title: Thin layer microcolony culture associated with PCR for early identification of Mycobacterium bovis.
abstract: The initial growth of mycobacteria from 49 samples of cattle and buffalo organs collected in commercial slaughterhouses was compared between modified Middlebrook 7H11 thin layer microcolony culture and Stonebrink medium used in the isolation of Mycobacterium bovis. Aliquots were decontaminated by Petroff's method, processed and cultured in both media. The identity of the acid-fast bacilli stained by Ziehl-Neelsen was confirmed by PCR. Optical microscopy showed that results of the early observation of Mycobacterium bovis colonies in thin layer culture were similar to those obtained in macroscopic observation of the colonies in Stonebrink medium. However, early observation of the colonies enabled early confirmation by PCR, given the shorter time to the visualization of colonies when thin layer culture was used (between the 12(nd) and 25(th) day of culture).
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo São Paulo SP Brazil.
authors.forename: Tatiana Reis
authors.initials: TR
authors.lastname: do Rosário
authors.affiliation: Laboratório de Tuberculose Centro de Pesquisa e Desenvolvimento de Sanidade Animal Instituto Biológico de São Paulo São PauloSP Brazil.
authors.forename: Cristina Corsi
authors.initials: CC
authors.lastname: Dib
authors.affiliation: Laboratório de Tuberculose Centro de Pesquisa e Desenvolvimento de Sanidade Animal Instituto Biológico de São Paulo São PauloSP Brazil.
authors.forename: Eliana
authors.initials: E
authors.lastname: Roxo
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo São Paulo SP Brazil.
authors.forename: Sônia Regina
authors.initials: SR
authors.lastname: Pinheiro
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo São Paulo SP Brazil.
authors.forename: Silvio Arruda
authors.initials: SA
authors.lastname: Vasconcellos
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo São Paulo SP Brazil.
authors.forename: Nilson Roberti
authors.initials: NR
authors.lastname: Benites
mesh_terms: D000003:Abattoirs; D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods*; D002417:Cattle; D008460:Meat / Q000382:microbiology*; D008853:Microscopy; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009163:Mycobacterium bovis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D013194:Staining and Labeling; D013997:Time Factors; D014380:Tuberculosis, Bovine / Q000175:diagnosis*
keywords: Mycobacterium bovis; PCR; cattle and buffalo organs; thin layer; tuberculosis