title: Evaluation of bacteriologic culture of pooled fecal samples for detection of Mycobacterium paratuberculosis.
abstract: OBJECTIVE
  To compare sensitivity of several methods of bacteriologic culture of pooled bovine fecal samples for detection of Mycobacterium paratuberculosis and evaluate homogeneity in number of M paratuberculosis in pooled fecal samples.
  
  
  METHODS
  Feces from 10 dairy cows that shed M paratuberculosis at various concentrations and 1 dairy cow known to be free of infection with M paratuberculosis.
  
  
  METHODS
  5 fecal pooling methods, 2 culture methods, and 2 pool sizes were evaluated. Each pooled sample contained 1 infected sample and 4 or 9 uninfected samples.
  
  
  RESULTS
  Sensitivity of detection of M paratuberculosis was greater with smaller pool size (5 vs 10 samples/pool). Detection sensitivity was also associated with concentration of bacteria in the infected sample. Results indicated that, compared with concurrent bacterial culture of individual infected samples, 37 to 44% of pooled samples with low bacterial concentrations yielded positive culture results and 94% of pooled samples with high bacterial concentrations yielded positive results.
  
  
  CONCLUSIONS
  Bacteriologic culture of pooled fecal samples may provide a valid and cost-effective method of detecting M paratuberculosis infection in cattle herds.
authors.affiliation: College of Veterinary Medicine, Department of Clinical and Population Sciences, University of Minnesota, St Paul 55108-1004, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Wells
authors.forename: Robert H
authors.initials: RH
authors.lastname: Whitlock
authors.forename: Cynthia J
authors.initials: CJ
authors.lastname: Lindeman
authors.forename: Terry
authors.initials: T
authors.lastname: Fyock
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods / Q000592:standards / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D005260:Female; D016015:Logistic Models; D015999:Multivariate Analysis; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000175:diagnosis* / Q000382:microbiology; D015995:Prevalence