Evaluation of Multivalent Leptospira Fluorescent Antibody Conjugates for General Diagnostic Use

Abstract

Abstract. Four lots of conjugate were evaluated for optimal dilution and degree of fluorescence produced with reference cultures and bovine and porcine leptospira isolates. One lot that uniformly produced better fluorescence was evaluated for sensitivity and specificity with reference cultures, isolates, culture-positive tissues, and 13 other bacterial species. Further evaluation of the conjugates was done with bovine, porcine, and ovine specimens submitted to a diagnostic laboratory. Leptospires were detected with the fluorescent antibody test (FAT) in 9 of 21 culture-positive bovine kidneys and were detected in diluted cultures when present at concentrations of 10 2 -1O 3 organisms/ml. With the exception of Treponema hyodysenteriae, FAT's of other bacterial cultures produced minimal fluorescence or were negative. Positives were characterized by moderate to brilliant fluorescence of typical cell forms, and most nonspecific fluorescence was eliminated with a flazo-orange counterstain. The results indicated that the FAT utilizing multivalent conjugates could be used successfully as an additional method for diagnosis of leptospira infections.

Causas de aborto bovino diagnosticadas no Setor de Patologia Veterinária da UFRGS de 2003 a 2011

“…com anticorpo comercial multivalente, na diluição de 1:20, segundo Miller et al (1989), em todos os casos.…”

Prevalence and Serovars of Leptospira Involved in Equine Abortions in Central Kentucky during the 1990 Foaling Season

“…If only numerous short brightly fluorescent particles without typical leptospira morphology were seen, the specimen was recorded as suspicious for leptospira. 12 Serologic examination. Fetal fluids and maternal sera were tested for leptospira antibodies by the microscopic aggluti- nation test (MAT).…”

“…Using the conjugate provided, c the following modifications were made to the methods previously described. 12 Tissue impressions were applied directly to the glass slide, and after staining the slides were examined using a 200-watt mercury bulb at a magnification of 950x. After February 2, 1990, the slides were examined using a 100-watt mercury bulb at a magnification of 400x.…”

Study on the role of gastric Helicobacter infection in gross pathological and histological lesions of the stomach in finishing pigs

“…The presence and amount of Helicobacter antigens were assessed as follows: category 0: not present; category 1: sporadic occurrence; category 2: easy to find or great amount. For the detection of Brachyspira the same procedure was performed in suspect cases on serial sections except for protease treatment, which was replaced by heating the sections in a microwave oven (750 W) for 20 min, and the H. pylori-specific antibody, which was replaced by a 1:5000 diluted rabbit polyclonal antibody (National Veterinary Services Laboratories, Ames, USA) specific for 14 Leptospira serovars and B. hyodysenteriae (Miller et al, 1989).…”