[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to estimate the prevalence of antibodies against Anaplasma marginale in sera from white-tailed deer (Odocoileus virginianus texanus) in the states of Nuevo Leon and Coahuila, Mexico. One hundred and sixty five deer from 5 farms were live-trapped in 2005 using the net-canyon method. Blood was extracted by jugular venipuncture using vacuum tubes. Antibodies in the sera were detected by the indirect immunofluorecent technique. Seroprevalence was high because 69.7% of deer reacted positively to A. marginale. The prevalences for the municipalities of Anahuac and Acuña were 61.9 and 83.3%, respectively. The risk of a seropositive animal was 3 times greater in the municipality of Acuña. The prevalence between sexes were equal (p>0.05). In conclusion, a high frequency of antibodies against A. marginale in white-tailed deer in northeastern Mexico was found. More studies are recommended with the aim of determine the risk of deer in the transmission of A. marginale to cattle.
[Show abstract][Hide abstract] ABSTRACT: Mast cells numbers and reactivity status based on their degranulation was determined in the skin of rabbits during the initiation and progression of the active Arthus reaction. New Zealand Rabbits divided in three groups (n = 5/group) were subjected to the reaction and killed at three different time periods. Briefly, the animals received three immunizations (seven days intervals) with bovine serum albumin intramuscularly and a challenge seven days apart intradermally. Animals were euthanized at 8 h, 24 h and 8 days, post challenge. One group served as control (saline for immunization and challenge) and was killed at 24 h. Skin samples were fixed in Carnoy`s solution and mast cells were identified employing a low pH toluidine blue stain. Numbers of mast cells were identified per square millimetre and, subsequently, those cells degranulated were identified and quantified to obtain absolute values. The values were transformed (natural logarithms) for appropriate statistical comparisons. An ANOVA test using a completely random design and a Tukey`s w test were carried out. The numbers of infiltrating mast cells were significantly different in all of the Arthus groups in comparison with controls (p<0.05). Although, all of the Arthus groups had higher values of degranulated cells, only group at 24 h was significantly different from controls. It was concluded that mast cells have a prominent role during the early and late phases of this inflammatory model.
[Show abstract][Hide abstract] ABSTRACT: The objective of the study was to estimate the prevalence of antibodies against Babesia bovis and B. bigemina in sera from 165 white-tailed deer in northeastern Mexico. Sera were collected in spring of 2003 in 5 mixed cattle and deer farms from the states of Coahuila and Nuevo Leon, Mexico. Animals were live-trapped by the drop net technique and once immobilized blood samples were obtained by jugular venipuncture using vacuum tubes. Antibodies were detected by the indirect immunoflourecent technique using blood smears with parasited erythrocytes for B. bovis or B. bigemina. Seropositivity in the deer was relatively high, because 87% (144/165) of the sera was positive. The seroprevalences for B. bigemina and B. bovis were 53% (88/165) and 75% (124/165). The sex of the deer was a risk factor for seropositivity to B. bovis but no for B. bigemina. The risk of infection with B. bovis was 2.4 times greater for females than for males. In conclusion, a high prevalence of antibodies against B. bigemina and B. bovis in the white-tailed deer was found at northeastern Mexico. More studies are recommended with the aim of detecting the role of deer in the transmission of babesiosis to cattle.
[Show abstract][Hide abstract] ABSTRACT: Herein, we explored the number of infiltrating mast cells in the skin of diabetic rabbits during the acute phase of the inflammatory response induced by an active Arthus reaction. New Zealand Rabbits were divided in 5 groups (n = 5/group). One group served as control while the others were subjected to the reaction. Two Arthus groups (groups 1 and 2) received alloxan to induce diabetes 75 days before the hyperimmunization protocol. Diabetes was confirmed by blood glucose tests 48 h after alloxan injection and at the time of euthanasia. An agar immunodifussion test showed that diabetics and non-diabetics (groups 3 and 4) had enough serum antibodies by the time of euthanasia. Rabbits were euthanized at 8 h (groups 1 and 3) and 24 h (groups 2 and 4). Controls (group 5, non-Arthus, non-diabetes) received saline and were killed at 24 h. Skin samples were fixed in Carnoy`s solution and mast cells were identified employing a low pH toluidine blue stain. Mast cells were quantified per square millimetre and then, those degranulated cells were registered to obtain absolute values. An ANOVA test employing a completely random design and subsequently, a Tukey`s w test were carried out. Arthus reaction influenced markedly mast cell infiltration. Although, diabetic animals had fewer mast cells than non-diabetics (p0.05). Diabetes markedly decreases the infiltration of mast cells during the active Arthus reaction in the skin. However, their degranulation status is comparable with non-diabetics.
[Show abstract][Hide abstract] ABSTRACT: A serological study for several serovars of Leptospira sp. was undertaken on a randomly selected population of beef cattle in 22 municipalities of Nuevo Leon, Mexico. Blood samples were collected from 1400 animals and sera were tested for antibodies against 12 serovars of Leptospira sp. (bratislava, canicola, gryppotyphosa, hardjo, hebdomadis, icterohaemohrragiae, panama, pomona, pyrogenes, shermani, tarassovi, wolffi) using the microscopic agglutination test. Antibodies against one or more serovars were detected in 646 sera (46%) of the 1383 samples tested. The most prevalent serovars detected were hardjo (19.8%), wolffi (18.6%) and tarassovi (6.5%).
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to determine the presence of Borrelia burgdorferi antibodies in horses from the metropolitan area of Monterrey, Nuevo León, México. Blood serum was obtained from a total of 100 horses residing at different counties in the area. From each animal data was obtained on age, sex, county of residence, presence of ectoparasites and clinical signs. All sera samples were analyzed by indirect immunofluoresence and the sera that resulted positive to this test was analyzed by Western blot. The serological test yielded 34 positive sera at 1:64 dilution, and from them 6 were positive at 1:128 dilution, 3 at 1:256, and only one at 1:512. Confirmation of the infection by Western blot was obtained only in the sample positive at the 1:512 dilution. These results shown a low frequency of seropositivity to B. burgdorferi of the horses in the area, confirming previous studies indicating that in northeast Mexico Lyme disease is present in different animal species.
Revista latinoamericana de microbiología 01/2001; 43(4):161-4.
[Show abstract][Hide abstract] ABSTRACT: In Mexico, brucellosis is a widely distributed disease of domesticated ruminants, but its frequency in wild ruminants has not been documented. Since northeast Mexico is the main distribution area of white-tailed deer and has been reported as an area positive for brucellosis in domesticated species, the present study was conducted in order to determine serological activity against several species of the genus Brucella in white-tailed deer. A total of 208 sera of white-tailed deer were collected during the springs of 1994 and 1995 in the north part of the states of Nuevo León and Coahuila. Each serum was analyzed for the detection of antibodies against two smooth (B. abortus and B. melitensis) and one rough (B. ovis) species of the genus Brucella. The serological tests used for the determination of the presence of antibodies against Brucella were card and plate agglutination for B. abortus, plate agglutination and rivanol precipitation for B. melitensis, and agar gel immunodiffusion for B. ovis. Each assay had positive and negative controls. None of the analyzed samples was found to be positive, and only two sera showed partial plate agglutination against B. melitensis at a dilution of 1:25; however, at higher dilutions and to the rivanol precipitation test the same samples were negative. Therefore, the percentage of positive sera was estimated at 0% (0/208). This result makes evident the absence of positive white-tailed deer against Brucella in the sampled area, despite that this disease is considered present in domesticated species. Therefore, white-tailed deer does not have, at the present time, an important role for the dispersion of the disease. The same result has been reported in other countries.
Revista latinoamericana de microbiología 01/1998; 40(3-4):124-7.
[Show abstract][Hide abstract] ABSTRACT: Porcine stress syndrome (PSS), caused by a point mutation in the gene coding for the ryano- dine receptor (locus ryr-1), is one of the problems the pork industry is facing today. PSS, also known as malignant hyperthermia, causes death in animals or lower meat product quality. These problems arise in the affected animals when they are under stressful conditions, such as during transportation. Currently, there are no data on the gene frequency of the condition in Nuevo Leon; however, anecdotal evidence points to a frequency similar to that of countries in which data do exist for the Landrace, Duroc, Large White and Hampshire breeds. In the present study a molecular biology technique was used to determine the genotype of animals for the syndrome, based on the polymerase chain reaction and the digestion of its products with a restriction enzyme (PCR-RFLP). A total of 77 animals were analyzed, of which 23 pre- sented the recessive allele (29.9%); according to the genotype, 26% were carriers (N/n) and 3.9% were affected (n/n); the rest, 54 animals (70.1%), had a normal genotype (N/N). There was no signifi cant difference in mutation frequency between males (33.4%) and females (26.3%), although there were more affected females than males (nn). Genotype frequencies found were 0.70 (54/77) for the dominant homozygote (NN), 0.26 (20/77) for the heterozygote (Nn) and 0.04 (3/77) for the recessive homozygote. Frequencies were 0.17 for the recessive allele (n) and 0.83 for the dominant one (N).
[Show abstract][Hide abstract] ABSTRACT: Lyme disease or Borreliosis, a tick-borne disease caused by Borrelia burgdorferi, has been described recently in dogs. A total of 850 blood samples were obtained from dogs in the metropolitan area of Monterrey, Mexico. An indirect immunofluorescent assay (IFA) was used to detect antibodies against Borrelia burgdorferi, the etiologic agent of Lyme disease in human beings. The 16% (136) of these dogs had positive results. These findings suggest that exposition to this microorganism is common in dogs in this area and that this disease is of importance to veterinarians.
Revista latinoamericana de microbiología 41(1):1-3.