Seroprevalence of antibodies to Borrelia burgdorferi in a population of horses in central Texas.

Four hundred sixty-nine serum samples were obtained from horses admitted to the internal medicine service of the Texas Veterinary Medical Center between Jan 1 and Dec 31, 1990. Serum samples were tested by ELISA for antibody to Borrelia burgdorferi. Of these 469 samples, 1 (0.2%) was repeatedly seropositive for the organism by ELISA. Confirmatory testing by protein immunoblot was negative. The observed seroprevalence was 0%; the upper bound of the 95% confidence interval was 0.6%. These findings indicate the evidence of infection with B burgdorferi is presently uncommon in horses in central Texas.

Comparison of results from five serologic methods used for detecting Brucella abortus antibody activity in coyote sera.

A total of 423 serum samples representing 94 coyotes which were wild trapped in east Texas were used to compare the serologic results from five different methods for detecting antibodies to Brucella abortus. The sera were tested for Brucella spp. antibody activity by the Card (CARD), rivanol precipitation (RIV), standard agglutination tube (SAT), cold complement fixation test (CF), and enzyme linked immunosorbent assay (ELISA) methods. Each serum sample selected for this comparison demonstrated antibody activity by one or more of the five serologic methods. When the serologic results of the five different methods were compared, 143 sera were positive according to the CF test and agreement was 67.1-70.6% with CARD, RIV and SAT. The maximum agreement for CF positive was with CARD (70.6%) and the lowest agreement fro CF negative was also with CARD (56.4%). Agreement among the serologic methods for the SAT positive ranged from 69.1% (CARD) to 72.7% (RIV). Agreement between SAT and ELISA was poor with only 38.1% agreement for SAT positive and 11.3% agreement for SAT negative. Agreement between methods for CARD positive sera was poor, with a low of 43% for both SAT and ELISA, and a high of 55.6% for RIV. Agreement between methods for 149 RIV positive sera was 83.2% for CARD, 67.8% for SAT, 64.4% for CF and only 50.3% for ELISA. Agreement between methods for ELISA positive results ranged from 49.0% for RIV to 62.7% for CARD.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibronectin concentration in plasma of mares and neonatal foals.

Plasma fibronectin concentrations were measured in clinically healthy mares and their neonatal foals, using a modified human fibronectin competitive enzyme-linked immunosorbent assay. Ranges of plasma fibronectin were established in clinically healthy horses, and the assay was reliable and reproducible. Plasma fibronectin concentrations were similar in mares and foals, both before and after colostrum ingestion.

[Isolated vitamin E deficiency]. / Isolierter Vitamin-E-Mangel.

Since the detection of vitamin E in 1922, nearly 50 years passed until the recognition that there is a pathogenic vitamin E deficiency in humans. Such a deficiency can be found mostly in a disturbed resorption or transport of the vitamin (mucoviscidosis, chronic cholestasis, abetalipoproteinaemia) and leads typically to a progredient spinocerebellar ataxia in combination with a polyneuropathy. Substitution of the vitamin may hinder a further progression or even lead to an amelioration of the symptoms. Prophylactic treatment in abetalipoproteinaemia prevents the otherwise unavoidable neurological deficits. Isolated vitamin E deficiency is a rare syndrome and the causes are still obscure. We observed a 26 year old male patient with such a isolated vitamin E deficiency who was hitherto thought to suffer from Friedreich's ataxia. The clinical feature showed in addition to the "classical" symptoms of vitamin E deficiency cranial nerve involvement, perioral dystonia and pyramidal signs. Histologically (M. gastrocnemius) we saw the described typical but not specific changes (neurogenic atrophy, phosphatase-positive vacuoles with myelin bodies, cores). An oral vitamin E resorption test yielded a very shortened serum half life. These results support the hypothesis that in the pathophysiology of isolated vitamin E deficiency malelimination plays an important role in addition the known malresorptions models.

Interspecific transmission of Brucella abortus from experimentally infected coyotes (Canis latrans) to parturient cattle.

In four separate trials, 10 coyotes (Canis latrans) which had been individually fed mascerated bovine placental tissue experimentally inoculated with Brucella abortus strain 2308 were placed in a 1 ha isolation area with six parturient, non-B. abortus vaccinated, Brucella spp. seronegative Hereford heifers. During the second trial, three of the heifers became Brucella spp. seroreactive (as determined by the card, standard agglutination tube, rivanol, complement fixation, and enzyme labeled immunosorbent assay tests) 14 days after exposure to the B. abortus infected coyotes. Five of 10 coyotes in the second trial seroconverted to Brucella spp. positive by day 14 postexposure (PE) and by day 27 PE seven of the 10 coyotes were Brucella spp. reactive. The three Brucella spp. seroreactive heifers subsequently aborted on days 35, 64 and 66 PE and B. abortus strain 2308 was isolated from vaginal swabs, milk, and placental and fetal tissues. There was no serologic or bacteriologic evidence of transmission from B. abortus infected coyotes to the susceptible cattle recorded in the other three trials.

Immunochemical studies on the binding properties of Brucella abortus lipopolysaccharides to bovine precipitating antibodies.

The binding properties of Brucella abortus smooth lipopolysaccharides (LPS) to the precipitating antibodies in the serum of a B. abortus S2308 infected cow were studied by quantitative precipitin and precipitin-inhibition assays. Crude B. abortus lipopolysaccharides (cLPS) and chemical modification products of strains 1119.3, 19 and 2308 (virulent) were used for this study. In the quantitative precipitin assay, 13 micrograms of cLPS precipitated about 4.0-5.2 micrograms nitrogen of precipitating antibodies in 10 microliter of serum. After alkaline treatment (0.125 N NaOH at 56 degrees C for 1 hr), the alkali-treated lipopolysaccharides (aLPS) from S19 and S1119.3 maintained the maximum precipitability, but the precipitation profile was changed from a sigmoidal to a bell-shaped curve, and aLPS from S2308 was reduced to about 40% of its reactivity. These results indicate that some of the antigenic determinants blocked by other molecules were reshielded by alkaline treatment, and possibly that structural differences exist between virulent (S2308) and nonvirulent (S19 and S1119.3) strains. Among the monosaccharides and glycosides tested for inhibition of precipitation, methyl alpha-D-mannose was most active and about 3.3 times as active as D-mannopyranose (DMan) and only 1/200 as active as acid hapten or the carbohydrate moiety of cLPS prepared from S1119.3 (expressed as a monosaccharide of mol. wt 200) implying that the carbohydrate determinants of this antigen are probably related to a DMan alpha 1----linked compound. The precipitability of the antibodies in this serum was greatly reduced after absorption with cLPS and the precipitin reaction was completely inhibited by the carbohydrate moiety of LPS (O-antigen) S1119.3 demonstrating that the common antigenic determinants (hapten) of B. abortus LPS reacting with these precipitating antibodies are in the region of the carbohydrate moiety of the LPS.

Experimental infection of captive axis deer with Brucella abortus.

Four captive-raised axis deer, Axis axis (Erxleben), which were negative serologically to Brucella were inoculated with 1 X 10(8) virulent Brucella abortus biotype 1 organisms (Texas #221 isolate) administered bilaterally into the conjunctival sac. Sera collected from each deer prior to inoculation and 30 days post-inoculation (PI) were examined for Brucella antibodies by the buffered Brucella antigen (card), the rivanol precipitation, the standard tube agglutination, and the cold complement fixation tube serologic tests. All four axis deer converted serologically as determined by all tests at 30 days PI. Brucella abortus biotype 1 was isolated from 26 of 32 tissue samples collected at necropsy and also from milk from the lactating female.

Interaction of specifically purified isotypes of bovine antibody to Brucella abortus in the haemolysis in gel test and enzyme-linked immunosorbent assay.

The detection limits for purified bovine IgM, IgG1 and IgG2 antibody to Brucella abortus in the haemolysis in gel test and in an enzyme-linked immunosorbent assay (ELISA) were established. The limits for IgM, IgG1 and IgG2, respectively, were: 5500, 60 and 4850 ng of antibody in the lytic test and 2750, 3.5 and 16 ng in the ELISA test. Bovine IgG2 produced lysis only in the presence of fresh, whole bovine serum.

Derivation of monoclonal antibodies against Brucella abortus antigens.

In vivo immunization, fusion, antibody detection, and cryopreservation procedures for monoclonal antibody production against antigens of Brucella abortus are described. Splenocytes from BALB/c mice immunized with irradiated B. abortus S2308 were fused with Sp2/O-Ag14 myeloma cells and 61 hybridomas secreting anti-Brucella antibodies were cloned. Hybridoma antibody synthesis was detected effectively and most efficiently by enzyme-linked immunosorbent assays. Antibodies from clones of hybridoma A23 reacted with S19 and S2308 whole bacterial cells, while hybridoma B49 reacted primarily with alkali--treated lipopolysaccharides of S19, S1119.3 and S2308. Cryopreservation of clones had no major effect on antibody synthesis. The application of monoclonal anti-Brucella antibodies in the differential diagnosis of bovine brucellosis is discussed.

Antibodies to Brucella abortus in sera from Strain 19 vaccinated and non-vaccinated cows as determined by enzyme linked immunosorbent assay and conventional serologic methods.

The sensitivity of an enzyme linked immunosorbent assay was compared with 4 other serologic methods for detecting antibodies in B. abortus vaccinated and non-vaccinated cows. Antibodies were detected by ELISA in sera from more than 93% of the culture positive cows, however, less than 55% of the infected animals were identified by any other serologic method. Similarly, antibodies were detected in 82% of the culture negative cows by the ELISA method.

Enzyme-linked immunosorbent assay for detecting antibodies to Brucella abortus in bovine milk and serum.

An enzyme-linked immunosorbent assay (ELISA) method was evaluated for the detection of antibodies to Brucella abortus in cows milk. Milk samples from seropositive or -negative cows were sed to determine the distribution of absorbance values to classify milk as ELISA positive or ELISA negative. Brucella abortus was isolated from milk samples from 10 (45%) of the 22 cows whose milk and serum were ELISA positive. The ELISA was evaluated and determined to be an appropriate method for detecting antibodies to B abortus in bovine milk.

Interpretation of spectrophotometric absorbance values to define results of enzyme-linked immunosorbent assays.

An enzyme-linked immunosorbent assay method was used to classify bovine serum as positive, negative, or doubtful for antibodies to Brucella abortus. Spectrophotometric data from assays of 64 serologically positive and 32 serologically negative bovine sera were analyzed statistically to define the range of spectrophotometric absorbance values which classify sera. Statistical analysis indicated that absorbance values less than 0.08 should be considered negative and values greater than 0.14 should be considered positive, with intermediate values declared doubtful, and that the probability of erroneously classifying a positive serum as negative or a negative serum as positive is less than 0.005.

Comparison of serological methods for the detection of B. abortus antibodies in sera from vaccinated and non-vaccinated cattle.

A total of 4551 sera from 863 Strain 19 vaccinated and non-vaccinated adult cattle, independent of disease status, were tested by five serological methods to detect the presence of antibodies to B. abortus. Results from Standard Agglutination Tube (SAT), Buffered Brucella Antigen or card (CT), Complement Fixation (CF), Enzyme Linked Immunosorbent Assay (ELISA) and Rivanol (Riv) methods were compared. There was a 95% probability for agreement among CT negative sera, between serological methods, for all groups of vaccinated and non-vaccinated cattle. The agreement between tests with Riv Positive sera, excluding the calfhood and adult vaccinated group tested by the CF method, was 91-100%. The probability of a serum which was serologically negative by other methods being Riv negative was 98%. The usefulness of serological results from Riv (greater than or equal to 1/50) tests for classifying the reactor status of cattle are of doubtful supplemental value to confirm card test positive results. Vaccination history is an important consideration when evaluating serological data on cattle sera particularly from SAT and CF methods.

Brucella abortus in coyotes. I. A serologic and bacteriologic survey in eastern Texas.

Prevalence of Brucella abortus serum antibodies in coyotes from east central Texas was determined by the buffered Brucella antigen (card test), rivanol, standard agglutination tube, and cold complement fixation tube tests. Eighteen percent (9 of 51) of the coyotes were positive serologically. B. abortus biotype 1 was isolated from various tissues from 7 of 43 coyotes by bacteriologic culture. Congenital transmission was found.

Evaluation of the enzyme-linked immunosorbent assay for detecting Brucella abortus antibodies.

The specificity of enzyme-linked immunosorbent assays (ELISA) corresponds to conventional methods for detecting brucella antibodies in bovine serum. The ELISA test detected brucella antibodies early in only 12.5% of the cattle sera tested. Also, the sensitivity of ELISA was comparable to complement-fixation and Rivanol methods, but less sensitive than the standard tube agglutination method.

Ocular squamous cell carcinoma: immunological responses to tumour tissue and phytomitogens.

Cows with histologically confirmed ocular squamous cell carcinoma were injected with autochthonous tumour brei in adjuvant. Lymphoproliferative responses of isolated peripheral blood lymphocytes exposed to phytomitogens and inhibition of cell migration indicated that afflicted animals were immunocompetent. Similar but lesser responses were evident when autochthonous tumour homogenates were used to stimulate lymphocytes.