• Korean Journal of Veterinary Service
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• v.14 no.2
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• pp.159-174
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• 1991

A field trial of norfloxacin on bovine 206, swine 222 and poultry 205 with respiratory diseases and diarrhea was conducted from Sept 1, 1990 to Jan 30, 1991 in Inchon and Kyonggi-do. The results are as follows. 1. Guinea pigs and rabbits were dosages 10 and 20 times normal. Ten days of observation saw no side effect. 2. Oral treatment on bovine, swine and poultry showed a curing rate of 82.00∼89.06%(Mean 86.00%), compared with 87.27∼96.36%(Mean 92.24%) by Injection. 3. The curing rate was 81.92% by the fourth treatment. 4. The curing rate with and without the use of adjuvant was 80.00∼100% and 83.60∼93. 10%, respectively, for swine, and 81.82∼100% and 82.00∼97.14% for bovine. 5. The curing rate was more dependent on seriousness of illness, environment and time than age. 6. The main disease causing bacteria of bovine respiratory diseases： Haemolytic Sta 27.62%, Haemolytic Str 33.33%, sum of this bacteria is 60.95%, diarrhea: Haemolytic coliform 80.20%, swine respiratory diseases； Haemophilus Spp 20.95%, Haemolytic Sta 72%, Haemolytic Str 21.90%, Sum of these bacteria is 68.57％, diarrhea; Haemolytic coliform 57.26%, poultry respiratory diseases； mycoplasma Spp 29.52%, Haemolytic Sta 13.33％, Sum of this bacteria is 42.85%, diarrhea； Haemolytic coliform 53.00%. 7. The curing rate of norfloxacin by species of strain, the unidentified bacteria on bovine respiratory diseases was the lowest with 77.78％, the others ranged from 84.21％ to 100％ with most of them over 90%. 8. The loss of clinical sign on bovine and swine was the highest when after 2∼4 application. 9. In terms of antibiotic sensitivity test, norfloxacin was the highest with 84.62∼100％ (mean 90.09％) among eight bacterias, only 5 of 15 antibiotics had a sensitivity of over 56.25%, showing a high degree of tolerance.

• KSBB Journal
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• v.18 no.1
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• pp.39-44
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• 2003

A Gene content phylogenetic tree and a 16s rRNA based phylogenetic tree were compared for 33 whole-genome sequenced procaryotes, neighbor joining and bootstrap methods (n=1,000). Ratio of conserved COG (clusters of orthologous groups of proteins) to orthologs revealed that they were within the range of 4.60% (Mezorhizobium loti) or 56.57% (Mycopiasma genitalium). This meant that the ratio was diverse among analyzed procaryotes and indicated the possibility of searching for useful genes. Over 20% of orthologs were independent among the same species. The gene content tree and the 16s rDNA tree showed coincidence and discordance in Archaeabacteria, Proteobacteria and Firmicutes. This might have resulted from non-conservative genes in the gene content phylogenetic tree and horizontal gene transfer. The COG based gene content tree could be regarded as a midway phylogeny based on biochemical tests and nucleotide sequences.

• Fisheries and Aquatic Sciences
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• v.23 no.8
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• pp.20.1-20.18
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• 2020

Background: Olive flounder, Paralichthys olivaceus, is an economically important aquaculture species in Korea. Olive flounders have been heavily damaged by streptococcal infections every year and are treated with antibiotics. However, antibiotic abuse is causing the emergence of resistant strains, and to overcome this, research has shown that new antibiotics must be applied. Tylosin is a relatively safe antibiotic and has good activity against Gram-positive bacteria and mycoplasma. We studied the therapeutic effects and side effects of tylosin on Streptococcus parauberis-infected olive flounder. Methods: After artificial infection of olive flounder with S. parauberis SPOF18J3, an appropriate dose of tylosin was confirmed by intramuscular injection (I.M.) at 2.5, 5, 10, and 15 mg/kg, and oral administration at 10 and 20 mg/kg. After I.M. and oral administration dosing of tylosin, side effects were confirmed by serological analysis, histopathological analysis, and median lethal dose (LD₅₀) analysis at both an appropriate concentration and a high concentration. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The appropriate I.M. and oral administration concentration of tylosin administered to olive flounder infected with S. parauberis SPOF18J3 was found to be 10 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were showed not significantly different between the control group and the experimental groups. The histopathologic results showed mild inflammatory responses in muscle and tubular vacuolization and tubular atrophy appeared, but there were no significant differences between the groups. The LD₅₀ was confirmed to be 461 mg/kg. Conclusion: In this study, an effective treatment method was provided by verifying the treatment effects and side effects of tylosin in olive flounder infected with S. parauberis, which can be applied directly to aquaculture sites. In addition, these results may be used as a reference for evaluation required upon request to obtain approval for tylosin antibiotics as fishery antibiotics in Korea. After approval, it is possible that a fishery disease manager will be able to prescribe and sell the antibiotic tylosin.

• Tuberculosis and Respiratory Diseases
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• v.80 no.4
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• pp.358-367
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• 2017

Background: Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods: Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results: A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ${\geq}16years$, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion: The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia.