• Tuberculosis and Respiratory Diseases
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• v.85 no.3
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• pp.264-272
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• 2022

Background: The current conventional drug susceptibility test (DST) for Mycobacterium tuberculosis (Mtb) takes several weeks of incubation to obtain results. As a rapid method, molecular DST requires only a few days to get the results but does not fully cover the phenotypic resistance. A new rapid method based on the ability of viable Mtb bacilli to hydrolyze fluorescein diacetate to free fluorescein with detection of fluorescent mycobacteria by flow cytometric analysis, was recently developed. Methods: To evaluate this cytometric method, we tested 39 clinical isolates which were susceptible or resistant to isoniazid (INH) or rifampin (RIF), or ethambutol (EMB) by phenotypic or molecular DST methods and compared the results. Results: The susceptibility was determined by measuring the viability rate of Mtb and all the isolates which were tested with INH, RIF, and EMB showed susceptibility results concordant with those by the phenotypic solid and liquid media methods. The isolates having no mutations in the molecular DST but resistance in the conventional phenotypic DST were also resistant in this cytometric method. These results suggest that the flow cytometric DST method is faster than conventional agar phenotypic DST and may complement the results of molecular DST. Conclusion: In conclusion, the cytometric method could provide quick and more accurate information that would help clinicians to choose more effective drugs.

• Korean Journal of Veterinary Service
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• v.17 no.3
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• pp.181-189
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• 1994

Sixty-three Salmonella Cultures were isolated from 600 msenteric lymphnodes and 600 rectal contents of apprently healthy pigs slaughtered at abattoris in Hapchun, changnyong, Keochang. The result observed were summaried as follows ; 1. Fifty-nine out of sixty-three cultures were serotyped and Salmonella enteritis(20 cultures) 2. Was found to be the most predominant serotpye. The remainder comprised of 15 serotypes were ; S. typhimuriu, S. derby, S. wagenia, S. infantis, S. thompson, S. tennessee, S. mission, S. anatum, S. give, S. nuwlands, S. newingtion, S. newhaw, S. neumuenstes, S. senftenberg, S. gbana 3. The antibiotic susceptibility of 9 were ; Baytril, Streptomycin, Cephalothin, Ampicillin, Tetracycline, Sulfadimethoxine, Rifampicin, Gentamicin, Kanamycln.

• Korean Journal of Veterinary Service
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• v.13 no.1
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• pp.69-74
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• 1990

The present study was conducted to investigate the incidence of pasteurella multocida infection in kyungbuk swine herds during the period from July 1989 to November 1989 and some properties of the isolated organisms. P. multocida was isolated from lungs of 155 slaughtered pigs, 43(27.7%) pigs were culture positive. The majority of biochemical and cultural properties of the P. multocida isolates were identical to those of the standard strains. The capsular serogroups and drug susceptibility of 43 isolates of P. multocida from pigs with pneumonic lesions were investigated. P. multocida isolates were typed for capsular serogroupes A by hyaluronidase inhibition of capsule and D by acriflavin auto agglutination. Most isolates(60.4%) were type A, 18.6% were type D, and the remaining 21.0% were untypable. In antimicrobial susceptibility test these isolates of P. multocida were susceptible in order of ampicillin (86.0%), trimethoprim sulfamethoxazole(83.7%), colistin(81.4%), chloramphenicol(79.1%), but the majority of them were resistant in order of streptomycin(30.2%), triple sulfa (4.6%).

• Journal of Veterinary Clinics
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• v.18 no.2
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• pp.98-104
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• 2001

The present study was conducted to investigate isolation and antimicrobial drug susceptibility of Pasteurella spp from pneumonic calves and cows (pneumonic lungs) in Gyeongnam south area from January to November 2000. Pasteurella multocida and P haemolytica were isolated 136 (53.8%) and 22(8.7%), respectively, from 158 of 253 pneumonic calves of 1 to 12 months of age and from pneumonic lungs and simultaneous isolation rate of P mutocida and P haemolytica was 4 (1.6%). Seasonal isolation rate of Pasteurella spp in calves and pneumonic lungs varied from 3 to 65.2%, and it was higher in Fall. The majority of biochemical and cultural properties of P multocida and P haemolytica isolated from calves and pneumonic lung were identical to those of the reference strains employed. Pneumonic lesions of the examined lungs were histologically identified as purulent bronchopneumonia and fibrinous pneumonia. All isolates were resistant to penicillin, amikacin, lincomicin, colistin, cloxacilling, sulfonamide, kanamycin, sulfamethoxasoletrimetoprim, and gentamicin(>80%), but some of them were susceptible to amoxicillin, norfloxacin, cephalexin, cefazolin, orbifloxacin, enrofloxacin, and ciprofloxacin(>60%).

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.83-87
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• 1988

The in vitro drug susceptibility of 83 strains of Bordetella bronchiseptica recovered from Korean pigs with atrophic rhinitis was investigated by the use of disk diffusion method. The majority of the organisms were highly resistant in order of prevalence to penicillin(98.7%), ampicillin(91.5%), streptomycin(90.3%), triple sulfa(83.1%), and trimethoprim/sulfamethoxazole(70.7%) while none of them were resistant to gentamicin, only 3.6% to colistin, chloramphenicol and kanamycin and 6.0% to tetracycline. The percentage of the organism resistant to bicozamycin, cephalothin and neomycin were 34.9%, 34.1% and 18.4%, respectively. A high prevalence of multiple drug resistance was observed and the 3 most common resistant patterns among 35 patterns noted were Am Pc Sm Sss Sxt(26.5%), Am Cf Pc Sm Sss Sxt(12.%) and Am Bm Pc Sm Sss Sxt(9.6%) patterns.

• Korean Journal of Veterinary Service
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• v.14 no.2
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• pp.121-126
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• 1991

The present study was conducted to investigate biochemical properties and antimicrobial drug susceptibilities of 36 strains of Pasteurella haemolytica(P haemolytica) isolated from pneumonic calves in Kyongbuk province during the period from January 1990 to December 1990. P haemolytica was isolated from 36 of 111(32.4%) pneumonic calves of 1 to 6 months of age. The majority of biochemical and cultural properties of P haemolytica isolated from calves were identical to those of the reference strains employed. All isolated were susceptible to baytril, gentamicin, and kanamycin, some of them were resistant to tetracycline, amikacin, streptomycin, and ampicillin.

• Tuberculosis and Respiratory Diseases
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• v.79 no.3
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• pp.134-142
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• 2016

In recent years, in spite of medical advancement, tuberculosis (TB) remains a worldwide health problem. Although many laboratory methods have been developed to expedite the diagnosis of TB, delays in diagnosis remain a major problem in the clinical practice. Because of the slow growth rate of the causative agent Mycobacterium tuberculosis, isolation, identification, and drug susceptibility testing of this organism and other clinically important mycobacteria can take several weeks or longer. During the past several years, many methods have been developed for direct detection, species identification, and drug susceptibility testing of TB. A good understanding of the effectiveness and practical limitations of these methods is important to improve diagnosis. This review summarizes the currently-used advances in non-molecular and molecular diagnostics.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.281-285
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• 2009

In this study, we compared the BacT/Alert liquid culture system with Ogawa and $L\ddot{o}wenstein$-Jensen (L-J) media for sputum culture and drug susceptibility test (DST) of Mycobacterium tuberculosis. Rapid liquid culture systems have been widely employed both for primary cultures of M. tuberculosis from clinical specimens and for drug susceptibility test because of its greater sensitivity and faster turn-around time than the conventional egg-based culture methods (Ogawa, $L\ddot{o}wenstein$-Jensen media). Sputum specimens were decontaminated with N-acetyl-L-cysteine (NALC)-4% NaOH and inoculated into the BacT/Alert culture bottles and Ogawa media. 95 from among 135 sputa were smear-positive, 97 (71.9%) were culture-positive by the BacT/Alert culture system, while 89 (65.9%) were positive by Ogawa media. The mean time to culture-positive by the BacT/Alert process system was about 11.3 days, which was significantly shorter than that by Ogawa media (22.4 days). Of 32 M. tuberculosis cultures examined for drug sensitivity, the concordant rate between the two methods (BacT/ Alert liquid culture system, $L\ddot{o}wenstein$-Jensen media) ranged from 87.5% for isoniazid and 90.6% for rifampicin.

• Tuberculosis and Respiratory Diseases
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• v.56 no.3
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• pp.261-268
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• 2004

Background : The resurgence of tuberculosis and outbreaks of multidrug resistant (MDR) tuberculosis have increased the emphasis for the development of new susceptibility testing of the Mycobacterium tuberculosis for the effective treatment and control of the disease. Conventional drug susceptibility testings, such as those using egg-based or agar-based media have some limits, such as the time required and difficulties in determining critical inhibitory concentrations, but these are still being used in many diagnostic laboratories because of no better lternatives, considering cost and accuracy. To overcome these limits, a rapid and simple method for new susceptibility testing, using live and dead assays, was applied for a bacterial cell viability assay to distinguish dead from live bacterial cells based on two-color fluorescence. Materials and Methods Strains : Forty strains were used in this study, 20 susceptible to all antituberculosis drugs and the other 20 resistant to the four first line antituberculosis drugs isoniazid, rifampicin, streptomycin and ethambutol. Antibiotics : The four antibiotics were dissolved in 7H9 broth to make the following solutions: $0.1{\mu}g\;isoniazid(INH)/m{\ell}$, $0.4{\mu}g\;rifampicin(RMP)/m{\ell}$, $4.0{\mu}g\;streptomycin(SM)/m{\ell}$ and $4.0{\mu}g\;ethambutol(EMB)/m{\ell}$. Results : Live and dead Mycobacterium tuberculosis cells fluoresced green and red with the acridin (Syto 9) and propidium treatments, respectively. These results are very well accorded with conventional drug susceptibility testing by proportional method on Lowensen-Jensen media (L-J) containing 4 drugs (INH, RMP, EMB and SM), showing a 93.7 % accordance rate in susceptible strains and 95% in resistant strains. Conclusion : The results of the drug susceptibility testing using the live and dead bacterial cell assay showed high accordance rates compared with the conventional proportion method on L-J. This finding suggests that the live and dead bacterial cell assay can be used as an alternative to conventional drug susceptibility testing for M. tuberculosis strains.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.413-420
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• 1990

The present study was conducted to investigate biochemical properties and antimicrobial drug susceptibilities of 47 strains of E rhusiopathiae isolated from the cases of acute septicemic swine erysipelas in Youngnam and Kyunggi provinces during the period from June 1988 to December 1989. The isolants were identified as E rhusiopathiae on the basis of cellular and colonial morphology, and characteristic reactions in some biochemical tests. All the organisms produced hydrogen sulfide in triple sugar iron agar and showed the characteristic "pipe cleaner" type of growth in gelatin stab cultures. The majority of biochemical and cultural properties of E rhusiopathiae isolated from pigs affected with acute erysipelas were identical to those of the reference strains employed. All the isolates were highly susceptible to penicillin G, ampicillin, erythromycin (MIC:0.025~0.39IU or ${\mu}g/ml$), and moderately susceptible to oleandomycin, oxytetracycline, chloramphenicol(MIC:$0.78{\sim}25{\mu}g/ml$). Kanamycin and sulfadimethoxine showed no activity against the isolates(MIC:>$400{\mu}g/ml$). The MICs of dihydrostreptomycin presented two distribution peaks; of 47 strains, 5(10.6%) were resistant to dihydrostreptomycin (MIC:$400{\mu}g/ml$), while the majority of them were susceptible to the drug.