• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.301-304
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• 2019

The objective of this study was to determine the in vitro intracellular and extracellular minimum inhibitory concentrations (MICs) of 13 antimicrobials against one recently isolate Lawsonia intracellularis, the etiological agent of proliferative enteropathy (PE). The final MICs were assessed by counting the number of heavily infected cells (HICs;>30 bacteria per cell) using an immunoperoxidase monolayer assay. Enrofloxacin (InMIC; 1~2 ㎍/mL and ExMIC; 16 ㎍/mL) still presented the most notable antimicrobial susceptibility, and marbofloxacin (2 ㎍/mL and 8 ㎍/mL) was followed. Colistin (0.25 ㎍/mL and 2 ㎍/mL) presented a susceptibility followed by tylvalosin (1 ㎍/mL and 2 ㎍/mL). Florfenicol and lincomycin had the weakest susceptibility and amoxicillin, penicillin G, chlortetracycline, oxytetracycline, tiamulin, tilmicosin, and tylosin displayed weak susceptibility. Although some antibiotics showed decreased susceptibility patterns, they showed similar patterns to recent antibiotic susceptibility patterns in Korea. In addition, these results could be one of contributions in clinical fields.

• Journal of fish pathology
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• v.16 no.1
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• pp.61-68
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• 2003

MICs of 8 chemotherapeutic agents against forty streptococcal isolates were determined. These strains were isolated from diseased olive flounder, Paralichthys olivaceus, and showed 2-5 multiple drug resistance against different antibacterial agents including ampicillin, doxycycline (DOXY), erythromycin, florfenicol, flumequine, norfloxacin, oxolinic acid, and oxytetracycline (OTC). In conjugation experiment, we found transferable R plasmids carrying OTC and DOXY resistance determinant in 3 drug resistance strains analyzed. Six out of 40 isolates showed positive signal in colony hybridization with the R plasmid DNA (pST9) as a probe. It suggests that other types R plasmid different from pST9 is also involving in multiple drug resistance of streptococci isolated from olive flounder.

• Korean Journal of Veterinary Service
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• v.37 no.3
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• pp.165-171
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• 2014

This study was conducted to investigate the species-specific gene detection, capsular serogroup and antimicrobial resistance pattern of Pasteurella multocida isolated from pneumonic lung lesion of swine in Gyeongbuk province. P. multocida isolates were typed for capsular serogroups by polymerase chain reaction. Of the 32 strains, 28 (87.5%) were typed serotype A, 3 (9.3%) were typed serotype D, and 1 strain was unknown (3.1%), respectively. In antimicrobial agents resistance test, almost of strains were susceptible to amoxicillin (100%), enrofloxacin (96.9%), ampicillin (93.8%), florfenicol (90.6%), chloramphenicol (90.6%) and were resistant to streptomycin (71.9%), spectinomycin (56.3%). All strains were resistant to clindamycin, erythromycin and lincomycin.

• Journal of Life Science
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• v.18 no.3
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• pp.369-373
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• 2008

Staphylococcus intermedius (S. intermedius) has been rarely isolated from horse. In this study, we investigated the antimicrobial susceptibility patterns of S. intermedius isolated from skin lesions of Thoroughbred horse in Daegu Equestrian Association. The skin lesions were showed with dehairing and slight purulent inflammation. Bacteria were isolated from skin lesions and identified as S. intermedius by biochemical tests and MicroLog (BIOLOG, California, USA). Antimicrobial susceptibility test of S. intemedius isolates was performed with 33 antimicrobial agents (BBL, Maryland, USA) by using the agar disk diffusion method. It showed a high sensibility in the amikacin, amoxycillin/clavuramic acid, ampicillin, cefoxitin, cephalothin, chloramphenicol, ciprofloxacin, enrofloxacin, florfenicol, kanamycin, neomycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin G, tetracycline and vancomycin. The horse was treated with penicillin, and cured completely after two weeks. The present results showed valuable information for treatment and prevention of skin disease in horse.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.838-844
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• 2016

In this study, epidemiological cut-off values were estimated for 44 Photobacterium damselae isolates, since clinical breakpoints have not been established for this pathogenic bacterium. The susceptibility of the isolates to 10 antibiotics was evaluated using internationally standardized disc diffusion protocols. Normalized resistance interpretation was used to generate statistically valid epidemiological cut-off values for the susceptibility data. There were not enough strains exhibiting full sensitivity to ampicillin and amoxicillin to allow analysis of these antibiotics. Because there were only a marginally sufficient number of strains exhibiting full sensitivity to oxytetracycline, the cut-off value generated provided only a provisional estimate. The valid wild-type cut-off values were <13, 13, 9, 22, 25, 27, and 28 mm for gentamicin, cephalexin, erythromycin, oxolinic acid, flumequine, florfenicol, and sulfamethoxazole/trimethoprim, respectively. The application of these cut-off values should greatly facilitate the rational selection of antibiotics for use in commercial fish farms.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.37-42
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• 2008

Riemerellosis, contagious disease of domestic ducks in Korea, occurred in December of 2007 in a farm located in Eumsung, Chungbuk province. The affected ducks were 22 days old and the owner reported that almost one hundred of ducks had died everyday for a few days after infection. Clinical signs were listlessness, ocular and nasal discharge, greenish diarrhea, ataxia, tremor of head and legs, and coma. On necropsy we found fibrinous exudate, which involved serosal surfaces in general, but most evidences were in the pericardial cavity and over the surface of the liver. The causative agent was isolated from the liver of the affected ducks and identified as Riemerella anatipestifer using biochemical tests. Also, the isolate was susceptible to ampicillin, cephalothin, sulfamethazole/trimethoprim, Florfenicol among the 23 species antibiotics (AST Discs, OXOID) used in our laboratory. Further studies should be needed for the more effective control and better epidemiological information such as pathogenicity, serotype, genotype and treatment.

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.43-48
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• 2009

Salmonella enterica serovar Gallinarum is the causative agent of fowl typhoid (FT) and Salmonella enterica serovar Pullorum is pullorum disease (PD), a severe systemic disease of chick and it has the same antigenic fomula, the close relation but distinct pathogen. The traditional bacteriologic and serologic methods routinely used but tedious, time consuming. some of biochemical differences are helpful in differentiating the two organisms, however variation in the characteristics of some strains can be observed. During 2006 to 2008, there was isolated 30 strains. The biochemical characteristics of S. Gallinarum was nonmotile, fermentation of dulcitol, maltose but positive arginine (6.6%), lysine (83.3%) and arabinose (20.0%). The antimicrobial susceptibility test showed 100% sensitive to amikacin, ampicillin, amoxicillin/clavulanic acid and florfenicol, but resistant to penicillin (100%) and erythromycin (60.0%). This PCR method can be applied in the diagnosis between S. Gallinarum and S. Pullorum.

• Korean Journal of Veterinary Service
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• v.41 no.3
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• pp.203-210
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• 2018

Pasteurella multocida is an opportunistic organism that plays a significant role in porcine respiratory disease complex (PRDC). In the current study, we provide nationwide information of P. multocida isolates from pneumonic lungs of slaughter pigs by determining their prevalence, subspecies, biovars, capsular types, virulence-associated genes, and minimum inhibitory concentrations. P. multocida was the second most frequently confirmed (19.2%) bacterial pathogen and most of the isolates (88.9%) showed simultaneous infection with other respiratory pathogens, especially Mycoplasma hyopneumoniae (63.3%, P<0.001) and porcine circovirus type 2 (53.3%, P=0.0205). Of 42 isolates investigated, 41 (97.6%) were identified as P. multocida subspecies multocida, and only one isolate was identified as subspecies septica (biovar 5). All the isolates were capsular type A and the most prevalent biovar was biovar 3 (40.5%), followed by biovar 2 (31.0%). Comparing virulence-associated genes and biovars, all biovar 2 isolates exhibited $hgbB^-pfhA^+$ (P<0.001); all biovar 3 (P=0.0002) and biovar 13 (P=0.0063) isolates presented $hgbB^+pfhA^-$. Additionally, all biovar 2 (P=0.0037) isolates and most of biovar 3 (P=0.0265) isolates harbored tadD. P. multocida showed the highest resistance levels to oxytetracycline (73.8%), followed by florfenicol (11.9%). Continuous monitoring is required for surveillance of the antimicrobial resistance and new emerging strains of P. multocida in slaughter lines.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.125-131
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• 2010

Bacterial contamination is an unavoidable finding of the semen collection process in boar and can lead in deleterious effects on semen quality and longevity if left uncontrolled. The purpose of this study is to identify the bacteria in extended boar semen and to select the effective antimicrobials to control of the contaminants. Of 116 extended boar semen samples submitted from eight AI centers in Korea, 39 (33.6%) samples were positive for bacterial contamination. Among 39 contaminated semen, most of them (84.6%) were contaminated with one or two bacterial species and there was no significant difference between two age groups $(\leq\;24\;and\;>\;24\;month\;old).$ Stenotrophomonas maltophilia (n = 18) was the most predominant bacterium followed by Elizabethkingia meningoseptica (n = 12), Sphingomonas paucimobilis (n = 12), Myroides spp. (n = 5), Ochrobactrum anthropi (n = 3), and so on. Enrofloxacin (72.9%), florfenicol (72.9%), bacitracin (49.2%) and tylosin (49.2%) showed higher sensitivity compared with penicillin (13.6%) or aminoglycosides (6.8%-18.6%). Brucella spp., Leptospira spp., Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycobacterium tuberculosis complex were not detected in semen by PCR.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.101-105
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• 2017

The purpose of this study was to investigate prevalence and antimicrobial resistance patterns of Campylobacter spp. from duck feces in northern area of the Gyeongnam province, Korea. Samples of 121 duck feces were taken from April to December 2014 for this survey. Samples were examined by bacteria isolation and reverse transcriptase-polymerase chain reaction assay for detection of Campylobacter spp. Campylobacter were isolated in 37 samples (30.6%). Among these samples, C. jejuni and C. coli were isolated in 35 samples and 2 samples, respectively. Minimum inhibitory concentration (MIC) test is performed to investigate antimicrobial resistance patterns of Campylobacter spp. C. jejuni were resistant to ciprofloxacin (85.7%), nalidixic acid(82.9%), tetracycline (77.1%), gentamicin (57.1%), azithromycin (40.0%), clindamycin (34.3%), erythromycin (22.9%), and florfenicol (8.6%). These data support a database of pollution and antimicrobial resistance of Campylobacter spp. from duck feces and provide a basic information of reducing the secondary damage of antibiotic misuse.