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1.
The efficacy of an intranasal haemorrhagic septicaemia vaccine containing live gdhA derivative Pasteurella multocida B:2 was tested in buffaloes in Sabah. Sixty buffaloes, kept grazing in the field with minimal human intervention were devided into three groups of 20 buffaloes per group. Buffaloes of group 1 were exposed intranasal to 5 ml vaccine containing 10(6) CFU/ml of live gdhA derivative P multocida B:2. Buffaloes of group 2 were not exposed to the vaccine but exposed to PBS and were allowed to commingle and graze in the same field as the buffaloes of group 1 while buffaloes of group 3 were similarly exposed to PBS and were grazing separately. Booster was on group 1, two weeks later. Twelve months after the first vaccination, three buffaloes from each group were brought into the experimental house and challenged subcutaneously with 10(9) CFU/ml of live wild-type P multocida B:2. All challenged buffaloes of groups 1 and 2 survived with only mild, transient signs while all control unvaccinated buffaloes developed severe signs of haemorrhagic septicaemia and were euthanased between 28 hours and 38 hours postchallenge with signs and lesions typical of haemorrhagic septicaemia. These data showed that the gdhA mutant strain, given intranasally as two doses two weeks apart, successfully induced systemic immunity in exposed buffaloes and also led to spread of vaccine strain to the in-contact animals, where it acted as an effective live vaccine to protect both exposed buffaloes and in-contact buffaloes against challenge with the virulent parent strain.  相似文献   

2.
Biochemical profiles, restriction endonuclease analysis (REA) and ribotyping were used to investigate a total of 38 Pasteurella multocida isolates from four separate outbreaks of pasteurellosis in Australian piggeries. Six isolates were obtained from Outbreak 1, 16 from Outbreak 2 and eight each from outbreaks 3 and 4. Outbreaks 1 and 2 were cases of pneumonic pasteurellosis while outbreaks 3 and 4 involved systemic pasteurellosis. Biochemical characterisation established that a number of different types of P. multocida were present in outbreaks 1 and 3 while outbreaks 2 and 4 were associated with a single type of P. multocida. Outbreaks 1 and 3 yielded isolates of P. multocida that belonged to the subspecies multocida and gallicida, with the subspecies multocida isolates being identified as biovar 3 (6 in total) or 12 (1 in total) and the subspecies gallicida isolates (7 in total) being identified as biovar 8. All 24 isolates from outbreaks 2 and 4 belonged to the subspecies multocida and were all biovar 3. REA and ribotyping showed that, in outbreaks 1 and 3, there were three different types of P. multocida in each outbreak with no common strains between the outbreaks. The molecular methods showed that only a single strain of P. multocida was associated with outbreaks 2 and 4, although the outbreaks were associated with strains that differed in REA profiles but shared a ribotype profile. This study has shown that both, systemic and pneumonic pasteurellosis can be associated with either a single strain or multiple strains of P. multocida. The results also indicate that the molecular typing methods of REA and ribotyping are superior to biochemical characterisation for epidemiological investigation of porcine pasteurellosis.  相似文献   

3.
The phylogenetic relationships of five isolates of Pasteurella multocida serotype B:2 belonging to buffalo, cattle, pig, sheep and goat were investigated by comparative sequence analysis of 16S rRNA gene. The 1468bp fragment of 16S rRNA gene sequence comparison showed that the isolates of cattle (PM75), pig (PM49) and sheep (PM82) shared 99.9% homology with the buffalo isolate (vaccine strain P52) whereas, the goat isolate (PM86) shared 99.8% homology with the vaccine strain. The 16S rRNA gene sequences of these isolates were also found monophyletic with type B reference strain NCTC 10323 of P. multocida subsp. multocida. The present study indicated the close relationships of haemorrhagic septicaemia causing P. multocida serotype B:2 isolates of buffalo and cattle with other uncommon hosts (pig, sheep and goat).  相似文献   

4.
AIMS: To examine pigs at slaughter in New Zealand for the presence of Pasteurella multocida, and to determine for isolates, their biochemical profiles, somatic and capsular types, and the presence or absence of the HSB and toxA genes, associated with haemorrhagic septicaemia (HS) and progressive atrophic rhinitis (PAR), respectively. METHODS: Swabs from 173 lungs, 158 palatine tonsils and 82 nasal passages of pigs at two abattoirs in New Zealand were cultured for P. multocida using conventional techniques, and isolated colonies were subjected to biochemical tests for identification of biovars. Somatic serotyping was conducted using an agar gel immunodiffusion (AGID) test. Polymerase chain reaction (PCR) assays were used to confirm phenotypic identification of colonies using species-specific primers, capsule type using serogroup-specific primers and multiplex PCR, and to test for the presence of HSB and toxA genes. RESULTS: Pasteurella multocida was isolated from 11/173 (6.4%) lung, 32/158 (20.2%) palatine tonsil and 5/82 (6.1 %) nasal swab samples, a total of 48 isolates from 413 samples (11.6%). Isolation rates per farm ranged from 1-53% of tissue samples collected from pigs 5-6 months of age. On phenotypic characterisation, isolates were allocated to seven main biovars, viz 1, 2, 3, 5, 9, 12, and a dulcitol-negative variant of Biovar 8, the majority (30/48) being Biovar 3. Of the 42 isolates for which somatic serotyping was conducted, 10% were Serovar 1, 79% were Serovar 3, 2% were Serovar 6,1, 2% were Serovar 12, and 7% could not be typed. All 48 isolates were confirmed as P. multocida using a species-specific PCR. In the capsular multiplex PCR, 92% of isolates were Capsular (Cap) type A, 2% were Cap D, and 6% could not be typed. None of the samples were positive for the HSB or toxA genes. CONCLUSION: Serovars or capsular types of P. multocida associated with HS or PAR in pigs were not detected. Establishment of species-specific, capsular and toxin PCR assays allowed the rapid screening of isolates of P. multocida, while serotyping provided an additional tool for epidemiological and tracing purposes.  相似文献   

5.
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6.
The safety, efficacy and cross-protectivity of a live intranasal aerosol haemorrhagic septicaemia vaccine containing Pasteurella multocida serotype B:3,4 were tested in young cattle and buffaloes in Myanmar, where more than 1.5 million animals had been inoculated with this vaccine between 1989 and 1999. A recommended dose of 2 x 10(7) viable organisms was used for the efficacy test. The administration of 100 times the recommended dose to 50 cattle and 39 buffalo calves was innocuous. Seven months after they were vaccinated, three of three buffaloes were protected and 12 months after they were vaccinated, three of four buffaloes were protected against a subcutaneous challenge with serotype B:2 which killed three of three unvaccinated buffaloes. Twelve months after they were vaccinated, eight of eight cattle survived a serotype B:2 challenge, which killed four of four unvaccinated controls. The vaccinated cattle had developed serum antibodies detectable by the passive mouse protection test. Indirect haemagglutination tests on sera taken from cattle 10 days and five weeks after they were vaccinated showed high titres of antibodies. The serum of vaccinated cattle cross-protected passively immunised mice against infection with P. multocida serotypes E:2, F:3,4 and A:3,4.  相似文献   

7.
A total of 36 tonsil swab samples were collected from healthy swine prior to slaughter at the abattoirs in Can tho and Tien giang provinces of Southern Vietnam. The presence of Pasteurella multocida in these samples was detected by the combination of direct cultivation and isolation, mouse inoculation and the polymerase chain reaction (PM-PCR). P. multocida was detected in 16 samples by PCR, with 17 strains ultimately isolated. All samples were negative for serogroup B by HSB-PCR and conventional serotyping, with isolates identified as A:3, D:1 or D:3. In addition, all samples were determined to be negative for the P. multocida toxin (PMT). Characterisation of isolated P. multocida by REP-PCR and biotyping revealed nine distinct REP profiles and seven biotypes among the 17 isolates. Some correlation was seen with P. multocida isolated from a previous Australian outbreak of acute swine pasteurellosis, and those isolated from fowl cholera outbreaks in Vietnamese poultry.  相似文献   

8.
Haemorrhagic septicaemia (HS) is caused by specific serotypes of Pasteurella multocida and is one of the major economic diseases of cattle and buffalo in South East Asia. Definitive diagnosis of the disease-causing organism with the available methods is labour intensive and not totally reliable, consequently, an ELISA system to identify P multocida organisms which cause HS was developed. One hundred and twenty-four P multocida isolates were tested, 58 were type strains and 66 were field isolates. Analysis of these strains indicated the assay had a specificity of 99 per cent and sensitivity of at least 86 per cent. The sensitivity could be an underestimate, as five isolates assumed to be false negative reactions may not all be HS-causing strains. The HS ELISA provides a rapid, simple, accurate and inexpensive diagnostic assay for identification of HS causing organisms but does not represent a new typing system for P multocida. This assay will also enable countries to assess the impact of HS more accurately.  相似文献   

9.
A whole blood lymphocyte stimulation assay to study cell-mediated immune responses in bovine pasteurellosis was developed. Peripheral blood lymphocytes from cattle artificially immunised with three Asiatic haemorrhagic septicaemia strains of Pasteurella multocida exhibited higher stimulation indices when incubated with antigen preparations from homologous strains than with the heterologous shipping fever strain. Lymphocytes from cattle immunised with the shipping fever strain of P multocida exhibited a higher stimulation index when incubated with an antigen preparation from the homolgous strain than with antigen preparations from heterologous haemorrhagic septicaemia strains. These results suggest that immunogenic differences exist between the haemorrhagic septicaemia strains and the shipping fever strain of P multocida. An assay using turkey whole blood lymphocytes was also developed. The use of small amounts of whole blood, microtitre plates, either 125I iododeoxyuridine or 3H-thymidine as the labelling agent, and a multiple cell-culture harvester makes the method simple, rapid and suitable for the study of immune competence and cell-mediated immune responses in turkeys on a flock basis.  相似文献   

10.
Pasteurella multocida is responsible for major animal diseases of economic significance in both developed and developing countries whereas human infections related to this bacterium are infrequent. Significantly, development of a carrier status or latent infections plays a critical role in the epidemiology of these diseases. Aiming at increased knowledge of these infections, we examine potential diagnostic and selected typing systems for investigating diseases caused by P. multocida. Detection of P. multocida from clinical specimen by; (i) isolation and identification, (ii) polymerase chain reaction (PCR), iii) specific hybridisation probes, (iv) serological tests and (v) other alternative methods is critically evaluated. These detection systems provide a wide spectrum of options for rapid diagnosis and for detecting and understanding of latent infections in herd/flock health control programmes, though PCR methods for detecting P. multocida in clinical specimen appear increasingly preferred. For establishing the clonality of outbreak strains, we select to discuss macromolecular profiling, serotyping, biotyping, restriction enzyme analysis, ribotyping and multiplex PCR typing. Although P. multocida infections can be rapidly diagnosed with molecular and serological tests, isolation and accurate species identification are central to epidemiological tracing of outbreak strains. Our review brings together comprehensive and essential information that may be adapted for confirming diagnosis and determining the molecular epidemiology of diseases associated with P. multocida.  相似文献   

11.
Pasteurella multocida B:2 is responsible for haemorrhagic septicaemia in cattle and buffaloes, causing severe economic losses in the developing countries. In the present study, the ahpA gene of P. multocida B:2 (P52) was cloned, sequenced and compared with the previously reported ahpA gene sequence in P. multocida A:1, which is responsible for its haemolytic phenotype. E. coli DH5a cells were further transformed with recombinant plasmid carrying the ahpA gene from P. multocida B:2 (P52) but SDS-PAGE analysis failed to show the expression of haemolysin protein. Slight haemolysis was albeit observed in horse blood agar plates streaked with recombinant E. coli carrying the ahpA gene. Our study indicates that there is 99.6% similarity and 0.4% divergence between ahpA gene of P. multocida B:2 (P52) and P. multocida A: 1, while membrane topology analysis has predicted that ahpA is an inner membrane protein with two strong hydrophobic regions at the N and C terminals. The presence of significant homology in ahpA sequence in A: 1 and B:2 perhaps suggests a common mechanism of pathogenesis in different species of animals.  相似文献   

12.
Repetitive extragenic palindromic sequence-based PCR (REP-PCR) was used to characterize 67 field isolates of Pasteurella multocida originating from different animal species and geographical regions of India. REP-PCR was found to be rapid and reproducible (three repeats were done). These isolates yielded different 23 profiles which were clustered into eight groups. The discrimination index was moderate (D value 0.83). Somatic and antigenic typing of the isolates did not reveal any correlation with REP-PCR profiles. There was no host-specific, type-specific, region-specific or pathenogenicity-specific pattern. The REP profiles of isolates obtained from wild animals were similar to those obtained from domestic animals. Two common bands were present in all the isolates irrespective of somatic or antigenic types. The results were not comparable with earlier findings, which had shown high discrimination index and correlation with disease presentation. Saxena, M.K., Singh, V.P., Kumar, A.A., Chaudhuri, P., Singh, V.P., Shivachandra, S.B., Biswas, A. and Sharma, B., 2006. REP–PCR analysis of Pasteurella multocida isolates from wild and domestic animals in India. Veterinary Research Communications, 30(8), 851–861  相似文献   

13.
The oropharyngeal regions of 680 meat turkeys and 55 breeder turkeys from nine outbreak farms, three history-outbreak farms, and 19 nonoutbreak farms in Ohio, Indiana, and Pennsylvania were cultured to determine the prevalence of Pasteurella multocida in turkeys. Pasteurella multocida was recovered from 32 out of 105 turkeys belonging to outbreak farms. Pasteurella multocida was not recovered from either history-outbreak or nonoutbreak farms. Characterization via capsular and somatic serotyping, biotyping, restriction endonuclease analysis, and antimicrobial susceptibility testing was performed on all recovered P. multocida isolates. Pasteurella multocida serotype A:1 and somatic serotype 1 with an un-typable capsular serogroup (UT:1) were the most common serogroups found. All isolates belonged to biotype P. multocida ssp. multocida. EcoRI, HpaII, and HindIII restriction enzyme digestions identified three, five, and five restriction fragment length polymorphism profiles, respectively. A majority of the isolates were susceptible to amikacin, ampicillin, ceftiofur, cephalothin, enrofloxacin, florfenicol, gentamicin, neomycin, novobiocin, oxacillin with 2% NaCl, sarafloxacin, tilmicosin, and trimethoprim with sulphadiazine and resistant to clindamicin, penicillin, tiamulin, and tylosin.  相似文献   

14.
Pasteurella multocida is a capsulated, gram-negative cocco-bacillus that can cause serious disease in a wide range of mammals and birds. P. multocida strains are classified into 16 serovars based on lipopolysaccharide (LPS) antigens. LPS is an essential virulence factor of P. multocida; mutants expressing severely truncated LPS are completely attenuated in chickens. LPS is also a major immunogen of P. multocida and protection against infections caused by P. multocida is generally considered to be serovar specific. In this review we summarize current knowledge of the structure and genetics of LPS assembly of P. multocida strains belonging to five different serovars. These include strains belonging to serovars 1 and 3, the most common serovars found in the poultry industry, and strains belonging serovars 2 and 5, the serovars associated with bovine haemorrhagic septicaemia outbreaks. A number of the serovars are genetically related; serovars 1 and 14 share the same LPS outer core biosynthesis locus, but due to a mutation within the phosphocholine biosynthesis gene, pcgA, the serovar 14 strain produces a truncated LPS structure. Similarly serovars 2 and 5 share an identical LPS outer core locus and express near-identical LPS structures. However, due to a single point mutation in the phosphoethanolamine (PEtn) transferase gene, lpt_3, the serovar 2 strain does not elaborate a PEtn residue on heptose II. Knowledge of the genetic basis for the LPS structures expressed by P. multocida will facilitate the development of rapid molecular methods for typing and diagnosis and will be essential for a rational approach to vaccine formulation.  相似文献   

15.
A total of 100 isolates of Pasteurella multocida from various ruminant species (cattle, buffalo and sheep) belonging to different parts of country were identified using Pasteurella multocida-PCR (PM-PCR) and capsular PCR assays. PM-PCR revealed an amplicon of approximately 460 bp in all the isolates tested. As regards capsular PCR, 36 of 38 cattle isolates and 30 of 34 buffalo isolates were found to belong to capsular serogroup B whereas rest of the cattle and buffalo isolates belonged to serogroup A of P. multocida. In case of sheep, a total of 26 out of 28 isolates were positive for serogroup A specific PCR while remaining 2 amplified a PCR product specific for serogroup F of P. multocida. All the isolates were subjected to antibiotic sensitivity testing using 17 different antibiotics. Enrofloxacin was found to be most potent antibiotic as it was effective against 94% of the isolates followed by ofloxacin (93%), chloramphenicol (93%), doxycycline (89%), tetracycline (86%) and ciprofloxacin (84%). Vancomycin, bacitracin and sulfadiazine were ineffective against P. multocida isolates showing 84%, 75% and 82% resistance, respectively. Further, the antibiogram also revealed the development of resistance against multiple drugs among various isolates of the organism.  相似文献   

16.
Identification and estimation of the prevalence of Pasteurella multocida organisms in different animal and avian species in India during November 2000 to July 2003 was carried out. Out of 418 samples collected from different outbreaks suspected to be caused by P. multocida, a total of 206 bacterial cultures were identified as P. multocida on the basis of cultural, morphological and biochemical characteristics. All the 206 cultures were isolated from different domestic animal species (cattle, buffalo, sheep, goat, pig and rabbit), avian species (chicken, duck, quail, turkey, goose) and wild animals such as leopard and deer. Serotyping of P. multocida cultures revealed the presence of various serotypes (A:1, A:3, A:1,3, A:4, B:2, D:1 and -:1) among the livestock population. P. multocida polymerase chain reaction (PCR) assay applied on different forms of bacterial cultures (bacterial culture lysate, direct bacterial colony and mixed bacterial culture lysate) yielded an amplified product of approximately 460 bp specific for P. multocida. The results of PCR assay correlated well with conventional methods of identification. The present investigation revealed the presence of varied serotypes among livestock and PCR assay was found to be useful for rapid, sensitive and specific diagnosis of pasteurellosis in animals and avian species.  相似文献   

17.
tRNA-intergenic spacer PCR (tDNA-PCR) was evaluated for its effectiveness in differentiating Pasteurella and Mannheimia (sub)species predominantly of ruminant origin. For this purpose, 38 reference strains and 13 field isolates belonging to both genera were investigated. tDNA-PCR enabled discrimination of all Pasteurella species tested (Pasteurella (P.) aerogenes, P. avium, P. canis, P. lymphangitidis, P. multocida, P. trehalosi). For the differentiation of the subspecies of P. multocida, an additional dulcitol reaction was required. Two of the five so far-defined Mannheimia species, M. granulomatis and M. varigena, had a distinct fingerprinting profile. The remaining three phylogenetically highly related species (M. haemolytica, M. glucosida, and M. ruminalis) clustered together. Nevertheless, M. ruminalis is non-haemolytic, and M. haemolytica and M. glucosida can be differentiated on the basis of two additional phenotypic characteristics (beta-glucosidase and aesculin hydrolysis). In conclusion, tDNA-PCR is a useful tool in differentiating organisms belonging to the genera Pasteurella and Mannheimia.  相似文献   

18.
Pasteurella multocida is an important veterinary and opportunistic human pathogen. The species is diverse and complex with respect to antigenic variation, host predeliction and pathogenesis. Certain serological types are the aetiologic agents of severe pasteurellosis, such as fowl cholera in domestic and wild birds, bovine haemorrhagic septicaemia and porcine atrophic rhinitis. The recent application of molecular methods such as the polymerase chain reaction, restriction endonuclease analysis, ribotyping, pulsed-field gel electrophoresis, gene cloning, characterisation and recombinant protein expression, mutagenesis, plasmid and bacteriophage analysis and genomic mapping, have greatly increased our understanding of P. multocida and has provided researchers with a number of molecular tools to study pathogenesis and epidemiology at a molecular level.  相似文献   

19.
The genomes from field isolates of Pasteurella multocida in turkeys and those of P multocida reference CU and M9 vaccine strains were analyzed and compared after cleavage with restriction endonucleases. The electrophoretic profiles obtained with DNA fragments from field isolates and vaccine strains of the same serotype were characteristic and reproducible. These features indicated the existence of differences among the isolates of the same serotype that cannot currently be detected, using available serotyping methods. However, several field isolates had electrophoretic profiles similar to those of either CU or M9 vaccine strain. It was concluded that restriction endonuclease analysis of DNA genomes from P multocida isolated from turkeys provides the information for differentiation of field isolates from vaccine strains of the same serotype.  相似文献   

20.
A review of hemorrhagic septicemia in cattle and buffalo   总被引：1，自引：0，他引：1  
Hemorrhagic septicemia (HS), an acute, fatal and septicemic disease of cattle and buffaloes caused by Pasteurella multocida, is important in tropical regions of the world, especially in African and Asian countries. The prevalence of disease has been well documented with predominant isolation of P. multocida serotypes B:2 and E:2. Conventional methods of identification such as serotyping, biotyping, antibiogram determination and pathogenicity as well as molecular methods (P. multocida-specific polymerase chain reaction (PCR), a serogroup B-specific PCR assay, multiplex capsular typing system and loop-mediated isothermal amplification techniques) and characterization (restriction endonuclease analysis, randomly amplified polymorphic DNA analysis, repetitive extragenic palidromic PCR and enterobacterial repetitive intergenic consensus PCR analysis) are applied in parallel for rapid epidemiological investigations of HS outbreaks. Although several vaccine formulations including alum precipitated, oil adjuvant and multiple emulsion vaccines are commercially available, the quest for suitable broadly protective HS vaccines with long-lasting immunity is on the upsurge. Concurrently, attempts are being made to unravel the mysteries of the pathogen and its virulence factors, pathogenesis and determinants of protective immunity as well as diversity among strains of P. multocida. This review highlights the advances in these various aspects of HS.  相似文献   

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