• Korean Journal of Veterinary Service
• /
• v.44 no.2
• /
• pp.103-111
• /
• 2021

Actinobacillus (A.) pleuropneumoniae is the etiological agent of a porcine pleuropneumonia and have great economic importance to the global swine industry. For recent 5 years, a total of 50 pleuropneumonia cases of 24 pig farms were selected from pig lungs submitted to the College of Veterinary Medicine, Jeju National University using polymerase chain reaction (PCR) analysis. Collected lungs were fixed in 10% neutral phosphate-buffered formalin and processed for histological examination. Serotypes of A. pleuropneumoniae in pneumonic lesions were analyzed by PCR methods. And the antimicrobial susceptibility of A. pleuropneumoniae isolates was determined by a disc diffusion test. Grossly, unilateral distribution of hemorrhagic or necrotic pneumonic lesions was more common than bilateral distribution in lungs. In peracute or acute cases, histopathologic changes were characterized by necrosis, hemorrhage, neutrophils infiltration, vascular thrombosis, widespread edema and fibrinous exudates. Following the acute response, macrophage infiltration, marked fibrosis around zonal necrotic areas, and marked fibrous pleuritis were characteristic in chronic cases. A total of 50 pleuropneumonia were associated with A. pleuropneumoniae serotype 5 in 46 cases (92%), serotype 2 in 3 cases (6%), and both 2 and 5 in 1 case (2%). More than 90% of collected isolates showed high sensitivity to ceftiofur, amoxicillin, and colistin. However, ampicillin, penicillin, and tylosin showed low susceptibility. The results of this study demonstrated that A. pleuropneumoniae serotype 5 was predominant at porcine pleuropneumonia cases in Jeju.

• Journal of Veterinary Clinics
• /
• v.14 no.1
• /
• pp.37-41
• /
• 1997

For the inspection of the occurrence situation of porcine pleuropneumonia and serotyping of Actinobacillus pleuropneumoniae strains isolated from lung lesions of pig in Korea, a series of experimentation have been carried out by the isolation and identification of A pleuropneumoniae, serotyping by coagglutination test, observation of lung lesion and clinical signs from 360 cases of porcine pneumonia in Clinical Pathology Laboratory, Bayer Veterinary Medical Research Institute. The results could be summarized as follows. The reaction of coagglutination between the reference antigens and the specific reagents of A pleuropneumoniae was strongly agglutinatied within 30 seconds without cross reaction. The 89 strains of A pleuropneumoniae were isolated from 360 cases of porcine pleuropneumonis and the biochemical properties of the isolates were same as the reference strains. The 89 isolated strains could be serotyped 39 strains as setotype 5, 34 strains as serotype 2, 8 strains as serotype 3, 2 strains as serotype 7 by coagglutination test, respectively. The clinical signs of pleuropneumonia were weakness, fever, anorexia, dyspnea and laboured breath in the later stages. The gross lesions of lung were haemorrhages, enlargement of interlobular septa, nodular formation and adhesion of the pleura.

• Korean Journal of Veterinary Research
• /
• v.24 no.1
• /
• pp.99-104
• /
• 1984

Authors observed an outbreak of porcine pleuropneumonia at a piggery in Gyeongbug, Korea, which were diagnosed on the ground of clinical and pathological findings with the following results. 1. One hundred and forty weanlings out of 200 ones died suddenly without noticiable signs during the period of 15 days. All of the dead pigs showed formy, blood-tinged discharge from the nose and mouth. 2. Main clinical findings observed from 60 alive pigs from group consisted of fever, cyanosis severe degree of dyspnea and pleuritic friction rub. 3. On hematological observation for typical 5 cases leukocytes showed marked degenerative left shift with leukopenia (10500-13070/cmm), neutropenia (7-13%) and increase in the number of band neutrophils (6-27%). 4. The most prominent and constant pathological changes observed at necropsy for dead or alive pigs consisted of fibrinous pleurisy with partial adhesion, overlying of the pulmonary surface with fibrinous menbrane and necrotic pneumonic lesions with marked edema and congestion of lung parenchyma. 5. From these results the outbreak was considered to be typical porcine pleuropneumonia, although no bacteriological isolation was attempted.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.1102-1105
• /
• 2001

In order to find therapeutic agents for porcine pneumonia, we screened far antibacterial activities of methanol extracts of 81 higher plants against four pathogenic microorganisms of Heamophilus parasuis, Pasteurella multocida, Actinobacillus pleuropneumonia, and Bordetella bronchiseptica, and found the bark of Cinnamomi cortex showed potent activities. Since this was inexpensive, we purified active compounds from it. The structures of the final active fractions were obtained through an activity-guided fractionation and their antibacterial activities are reported here.

• Korean Journal of Veterinary Service
• /
• v.30 no.1
• /
• pp.51-66
• /
• 2007

The purpose of this study was to evaluate the effect of a subsequent infection of porcine reproductive and respiratory syndrome(PRRS) virus to pigs with A pleuropneumonia. Twenty three 7-week-old commercial pigs were infected intratracheally with PRRS virus and/or A pleuropneumoniae serotype 5. Serum antibody titers were examined by an enzyme-linked immunosorbent assay(ELISA) and proportion of porcine leukocyte subpopulations in peripheral blood was examined by flow cytometry. In this experiment, antibodies against PRRS virus and A pleuropneumoniae were detected at 2 weeks and 1 week postinfection and the number of antibody positive pigs were gradually increased. And in proportion to leukocyte subpopulations in peripheral blood of pigs infected with A pleuropneumoniae compared with pigs administrated with saline, the proportion of PoCD4 and N cells were increased(P<0.1). Furthermore, in proportion to leukocyte subpopulations in peripheral blood of pigs infected with PRRS virus followed by A pleuropneumoniae compared with pigs administrated with saline, the proportion of MHC class II, PoCD4 and B cells were significantly increased(P<0.1). The results indicated that dual infection with PRRS virus and A pleuropneumoniae induced the stronger immune responses associated with macrophages and Th cells in pigs than single infection with PRRS virus or A pleuropneumoniae.

• Korean Journal of Veterinary Pathology
• /
• v.7 no.1
• /
• pp.27-41
• /
• 2003

The purpose of this study was to evaluate the effect of a subsequent infection of porcine reproductive and respiratory syndrome(PRRS) virus to pigs with A. pleuropneumonia in pigs. Twenty three 7-weeks-old commercial pigs were infected with PRRS virus and/or A. pleuropneumoniae serotype 5 intratracheally. Feed conversion, clincal signs, gross and histopathological lesions and immunohistochemical findings were examined. 1. Feed conversion ratio in dual-infected pigs with PRRS virus and A. pleuropneumoniae were higher than that of single- infected pigs with PRRS virus or A. pleuropneumoniae. 2. Dual-infected pigs with PRRS virus followed by A. pleuropneumoniae showed more severe clinical signs and gross, histopathological and immunohistochemical pulmonary lesions. The results indicated that dual infections with PRRS virus and A. pleuropneumoniae caused more severe respiratory lesions and growth retardation in pigs than single infection with PRRS virus or A. pleuropneumoniae.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.10
• /
• pp.1606-1613
• /
• 2015

Porcine pleuropneumonia is an infectious disease caused by Actinobacillus pleuropneumoniae. The identification of A. pleuropneumoniae genes, specially expressed in vivo, is a useful tool to reveal the mechanism of infection. IVIAT was used in this work to identify antigens expressed in vivo during A. pleuropneumoniae infection, using sera from individuals with chronic porcine pleuropneumonia. Sequencing of DNA inserts from positive clones showed 11 open reading frames with high homology to A. pleuropneumoniae genes. Based on sequence analysis, proteins encoded by these genes were involved in metabolism, replication, transcription regulation, and signal transduction. Moreover, three function-unknown proteins were also indentified in this work. Expression analysis using quantitative real-time PCR showed that most of the genes tested were up-regulated in vivo relative to their expression levels in vitro. IVI (in vivo-induced) genes that were amplified by PCR in different A. pleuropneumoniae strains showed that these genes could be detected in almost all of the strains. It is demonstrated that the identified IVI antigen may have important roles in the infection of A. pleuropneumoniae.

• Korean Journal of Veterinary Service
• /
• v.39 no.4
• /
• pp.231-237
• /
• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).

• Korean Journal of Veterinary Service
• /
• v.38 no.2
• /
• pp.89-94
• /
• 2015

Respiratory disease in pigs is common in modern pork production worldwide and is often referred to as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. The control of swine respiratory disease requires an understanding of the interactions between the organisms that can cause this illness, the pig and management of the environment. This study was carried out to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. A total of 900 lung samples, 45 farms were collected randomly from slaughtered pigs in Jeonbuk province from April to December in 2014. Gross lesions such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis, liver white spots were examined for the pigs. Overall prevalence of SEP was 70.8%. According to season, the incidence occurred higher in summer than winter, fall and spring. The mean SEP score was 1.4, the highest incidence occurred in fall. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 26.1%, 71.4%, 2.8%, 21.6%, respectively. In the detection of pathogens, PRRS was not detected, PCV2 was positive in 87.6%.

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