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Title: Enhanced radiometric detection of Mycobacterium paratuberculosis by using filter-concentrated bovine fecal specimens

A commercial radiometric medium, BACTEC 12B, was modified by addition of mycobactin, egg yolk suspension, and antibiotics (vancomycin, amphotericin B, and nalidixic acid). Decontaminated bovine fecal specimens were filter concentrated by using 3-microns-pore-size, 13-mm-diameter polycarbonate filters, and the entire filter was placed into the radiometric broth. Comparison of the radiometric technique with conventional methods on 603 cattle from 9 Mycobacterium paratuberculosis-infected herds found that of 75 positive specimens, the radiometric technique detected 92% while conventional methods detected 60% (P less than 0.0005). Only 3.9% of radiometric cultures were contaminated. To measure the effect of filter concentration of specimens on the detection rate, 5 cattle with minimal and 5 with moderate ileum histopathology were sampled weekly for 3 weeks. M. paratuberculosis was detected in 33.3% of nonfiltered specimens and 76.7% of filtered specimens (P less than 0.005). Detection rates were directly correlated with the severity of disease, and the advantage of specimen concentration was greatest on fecal specimens from cattle with low-grade infections. Detection times were also correlated with infection severity: 13.4 +/- 5.9 days with smear-positive specimens, 27.9 +/- 8.7 days with feces from cows with typical subclinical infections, and 38.7 +/- 3.8 days with fecal specimens from cows withmore » low-grade infections. Use of a cocktail of vancomycin, amphotericin B, and nalidixic acid for selective suppression of nonmycobacterial contaminants was better than the commercial product PANTA (Becton Dickinson Microbiologic Systems, Towson, Md.) only when specimens contained very low numbers of M. paratuberculosis.« less
Authors:
; ; ; ; ;  [1]
  1. (Univ. of Wisconsin, Madison (USA))
Publication Date:
OSTI Identifier:
6070130
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Clinical Microbiology; (USA); Journal Volume: 28:11
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; FECES; RADIOMETRIC ANALYSIS; TUBERCULOSIS; DIAGNOSIS; CATTLE; CULTURE MEDIA; FILTRATION; MYCOBACTERIUM TUBERCULOSIS; SENSITIVITY ANALYSIS; ANIMALS; BACTERIA; BACTERIAL DISEASES; BIOLOGICAL MATERIALS; BIOLOGICAL WASTES; CHEMICAL ANALYSIS; DISEASES; DOMESTIC ANIMALS; INFECTIOUS DISEASES; MAMMALS; MATERIALS; MICROORGANISMS; MYCOBACTERIUM; QUANTITATIVE CHEMICAL ANALYSIS; RUMINANTS; SEPARATION PROCESSES; VERTEBRATES; WASTES 550601* -- Medicine-- Unsealed Radionuclides in Diagnostics