Oral and Poster Abstracts

was to evaluate, by serology, prevalence of Coxiella burnetii infection
in herds of Caltanissetta district. 124 of 289 herds were selected, with
stratified random sampling, distributed in four parts of Caltanissetta
district. Particularly 71 herds were chosen from Caltanissetta territory,
9 from Gela, 29 from Mussomeli and 15 from San Cataldo. 1711 sera
were collected to test the presence of specific antibodies to C. burnetii.
Sera were tested by a commercial available ELISA (Chekit Q-fever;
IDEXX Laboratoires). Results showed serological positivity in 60/124
(48,4%) herds with 118 positive sera/1711 (6,9%).
727 Apparent Prevalence of Antibodies to Coxiella burnetii (Q
Fever) in Bulk Tank Milk of Dairy Herds in the Walloon
Region of Belgium
G. Czaplicki 1 , J. Houtain 1 , C. Manteca 2 , C. Saegerman 3
1
ARSIA, Diagnostic Center for Animal Diseases, Loncin, Belgium
2
CEVA santé Animale, Diagnostic Center for Animal Diseases,
Libourne, France
3
University of Liege - Faculty of Veterinary Medicine, Epidemiology
and Risk Analysis applied to Veterinary sciences, Faculty of, Liege,
Belgium
Objectives: Q Fever is a zoonotic disease caused by Coxiella burnetii,
an obligate intracellular bacteria. Ruminants (sheep, goats and cattle)
remain the major natural reservoir for human infection. The aim of the
present study was on the one hand, to evaluate the apparent prevalence
in the Walloon dairy herds and on the other hand, to identify herd level
risk factors and clinical signs statistically associated with seropositivity
in the population of randomly selected Walloon dairy cattle.
Material and methods: 566 herds were randomly selected according to a
classical methodology (Jenicek and Cléroux, 1987). Herd level predictors
data were collected from a questionnaire on farm demographics,
management practices and observed clinical signs during the twelve last
months. Two hundred and six farms responded on a voluntary basis to this
questionnaire and submitted a sample of bulk tank milk sampled in
February 2006. Bulk milks were centrifuged and stored at 20°C until
testing for antibodies to Coxiella burnetii with a commercial Indirect Elisa
test (LSI). Apparent prevalence was estimated with a ninety-five percent
confidence intervals (95% CI) assuming a binomial exact distribution.
Statistical analysis of the data was done using a chi square test and the
tendency of each parameter to become a risk factor was evaluated by an
odds ratio calculation with 95% confidence intervals (logarithmic
approximation); a P value < 0.05 was considered significant.
Results: Global apparent prevalence: 54.9 % (95% CI : 47.8-61.8%) of
herds show serological evidence of Coxiella burnetii infection. Clinical
signs as abortion in heifers and in cows, stillborn or weak calves are
statistically associated with seropositivity. Risk factors associated with
seropositivity are free stalling and watering with well water while
blocked stalling, watering with tap water and disinfection of sheds act
as protectors of infection.
Conclusions: This first report on Q Fever infection prevalence in
Walloon dairy herds indicates a quite high level of infection. Seropositivity
at herd level does not mean shedding of Coxiella burnetii, but
identifies herds where at least 10% of lactating animals are sero-positive
to C. burnetii. A significant association exists between sero-positivity
and typical clinical signs of Q Fever observed in those herds. Some risk
factors and some protectors are identified on a statistical basis.
Key words: bovine, Q Fever, serology, prevalence
728 Identification of Bovine Viral Diarrhoea Virus
Mimotopes/Epitopes through Selection from a Peptide 12-mer
Phage Display Library
A. Zamit 1 , M. Ostrowski 2 , N. Fondevila 1 , O. Lopez 3 , A. Bratanich 4 ,
S. Romera 1
1
Instituto Nacional de Tecnología Agropecuaria-INTA, BUENOS
AIRES, Argentina
2
Institut Curie, Paris, France
3
Northern Michigan University, Marquette, United States
4
Facultad de Cs Veterinarias-UBA, BUENOS AIRES, Argentina
Bovine Viral Diarrhoea Virus (BVDV) is a worldwide distributed
pestivirus that causes important economical losses to cattle industry.
Argentine is no exception with a population of 50 million bovines and
high seroprevalences up to 90%. The aim of our study is epitope
mapping of immunodominant E2 protein of BVDV using a peptide 12mer
phage display library.
Materials and Methods: A peptide 12-mer phage display commercial
library was depleted of mimotopes resembling BVDV proteins except
those corresponding to E2, by using serum from a calf immunized
against recombinant BVDV-E2 BDV. Then, a positive selection was
performed with affinity purified antibodies against BVDV strain NADL.
Individual phage clones were amplified and displayed peptide sequences
analyzed using CLUSTALX with Tudos matrix. Four peptides were
designed for immunization purposes and sent to synthesize. Two bovines
and 4 groups of guinea pigs were vaccinated with peptides coupled to
KLH. Also, phages displaying chosen peptides were amplified and used
to immunize mice. Sera were analyzed by peptide-ELISA, phage-
ELISA, indirect ELISA and seroneutralization.
Results: Enrichment of specific clones was achieved in 4 rounds of panning
and 30 clones were individually amplified. Multiple sequence alignment
analysis with modified parameters and substitution matrix allowed a better
clustering of peptides. Considering clusters, peptide frequency and
hydrophobicity and aminoacids representativity in library, 4 rationally
designed peptides with immunogenic properties were obtained. Satisfactory
antibody responses against peptides were observed in mice immunized with
phages, and bovines and guinea pigs vaccinated with synthetic peptides.
Also, antibodies produced in mice recognized synthetic peptides. Sera from
immunized animals were either citotoxic or not neutralizing. Indirect
ELISA showed high background and was not conclusive.
Conclusions: It was possible to obtain immunogenic peptides
resembling epitopes of BVDV using a peptide 12-mer phage display
library as mapping strategy. Epitope mapping is imperative for
improving local vaccines design and control.
Key words: BVDV, mimotope, phage display, E2
729 Amplification of Inv Gene of Salmonalla Serotypes by
Polymerase Chain Reaction (PCR) as a Specific Method of
Detection of Salmonellae
T. Zahraei Salehi 1 , M. Mahzonieh 2 , A. Ashrafi 1
1
Faculty of Veterinary Medicine, University of Tehran, Microbiology,
Tehran, Iran
2
Faculty of Veterinary, Pathobiology, Shahrekord, Iran
Background: Detection of inv gene in Salmonella serotypes by PCR.
Materials and Methods: Sixty Salmonella strains were isolated from
animals and human sources. In this research, at first 60 isolated
Salmonella from animals and human were tested by biochemical tests
such as carbohydrate utilization tests and urease test and then were
serogrouped by Salmonella O anisera. DNA of isolated Salmonella
were extracted by Holmes and Quigley method. Two primers (St139
and St141) and PCR reagents from fermantas company were used for
amplication of inv gene. PCR reaction was carried out in Master cycle
(Eppendorf). The PCR product were loaded into 1.2% agarose gel and
electrophoresed for 60 minutes at 120 V.
Results: All isolates showed biochemical properties of Salmonellae. In
PCR assay, target gene (invA gene) with 284 bp size were observed in all
the strains, which is corresponded with size of band of positive control and
DNA marker. So, all of the strains in this survey had invA gene.
Conclution: According to the results of this study PCR method based
on inv gene is useful to rapid identification of Salmonella serotypes.
Key words: Salmonella, invA gene, PCR
730 Toxoplasmosis in a Commercial Dairy Farm in Turkey
S. Gazyagci 1 , C. Babur 2 , S. Kilic 2 , B. Celebi 2 , A. Gazyagci 2 ,
B. Yagci 1
1
Faculty of Veterinary in Kirikkale University, Department of
Internal Medicine, Kirikkale, Turkey
2
National Research Center, Epidemiology and Public Health,
Ankara, Turkey
Blood samples were taken from 742 dairy cattles in a commercial farm.
Antibody titers were determined against Toxoplasma gondii by Sabine-
Feldman Dye method. Serological examination revealed 640 cattle to
be seropositive. Among these sera the numbers of seropositive samples
at certain dilution steps were as follows: 268 at 1/16, 184 at 1/64, 112
at 1/256 and 76 at 1/1024. Three cats could circulate in the warehouse
in the farm. All sera were tested with Sabin-Feldman Dye test for
Toxoplasma gondii spesific antibodies. Antibody titers were 1/256 all
of them.This study investigates the seroprevalence of Toxoplasma
gondii in dairy cattle from a commercial farm in Turkey.
Key words: cattle, Sabin Feldman dye test, Toxoplasma gondii
Infectious and Zoonotic Deseases (Public Health) 109