NTM) diseases are increasing worldwide. However NTM lung disease in organ transplant recipients has been rarely reported. Here, we report 2 cases of NTM lung disease in heart transplant recipients. A 37-year-old man, who had undergone a heart transplant one year previous, was admitted to hospital due to a cough. Chest CT scan showed multiple centrilobular nodules in both lower lungs. In his sputum, M. abscessus was repeatedly identified by rpoB gene analysis. The patient improved after treatment with clarithromycin, imipenem, and amikacin. An additional patient, a 53-year-old woman who had undergone a heart transplant 4 years prior and who suffered from bronchiectasis, was admitted because of purulent sputum. The patient's chest CT scan revealed aggravated bronchiectasis; M. intracellulare was isolated repeatedly in her sputum. Treatment was successfully completed with clarithromycin, ethambutol, and ciprofloxacin. NTM lung disease should be considered as a potential opportunistic infection in organ transplant recipients.

• Childhood Kidney Diseases
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• v.10 no.2
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• pp.182-191
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• 2006

Purpose : We studied the degree of changes in antibiotic sensitivity toward causative organisms, prevalence and clinical manifestations of extended-spectrum $\beta$-lactamase(ESBL)-producers of urinary tract infection(UTI) for a period of three years. This serves to provide useful information in selecting adequate drugs for the treatment of UTI. Methods : We recruited 137 patients who grew more than $10^5$ CFU/mL in their urine culture among 250 patients who visited and were admitted to Handong University's Sunlin Hospital for UTI treatment from January 2003 to December 2005. We retrospectively analyzed the data from the medical records. Results : The common pathogenic organisms were Escherichia coli(65.0%), Klepsiella pneumoniae(14.0%), Enterococcus faecalis(5.8%) and Proteus vulgaris(2.9%) in consecutive order. The prevalence of ESBL-producers among isolated E. coli and K. pneumoniae was 4.5%(4 cases) and 14.3%(2 cases), respectively. The antibiotic sensitivity rates of E. coli were relatively high to amikacin(100%), imipenem(100%), ceftriaxone(95.5%) and tobramycin(91.4%) while relatively low to TMP/SMZ(55.4%), ampicillin/sulbactam(29.4%) and ampicillin(24.2%). Conclusion : The use of ampicillin, ampicillin/sulbactam and TMP/SMZ, which have been the first choices in the treatment of UTI, should be reconsidered due to the low sensitivity rates towards these antibiotics. Due to the high incidence and antibiotic tolerance of ESBL that might have risen from the development of new antibiotics and increased antibiotic use, it is necessary to consider changing the standard antibiotics that have been used in the treatment of UTI.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.220-226
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• 2014

Sixty-seven Vibrio parahaemolyticus isolates from surface seawater from the Wando area, on the southern coast of Korea, were analyzed for their susceptibility to 15 different antimicrobials and the presence of virulence genes. According to the disk diffusion susceptibility test, all of the strains studied were resistant to ampicillin and oxacillin, while decreasing percentages were resistant to vancomycin (64.2%), streptomycin (56.7%), amikacin (31.3%), kanamycin (22.3%), cephalothin (20.9%), erythromycin (10.4%), ciprofloxacin (4.5%), and tetracycline (3.0%). All of the strains were susceptible to five antimicrobials: chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. Fifty-nine isolates (88.1%) were resistant to three or more classes of antimicrobial and defined as multidrug resistant, and two strains were resistant to seven antimicrobial agents. The minimum inhibitory concentration (MIC) of the 67 V. parahaemolyticus isolates to ampicillin and oxacillin ranged from 512-2,048 and $64-512{\mu}g/mL$, respectively. All 67 isolates were also examined for the presence of the tdh and trh virulence genes using the polymerase chain reaction (PCR). However, no isolates possessed either tdh or trh. The VPA0477 (${\beta}$-lactamase) gene, present in all of the tested strains, was validated as a new specific marker gene in PCR assays for the accurate detection and identification of V. parahaemolyticus.

• Korean Journal of Veterinary Service
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• v.23 no.1
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• pp.19-28
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• 2000

There are several main antibacterial susceptibility tests, such as agar dilution method, broth dilution method and disk diffusion technique. Especially, for minimal inhibitory concentration (MIC) test, agar dilution method has been widely used. But that method is so complicated and bothering that it's difficult to treat a large amount of strains. On the other hand, modified broth dilution method(add 1% glucose and 0.018% phenol red as a pH indicator to broth) is fast and easy to perform. Most of all, it can visualize the result by color. The MICs of 22 antibiotics Including penicillins, aminoglycosides, cephalothin, chloramphenicol, lincomycin, ceftiofur, vancomycin and quinolones, erythromycin, colistin. sul-fadimethoxine, trimethoprim for arcanobacterium pyogenes 14 strains, actinobacillus pleuropneu-moniae 41 strains and pasteurella multocida 37 strains, which were collected from porcine during 1996 ∼ 1999, were determined by modified broth dilution method. Actinobacillus pleuropneumoniae was highly susceptible to all kinds of quinolones such as ciprofloxacin, enrofloxacin and norfloxacin and to all aminoglycosides, like gentamicin, apramycin, kanamycin and ampicillin, cephalothin and ceftiofur. But It was quite resistant to solfadimethoxin, colistin and vancomycin. Pasteurella multocida was found to have high susceptibility to ampicillin, cephalothin, chlorampenicol and gentamicin but had mid-degree susceptibility to other aminoglycosides. In addition, it was susceptible to norfloxacin and nalidixic acid, but not to newer fluoroquinolone like ciprofloxacin and enrofloxacin and it was resistant to colistin and kanamycin. Arcanobacterium pyogenes was highly susceptible to most of quinolones such as cipoofloxacin, enrofloxacin and norfloxacin and gentamicin and penicillin G. But it also obtained high resistance against the early quinolone, nalidixic acid and aminoglycosides such as amikacin, apramycin and kanamycin and erythromycin, chlorampenicol, tetracyclin and vancomycin.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.241-249
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• 2009

Shiga toxin (Stx)-producing Escherichia coli (STEC) strains can cause broad spectrum of human disease, including diarrhea, hemorrhagic colitis, and the life-threatening hemolytic uremic colitis (HUS). We examined 868 samples was taken from bovine feces and carcass from January to December 2008 in Seoul. Twenty two (9.5%) shiga toxin -producing Escherichia coli were isolated from the 230 of bovine feces, and two (0.31%) were isolated from the 638 of carcasses. Serotype of E. coli isolates were O157 (10, 41.6%), O26 (10, 41.6%), O111 (1, 4.2%) and UT (3, 12.6%). In PCR, the isolates displayed three different stx gene combination (stx1 [2, 8.4%]), stx2 [3, 12.6%] and stx1 and stx2 [19,87.5%]). The eaeA and hlyA gene were found in 11 (45.8%) of the 24 strains. Saa gene was present only one strains (4.2%). Toxin typing using reverse passive latex agglutination test showed the same result in VT 1. But it showed different result in VT 2. In antimicrobial susceptibility test, all isolates were sensitive to amikacin, amoxicillin/clavulanic acid, ciprofloxacin and colistin. Eighteen strains (75.0%) of 24 isolates showed the multi-resistant patterns with over 3 drugs. PFGE was performed after the genomic DNA of twenty four isolates was digested with Xba I. the 24 isolates showed 7 (A~G) PFGE type.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.305-313
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• 2008

The present study was conducted to investigate the epidemiological characteristics such as isolation rate and antimicrobial drug susceptibility of etiological agents. The specimens (stool or intestine) were collected from 319 calves with clinical diarrhea from 195 farms in Gyeongnam south area (Gosung, Tongyung, Hadong) from June 2005 to August 2006. The isolation rate of Salmonella spp was higher in summer (8.4%) than in winter (4.8%) and the average was 7.2% (23/319 head). Some of Salmonella spp isolated were resistant to penicillin, oxytetracycline, tetracycline, and cephalexin (>90%), but some of them were susceptible to norfloxacin, ciprofloxacin, sulfamethoxazole/trimethoprim and amikacin(>30%). There was no statistical difference in the isolation rate of Eimeria spp between summer(48.9%) and winter(42.3%). For the evaluation of infection level of Eimeria spp oocyst per gram of feces (OPG) was examined, and severe, moderate and light infection level were 11.9%, 12.5% and 22.3%, respectively. In the isolation rates of Eimeria spp the calves under 19 days was lowerthan those over 60 days, but there was not different among herd size.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.31-37
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• 2020

Clostridial bacteria are zoonotic agents, which cause severe necrotizing enteritis, pseudo-membrane colitis, enterotoxemia to both humans and animals. The objective of this study was to monitor the antibiotic resistance of Clostridium isolates on clinical specimens from wild animals in Seoul zoo for 5 years. Clostridium isolates were verified by using Vitek2 compact machine. Antibiotic susceptibility was assessed by antibiotic disc diffusion test, which was followed by Kirby-Bauer disc diffusion test method. The frequency of Antimicrobial resistance of Clostridium isolate was the greatest in gentamicin (87%), then in order of amikacin (80%). There were 55.6% of Clostridium isolates showed multiple drug resistance (MDR). These results showed that a lot of Clostridial bacteria from wild animals in Seoul zoo were acquired antibiotic resistance. Because of the wild animal's aggressive manner, it has been hard to collect clinical samples from wild animals in a zoo to exam antibiotic susceptibility. For these reasons, empirical use of antibiotics has been performed in frequently. It may cause to increase the emergence of antibiotic resistance bacteria. In addition, the antibiotic resistance bacteria from zoo animals can be spread to other wild animals which inhabit around the zoo. Therefore, regular monitoring of antibiotic resistance Clostridial bacteria is important to protect animals and humans from Clostridial diseases.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.89-98
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• 2004

This study was carried out to investigate the serotype, and antimicrobial susceptibility and analyze the plasmid profile for the 145 isolates of L. monocytogenes isolated from livestock products and these product processing plants in Gyeongnam, Korea. All of L. monocytogenes strains belonged to serotype 1/2b (57.9%), 1/2a (20.0%), 4b (11.4%), 1/2c, 3b, 4c (each 2.9%) and 4d (0.7%). Serotype 1/2b, 1/2a, 4b from each source were found predominantly. Serotype 1/2b was predominantly higher than other serotype, and there was no significant difference between serotypes isolated from livestock products and product processing plants. 4b was major serotype isolated from raw milk and pork, and serotypes isolated from beef, chickens and slaughterhouse were 1/2b and 1/2a. The susceptibility of 145 strains of L. monocytogenes to 14 antibiotics commonly used in veterinary and human therapy was determined by disk diffusion method. All of L. monocytogenes strains were susceptible to amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, neomycin and penicillin. L. monocytogenes strains had the highest resistance with colistin (100%), oxytetracycline (44.8%), tetracycline (43.4%) followed by erythromycin (2.8%), spectinomycin (1.4%) and streptomycin (0.7%). Tetracycline resistance, and serotype distribution of the isolates from sample sources were significantly different. Resistance to at least one antibiotic was observed in all of them and 7 different resistant profiles were recorded. The most common resistance pattern were CL-OTC-TC (colistin-oxytetracycline-tetracycline) (42.8%). Among all tested isolates, two different plasmid profiles were observed. Of the 97 examined strains, 14 (14.4%) contained either the 8 and 11 kb plasmid or the 11 kb.