• 한국동물위생학회지
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• 제41권3호
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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.

• 대한수의학회지
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• 제40권1호
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• pp.63-71
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• 2000

An immunogenic, high molecular weight lipopolysaccharide (LPS)-protein complex isolated from a potassium thioncyanate extract of a Pasteurella multocida (P multocida ; strain P-2383, capsular type A and somatic type 3) was characterized. Chemical analysis of the complex by gas chromatography on a capillary column demonstrated that this complex contained most of the chemical constituents characteristic of LPS extracted by the phenol-water methed from the whole bacterium. However, there was proportionately more carbohydrate than fatty acid in the complex in contrast to LPS in which fatty acid seemed to be in excess. When toxicity of the complex was evaluated in 10-day-old chicken embryos, the complex was less toxic ($LD_{50}=12.72{\mu}g$) than the purified LPS ($LD_{50}=0.44{\mu}g$). The $LD_{50}$, of the LPS moiety extracted from the complex was $5.24{\mu}g$. Composition of the complex was analyzed by SDS-PAGE with silver staining and Western immunoblotting. The complex did not migrate through the polyacrylamide gel unless dissociated with SDS. The complex dissociated with SDS contained at least 32 different protein and polysaccharide components: 18 components reacted with an antiserum against the complex. There was no significant compositional variation between the complexes from different strains, but quantitative differences in individual components were noted. When cross-protectivity of the complex was evaluated in mice, this complex provided substantial protection not only against the homologous bacteriun but also against different P multocida strains of the same serotype. LPS-protein complexes isolated by the same method from other strains also induced protection against an challenge with P-2383.

• 대한수의학회지
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• 제46권2호
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• pp.127-133
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• 2006

Pasteurella multocida is a terrible veterinary pathogen that causes widespread infections in husbandry. To induce homologous and/or heterologous immunity against the infections, outer membrane protein Hs (OmpH) in the envelope of different strains of P. multocida are thought to be attractive vaccine candidates. Previously we cloned and characterized a gene for OmpH from pathogenic P. multocida (A : 3) (In Press, Korean J. Microbiol. Biotechnol. 2005, 33, December). The gene is composed of 1,047 nucleotides (nt) coding 348 amino acids (aa) with signal peptide of 20 aa. The truncated ompH, a gene without nt coding for the signal peptide, was generated using pRSET A to name "pRSET A/OmpH-F2". This truncated ompH was well expressed in Escherichia coli BL21 (DE3). Truncated OmpH was purified for induction of immunity against live pathogen of fowl cholera (P. multocida A : 3) in mice. Some $50{\mu}g$ of the purified polypeptide was intraperitoneally injected into mice two times with 10 day interval. Lethal dose ($25{\mu}l$) of live P. multocida A : 3 was determined by directly injecting the pathogen into wild mice (n = 25). To demonstrate the vaccine candidate of the truncated OmpH, the live pathogen ($25{\mu}l$) was challenged with the OmpH-immunized mouse group as well as positive & negative controls (n = 80). The results show that the truncated OmpH can be used for an effective vaccine production to prevent fowl cholera caused by pathogenic P. multocida (A : 3).

• Journal of Microbiology
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• 제45권4호
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• pp.364-366
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• 2007

The immunological role of the Pasteurella multocida toxin (PMT) in mice was examined using a PMT mutant strain. After a nasal inoculation, the mutant strain failed to induce interstitial pneumonia. Moreover, PMT had no significant effect on the populations of CD4+, CD8+, CD3+, and CD19+ immunocytes in blood or on the populations of CD4+ and CD8+ splenocytes (P<0.01). However, there was a significant increase in the total number of cells in the BAL samples obtained from the wild-type P. multocida-inoculated mice. On the other hand, the level of IL-l expression decreased when the macrophages from the bronchio-alveolar lavage were stimulated with PMT. Overall, PMT appears to play some role (stimulating and/or inhibiting) in the immunological responses but further studies will be required to confirm this.

• 한국임상수의학회지
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• 제41권1호
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• pp.54-59
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• 2024

A 12-year-old female small-clawed Asian otter (Anoyx cinereus) with a one-week history of anorexia, chills, and abdominal distension was found dead. Grossly, yellowish-brown turbid fluids accumulated in abdominal cavity of the otter, and yellowish thread-like fibrinous materials were found on the surface of abdominal organs. Several variable sized yellowish-white crystalloids were scattered on the medullary space of kidneys. Histologically, diffuse serositis (peritonitis) characterized by the fibrinous exudates, thickened serosal capsule and the swelling of mesothelial cells were observed in the serosa of liver, spleen, stomach, and intestine. Multifocal necrosis, hemorrhage, infiltration of macrophage, and brown pigments were presented in the liver. Isolated bacteria from ascites and fibrinous materials in abdominal visceral surface were white, smooth and convex with characteristic mousy odor on blood agar plate. These bacteria were confirmed as Pasteurella (P.) multocida type A by polymerase chain reaction analysis. Based on the gross examination, histopathologic findings and bacterial experiments, this otter was diagnosed as severe peritonitis associated with P. multocida and necrotic hepatitis.

• 대한수의학회지
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• 제48권1호
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• pp.53-60
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• 2008

We have investigated efficiency of a recombinant subunit Pasteurella multocida toxin (PMT) that was mixed with a vaccine consisted of inactivated whole cells of Bordetella bronchiseptica, P. multocida (types A and D). For verification of the efficacy of the vaccine, all experimental pigs (suckling piglets, sow and gilts) in the three farms were vaccinated. Antibody titers against B. bronchiseptica and P. multocida type A of the vaccinated pigs by microplate agglutination were significantly higher than those of the control pigs (p < 0.05). Similar patterns were observed in the analysis of anti- PMT neutralizing antibody by serum neutralizing method using Vero cell (p < 0.05). Anti- P. multocida type D antibody titer of the vaccinated sows and gilts by ELISA showed significant differences with those of the non-vaccinated pigs (p < 0.05). Although antibody titers increased, it was unable to find out the difference in the clinical signs between the vaccinated and non-vaccinated pigs. However, the increase in body weight of the vaccinated piglets was observed in comparison with the non-vaccinated piglets on a farm. At slaughtering of the pigs, pathological lesions in the turbinate bones of the vaccinated pigs were significantly lower than those of the non-vaccinated pigs (p < 0.001). These results suggested that efficacy of the vaccine in pigs demonstrated to protect against atrophic rhinitis in Korea.

• 대한수의학회지
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• 제39권2호
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• pp.327-337
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• 1999

The transposon TnphoA was used to generate avirulent mutants from a type A Pasteurella multocida. A suicide vector plasmid pRT733 carrying TnphoA, having the kanamycin resistant gene and harbored in Escherichia coli K-12 strain SM10(${\lambda}pir$), was mated with streptomycin resistant P. multocida P-1059 strain as recipient. This resulted in the generation of two TnphoA insertion mutants (transconjugants, tc95-a and tc95-b) which were resistant both to kanamycin ($Km^{R}$) and streptomycin ($Sm^{R}$), secreted alkaline phosphatase, and were avirulent to turkeys. Southern blot hybridization using two probes derived from internal fragments of TnphoA, confirmed the insertion of TnphoA into 12.9kb or 13.7kb DNA fragment from the EcoRV digested genomic fragments of transconjugants. The two transconjugants, tc95-a and tc95-b, were distinguishable from their parent strains by differences in ribotypes, and outer membrane protein profiles. TnphoA insertion in both transconjugants also resulted in constitutive expression of a 33Kd iron regulated outer membrane protein (IROMP). The gene encoding $Sm^{R}$ was also located within the same 12.9kb EcoRV genomic fragment from both transconjugants. Furthermore, our finding that the recipient P. multocida P-1059 $Sm^{R}$ strain and both transconjugants were avirulent to turkeys suggest that the either 12.9kb or 13.7kb genomic DNA contains the virulence gene and speculate that the presence of $Sm^{R}$ gene or TnphoA insertion may be responsible for regulating and inactivating the gene(s) encoding virulence in P. multocida.

• 한국미생물·생명공학회지
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• 제33권4호
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• pp.274-280
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• 2005

Pasteurella. multocida 균은 광범위한 질병을 야기시키는 악성 감염원으로 알려져 있다. 그람 음성균의 동종 및 이종간에 의한 감염에 대한 강력한 백신 후보 물질로써 OmpH라고 불리는 porin 단백질이 고려되어 왔다. 이 OmpH가 이번 연구에서 분리 및 정제되었다. 선도 단백질을 제거한 재조합 OmpH 단백질은 pRSET A발현벡터를 이용하여 40kDa로 발현되었으며, 친화성 크로마토그래피 정제되었다. OmpH에 대한 면역혈청을 얻기 위해, 한마리의 실험용 쥐에 한번에 50ug의 단백질을 복강 주사를 통해 2회에 걸쳐 주사했다. 항 OmpH 면역혈청의 증가는 ELISA로 측정되었다. 이번 실험에서 확인된 면역혈청의 증가는 OmpH단백질이 병원성 파스튜렐라 균이 일으키는 가금 콜레라를 예방하기 위한 백신의 강력한 후보임을 보여주고 있다.

• 한국동물위생학회지
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• 제27권3호
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• pp.257-263
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• 2004

This study were carried out to investigate isolation of Pasteurella multocida from respiratory disorder piglets, to examine the biochemical properties and antimicrobial susceptibility. The results were summarized as follows; P multocida was isolated from 31($10.3\%$) of the 302 respiratory disorder or growing piglets of $4{\sim}10$ week olds. The majority of biochemical and cultural properties of the P multocida isolates were identical to those of the standard strains. The isolates were highly susceptible to norfloxacin($100.0\%$), enrofloxacin($96.8\%$) and ampicillin($87.1\%$), but resistant to streptomycin ($77.4\%$), penicillin($61.2\%$) and neomycin($54.8\%$).

• 대한수의학회지
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• 제29권4호
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• pp.577-587
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• 1989

소의 하부호흡기계 질병을 진단하고자 기침과 비루를 주증상으로 하는 31두의 환우와 임상증상을 나타내지 않는 9두의 소에 5 fr. urinary catheter를 이용한 transtracheal aspiration technique를 적용하고 이 방법의 유용성 및 분리된 병원성 세균과 세포상을 임상증상과 관련하여 조사하여 다음과 같은 결과를 얻었다. Transtracheal aspiration technique은 구강내 정상상재균에 오염되지 않은 가검물을 하부호흡기로부터 채취하는데 호흡장애와 합병증을 유발하지 않았다. 총 40두로부터 분리한 세균중 Pasteurella multocida가 48.7%로 가장 많이 분리되었으며 점액 화농성 염증이 40%로 가장 많이 나타났다. 심한 임상증상을 보인 소중 점액화농성 염증이 60%로 가장 많이 나타났으며 Pasteurella multocida가 63.2%로 높게 분리되었다. 경미한 임상증상을 보인 소에서는 염증세포에 따른 세포상이 고루 나타났으며 Pasteurella multocida가 40% 분리되었다. 세포학적 관찰에서는 정상인 경우는 섬모원주상피세포가 다수 관찰되었고 점액성 염증인 경우는 소수의 호중구 및 상피세포가 관찰되었으며 점액화농성 염증인 경우는 다수의 밀집된 호중구, 상피세포 및 점조한 삼출물이 동시에 관찰되었다. 복합세포성 염증에서는 대식구, 호중구, 임파구 및 상피 세포가 혼재하였다. 이상의 결과로부터 transtracheal aspiration technique은 소의 하부호흡기계 질병을 진단하는데 실제 임상에서 응용할 수 있는 쉽고 안전하며 유익한 방법으로 사료된다.