Oral and Poster Abstracts

esponse in the eye produces accumulation of polymorphonuclear
neutrophils (PMNs) in tissue and ocular fluids, increase of the vascular
permeability and therefore an increase of AH proteins. The increase of
PMNs explains the larger concentrations of TMS reached in AH of the
animals with keratoconjunctivitis. Although TMS levels in AH (either at
5 or 10 mg/kg) persisted during 72-96 h, they never surpassed the M. bovis
MIC (< 1 µg/mL). Nevertheless a longer TMS persistence was evident in
sick animals, being documented through longer mean residence time
(41.2, 45.7 and 22.7 vs 15.9 h for the G1, 2, 3 and 4 respectively) and a
smaller clearance from AH (222.8, 469.5, 773.3 vs 1613.5 mL/h/kg for
the G 1, 2, 3 and 4, respectively). These information suggest that TMS
penetrate to the ocular balloon and concentrates in AH depending on the
degree of inflammation. Concentrations in vitreous humors and ocular
tissue, should be evaluated in the future to consider the use of the TMS for
the treatment of certain ocular infections.
Key words: tilmicosin, aqueous humor, keratoconjunctivitis,
pharmacokinetic, cattle
697 The use of PCR for Identification of Brucella abortus in
Samples from Aborted Fetuses in a Dairy Farm in the State of
Aguascalientes, Mexico
D. Limón 1 , G. Martínez 1 , G. Zenteno 1 , B. Arellano 2 , E. Diaz 1 ,
R. Flores 1 , F. Morales 1
1 INIFAP, CENID Microbiologia, MEXICO, D.F., Mexico
2 Universidad Nacional Autonoma de México, Facultad De Medicina
Veterinaria, MEXICO, D.F., Mexico
Abomasal fluid and tissues conserved in 10 % bufferated formalin
solution from 13 aborted fetuses, as well as sera from 55 aborted cattle
were collected in a dairy farm located in Aguascalientes, Mexico and
were transported to the Diagnostic Laboratory of CENID-
Microbiologia, INIFAP. The abomasal fluid samples were inoculated
in enriched Farrel’s medium in order to attempt the Brucella abortus
isolation. The tissues samples were processed for histophatological
analysis, while the sera were used for detection of BVD, IBR,
Neospora, Leptospira and Brucella antibodies. Those Brucella spp
suggested isolations were examined by using a PCR procedure.
Depending of the amplified fragments (361, 456, 1063 and 1298 bp) it
is posible the identification and differentiation of field and vaccinal
Brucella abortus strains. Six isolated strains were cultured from the
abomasal fluid and all of them were identificated as Brucella abortus
field strains by PCR. Brucellosis typical lesions (multifocal necrotical
hepatitis and exudative pneumonia) were observed in 4/13 studied
fetuses. The result of serological examination of 55 samples was as
follows: Brucellosis, 27 %; Neosporosis, 40 %; Leptospirosis, 65 %
(titers > 1:400) and IBR, 100% and BVD 80 %. During the last few
years Leptospirosis and Neosporosis have shown an increase in their
importance as a cause of abortion in cattle in Mexico, our results in the
present study confirm this affirmation. The fact that a specific
vaccination program to prevent neosporosis does not exist in the dairy
farm under investigation, makes it important to consider this agent as
important causal of the abortion. In regards to Brucellosis, it is a
disease with high prevalence in the dairy cattle farms despite the fact
that there is an intensive official control campaign in Mexico and
excellent vaccines such as S19 and SRB51 exist; for this reason it is
important to have diagnosis techniques with high sensivity and
specificity as it is the case of PCR technique. It is important to promote
the use of integral etiological diagnosis of abortions in order to be in
conditions to apply adequate and effective control measurements. It
often occurs that in some laboratories in Mexico the samples are tested
only for diagnosis of brucellosis and do not consider the use of
techniques for determinate the possible presence of other
microorganisms associated with reproductive problems.
Financial support SAGARPA-CONACyT. (2004/COI/23)
Key words: PCR, Brucella abortus, aborted fetuses
698 Long-Term Excretion of Brucella abortus, Strain B19 in Milk
and Urine by Vaccinated Adult Female Bovines
M. Genovez 1 , W. Pacheco 1 , C. Pozzi 2 , L. Paulin 1 , M. Gamberini 3 ,
S. Azevedo 4
1 Instituto Biológico, Animal Health Center, Sâo Paulo, Brazil
2 Instituto de Zootecnia, Animal Health Center, Nova Odessa, Brazil
3 Universidade Federal de Goiás, Animal production, Goiania, Brazil
4 Universidade Federal De Campina Grande, Department for
Infectious diseases- Epidemiology, Patos, Brazil
Abortion caused by Brucella abortus is a common bovine
reproductive disease in many countries and may be currently
prevented by vaccination with live B19 vaccine, administered to 3-8
month old heifers. The length of excretion, its relation to the
hormonal cycle and its effect on contactant and susceptible animals,
including man, are not completely known. The persistence of B19
excretion in milk and urine by adult dairy cows vaccinated at 3-8
months old was investigated in this study. Samples were collected
during 12 months (15 collections), beginning at estrus until
immediate post-partum, from 14 females in three groups: G1(3-4
years old), G2 (5-6 years old) and G3 (7-9 years old). Milk and urine
samples were monitored by bacteriologic analyses and Multiplex
PCR differential for B.abortus and B19 strain; blood serum samples
were analyzed by Rose Bengal test for brucellosis diagnosis and
direct estradiol ELISA KIT and progesterone ELISA KIT
(Diagnostics Biochem., Canada) were used for hormone monitoring.
All milk samples were negative in serology and bacteriologic
examination. B19 was detected by PCR in 74/210 (35.2%) and
12/210 (5.7%) from urine and milk samples, respectively (p=0.001).
Excretion mainly occurred from the beginning of estrus to 150 days
of pregnancy and for 30 days after parturition. Hence, excretion was
intermittent, no matter the age of the animal and the time after
vaccination. Hence, excretion was intermittent, no matter the age of
the animal, the time after vaccination, and occurred in cows up to
nine-year old. Hormonal stage did not seem to affect B19 excretion,
and may be associated with erythritol scarcity. The impact of longterm
B19 excretion requires more attention. B19 may remain in the
environment with a real possibility of transmission to negative cattle
herds, mainly to bulls, or even to other susceptible animal species,
including man. Urine was the best sample for B19 detection.
This paper was supported by FAPESP: Fundaçao de Amparo a
Pesquisa do Estado de Sao Paulo, Brazil
Key words: bovine brucellosis, B19 excretion, hormonal cycle
699 Main Causes of Abortion in Cattle at Different Areas of
Mexico
G. Zenteno 1 , F. Manrriquez 1 , I. Vitela 2 , L. Diaz 4 , R. Flores 1 ,
D. Martinez 3 , F. Morales 1
1
INIFAP, CENID Microbiologia, México DF, Mexico
2
Instituto Tecnológico el Llano, Microbiología, Aguascalientes,
Mexico
3
Universidad Veracruzana, Facultad de Medicina Veterinaria y
Zootecnia, Facultad De Medicina Veterinaria, Veracruz, Mexico
4
Gobierno del Estado de Aguascalentes, Comité de Fomento y
Protección Pecuaria, Aguascalientes, Mexico
Data related to the incidence and prevalence of etiological agents
associated with reproductive failures in cattle of Mexico are the result
of isolated studies, only a few cases include results of integrated
diagnosis. Some papers describe the results of serological profiles, but
in most of them the interpretation of the results does not permit the
diagnosis of the etiological agent. For example, previous studies
performed by our research group demonstrated different prevalences
of brucellosis, BVD, IBR, neosporosis and leptospirosis as follows:
The brucellosis prevalence was always high (12-21 %) except in
Veracruz (3%); Leptospirosis was similar to brucella with the highest
prevalence in Aguascalientes (27%) and the lowest in Veracruz (3%).
The BVD and IBR highest prevalences were observed in the same
states (56-86%) while in Veracruz there were lower (47 and 38 %
respectively). The prevalence of neosporosis varied between 30 and 45
% in most states, but in Veracruz was only 15 %. With these results it
was impossible to relate the abortions with a particular infectious agent.
The purpose of this study was to perform an integral, comparative
serological profile, in sera collected from aborted and non aborted
animals from 7 dairy cattle in different areas of the state of
Aguascalientes, Mexico. Blood samples were collected from cattle
aborted during a five month period previous to the collection and from
non aborted animals. All samples were tested for the identification of
Brucelosis, BVD, IBR, Neosporosis and Leptospirosis antibody titers.
The results of this serological study, were then used in order to compare
the prevalences of each etiological agent with either, aborted and non
aborted populations. The results of this comparative study
demonstrated that in some farms more than one etiological agent was
found to be important: in 4 cattle farms brucellosis was a serious
problem; in one farm the main cause of abortion was IBR, while BVD
and neospora appeared to be the most important causes of abortion in
Infectious and Zoonotic Deseases (Public Health) 101