Oral and Poster Abstracts

Conclusion: The high incidence of TBDs here reported suggests the
importance of some factors in the development of clinical forms in
endemic areas. We suppose that the rapid temperature decrease have
played a determining role in the onset of the outbreak of babesiosis as
well as the oxytocin administration and/or the stress of post-partum in
the development of cases of anaplasmosis. Dairy cattle living in
endemic areas for the TBDs can develop clinical simptoms starting
from a latent infection. The delicate balance that is established between
parasite and host is influenced by several intrinsic and extrinsic factors.
These factors could play a decisive role in the onset of clinical forms of
the disease in endemic areas. Thus, their occurrence is not only due to
the presence of the pathogen and vectors but, significantly, to
concomitant conditioning factors.
Key words: dairy cattle, tick-borne diseases, Anaplasma marginale,
Babesia bigemina, conditionig factors
1130 Serological Determination of Leptospirosis and Brucellosis
in Bovine Fetuses
MP. Estrada 1 , J. Torres 1 , LP. Moles 1 , P. Melendez 1 ,
L. Benavides 1 , R. Soto 2 , L. Hernandez 3
1 Universidad Autonoma Metropolitana-Xochimilco, Producción
Agrícola y Animal, MEXICO, D.F., Mexico
2 Cuenca Lechera de Tizayuca Hidalgo, México, México DF, Mexico
3 INIFAP, Cenid Microbiologia, México D.F., Mexico
Objective: The aim of this work was the serological determination of
leptospirosis and brucellosis in bovine fetuses from the dairy complex
at Tizayuca (DCT) in the Hidalgo State of Mexico, with an
approximately 29.000 cows in production.
Materials and Methods: We analyzed samples of sera from 17
aborted fetuses and 15 fetuses still in utero of dead cows, from different
farms in DCT. Also 133 non pregnant cows were sampled from the
same farms where the fetuses’ samples were obtained. The
antileptospiral titration of the sera was performed by the micro
agglutination (MAT) technique using 13 serovars of Leptospira as
antigens. The titer was considered as the maximal dilution of sera in
which 50% of agglutination of the antigens was observed. For the
definition of anti brucella antibodies the radial immunodiffusion (RI)
test was used with an antigen preparation of Brucella mellitensis.
Results: From the 32 analyzed fetuses only one reacted against two
serovars of Leptospira, at the dilution 1:20 with Hardjo Hardjoprajitno
strain H-89 isolated in DCT in 1989 and at 1:40 dilution against Wolffi,
the fetus was aborted at the 240 th day of gestation. Seventy four percent
of the sera from the producing cows reacted against one or more
serovars of Leptospira, the most frequent ones were: Hardjoprajitno H-
89 (23.6%), Hardjo (17.5%) and Icterohaemorrhagiae (12.2%). Only
the serum of one in utero fetus of approximately 180 days of gestation
reacted against the Brucella antigen.
Conclusions: It is known that bovines are immunocompetent since 160
days of gestation. The OIE have suggested that positive titers of
specific antibodies against Leptospira or Brucella in the sera of bovine
fetuses may be taken as a definitive diagnosis of these infections.
Therefore our findings indicate that the two seropositive fetuses were
produced by an active infection of Brucella and Leptospira.
Key words: determination, leptospirosis, brucellosis, bovine fetuses
1131 Evaluation of Vaccine Preparations for Bovine Leptospirosis
by the Micro Agglutination and Growth Inhibition Tests
C. Cedillo 1 , K. Morales 1 , H. Castillo 1 , JI. Torres 1 , L. Benavides 2
1 Universidad Autonoma Metropolitana-Xochimilco, Producción
Agrícola y Animal, Mexico, Mayotte
2 Universidad Autonoma Metropolitana-Xochimilco, Sistemas
Biologicos, MEXICO, D.F., Mexico
We compared the microscopic agglutination test (MAT) and the growth
inhibition test (GIT) in the evaluation of the antibody production elicited
by three vaccine preparations from different serovars of the Sëjroe
serogoup of Leptospira. Forty Holstein Friesian calves seronegatives
against Leptospira were divided in four groups of ten individuals each.
Group A was inoculated with a trivalent bacterin prepared with
Hardjoprajitno strain H-89 isolated in Mexico, Hardjo and Wolffi; Group
B with an univalent bacterin from Hardjoprajitno strain H-89; Group C
with a commercial bacterin from Hardjo Bovis and Group D was the
control group, unimmunized. The animals were immunized
subcutaneously on days 0 and 15 and were bled on days 0, 7, 14, 21 post
inoculation (pi). For the evaluation of the capacity to elicit an immune
response we used the MAT with the homologue serovars as antigens. In
the GIT, 3 ml of modified Cox medium with 0.3 ml of sterile rabbit serum,
0.03 ml of the sterile problem serum and 0.3 ml of a culture of the strain
Hardjoprajitno H-89 of Leptospira, or 0.3 ml strains: Hardjoprajitno H-
89, Hardjo and Wolffi. No problem serum was added to the control tubes.
Cultures were incubated a 28°C and observed at the dark field microscope
periodically. The A and B groups stimulated antibody production from
day 7 pi, the antibodies decayed at day 21. Fewer animals inoculated with
the commercial bacterin responded and at lower titers (two to three
dilutions less), compared with those of groups A and B. In group D, the
control animals were all negatives. With both tests MAT and GIT the
effect of vaccination was statistically significant (p < 0.0001). The IEO
recommends the utilization of virulent strains to test the efficiency of the
vaccines in development but this type of tests are risky and the
maintenance of such strains is difficult and costly; our results reinforce the
value of GIT and MAT as tests for evaluation of the inmunogenicity of
vaccine preparations.
Key words: evaluation, vaccine, leptospirosis, MAT, GIT
1132 Genotyping of Mycobacterium Avium Subsp.
Paratuberculosis Isolates Based on Mycobacterial
Interspersed Repetitive Units (MIRU) Methods
A. El-Sayed 1,2 , S. Natur 2 , W. Wolter 2 , M. Zschöck 2 , A. Hassan 2
1 Faculty of Veterinary Medicine, Cairo university, Institute of
Internal Medicine and Animal Infectious Disease, Cairo, Egypt
2 Landesbetrieb Hessiches Landeslabor, Institute of Internal Medicine
and Animal Infectious Disease, Giessen, Germany
Mycobacterium avium subsp. paratuberculosis (MAP) is the
etiological agent of severe gastroenteritis in both ruminants (Johne's
disease) and human (Crohn`s disease). The molecular diversity of 109
MAP isolates were investigated in the present study. Six different
Mycobacterial interspersed repetitive units (MIRU) methods were
applied to classify the MAP isolates in to subgroups. The genotypic
characterization revealed the presence of 25 different profiles and two
of them dominate among investigated strains. The first profile could be
detected in 41 isolates (37,6%) with amplicon size of 300, 200, 350,
200, 210 and 210 bp for the primer pair (292-F, 292-R); (X3-F, X3-R),
(25-F, 25-R); (3-F, 3-R); (7-F, 7-R) and (47-F, 47-R), respectively. The
second profile is present in 28 isolates (25,7%) with amplicon size of
350, 250, 350, 200, 190 and 210 bp for the same primers, respectively.
In addition, 16 profiles were represented by one strain per profile.
Using different MIRU methods in the present study showed promising
results for improvement of epidemiological studies of MAP.
Key words: Mycobacterium avium subsp. paratuberculosis,
Mycobacterial interspersed repetitive units (MIRU), Johne's disease,
Crohn`s disease, epidemiology
1133 Detection of Mycobacterium Avium Subsp. Paratuberculosis
in Manure, Environmental Samples and Milk Filters of
Dairy Herds
A. Hassan, S. Natur, A. El-Sayed, W. Wolter, M. Zschöck
Landesbetrieb Hessiches Landeslabor, Abteilung Veterinärmedizin,
Giessen, Germany
Mycobacterium avium subsp. paratuberculosis (MAP) is a robust
worldwide spread microorganism which causes specific incurable chronic
enteritis in cattle and many animal species. The objective of this study was
the detection of MAP in manure, in environmental and milk filter samples
of dairy herds in Hesse region, Germany. Manure samples (n = 60),
environmental samples (n = 19) and milk filter samples (n = 60) were
collected from 60 herds which are known serologically to be MAP
positive and MAP negative. All samples were cultured using Herrold's
Egg Yolk Medium (HEYM) after a decontamination step with
Hexacetylpyridium chloride (HPC 0.75%) for 18 h. Among all herds
investigated five manure (8.3%), two environmental samples (10.5%) and
two milk filter samples (3.3%) showed typical growth of MAP. The
molecular identification of the isolates could successfully be performed
using species specific PCR methods based on insertion sequence IS900
and the gene f57. According to the present results manure, environmental
and also milk filter samples seem to be of importance for management
strategies to control paratuberculosis in dairy herds.
Key words: Mycobacterium avium subsp. paratuberculosis,
environmental samples, disease control
Herd Health Management and Epidemiology 175