• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.103-125
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• 1997

An epidemiologic study on pleuropneumonia in the slaughter pigs(Chonan and Asan area, Chungnam province, Korea) during the period of January 1994 through December 1995 was conducted. Isolation of A pleuropneumoniae was attempted in 425 pigs with pneumonic lesions. Biochemical properties, antimicrobial susceptibility, serotypes and pathogenicity of isolated A pleuropneumoniae were investigated. In addition, outer membrane protein(OMP) of the Isolates were extracted to determine its properties and immunogenicity in both mice and piglets The results obtained through this study were summarized as followed ; 1. Of 3, 395 slaughter pigs, pleuropneumonia was observed in 425 pigs(10.6%). A pleuropneumoniae was isolated from 22 pigs(5.2%) out of 425 pigs with pneumonic lesions. The biochemical properties of all isolates were same as those of reference A pleuropneumoniae strain. Among 22 isolates, 9, 1 and 12 isolates were serovar 2, 3 and 5, respectively. 2. The results of antimicrobial susceptibility test revealed that the isolates showed high susceptibility to ciprofloxacin and cephalothin, moderate susceptibility to amikacin, gentamicin, kanamycin and streptomycin, and low susceptibility to erythromycin, tylosin and sulfadimethoxin. 3. The isolates were varied in pathogenicity to mice. Median lethal dose of LE9402(serovar 2) and LE9511(serovar 5) were $9.2{\times}10^7$ CFU and $2.8{\times}10^7$%CFU, respectively. Specific pneumonic lesions were observed from the infected mice with clinical signs. Bacteria recovery rate was high in the lung, but low In heart blood and tracheas. 4. Serovar 2 was found to be more pathogenic than serovar 5 in guinea pig. Mortality on guinea pigs inoculated with serovar 2($5.4{\times}10^8-5.4{\times}10^6$CFU) and serovar 5($2.8{\times}10^8-2.8{\times}10^6$ CFU) was 20~40% and 40~80%, respectively. A severe hemorrhagic lesions and focal pneumonic lesions were observed from dead guinea pigs. Bacteria recovery rate was relatively higher in the lung than that of other organs. 5. In the SDS-PAGE analysis, OMP-enriched fractions of both isolates and reference strains contain common peptide bands equivalent to molecular weight of 17, 27, 42, 52 and 95Kd. In addition to common peptide bands, the bands which are specific to each isolate were also observed. The profiles of Sephadex G25 fractions showed 3 major peaks. The common peptide bands which were observed by SDS-PAGE of the crude OMPs were found in the peaks 1 and 2. 6. The OMPs extracted from serovar 2(LE9402) and serovar 5(LE9511) provided high level of protection in mice(70~80%) and pigs(100%). All animals inoculated with OMPs were seroconverted, showing micro-agglutination titer of 640 to 1280.

• Korean Journal of Veterinary Research
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• v.42 no.1
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• pp.45-54
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• 2002

The study was carried out to characterize the pharmacokinetics after intravenous (iv, 20 mg/kg) and oral (p.o. 100 mg/kg) administration as oxytetracycline (OTC) and tiamulin (TIA) mixture in swine and to determine interaction between OTC and TIA against various pig pathogenic bacteria. The antibacterial effects of OTC in combination with TIA in vitro showed synergistic effect against Salmonella typhimurium 1925, Pasteurella multocida Type A, P. multocida Type D, Krebsiella Pneumoniae 2001, K. Pneumoniae 1560, K. Pneumoniae 2208, Haemophillus pleuropneumonia S 2, and H. pleuropneumonia S 5, but against additive effect E. coli K88ab and S. choleraesuis on the basis of fractional inhibitory concentration (FIC) index. On the while, after i.v. and p.o. administration of OTC and TIA mixture, each OTC and TIA concentrations in plasma were fitted to an open two-compartment model. After i.v. administration of OTC-TIA mixture, the mean distribution half-life ($T_{1/2{\alpha}}$) of OTC and TIA in plasma showed 0.29 h and 0.17 h, and the mean elimination half-life ($T_{1/2{\beta}}$) of those was 4.36 h and 6.64 h, respectively. The mean volume of distribution at steady state ($Vd_{ss}$) of OTC and TIA was $0.85{\ell}/kg$ and $2.44{\ell}/kg$, respectively. After oral administration of OTC and TIA mixture, the mean maximal absorption concentrations ($C_{max}$) of OTC and TIA were $0.60{\mu}g/m{\ell}$ at 1.07 h ($T_{max}$) and $1.68{\mu}g/m{\ell}$ at 1.85 h ($T_{max}$), respectively. The mean elimination half-life ($T_{1/2{\beta}}$) of those showed 6.84 h and 6.36 h. In conclusion, we could suggest in this study that the combination of OTC and TIA may be recommended for the antibacterial therapy against polymicrobial infections, and both OTC and TIA showed large distribution to tissues and high $C_{max}$ after p.o. administration.

• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.27-35
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• 1997

An abattoir survey of pneumonia and other lesions in slaughtered pigs from 5 selected herds located In the Western Kyongbuk was carried out during the period from March to December 1995. Pneumonic lungs was attempted bacteriological finding and antibiotic susceptibilities. From 583 slaughtered pigs, 445(76.3%) case was pneumonic lungs, seasonal patterns were Winter, Spring, Autumn, Summer in the order named. Among them, 127(21.8%) case was mycopla-sma pneumonia and 65(11.2%) case was pleuropneumonia. In snout lesion grade from 337 slaughtered pigs, above grade II score was 107(31.8%). In the white spot of liver, grade I was 544(93.3%), grade II32(5.5%) and grade III 7(1.2%). In the gastric ulcer, normal was 350(60.0%), grade I168(28.8%), grade II59(10.1%) and grade III 6(1.1%). Among the pigs(n=271) with pneumonic lesions above 20%, 162 strains werr isolated from 87(32.1%) pigs. The bacteria isolated from pneumonic lesions was Pasteurella sp 61(37.7%), Streptococcus sp 31(19.1%), Actinobacillus sp 3(1.9%), Coliform bacteria 19(11.7%) and the other bacteria 48(29.6%) These isolates were highly susceptible to the antibiotics including ENR 142(87.7%), Cft 138(85.2%) and Cf 126(77.8%).

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1037-1043
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• 2020

Actinobacillus pleuropneumoniae (APP) is a causative agent of porcine pleuropneumonia. Therefore, the development of an effective vaccine for APP is necessary. Here, we optimized the culture medium and conditions to enhance the production yields of Apx toxins in APP serotype 1, 2, and 5 cultures. The use of Mycoplasma Broth Base (PPLO) medium improved both the quantity and quality of the harvested Apx toxins compared with Columbia Broth medium. Calcium chloride (CaCl₂) was first demonstrated as a stimulation factor for the production of Apx toxins in APP serotype 2 cultures. Cultivation of APP serotype 2 in PPLO medium supplemented with 10 ㎍/ml of nicotinamide adenine dinucleotide (NAD) and 20 mM CaCl₂ yielded the highest levels of Apx toxins. These findings suggest that the optimization of the culture medium and conditions increases the concentration of Apx toxins in the supernatants of APP serotype 1, 2, and 5 cultures and may be applied for the development of vaccines against APP infection.

• Korean Journal of Veterinary Service
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• v.29 no.1
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• pp.27-36
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• 2006

This studies were carried out to investigate the rearing managements of pig farms and survey on pneumonia of the slaughtered pigs from 5 selected herds located in Jangsu, Jeonbuk. Isolated aerobic microorganisms from pneumonic lung were examined antibiotic susceptibility and tested serological antibody titers of the herd base. Prevalence rate of pneumonia were examined according to rearing and health management conditions of pig farms. Prevalence rate of pneumonia were detected in 78.8% and enzotic pneumonia. In 47.7%, pleuropneurnonia in 31.1%. In serological antibody titers showed the positive reaction with 54.4% in Actinobacillus pleuropneumonia serotype 5, 44.8% in Pasteurella multocida, 36.8% in A pleuropneurnonia serotype 2, 13.6% in Mycoplasmal pneumonia. Isolated aerobic microorganisms were examined antibiotic susceptibility and showed the high activity in gentamicin (58.3%), enrofloxacin (53.3%), norfloxacin (51.6%), cephalothin (41.7%) and low activity in amoxycillin (98.3%), oxytetracycline (98.3%), penicillin G (90.0 %), tetracycline (88.4%), ampicillin (88.3%). Farm managements were deficient effect of humidity in swine house but ammonia gas all appeared the 10 ppm that were recommendation density, below.

• Korean Journal of Veterinary Service
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• v.29 no.1
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• pp.79-82
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• 2006

A 5 years old gelding (Thoroughbred, Equus caballus) had shown severe abdominal pain, colic, after overeating of hay in the feed storage. following through treatment, it subsequently died. Grossly, the large colon was impacted with firm mass of food and congestion of blood vessel in the intestinal wall. There were mild peritonitis and pleuropneumonia. This case demonstrates typical large colon impaction with hard consistence ingesta due to improper management of horse.

• Korean Journal of Veterinary Research
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• v.52 no.3
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• pp.177-181
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• 2012

Actinobacillus (A.) pleuropneumoniae is the causative agent of pleuropneumonia which is one of the most important respiratory diseases in pigs worldwide. A total of 32 A. pleuropneumoniae isolates from diseased pigs during 2008 to 2010 were serotyped by polymerase chain reaction method. The susceptibility of the isolates to 13 antimicrobial agents were determined by disk diffusion test. In all the 32 isolates examined in this study, serotype 5 (16 isolates: 50%), 1 (7 isolates: 21.9%), 2 (5 isolates: 15.6%) and 12 (1 isolate: 3.1%) were found. Of all tested antimicrobial agents, resistance to oxytetracycline was found in 96.9% of isolates, followed by resistance to amikacin (81.2%), neomycin (68.7%), kanamycin (53.1%), penicillin (50.0%), gentamicin (43.7%), florfenicol (25.0%), ampicillin (18.7%), colistin (9.4%), trimethoprim/sulfamethoxazole, ceftiofur (8.3%), amoxicillin/clavulanic acid (3.1%) and enrofloxacin (0%). Oxytetracycline or florfenicol-resistant isolates were examined for the presence of resistance gene. Among the 31 oxytetracycline-resistant isolates, tetB, tetH and tetO genes were detected in 22 (71%), 8 (26%) and 1 (3%) isolates, respectively. The floR genes were detected in 8 (100%) of the 8 florfenicol-resistant A. pleuropneumoniae isolates.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.185-189
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• 2005

Actinobacillus pleuropneumoniae is the causative agent of a porcine contagious pleuropneumonia. Among several virulence factors including exotoxin (Apx toxins), LPS, transferrin-binding proteins, OMPs, and some proteases, Apx toxins have been major targets for the protection study. In this study, cloning and expression of A. pleuropneumoniae Apx I and Apx II toxin, which are produced by all highly virulent strains, were performed by Escherichia coli expression system. Genes coding Apx I and II toxin were amplified from the A. pleuropneumoniae serotype 5 genomic DNA using polymerase chain reaction and cloned to a prokaryotic expression vector, pRSET. Expression of the Apx I and Apx II coding sequences in E. coli resulted in the formation of insoluble inclusion bodies purified according to a denaturing purification protocol, which employs the use of guanidium. Recombinant proteins were purified using $Ni^{2+}$-charged resin affinity purification. This expression and purification system made it possible to produce Apx I and Apx II in large amounts for further immunologic studies.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.362-366
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• 2005

Actinobacillus pleuropneumoniae is an important pig pathogen, which is responsible for swine pleuropneumonia, a highly contagious respiratory infection. To develop subunit vaccines for A. pleuropneumoniae infection, the Apx toxin genes, apxI and apxII, which are thought to be important for protective immunity, were expressed in Saccharomyces cerevisiae, and the induction of immune responses in mice was examined. The apxI and apxII genes were placed under the control of a yeast hybrid ADH2-GPD promoter (AG), consisting of alcohol dehydrogenase II (ADH2) and the GPD promoter. Western blot analysis confirmed that both toxins were successfully expressed in the yeast. The ApxIA and ApxIIA-specific IgG antibody response assays showed dose dependent increases in the antigen-specific IgG antibody titers. The challenge test revealed that ninety percent of the mice immunized with ApxIIA or a mixture of ApxIA and ApxIIA, and sixty percent of mice immunized with ApxIA survived, while none of those in the control groups survived longer than 36 h. These results suggest that vaccination of the yeast ex­pressing the ApxI and ApxII antigens is effective for the induction of protective immune responses against A. pleuropneumoniae infections in mice.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.371-376
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• 2002

Swine respiratory diseases have induced severe economic lasses in swine industry worldwide. Therefore, several methods have been made and applied to prevent and control the diseases. However, these methods still have a problem and also induce side effects. Recently, the use of egg yolk antibody was introduced to control and prevent the diseases as one of new trials. As a study of using egg yolk antibody, antibody titers against several different antigens of major pathogens in swine respiratory diseases were compared in egg yolk and serum of hens immunized with those antigens. The titers were measured by ELISA using the antigens as coating antigens. The relationship in antibody titers between egg yolk and serum were identified by analysis of variance for linear regression. Almost of antigens used in this study showed the high relationship in antibody titers between egg yolk and serum (r = 0.87 ~ 0.93) even though the relationship in antibody titers against P. multocida A:3 IROMP was slightly low (r = 0.74)(P<0.01). These results indicated that antibody titer in egg yolk could be useful to predict the titer in serum of chicken.