Myra T. Blanchard, Kassidy M. Collins, Jeffrey L. Stott
{"title":"Assessment of an indirect fluorescent antibody test for the detection of antibodies specific for Pajaroellobacter abortibovis in adult cattle","authors":"Myra T. Blanchard, Kassidy M. Collins, Jeffrey L. Stott","doi":"10.1016/j.vetimm.2025.110927","DOIUrl":null,"url":null,"abstract":"<div><div>A highly specific, sensitive, and reproducible indirect immunofluorescent antibody test (IFAT) capable of detecting antibodies bound to <em>Pajaroellobacter abortibovis</em> was previously described and validated for use with bovine fetal fluid. Similar validation has not been demonstrated with cow sera. Adult cattle show no sign of infection with <em>P. abortibovis</em> prior to abortion and therefore it is difficult to identify exposed animals. To address this problem, paired sera from 107 dams, that had lost calves due to EBA, were tested by the <em>P. abortibovis</em>-specific IFAT. Specificity and sensitivity were determined by comparing IFAT antibody titers before <em>P. abortibovis</em> exposure to those at or near the time of EBA abortion. Fifty-six samples from a combination of experimental negative controls and animals originating from non-endemic areas were added to increase the sample size when calculating specificity. None of the 107 sera collected from cows prior to <em>Pajaroellobacter abortibovis</em> exposure had detectable IFAT titers (i.e. <200), nor did sera from non-endemic (n = 46) and negative control cows (n = 10). In contrast, <em>P. abortibovis</em>-specific antibodies titers of ≥ 200 were detected in all 107 serum samples collected at or near the time of an EBA abortion. Specificity and sensitivity for dam sera were both established at 100 % when cutoff criteria for positive tests were assigned a titer of ≥ 200. This <em>P. abortibovis</em>-specific IFAT is a powerful tool for identifying exposure to the etiologic agent of epizootic bovine abortion in adult cattle and will facilitate future studies to better define the geographic distribution of the disease.</div></div>","PeriodicalId":23511,"journal":{"name":"Veterinary immunology and immunopathology","volume":"283 ","pages":"Article 110927"},"PeriodicalIF":1.4000,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Veterinary immunology and immunopathology","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0165242725000479","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
A highly specific, sensitive, and reproducible indirect immunofluorescent antibody test (IFAT) capable of detecting antibodies bound to Pajaroellobacter abortibovis was previously described and validated for use with bovine fetal fluid. Similar validation has not been demonstrated with cow sera. Adult cattle show no sign of infection with P. abortibovis prior to abortion and therefore it is difficult to identify exposed animals. To address this problem, paired sera from 107 dams, that had lost calves due to EBA, were tested by the P. abortibovis-specific IFAT. Specificity and sensitivity were determined by comparing IFAT antibody titers before P. abortibovis exposure to those at or near the time of EBA abortion. Fifty-six samples from a combination of experimental negative controls and animals originating from non-endemic areas were added to increase the sample size when calculating specificity. None of the 107 sera collected from cows prior to Pajaroellobacter abortibovis exposure had detectable IFAT titers (i.e. <200), nor did sera from non-endemic (n = 46) and negative control cows (n = 10). In contrast, P. abortibovis-specific antibodies titers of ≥ 200 were detected in all 107 serum samples collected at or near the time of an EBA abortion. Specificity and sensitivity for dam sera were both established at 100 % when cutoff criteria for positive tests were assigned a titer of ≥ 200. This P. abortibovis-specific IFAT is a powerful tool for identifying exposure to the etiologic agent of epizootic bovine abortion in adult cattle and will facilitate future studies to better define the geographic distribution of the disease.
期刊介绍:
The journal reports basic, comparative and clinical immunology as they pertain to the animal species designated here: livestock, poultry, and fish species that are major food animals and companion animals such as cats, dogs, horses and camels, and wildlife species that act as reservoirs for food, companion or human infectious diseases, or as models for human disease.
Rodent models of infectious diseases that are of importance in the animal species indicated above,when the disease requires a level of containment that is not readily available for larger animal experimentation (ABSL3), will be considered. Papers on rabbits, lizards, guinea pigs, badgers, armadillos, elephants, antelope, and buffalo will be reviewed if the research advances our fundamental understanding of immunology, or if they act as a reservoir of infectious disease for the primary animal species designated above, or for humans. Manuscripts employing other species will be reviewed if justified as fitting into the categories above.
The following topics are appropriate: biology of cells and mechanisms of the immune system, immunochemistry, immunodeficiencies, immunodiagnosis, immunogenetics, immunopathology, immunology of infectious disease and tumors, immunoprophylaxis including vaccine development and delivery, immunological aspects of pregnancy including passive immunity, autoimmuity, neuroimmunology, and transplanatation immunology. Manuscripts that describe new genes and development of tools such as monoclonal antibodies are also of interest when part of a larger biological study. Studies employing extracts or constituents (plant extracts, feed additives or microbiome) must be sufficiently defined to be reproduced in other laboratories and also provide evidence for possible mechanisms and not simply show an effect on the immune system.