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2nd International Symposium on Turkey Diseases
Berlin, 24th - 27th March 1999
This is the second meeting on turkey diseases organised at the same venue by Prof. Hafez. Unfortunately I was unable to be present for the first afternoon sessons. These are my notes made during most of the presentations, offered not as a transcript but as a "best effort" at a personal interpretation of the papers. This document is, necessarily a very poor substitute for being at the meeting. See details at the end of the document about how to get a copy of the proceedings .
If you are an author and would like to correct any errors I may have made in this text please forward the specific correction by e-mail: (mailto:email@example.com)
Thirsk, 11th July 2000
1. Fadly, A. Reticuloendotheliosis and
other related tumor virus infections in turkeys. TurkBerlin99
Keywords : virus; infections; turkeys; Chickens; disease; Birds; vaccine; PCR; elisa; epidemiology; serology; Liver; rev; Reticuloendotheliosis;
Notes : REV is an avian retrovirus which causes a stundint syndrome/immunosuppression and tumours. The tumours may be acute or lymphoretricular neoplasia (chickens and turkeys, Bursal lymphoma (like LL) in chickens. Strian T (defective) causes acute tumours while the Strain A (non-defective) causes chronic disease. It is possible to sub-type using MCA in 3 groups (Cook, SNV, and CSV - chick syncitial virus). It may be transmitted congenitally, or contact bird to bird, or accidental contamination of vaccine (not likely in turkeys). There are indications that mosquitos may be involved. Vaccine-related problems have been reported in Japan and Australia (MD-related runting syndrome) and pox vaccine in the US (Bursal RE in chickens injected at 7 days of age). Samples which may be used - blood serum plasma, egg albumen,embryos and tumours. Antibody may be detected in plasma and serum (commercial IDEXX test kit). Tests used in East Lansing lab Immuno-flourescence, virus isolation/Elisa, virus isolation/COFAR, AGP, PCR using ZDNA Antibody by AGP, ELisa, Serum neutralisation. Criteria for diagnosis: Epidemiology, pathology, virology, serology, histochemical, molecular. Gross or micrscopic lesions are not diagnostic. The epidemiology is based on the case history and age of onset (especially with respect to vaccine contaminants). Pathology Gross lesions, pathognomic lesions - tumours in heart, enlarged spleens, kidneys, caecal tonsils - diffuse lympho-reticular nodules in enlarged livers (like Marek's) Differential diagnosis - Lympho-proliferative Disease, Marek's. AGP is easy to use but if negative of little significane. Immuno-flourscense is a very good option. PCR can provide a specific diagnosis (identification by southern blotting). In the US lymphomas were common in the 60's and early 70's but is now rare. The pattern in breeders is similar except for a peak in late 80's related to 1 company in Pennsylvania. Most of the information on this disease is based on experimental studies. In turkeys it is usually mild. The tumours may be confused with LPD and Marek's disease. Eradication may be progressed if required using LL-type techniques ("might work"). There are no commercially available vaccines at possible though the knowledge is now available to develop one if required.
Ref Number : 169
2. Hafez, H.M. Serologic surveillance of reticuloendotheliosis in meat turkey flocks. TurkBerlin99 1999.
Keywords : Reticuloendotheliosis; Meat; turkey; chicken; turkeys; Ducks; Quail; Incidence; Birds; infections; vaccine; serology;
Notes : The clinical signs are inappetance, stunting and tumours. The host range includes chicken, turkeys, ducks, quail. Antibodies persist for a variable period. The incidence of seropositive bird varies widely. Pooling of samples for testing is not recommended. This survey referred to BUT Big-6 from 5 commercial flocks - 20 birds per flock were tested at 2-4 weeks from 2 weeks to slaughter. A further 345 samples were collected from 18 other flocksw. The test used was IDEXX commercial kit. In the survey flocks 4/5 were negative. In one commercial breeder flocks 3 samples were positive at 1 day and again at 16 weeks - other samples all negative. Of the commercial flocks 5/18 were positive, the % positive varied between 10 and 40%, the highest incidence was found at 16 weeks. The questions raised: 1 what do these reactions mean 2. are these reactions specific 3. What are the effects of this infection on other vaccine responses.
Ref Number : 170
3. Panshin, A., Shihmanter, ,E., Weisman, Y. and Lipkind, M. The influence of antigenic cross reactivitiy between different serotypes of avian paramyxoviruses on their serological diagnostics; The way to overcome this obstacle. TurkBerlin99 1999.
Keywords : elisa; assay; infections; PMV;
Notes : There are reports of corss-reactivity between different paramyxoviruses e.g. 1 and 3 by Elisa and HI and NI, 1 against 3,4, and 9 etc. Different mono-clonals can show varying specificity - for some antigens there is full binding, with others it is partical. 2 methods were found to eliminate cross-readctivity: 1. treat sera with NDV to absorb cross-reacting PMV-a antibody 2. treatment of the anti-PMVV-3 hyperimmune serum with purified NDV then use in a competitive biotin-labeled assay Both methods allow the differentiation of dual PMV-1/PMV-3 infection from pure PMV-3 infection.
Ref Number : 171
4. Hess, M., Havez, H.M., Prusas, C. and Cavanagh, D. Characterisation of avian pneumovirus German isolates using nested PCR. TurkBerlin99 1999.
Keywords : pneumovirus; PCR; virus; Human; turkey; chicken; TypingPCR;
Notes : Classification of TRT virus is family paramyxoviridae, sub fam pneumovirinae. A new genus has been created recently metapneumovirus ti distinguish from human viruses. Strain variation is definable through monoclonal and polyclonal antibody and this was confirmed by nucleic acid sequencing. The recent isolate from Colorado is different from either of the previous types (designated C or CO). R values for cross-neutralisation suggests that UK and German turkey isolates are similar, French turkey and chicken isolates are also similar. UK isolates prior to 1993 were all type A, isolates in 1994/1995 were B. Continantal Europe isolates have been mainly B. This work was done with the G gene (attachment protein). Different oligos are used for the 2 sub-types - the size of the product tells us the type A = 250 BP, B is 350 or so. The results suggest that isolates in germany in 1986-91 were predominantly subtype A. Turkey isolates were mainly type A, French and chicken isolates were B. The C isolate in the US is reported to vary by 10-15% in the structure of the matrix protein.
Ref Number : 172
5. Jones, R.C. and Khehra, R.S. Local and systemic class-specific antibody responses to avian pneumoviruses: Comparison of chicken and turkey. TurkBerlin99 1999.
Keywords : chicken; turkey; Birds; T cells; virus; IgG; elisa; control; disease;
Notes : Maternal antibody is not effective in protecting. Humoral antibodies correlate poorly with protection (e.g. vaccinated birds without antibody are often immune). T cells help virus clearance and recovery. What is the role of local antibodies (iGA and iGG). Use maternal-antibody free 2 week old chicks and poults. A turkey-derived virulent strain was used in comparson to attenuated virus. The initial priming was by eye-drop at 2.5 logs then virulent challenge 2 weeks later. Observations - clinical csores 0-3, virus isolation and titration from HG, turbinates, trachea in TOC(VS) or Vero cells (AS) 3. APV class-specific elisas using chicken ig MAPVS. Chicks Clinical signs marked in VS peaking at 6 days, none with AS. The virulent strain could be reisolated not the AS. IgA marked in tears of VS birds, little or none in controls, little present in trachea or serum. IgG in tears was very similar to IgA, but there was a good response to VS in serum. After challenge AS birds only slightly less than controls - VS primed birds showed total protection. Virus titre in turbinates closely matched the clinical signs. There was a marked boost in IgA and IgG in VS birds tears but AS was similar to controls. VN was used to confirm that these antibodies are active - similar pattern of titres to Elisa. Serum showed similar pattern to local antibodies. Poults Clinical signs similar to chicks. Virus was readily identified in harderian glands up to 7 days, not AS. However the AS produced marked response of IgA and IgG in tears and also in serum (intermediated between VS and COntrols). Both VS and AS protected against clinical disease. Anamnestic response was visible in local iGA and IgG and in serum levels, always intermediate between VS and controls. Summary: At the dose use the chick and poult respond differently, attenuated virus is effective in the poult not the chick. At higher doses AV is effective in chicks (other experiments). Antibodies to APV in tears have virus neutralising activity. Tears were collected with a few crystals of salt then collection with a pipette. This may provide a better correlation with protection than serum antibody.
Ref Number : 173
6. Cook, J. TRT Vaccination, yesterday, today and tomorrow. TurkBerlin99 1999.
Keywords : infections; Antibiotics; bacteria; management; control; vaccine; turkeys; elisa; Chickens; Birds; production; immunity; virus; typing; pneumovirus; TRT;
Notes : When TRT appeared no treatment was effective for primary infection, but antibiotics were used to treat secondary bacteria. Improved management is vital for the control. Controlled exposure was found to be effective. An inactivated vaccine on its own was not effective. By the late 80's the first live attenuated vaccine was launched (Turkadin - Houghton/Pitman-Moore). One fo the first respiratory vaccines in turkeys - application was crucial - licensed only from 7 days on. It was effective but vaccine reactions occurred. By the late 80's the causal agent was identified, management imporved and a first attentuated vaccine was in use - Serological tests were being developed. Early French work indicated that the early test kit was poor in sensitivity - confirmed in Germany. TRT today Vaccination is widely practiced and different vaccines are available. Various Elisa test kits are available and are improving. A new type has been found in the US. The 2 sub-groups are differentiatable on mono-clonals and sequencign. Serum-neutralization suggests that the Colorado strain is radically different. Williams et al did work on vaccine development in Liverpool. TOC passage does not attenuate - severe reactions good protection CEF28 is well attenuated but does not protect VERO17 is attenuated and protective. It seems likely that it is the cycles of attenuation rather than the route ((CEF/VERO) in this. Vaccine availability varies markedly around Europe. Aviffa is available in most European countries as is NObilits. Poulvac and Nemovac are only available in UK (Nemovac only licensed for chickens). Of inactivated TUR3 and Nobicac are abailable in most countries - none are licensed in Belgium. Methods of vaccination is highly variable : For vaccination of healthy, susceptible immunocompetent turkeys. UK from day old by spray or eyedrop. Germany spray at day old one or more revaccinations in drinking water. Hatchery or day-old on farm application is practices in the UK, careful application is essential - preferably leaving birds in boxes. Ensure all birds vaccinated at same time. There may be cycling of vaccine and rolling infections. Early vaccination essential because maternal antibody is not protective (though clinical scores may be reduced). There is no doubt that TRT vaccination of growing turkeys is beneficial. Challenge studies show very good cross-protection between A and B groups. Both A and B sub-group vaccines seem to protect against Colorado strain. Inactivated vaccines protect against egg production drops but live priming is important. Where live vaccines are not available the inactivated may still be helpful. Our understanding of the mechanisms of immunity (see Jones paper in this meeting and other publications). TRT Tomorrow: Needs Improved serological tests and improved virus detection methods. The perfect vaccine is a goal. Interactions and secondary infections - Use of PCRF in Diagnosis - dried oesophageal swabs are suitable - it detects nucleic acid, not wild virus - but it does tend to be well correlated with virus isolation in experimental studies. It may help differentiate field and vaccinal virus. The objective should be good protection without reaction. A fowl-pox contruct innoculated twice by wing web has produced some protection. Much has been achieved - agent identification, virus typing, pathogenesis understood, safe and effective vaccines and good cross protection. We need improved tests and vaccines/application and better understanding of epizootiology.
Ref Number : 174
7. Nagaraja, K.V., Sprenger, S.J., Back, A., Shaw, D.P. and Halvorson, D.A. Ornithobacterium rhinotracheale as a primary pathogen of respiratory disease in turkey. TurkBerlin99 1999.
Keywords : Ornithobacterium; Ornithobacterium rhinotracheale; disease; turkey; turkeys; Chickens; Birds; growth; production; culture; feed;
Notes : First isolated in 1993, in US in 1995 - associated with an emerging respiratory disease, mainly in turkeys, some in chickens. Mostly in market-age birds, coughing even of blood. Associated with mortality, growth suppression, decreased egg production. There is severe necrotizing fibrino-purulent pneumonia. It has been found in Germany, South Africa, Netherlands, UK, US etc. When 1995 outbreak occurred it was associated with increased condemnations from pneumonia and septicaemia - but Or also isolated to asymptomatic birds. The litereature suggests that it may be a primary or secondary opportunistic pathogen. Attempts to reproduce field associated lesions have not been successful. Prior exposure to Bordetella avious, association with ND also possible. This paper reports an attempt to reproduce the disease. The Or was isolated in pure culture form pneumonic lung. A 10% suspension was made in PBS, filtered through sterile gauze, count 2.3 x 10^8 cfU/ml. 22-week old commercial turkeys which were negative for antibodies and culture for Or were infected with either pure culture, lung homogenate or saline, either aerosol or by the intra-tracheal route. 24 pi in IT group were depressed, coughing with decreased feed intake. By 48 pi they were coughing with bloody mucus and died within 72 hours PM lungs red wet heavy and failed to collapsed - also fibrinous pleurisy. Sometimes bilateral, sometimes unilateral. Pericarditis was also seen. In every case it was possible to reisolate the organism Lesions from aerosol exposure were much milder. Clinical disease similar to that in the field was reproduced. Or can be a primary pathogen!
Ref Number : 175
8. Korbel, R., Jakoby, J.R., Kosters, J. and Hafez, H.M. Ocular symptoms of Ornithobacterium rhinotracheale infections in turkeys. TurkBerlin99 1999.
Keywords : Ornithobacterium; infections; turkeys; Birds; disease; Opthalmology;
Notes : O.r. a pastuerella-like organism is a ploymorphic gram-negative rod which may be found in birds of various species. It may be isolated from various tissues, usually after 2 weeks of age. This refers to s flock of tukreksy at 12-17 weeks originating in Italy. Various signs, arthritis etc were seen. It was M.m. seropostive and O.r. 70% seropositive (M.g. and M.s. negative) Use an avian ocular examination procedure using a monocular indirect opthalmoscope. Tonometry was performed using Tono-Pen XL. Signs were mild conjunctivits, frothy secretion into palpebral fissue, increased motility of lids, blepharospasm, photphobia, anterior uveitis and hypotension in globe (<12 mmHg) up to day 3 after infection. Later on relative glaucoma occurs (>22 mm). Sev ere blepharitis occurred. At 7-14 days theres is mixed superficial and deep keratitis, corneal ulcers, superficial and deep corneal ulceration. Afte 14 days there was anterior uveitis with depigmentation of iris and resultant glaucoma. Bacterial infection not solely responsible for the ocular discharge. Opthalmology is a diagnostic tool for detection of systemic disease. Eye lesions were present in only 1-2% of the flock.
Ref Number : 176
9. Back, A., Halvorson, D.A. and Nagaraja, K.V. Development and evaluation of a polyvalent serum plate agglutination test in the detection of O.r. infection in turkeys. TurkBerlin99 1999.
Keywords : infections; turkeys; Ornithobacterium; Ornithobacterium rhinotracheale; disease; turkey; Agar; density; Sensitivity and Specificity; Birds; serum agglutination; serology;
Notes : Isolateions from early 80's to early 90's in various countries, named in 1994 as Ornithobacterium rhinotracheale by Vandamme et al. Pleomorphism is very characteristic of the organism. On EM it appears to have a capsule. It causes mainly a respiratory disease resulting in lung lesions (fibrinopurulent pneumonia). In US it is mainly market age turkeys. Procedure - turkey isolate, serotype A, grown on blood agar with 5% sheep blood, adjust density by serial dilution with known positive serum. Sensitivity and specificity 100% for birds after 0.5 x 10^9 cfu artificial infection. Subsequently tested 108 flocks (14 negative rest positive) - 100% sensitivity and specificity. With artificial exposure at 5 weeks flocks sero-convert at 7 weeks, 9 weeks of age 1/15 positive, and at 12 weeks of age all negative. In breeders demonstrated sero-conversion 28 weeks all negative (clinical signs, bact positive), 30 weeks 50% seropositive and by 32 weeks only 1/25 positive. Serotypes A-I at least many of which are present in the US. Currently use A,C,E,I, to provide a broad spectrum of sensitivity. This test has now been used extensively and has benefits in serological surveillance.
Ref Number : 177
10. Atoussa, M., Sting, R. and Hafez, H.M. Comparison of a self-made Elisa with one commercial Elisa for detection of antibodies against different O.r. serotypes. TurkBerlin99 1999.
Keywords : elisa; Chickens; ORT; Biochek; Self-made;
Notes : This study used antisera prepared in 4 weeks old chickens given by IN, IO and IM at 10^7 CFU - boosted similarily 2 weeks later. The test used a commercial ORT test kit (Biochek). Anntigen for own test was grown on 10% sheep blood aagar for 48 hours, cells harvested, washed, suspended in 1 M tris buffer, inactivated dialysed with coating buffer etc There were a number of differences between the 2 Elisa methods. Both tests were capable of detecting antibodies raised against each of the strains. Titres were generally higher for the self-made Elisa. A collection of 396 samples were collectedfrom commercial flocks - results were similar for both tests on a flock basis (84% correlation. On an individual sample basis the correlation was poorer (correlation 64%). There were more suspects in the commercial Elisa but many were positive on the self-made. The reason for the variation may be related to the strain of antigen, antigen preparation or the wide suspect zone in the commerical Elisa. In suspect circumstance it is best to retest in the same lab rather than splitting samples and sending to different laboratories.
Ref Number : 178
11. Hafez, H.M., Jodas, S. and Stadler, A. Efficacy of O.r. inactivated vaccine in commercial turkeys under field conditions. TurkBerlin99 1999.
Keywords : vaccine; turkeys; control; infections; disinfection; Self-made; TRT; Male; Female; Ornithobacterium;
Notes : Control options : Hygiene, Vaccine O.r. is highly sensitive to organic acid and formalin. In multi-age rearing system the infection circulates in spite of routine disinfection measures. The intrdoction of infection is difficult to prevent. The sensitivity of O.r. strains is highly variable but both amoxycillin and tetracycline have a beneficial effect. Field response is often poor. This study examines the efficacy of experimenatl mono and trivalent bacterins. The first trial was with a monovalent A in aqueous adjuvant, the 2nd with trivalent ACD. The studies were split ouse. Vaccination was at 7 and 10 weeks of age. A good serological response was demonstrated with the self-made test kit. The unvaccinated flock sero-converted to TRT at 12-16 weeks. Mortality was substantially reduced (halved in males and females) condemnations were slightly reduced. In trial 2 3 control houses 3 vaccinated. Vaccinated s.c. at day old and 3 weeks. Antibody response occurred only after 2nd injection and was only moderate - the controls sero-converted probably from field challenge. Again TRT and PMV1 titres tended to be higher in the teen weeks in controls. In this trial there was not a benefit in terms of mortality. There are many unanswered questions : Could oil adjuvant strains work better? What about attenuated live vaccines Why doees TRT seroconversion tend to occur in controls and NDV in the vaccinates? Van Impel contributed that oil-based vaccine is more effective, but it is difficult to find strains suitable as live vaccines. Nagaraja reported that US producers have used early exposure to low dose O.r.
Ref Number : 179
12. Bradbury, J. Turkey Mycoplasmas revisited. TurkBerlin99 1999.
Keywords : turkey; Mycoplasma; turkeys; economics; production; leg problems; growth; infections; vaccine; control; chicken; Ducks; Geese; Quail; Pigeons; Birds; Feathers; elisa; culture; typing; antimicrobial; epidemiology;
Notes : At least 9 mycoplasmas can infect turkeys but only M.g., M.s., M.m. and M.i. are of economic significance. The first report of an avian mycoplasma was from turkeys in England in 1905 (Dodds) In 60's/70's the primary breeders progressed eradication of M.g., M.s. and M.m. In 80's/90's M.i. eradication ongoing. In late 90's there have been increasing breaks of the classical mycoplasmas. M.g. typically sinusitis, also airsacculitis, reduced weight gain and hatchability and egg production (possible CNS involvement). M.s.associated with leg problems, synovitis, possible sinusitis, sternal bursitis. M.m. reduced hatchability and growth rate, condemnations, leg problems such as TS65. Occasionally produces wry-necks. M.i. cause embryo mortality, possibly airsacculitis and skeletal defects (not often seen in the field. Mixed infections can be important - syntergism demonstrated: Mg/Ecoli, Mg/Influenza,Mg/TRTV,Mm/Ecoli,Mm/Ms (sinusitis), Mm/Mi (airsacculitis). In liverpool failed to demonstrate synergism Ms/TRTV, Ms/reovirus, Mm/TRTV, Mi/TRTV There is evidence that turkey mycoplasmas can cause a transient immunosuppression Mg - response to TRTV, Mm - response to inactivated vaccine, M.i.- delayed HA response to SRBC's Why are mycplasmas still a problem? Mycoplasmas should be easy to control because: A. primary breeding flock is free but there are reservoirs of infection (Ms) especially on continuous production sites - perhaps live vaccines may help replace these. However vaccines are not available for turkeys yet and the F strain is actually virulent for turkeys. B.restricted host range M.g. chicken duck turkey geese pheasant quail partridge guinea-fowl pigeon parrot, feafowl, house and goldfinches, peregrine falcon, crow? M.s. chicken turkey duck goose pheasant quail, partridge, guineafowl pigeon house sparrows M.m. turkeys and raptors M.i. chicken turkey wild and exotic birds C. spread requires close contact? In general this is true - some circumstantial evidence of aerosol spread esp M.s. It has been demonstrated by M.hyopneumoniae. AI a special hazard in turkeys. D.short survival outside host? This is truen for M.g. it has been shown to be 2-4 days for many materials (best on feathers and cotton). It also survives on on hair. Survived in nasal passages for 1 day. E. readily killed by disinfectants? probably yes if properly applied F. Range of diagnostic tests False positives in RPA's and false negatives with some specific strains and batch-to-batch variation in antigens. Commercial Elisa kits have improved and they tend to suffer similar problems to RPA's HI tests are technically demanding and strain-specific. Does antigenic variation affect the accuracy of these tests. All mycoplasmas have demonstrated the ability to vary surface antigens (epitopes switched on/of and varying in size). This may explain the chronic nature of infection but it also happens in vitro so could affect diagnostics. Culture is still the gold standard - we need isolates for strain typing and sensitivity testing. No standard for molecular typing yet but various being investigated. PCR's are generally more sensitive than culture. The commercial M.s. kit appears to be less reliable than culture - at least when negative (excessive load?) G. susceptible to antimicrobials Though the cornerstone of eradication schemes but unlikely to eliminate infection. Little recent work. There is a wide range of MIC's found within a dincle flock and single bird infected with Mm and Mi (Levisohn, 1998). Mycoplasma may evade treatment by becoming intracellular. Currently there is an industry-funded study on the epidemiology of break-down of mycoplasma infection. Better understanding of epidemiology should improve control. Better diagnostic techniques are also required.
Ref Number : 180
13. Szolgyenyi, W. Fluorescence in situ hybridisation method for the diagnosis of avian mycoplasmosis. TurkBerlin99 1999.
Keywords : In-situ hybridisation; disease; PCR; fish;
Notes : FISH is used for diagnosis of chromosomal abnormalities and infectious diseases. Its advantages as opposed to PCR No contamination problems by amplified products No inhibitory effects (Phenol, SDS, Hb) Speed (1 day) but at present more expensive than PCR Sample is prepared on micoscope slides and fixed A number of stages are gone through and the slides are finally read using a fluorescent microscope.
Ref Number : 181
14. Wilding, P. The use of Elisa kits in turkeys - Some observations. TurkBerlin99 1999.
Keywords : elisa; turkeys; serology; epidemiology; rev; chicken; turkey; Chickens;
Notes : There are varying reasons for using serology, export regulation, customer assurance, diagnosis, epidemiology, eradication programmes, vaccination monitoring. For test validation initial numbers required are 300 positive and 1000 negative (OIE standards). In practice tests may be validated by following known infected flocks over time, comparing with another test or gold standard. In the REV test validation there were similar for chicken and turkey conjugates., depending on the test system it si sometimes higher for homologous conjugate sometimes higher. On the other hand if a kit is marketed only for chickens the response in turkeys may be very different. Ongoing test validation is required and should be a core product of veterinary diagnostic laboratories. The author believes that data available in laboratories would be most useful for this purpose. Specificity is a major issue for many Elisa's. Moving the cut-off point up in many kits would be appropriate and would not affect the basic usefulness of the kits. There are technical problems relating to the technology if the same kit/dilution is expected to detect both very low level antibody and that from a hyper-immunisation programme. Repeatability issues are also significant. The balance of sensitivity/specificity and repeatibility will vary according to the actual objective of the test.There is an urgent need to imptove the liaison between manufacturers and users. r results fiwth
Ref Number : 182
15. Raue, R., Hafez, H.M. and Hess, M. Rapid diagnosis of haemorrhagic enteritis virus by PCR. TurkBerlin99 1999.
Keywords : enteritis; virus; PCR; Chickens; elisa; turkeys; Haemorrhagic enteritis; adenovirus;
Notes : Adenoviridae divided in 2 general - mammalian and avian. Avian is divided in 3 groups - classical, HEV/MSDV/avian splenomegaly virus of chickens, and group 3 EDS. Diagnostic methods Isolation - difficult excpe in MDTC-RP19 Electron micrscopy possible but poorly sensitive AGP and Elisa are most commonly used. For PCR the key decision relates to the choice of the primers. The genome size decreases with the group number (EDS Shortest).
Ref Number : 183
16. Fulton, R.M. Pathologic chaqracterisation of a unique strain of E.coli causing septicaemia in 2-week-old turkeys and its implication to turkey growers. TurkBerlin99 1999.
Keywords : E.coli; turkeys; turkey; DNA Fingerprinting; Heat; culture; control; Birds; Liver; pneumonia;
Notes : In investigating polyserositis in 2 week old turkeys E.coli isolates were found which were untypable using conventional methods. Isolates were submitted to Ames for DNA fingerprinting - many different strains were found. One particular fingerprint type was found on 2 company farms and one independent farm. These 3 farms were supplied by the same hatchery. The isolate was negative for heat stable and labile enterotoxins but was cytopathogenic on cell culture. The project was to establish its pathogenicity and its combination with HE. 4 week old turkeys were used. 100 day-old turkeys were reared in isolation then transferred to isolators. They were infected orally, IT or IV with 5 x 10^8 in BHI broth. The control birds got broth only. After euthanasia liver culture was practiced. Polyserositis was observed, as well as necrotising hepatitis (only in the O78 inoculated ) and splenomegaly. Clinical signs peaked at 24 hours as did mortality. Splenomegaly persisted for up to a week especially in IV groups. Bacteriology paralleled lesions but was negative from 72 hours. Pneumonia only occurred by the IT route, hepatitis was only IV O78. The new strain caused more sickness and mortality. A common source such as a hatchery can cause problems on different farms. E.coli septicaemia can occur via respiratory tract, especially when pneumonia is seen. Splenomegaly may indicate previous septicaemia even if culture is negative.
Ref Number : 184
17. Van de Zande, S., Nauwynck, H. and Pensaert, M. Effect of avian pneumovirus on the outcome of an E.coli infection in turkeys. TurkBerlin99 1999.
Keywords : pneumovirus; E.coli; infections; turkeys; management; disease; Birds; Liver;
Notes : It is recognised that many factors such as environmental conditions, and management affect outcome of APV infection in turkeys. This work looks at the complicating role of E.coli. This attempts to reproduce the disease seen in the field using intra-nasal infection routes. It also compares SPF and field turkeys. Innoculations were: APV belisian strain 4.4. TCID E.coli Inoculated APV at 2 weeks, then E.coli at 3,5,7, days. Individual birds were killed at intervals after second inoculation. Clinical signs were scored Samples of turbinates, trachea, lungs and liver collected for viral titration and bacterial titration. Samples negative for E.coli on direct examination were enriched overnight on BHI. In SPF birds E.coli had no effect alone on clinical signs. Marked synergy occurred when E.coli was administered 3 days after APV infection. When the E.coli was administered at 5 and 7 days extension of clinical signs was the main effect. In conventional birds the same effect was seen though the scores were generally lower because they were inoculated at 3 weeks rather than 2. There were no differences in viral isolation between single and dual infected birds. E.coli in single-infected groups cleared rapidly - only present at 1.5 days p.i. - in dual infected groups it persisted in the nasal cavity for the full duration, there were also isolates from trachea and lungs but less severe.
Ref Number : 185
18. Escalante-Ochoa, C., Ducatelle, R. and Haesebrouck, F. Turkey chlamydia psittaci: New insights in the interaction with host cell and possible consequenced for future control measures. TurkBerlin99 1999.
Keywords : turkey; control; Antibiotics; Temperature; Chlamydia psittaci;
Notes : P.psittaci is an obligate intracellular organism for the purposes of multiplication. Its intracellular location makes it less susceptible to antibiotics and the immune system. The objectives of this study were to characterise the internalisation pathway in fibroblast and epithelial cells and to determine the participation of the cytoskeletal components in the development of C.psittaci. The organisms microfilaments were manipulated with drug and temperature, as was the involvement of kinesin in the receptor-mediated endocytosis. The results suggest that the mechanism of endocytosis is primarily phagocytosis for fibroblasts but receptor-mediated for epithelial cells
Ref Number : 186
19. Irion, T. Diagnosis of turkey coccidiosis: clinical signs and lesion scoring. TurkBerlin99 1999.
Keywords : turkey; disease; production; Chickens; eimeria; Coccidiosis; Scoring;
Notes : In the clinical disease clinical signs are obvious, for sub-clinical disease there may be no warning of the effect on production parameters. Faecal oocyst counts and lesion scores may be of benefit. The diagnosis is more difficult than for chickens. The main pathogens are adenoides (caecal) and meleagrimitis (intestinal) - the remaining strains are rare in Europe
Ref Number : 187
20. Schroeter, A., Rabsch, W. and Helmuth, R. The current situation on Salmonella in turkey. TurkBerlin99 1999.
Keywords : Salmonella; turkey; Animal; feed; environment; poultry; layers; turkeys; Ducks; DT104; Antibiotics; resistance; Meat;
Notes : 7000 isolates/ year, 56% animals, 21% food, 5% feed and 16% environment. Poultry 630 isolates, 46 from layers, 31% turkeys, 13% ducks, 4% goose and 6% others. Dominant turkey serovar 76 heidelberg, S.t. 21 isolates, Saint paul 13, Hadar 18 - no change from previous years. 60% of DT104 are resistant to at least 5 antibiotics - CTASS. 70% of turkey isolates are resistant to at least one antibiotic. In 1998 24 resistant isolates in 1998 - % resistance is higher in turkey isolates similar levels in meat and turkeys. Percentage of multi-resistant strains high.
Ref Number : 188
21. Wray, C., Davies, R., Helmuth, R. and Jones, Y.E. Further studies on antimicrobial resistance in salmonella isolated from turkey. TurkBerlin99 1999.
Keywords : antimicrobial; resistance; Salmonella; turkey; DT104;
Notes : This reports an update on the information presented at the same meeting last year. This includes the first 6 months of 1998 - now testing only the first isolate from each farm - 200 isolates/year. 80% of isolates show resistance to 1 or more antimicrobials. Salmonella non-S.t. NALR about 24%-compares with 3-9% in other species - it is mostly newport. Non-104 S.t is nearly always resistant to NAL, DT104 currently showing 70-80% positive. Also included Salmonella in US - statistically based but only 8-14% depending on the type.
Ref Number : 189
22. Jodas, S., Stadler, A. and Hafez, H.M. Sureveillance on antimicrobial resistance in E.coli and Salmonella isolates for meat turkey between 1993 and 1998. TurkBerlin99 1999.
Keywords : antimicrobial; resistance; E.coli; Salmonella; Meat; turkey; transposons; turkeys; disease; Agar;
Notes : Resistance genese may be chromosomal (non-transmissable) or transmissible (integrons, transposons, plasmids). Development of resistance is influenced by many factors - product, period of exposure and species. Recent UK data suggested that turkeys are a special issue. Disk methods are widely use however the methodology varies. Comparison of results within the same laboratory is most advisable. 966 clinical E.coli isolates about 85% with respiratory disease - remainder enteric. Test using Sensitest agar and disks - NEO TET 30 mcg, ENR 5, Chloranp/FD 15 mcg. Tet 80%, ENR averages 20%, Neomycin and furazolidone with downward trend.. For Salmoella (small sample size) - only 4% enr resistant. Resistance profile of E.coli differs from that in Salmonella strains. Results similar in Netherlands
Ref Number : 190
23. Rukaberle, E., Sting, R. and Hafez, H.M. Studies on the efficacy of disinfection of turkey houses and slaughter house to combat foodborne pathogens. TurkBerlin99 1999.
Keywords : disinfection; turkey; Meat; dust; Salmonella; Campylobacter; infections;
Notes : Studies on 10 meat turkey farms. Samples taken 1-2 weeks prior to slaughter, before cleaning and disinfection and aftercleaning. Samples included dust, curtains, feeding and water systems etc. At the slaughterhouse 36 samples were collected during slaughter and further after cleaning/disinfection. Farm System based on manual removal of litter, washing with hot water and disinfection. Slaughter house similar foaming daily with 2% of active chlorine and periodically 2% ? acid followed by rinsing. Swabs aimed to sample half of a square metre. Salmonella system - BPW then RV then BG+ Samples were also tested for Campylobacter. Campylobacter was present in 70% before slaughter - no Salmonella or VETEC. At slaughter only 1 farm was still Campylobacter positive. Before cleaning and disinfection Salmonella was on 3, Campylobacter on 8. After cleaning and disinfection only 1 farm still was positive for Salmonella. Campylobacter was common in the processing plant (9/12) - after cleaning and disinfection no Salmonella or disinfection positive. Currently Campylobacter is the commonest food-borne infection on turkey farms.
Enquries relating to proceedings and future meetings:
Prof. Dr. H. M. Hafez
Institute for Poultry Diseases,
Free University, Berlin, Koserstr. 21, 14195 Berlin, Germany
Tel +49 30 83853862
Fax +49 30 83855824
E.-mail : firstname.lastname@example.org