Pasteurella anatipestifer infection in turkeys

In a case of excessive mortality in seven-week-old turkeys, the primary lesion at necropsy was severe fibrinous pericarditis and epicarditis. After 48 hours of incubation at 37 C, Pasteurella anatipestifer was isolated. The infection responded to antibiotic therapy with a combination of neomycin and oxytetracycline in the drinking water. The lesions suggested chlamydial infection, but cultural procedures for chlamydia were negative.     

Pasteurella anatipestifer infection in commercial meat-type turkeys in California

A disease outbreak characterized by respiratory signs, occasional neurologic signs, and increased mortality in commercial meat turkeys from four separate companies in central California was investigated in the late summer and early fall of 1986. The disease syndrome affected turkeys from 6 to 15 weeks of age and caused a severe fibrinous pericarditis, perihepatitis, and airsacculitis. Bacteriologic and serologic examinations as well as virus- and chlamydia-isolation attempts initially failed to implicate an etiologic agent. Eventually culture attempts were made in a 5% CO2 incubator, resulting in isolation of Pasteurella anatipestifer. The disease syndrome was reproduced in young turkeys and broiler chicks inoculated with the organism.     

鹅的鸭疫里氏杆菌和大肠杆菌混合感染

鸭疫里氏杆菌(Riemerella anatipestifer, RA)可引起家鸭、火鸡和多种禽类的急性或慢性传染病,主要致2～3周龄小鸭的传染性浆膜炎.环境条件差或并发感染可加重死亡,给养鸭业造成极大的损失.一般来说,除鸭外,火鸡、鹅、雉鸡、鹌鹑以及鸡亦可感染发病,但少见.     

Spondylitis in turkeys associated with experimental Pasteurella anatipestifer infection.

Nine previously vaccinated turkeys were inoculated intravenously with Pasteurella anatipestifer, and blood samples were taken periodically to evaluate the potential of chronically infected turkeys to serve as reservoirs of infection for blood-feeding arthropod vectors. Vertebral osteomyelitis (spondylitis), as yet unreported in the literature in association with infection with the organism, was found in the thoracic vertebrae of five out of nine inoculated turkeys, and P. anatipestifer was isolated from the thoracic vertebrae of three of the five. The organism was isolated from the peripheral blood of six turkeys 24 hours postinoculation and from the peripheral blood of one turkey 7 days postinoculation. The organism was also isolated from the heart blood of two birds at necropsy--from one at 21 days and, following an intramuscular injection of dexamethasone, from the other turkey at 38 days postinoculation.     

鸭疫巴氏杆菌病的预防与治疗

鸭疫巴氏杆菌(Pasteurella anatipestifer,PA)病是家鸭、火鸡和多种禽类的一种高度接触性传染病,又称为新鸭病、鸭败血症、鸭疫综合征、传染性浆膜炎、鸭疫里雷默氏杆菌(Riemerella anatipestifer,RA)病。鸭疫巴氏杆菌病于1932年由Hendrickson J M.首次报道,我国郭玉璞等于1982年在北京首次报道,并对本病病原菌进行了分离和鉴定。     

武汉地区鸭疫巴氏杆菌的分离鉴定

２０００年３～５月,对送检于华中农业大学兽医院的病鸭进行病理剖检及细菌分离鉴定,确定送检病例５０％以上由鸭疫巴氏杆菌（ＰＡ）引起,其发病日龄为７～５０日龄。从病鸭的脑脊液、心血、肝等均易分离到ＰＡ。药敏试验显示所有菌株对氯霉素高度敏感。此次试验结果说明,在武汉地区鸭疫巴氏杆菌确已存在,并已成为严重危害当地养鸭业的重要疾病之一。     

鸭传染性浆膜炎免疫研究进展

鸭传染性浆膜炎是由鸭疫里氏杆菌(RA)又名鸭疫巴氏杆菌引起的一种严重危害雏鸭的传染病。本病呈急性败血症或慢性过程，以纤维素性心包炎、肝周炎、气囊炎、脑膜炎和干酪性输卵管炎为特征。1～8周龄雏鸭易感，恶劣环境条件可诱发此病。死亡率最高可达75％。慢性经过的鸭主要表现脑膜炎症状，即斜颈，生长缓慢成僵鸭，给养鸭业造成巨大的损失。　　药物防治是我国目前控制该病的主要措施。虽然药敏试验表明该菌对多种药物敏感，但实际防治效果并不理想；加上肉鸭在养殖全程均对该菌易感，要达到较好的治疗效果，必须反复投药，既增加了成本…     

Protection of ducklings with a broth-grown Pasteurella anatipestifer bacterin

Pasteurella anatipestifer (PA) serotypes 1, 2, and 5 grew to high densities in tryptic soy broth and tryptose broth (TB) when the media were continuously shaken or aerated. Growth in 100 ml to 15 liters of TB exceeded an absorbance of 1.0 at a wavelength of 525 nm (about 0.7 for a 1/3 dilution) and contained more than 10(10) colony-forming units per ml. A bacterin was prepared from the three serotypes of PA grown in aerated TB. Two subcutaneous injections of this bacterin protected 70% to 85% of ducklings against experimental challenge with each of the three PA serotypes, which killed 90% to 100% of unimmunized controls. The bacterin could be diluted 1/5 without decreasing protection below 80%. Field studies on Long Island duck farms in 1980 and 1981 demonstrated significant reductions in mortality with the use of the broth-grown PA bacterin.     

Laboratory assessment of protection given by experimental Pasteurella anatipestifer vaccine

An experimental, inactivated P. anatipestifer type 'G' vaccine was produced containing 10(9) CFU/0.5 ml and aluminium hydroxide adjuvant (25% final concentration). From comparative pathogenicity studies of field isolates type 'A', 'D' and 'G', the 'G' serotype was selected as being most virulent and suitable for challenge. Vaccination trials, in the laboratory, showed that a single subcutaneous inoculation (0.5 ml) of the above vaccine at 14 days provided the best protection against challenge up to 5 weeks of age. During the course of investigations, maternal antibodies were encountered in ducklings up to the age of 6 days and natural resistance to infection in adults from 5 weeks upwards. Evidence has also been provided of cross antigen-antibody reactions detected in the ELISA, between the 'A', 'D' and 'G' serotypes. A threefold 'protective index' system is described which provides a very sensitive measurement of effective vaccination.     

Detection of florfenicol resistance genes in Riemerella anatipestifer isolated from ducks and geese

The cat gene, coding for chloramphenicol acetyltransferase has been reported for conferring the chloramphenicol resistance for Riemerella anatipestifer. Chloramphenicol acetyltransferases, however, are unable to inactivate florfenicol. In this study, 66 R. anatipestifer isolates were investigated for their susceptibility to chloramphenicol and florfenicol and the presence of floR gene. Results showed nine florfenicol intermediate or resistant R. anatipestifer isolates were all floR positive. The expression of floR gene in E. coli and inhibition studies with PAβN indicated that the floR gene was as an efflux pump conferring resistance to both chloramphenicol and florfenicol. Southern hybridization revealed the floR was located in the plasmid DNA of five isolates and in the chromosomal DNA of four isolates. Furthermore, two novel floR-carrying plasmids designated pRA0726 and pRA0846 were sequenced completely. pRA0726 was 11,704 bp in size with 10 putative open reading frames which included the floR, catB and bla(OXA-209) resistance genes. The most differences between sequences of pRA0846 and pRA0726 were the absence of a bla(OXA-209) gene and the deletion of 321 nucleotides of orf1 in pRA0846. Plasmid curing tests demonstrated that pRA0726 carried functional coding proteins for resistance to phenicol and β-lactam antimicrobials. To the best of our knowledge, this is the first report of presence of the floR and bla(OXA-209) resistance genes in R. anatipestifer.     

Influence of the route of infection of Pasteurella anatipestifer on the clinical and immune responses of white Pekin ducks

The clinical, pathological and immunological responses were compared in ducklings infected by the intramuscular, oral and intranasal routes with virulent Pasteurella anatipestifer. Intramuscular challenge resulted in clinical signs of infection and caused 100 per cent mortality within three days. No disease signs or death were observed in the orally challenged ducks. Whereas intranasal inoculation caused no deaths, signs of infection were observed in two of 12 birds four days later. In the orally challenged group, low concentrations of antibodies (0.17 log2 to 4.5 log2) were detected in the tracheal washes of five of nine birds examined using an enzyme-linked immunosorbent assay. Humoral antibodies were detected in only one of these birds. In the intranasally infected group, serum antibody levels ranging in titre from 0.62 log2 to 6.2 log2 were found in four of nine birds examined over seven to 14 days following infection. Nine of the birds in this group were shown to have low concentrations of antibodies (0.50 log2 to 6.33 log2) in the tracheal washings. The demonstration of antibodies in the tracheal washings, but not in the serum of nine birds examined, suggested that a local immune response had occurred. However, these studies have shown that antibodies present on the tracheal surface can also be derived from antibodies given intraperitoneally.     

Serologic types and physiologic characteristics of 46 avian Pasteurella anatipestifer cultures

Forty-six strains of Pasteurella anatipestifer isolated from different avian species were examined to determine their serologic types and physiologic characteristics. Serologic types were determined by a gel-diffusion precipitin test. Antigens from 39 field isolates reacted with antisera prepared from seven P. anatipestifer reference strains representing serotypes 1, 2, 4, 6, and 7. Antigens from five isolates did not react and could not be typed with available reagents. Gel precipitin reactions involving serotype 1 (43.6%) and serotype 2 (25.6%) were the most prevalent. Generally, the physiologic characteristics from 40 tests were typical for P. anatipestifer, and variations were observed among the strains in urease production, hemolysin production, litmus milk reaction, and gelatin liquefaction.     

Infection of duck plague carriers with Pasteurella multocida and P. anatipestifer

Mallards (Anas platyrhynchos platyrhynchos) and white pekin ducks (Anas platyrhynchos domesticus) were infected with duck plague virus and challenged with LD20's of Pasteurella multocida and P. anatipestifer. There was no difference between mortality rates of duck plague-infected ducks and controls, suggesting that these organisms do not act synergistically under the conditions of our experiments. There was a difference of about 500-fold between the LD20 of P. multocida for mallards and that for white pekin ducks, indicating that mallards are much more susceptible to avian cholera than white pekin ducks.