Characterization of Pasteurella multocida isolated from rabbits in Canada.

In a survey for the somatic and capsular serotypes of Pasteurella multocida present in domestic rabbits in Canada, but mainly in Ontario, samples were obtained from research facilities, commercial rabbitries and from abattoir and necropsy specimens. Sources of isolates were upper respiratory tract infections, localized bronchopneumonias , acute fibrinous pneumonias, abscesses and otitis media. Of 59 isolates obtained, 47.0% were type 12:A, 30.5% 3:D and 12.0% were 3:A. Less common types were 12(4):A, 12:D, 4(12):A and 3:untypable. Somatic group 3 was most commonly isolated from acute pneumonic disease, while serogroup 12:A was most commonly found in upper respiratory tract infections and in localized chronic bronchopneumonia. Two serotypes of P. multocida were isolated from four pneumonic lungs collected from abattoir specimens. Most isolates were susceptible to the commonly used antibiotics.     

Identification of Pasteurella multocida Serogroup F isolates in rabbits

A total of 24 Pasteurella multocida rabbit isolates obtained from 24 rabbit flocks in the Czech Republic during the period of between 2001 and 2004 were analysed by capsular PCR typing. Apart from isolates identified as serogroups A (n = 14, 58.4%) and D (n = 2, 8.3%), eight isolates (33.3%) were identified as members of serogroup F. This serogroup had been predominantly associated with poultry infections so far. The rabbit serogroup F isolates were characterized in detail by ribotyping with restriction to endonuclease MspI revealing two distinct ribotypes. Seven serogroup F isolates were assigned to ribotype 1 and one isolate was assigned to ribotype 2.     

Evaluation of Pasteurella multocida isolated from rabbits by capsular typing, somatic serotyping, and restriction endonuclease analysis.

The goal of this study was to characterize Pasteurella multocida isolated from rabbits. Five hundred and fifty-three apparently healthy rabbits were sampled for this study. Nasal swabs were collected from each rabbit for P. multocida isolation and identification. Isolates were further characterized by capsular and somatic antigens and genomic DNA fingerprinting. Thirty-nine P. multocida isolates were recovered from 553 rabbits (7%). Capsular typing was done by depolymerization of P. multocida capsule by Staphylococcus aureus hyaluronidase and by disc diffusion with mucopolysaccharidase enzymes (heparinase III, chondroitinase AC, and hyaluronidase). Thirty-one (79%) of the isolates were capsular type A, and 8 isolates (21%) had untypable (UT) capsules. The gel-diffusion precipitin test was used to determine the somatic type of P. multocida isolates. Nineteen isolates were somatic serotype 3 (49%), 12 were serotype 1 (31%), 1 was serotype 2, 2 were serotype 5, 2 were serotype 12 with a weak reaction to antiserum raised against serotype 7 (5%), and 1 was serotype 4. Two of the isolates (5%) were UT. Restriction endonuclease analysis of the DNA of the isolates revealed 7 distinct profiles by digestion with HindIII, and 12 profiles were obtained with HpaII, whereas digestion with EcoRI did not differentiate between any of the P. multocida DNA isolates studied. The DNA restriction endonuclease enzyme HpaII was found more useful for differentiating between DNA fingerprints of P. multocida rabbit isolates. However, no correlation between capsular type, somatic serotypes, and DNA fingerprints was seen in this study.     

Prevalence and characteristics of Pasteurella multocida in commercial turkeys

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.     

PCR detection and analysis of Pasteurella multocida from the tonsils of slaughtered pigs in Vietnam

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.     

Induction of pneumonia in rabbits by use of a purified protein toxin from Pasteurella multocida.

Heat-labile toxin from a cell sonicate of a virulent type-D strain of Pasteurella multocida was purified by ammonium sulfate precipitation followed by ion exchange chromatography, gel filtration chromatography, and polyacrylamide gel electrophoresis. Toxic activity was assayed during toxin purification by cytopathic effect in Vero or bovine embryonic lung cell cultures. Toxicity for cells correlated with dermonecrosis in guinea pig skin. Toxicity was accounted for by a single protein with a molecular weight of 149,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Rabbits were inoculated intranasally with purified toxin to determine whether toxin had a role in the induction of pneumonia in rabbits infected with P multocida. Pneumonia, pleuritis, acute hepatic necrosis, and splenic lymphoid atrophy were found in 4 of 5 rabbits. One of 5 rabbits had bilateral turbinate atrophy. Western blotting with monoclonal antibodies to toxin from a P multocida isolate causing atrophic rhinitis in pigs revealed the toxin that induces pleuritis and pneumonia in rabbits to be the same or a closely related toxin.     

Capsular serogroups of Pasteurella multocida isolated from animals in Zimbabwe

Pasteurella multocida is isolated from a variety of disease conditions from different animal species in our diagnostic laboratory. In order to determine serogroup distribution among the isolates, an indirect haemagglutination test using glutaraldehyde-fixed sheep red blood cells was employed. A serological examination of 79 isolates revealed that 47/79 were of capsular serogroup A, 11/79 capsular serogroup D, 4/79 capsular serogroup B and 17/79 were untypable strains. None of the isolates belonged to either serogroup E or F. All those from cases of classical pasteurellosis could be grouped, but a significantly high proportion of those which originated from companion animals were untypable. The significance of these results is discussed. This report appears to be the first detailed information on the prevalence of various serogroups of P. multocida in animals in southern Africa.     

Random amplification of polymorphic DNA and phenotypic typing of Zimbabwean isolates of Pasteurella multocida

Eighty-one isolates presumptively identified as Pasteurella multocida from a variety of diseases in animals in Zimbabwe were subjected to biochemical characterization, capsular typing and RAPD analysis. The majority of isolates (over 80%) were assigned into named taxa and were predominantly P. multocida subsp. multocida and P. multocida subsp. septica, whilst the remainder were unassigned. Serogroup A was predominant among the three capsular types (A, B and D) of P. multocida detected. Three main RAPD clusters and three subclusters were observed among the majority of isolates (93.8%), whilst the remainder was found to be weakly related. Nine different groups of strains with similar RAPD profiles (100% similarity) were also observed. The reference strain of capsular serogroup F clustered with the reference strain of P. multocida subsp. septica, whilst all other serogroups clustered with reference strains of subsp. multocida and gallicida. Notably, serogroups A and D were observed to be closely related to the reference strain of subsp. multocida. The relationship between biotype, capsular type, host origin and disease manifestation was not clear-cut. However, most pig isolates of subsp. multocida clustered together as did most cattle isolates of subsp. multocida. RAPD tended to separate subsp. multocida from septica.     

猪多杀性巴氏杆菌的分离鉴定及生物学特性研究

用PCR方法配合生化鉴定，从有肺炎症状猪的肺脏及进行性萎缩性鼻炎(Progressive atrophic rhinitis，PAR)症状猪的鼻拭子中分离出66株多杀性巴氏杆菌(Pasteurella multocida，Pm)。然后做了药敏试验，并用PCR方法对这66株Pm进行分型及毒素基因的检测，用豚鼠皮肤坏死试验及小鼠致死试验对产毒素多杀性巴氏杆菌(Toxigenie Pasteurella multocida，T^ Pm)进一步鉴定。结果显示PCR鉴定与生化鉴定Pm结果完全一致；PCR分型表明有46株为D型Pm，18株为A型：Pm，1株为B型Pm，1株无法定型；有8株用PcR检测为T^ Pm；豚鼠皮肤坏死试验及小鼠致死试验对这8株T^ Pm的进一步鉴定也表明均为产毒素菌株。所鉴定的8株T^ Pm都为D型，都分离于有严重PAR症状的猪。     

Restriction endonuclease analysis of porcine Pasteurella multocida isolates from Quebec

We have used restriction endonuclease analysis (REA) of genomic DNA to classify porcine Pasteurella multocida isolates with similar capsular and somatic serotypes, and to monitor the distribution of isolates from 12 different herds in Quebec. Within herds, P. multocida isolates of similar capsular and somatic serotypes showed similar REA fingerprints. Between herds, some isolates had similar REA fingerprints. However, differences in REA enabled subtyping of many P. multocida isolates with the same antigen types. Our data indicate that REA would enable accurate epidemiological typing of P. multocida in conjunction with classical capsular and somatic typing.     

Characterization and comparison of antimicrobial susceptibilities and outer membrane protein and plasmid DNA profiles of Pasteurella haemolytica and certain other members of the genus Pasteurella.

The outer membrane protein (OMP), plasmid, and antimicrobial resistance profiles of Pasteurella haemolytica serotypes 1 through 12, a bovine isolate of P multocida, a chicken isolate of P multocida, and an unidentified Pasteurella species of bovine origin were examined. Isolates of P haemolytica serotypes belonging to the same biotype possessed similar OMP profiles. Biotype A isolates contained 2 prominent OMP of 43 kilodaltons (kD) and 29 kD, whereas biotype-T serotypes contained 3 major OMP of 43, 36, and 25 kD. The major OMP profiles of the 2 P multocida isolates and the unidentified Pasteurella species were different from each other and from P haemolytica isolates. Plasmid DNA screening indicated both plasmid-containing and plasmid-free P haemolytica and P multocida isolates. Multiple drug resistance was found in pasteurellae isolates with and without plasmids. However, a relationship between drug resistance and plasmid isolation was found in 3 of 4 haemolytica serotype 1 field isolates, all of which contained a 2.51-megadalton plasmid and had multiple drug resistance for benzylpenicillin, ampicillin, streptomycin, and tetracycline.     

Virulence of raptor-origin Pasteurella multocida in domestic chickens.

Pasteurella multocida belonging to somatic serotype 1 and capsular type A has been known to cause avian cholera in domestic poultry. Pasteurella multocida serotype 1 has also been isolated from raptorial birds. However, the capsular type for these raptorial isolates remains unknown. Moreover, the virulence of these raptorial isolates for domestic poultry has not been determined. The objectives of this study were to determine the capsular type of raptorial P. multocida serotype 1 isolates and to determine if these isolates were virulent for domestic chickens. Study chickens were inoculated with one of three P. multocida isolates. Isolate WESO-1 was obtained from a western screech owl (Otus kennicottii) and isolates RTHA-2 and RTHA-4 were isolated from two red-tailed hawks (Buteo jamaicensis). These isolates were given by either the oral, intravenous, or intraocular route. Control birds were given brain-heart infusion broth. The capsular serotypes of three isolates were also determined. The RTHA-2 and RTHA-4 isolates belonged to P. multocida capsular type A. The WESO-1 isolate belonged to capsular type F. Results also demonstrated that, for the isolates examined, the intraocular route did not cause mortality in chickens. There was mortality in all groups for the intravenous route. However, various mortality patterns were observed when P. multocida was given orally for the three different isolates. The RTHA-4 isolate (serotype 1:A) was the most virulent for domestic chickens. The WESO-1 isolate (serotype 1:F) was the least virulent for chickens among the raptorial isolates examined.     

Pasteurella multocida and bovine respiratory disease

Pasteurella multocida is a pathogenic Gram-negative bacterium that has been classified into three subspecies, five capsular serogroups and 16 serotypes. P. multocida serogroup A isolates are bovine nasopharyngeal commensals, bovine pathogens and common isolates from bovine respiratory disease (BRD), both enzootic calf pneumonia of young dairy calves and shipping fever of weaned, stressed beef cattle. P. multocida A:3 is the most common serotype isolated from BRD, and these isolates have limited heterogeneity based on outer membrane protein (OMP) profiles and ribotyping. Development of P. multocida-induced pneumonia is associated with environmental and stress factors such as shipping, co-mingling, and overcrowding as well as concurrent or predisposing viral or bacterial infections. Lung lesions consist of an acute to subacute bronchopneumonia that may or may not have an associated pleuritis. Numerous virulence or potential virulence factors have been described for bovine respiratory isolates including adherence and colonization factors, iron-regulated and acquisition proteins, extracellular enzymes such as neuraminidase, lipopolysaccharide, polysaccharide capsule and a variety of OMPs. Immunity of cattle against respiratory pasteurellosis is poorly understood; however, high serum antibodies to OMPs appear to be important for enhancing resistance to the bacterium. Currently available P. multocida vaccines for use in cattle are predominately traditional bacterins and a live streptomycin-dependent mutant. The field efficacy of these vaccines is not well documented in the literature.     

Characterisation and quantitation of pilus antigens of Moraxella bovis by ELISA

Hyperimmune serums raised in rabbits to purified pili from 9 Australian and 2 American strains of Moraxella bovis from infectious bovine keratoconjunctivitis (IBK) affected herds were used to study the degree of binding between combinations of antigen and antiserum in a conventional enzyme linked immunosorbent assay (ELISA). With the aid of appropriate absorption tests major antigenic differences among pili were found permitting 6 distinct serogroups to be recognised. Further, production of specific antiserums to representative strains of each serogroup in goats facilitated the development of a double antibody sandwich ELISA which could be used to quantitate pilus expression of a given strain of M. bovis, or to differentiate pilus serogroups of 22 strains of M. bovis obtained from a total of 12 Australian herds. Most isolates were found to belong to serogroups designated IV and V. One strain from the United States of America showed total homology with Australian serogroup IV while the other showed some cross-reactivity with serogroups V and VI.     

Pasteurella multocida in wild mammals and birds in California: prevalence and virulence for turkeys

Samples collected from the oropharynx of wild mammals and birds trapped on 36 turkey farms in California were evaluated for the presence of Pasteurella multocida. A total of 966 animals were collected from 18 premises that had experienced an outbreak of fowl cholera within the past 2-8 months; samples were collected from 16 of these 18 premises within 2-8 weeks of outbreak notification and while the infected flock was still present. A total of 939 animals were trapped from an additional 18 premises that had not reported any outbreaks of fowl cholera within at least 4 months, if ever. Forty-eight isolates of P. multocida, of a variety of somatic serotypes, were recovered from 6 species of mammals and 3 species of birds. On only 2 of 7 premises was the somatic serotype of the isolates obtained from wildlife the same as the isolate obtained from tissues of turkeys that had died of fowl cholera on the same premises. Tests for virulence to turkeys were conducted with 31 of the isolates. Seventeen of these isolates caused mortality in turkeys. Wide ranges in mortality rates and median times to death were observed.     

Classification of Bacteroides nodosus by agglutination tests

One thousand two hundred and sixty seven isolates of Bacteroides nodosus from 292 sheep in 58 flocks were examined. Of these, 1260 could be classified by slide agglutination into 8 serogroups designated A to H. Up to 6 serogroups were detected in individual flocks, with up to 4 serogroups being detected in a single foot. Of the 292 sheep examined, 38 (13%) carried mixed serogroup infections. Determination of the range of serological types infecting a flock frequently required the examination of a number of isolates from each of a number of sheep. Cross-tube agglutination tests carried out on 44 isolates and their antiserums indicated that members of some serogroups could be divisible into subgroups or serotypes. These results suggested that 16 or more serotypes of B. nodosus might exist. The nature of the antigens responsible for both slide and tube agglutination reactions needs to be determined.     

Characterization of nine Pasteurella multocida isolates from avian cholera outbreaks in Indonesia

Avian cholera outbreaks have been identified in Indonesia in recent years. Despite vaccination programs, outbreaks continue to occur. To date, there has been a lack of information on the characteristics of Pasteurella multocida isolates involved in these outbreaks. Hence, the objective of this study was to characterize Indonesian P. multocida isolates in poultry. During 1998-99, 20 field outbreaks were reported in Indonesia. Nine isolates of P. multocida were recovered from these field outbreaks. The isolates were compared with four vaccine strains that were used in Indonesia and designated PM-V1, PM-V2, PM-V3, and PM-V4. The isolates were characterized by biotype, capsular type, somatic serotype, restriction endonuclease analysis, plasmid presence, and antimicrobial susceptibility patterns. Of the nine Indonesian isolates, three were of capsular type A (A:1,3,13; A:1,3; and A:8). One isolate was of type B:2,3 and one isolate was of capsular type F. For three isolates, the capsular serogroup could not be identified. Plasmids the size of 2.3 kbp were present in three of the field isolates and two of the vaccine strains. One plasmid less than 2 kbp was isolated from the vaccine strain PM-V4. Eight distinct DNA profiles were obtained from digestion with the restriction endonuclease EcoRI, and seven distinct DNA profiles were obtained from digestion with the restriction endonuclease HindIII. All of the isolates were resistant to lincomycin and sulfadiazine and were susceptible to ampicillin and trimethoprim. Of the nine isolates, seven (78%) were susceptible to doxycycline and gentamicin and six (67%) were susceptible to enrofloxacin.     

Experimental study of pathogenicity of Pasteurella multocida serogroup F in rabbits

The role of Pasteurella multocida serogroup F in inducing disease in rabbits was investigated in this study. Three groups of 12 Pasteurella-free rabbits each were intranasally (i.n.), subcutaneously (s.c.), and perorally (p.o.) challenged, respectively. Six rabbits of each group were immunosuppressed using dexamethasone. Eight rabbits (four of them immunosuppressed) inoculated i.n. showed symptoms of respiratory distress resulting in respiratory failure and died or were euthanized in the terminal stage of the disease 3-6 days post-infection (p.i.). The main pathological findings were fibrinopurulent pleuropneumonia (immunocompetent rabbits) or diffuse haemorrhagic pneumonia (immunosuppressed rabbits). Septicemic syndrome ending with shock occurred in 11 rabbits (6 of them immunosuppressed) inoculated s.c., which died or were euthanized in the terminal stage of the disease 2-3 days p.i. The most significant pathological findings were extensive cutaneous and subcutaneous lesions. All of the p.o. inoculated rabbits survived the challenge showing no clinical signs of the disease and no macroscopic lesions. The observations in this study indicate that in addition to serogroups A and D of P. multocida, serogroup F also can be highly pathogenic for rabbits and therefore might be a cause of considerable economic loss in commercial rabbit production.     

Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from swine.

Twenty-nine field isolates of porcine Pasteurella multocida were characterized for their capsular and somatic types and were evaluated for their susceptibility to 10 antimicrobial agents. Plasmid DNA-screening experiments were conducted to determine whether a relationship existed between the presence of plasmids and antibiotic resistance. Field isolates of P multocida were susceptible to most of the antimicrobials tested, but all isolates were resistant to clindamycin. Eleven isolates of serogroup D were resistant to 1 or 2 antimicrobial agents. Resistance to sulfonamides and streptomycin was observed in 7 isolates. These isolates contained R plasmids conferring resistance to streptomycin and sulfonamides. The R plasmids belonged to 2 groups, one of 5.6 kilobase and the other of 5.9 kilobase. Restriction endonuclease mapping and DNA hybridization revealed that these R plasmids were related to RSF1010 from Salmonella panama, which also confers resistance to streptomycin and sulfonamides.     

Isolation of Leptospira interrogans from kidneys of Zimbabwe beef cattle.

Four hundred and eighty bovine kidneys were collected from an abattoir near Harare between December 1987 and November 1988, and leptospires were recovered from 50 (10.4 per cent) of them. The isolates were identified to serogroup level by the microscopic agglutination test; 32 belonged to serogroup Sejroe, seven were Pyogenes, four Hebdomadis, two Tarassovi, and one isolate each belonged to serogroups Australis, Bataviae, Grippotyphosa, Icterohaemorrhagiae and Pomona.