title: Genotyping did not evidence any contribution of Mycobacterium bovis to human tuberculosis in Brazil.
abstract: The contribution of Mycobacterium bovis to the global burden of tuberculosis (TB) in man is likely to be underestimated due to its dysgonic growth characteristics and because of the absence of pyruvate in most used media is disadvantageous for its primary isolation. In Brazil Mycobacterium culture, identification and susceptibility tests are performed only in TB reference centers, usually for selected cases. Moreover, solid, egg-based, glycerol-containing (without pyruvate supplementation) Löwenstein-Jensen (L-J) or Ogawa media are routinely used, unfavouring M. bovis isolation. To determine the importance of M. bovis as a public health threat in Brazil we investigated 3046 suspected TB patients inoculating their clinical samples onto routine L-J and L-J pyruvate enriched media. A total of 1796 specimens were culture positive for Mycobacterium spp. and 702 TB cases were confirmed. Surprisingly we did not detect one single case of M. bovis in the resulting collection of 1674 isolates recovered from M. bovis favourable medium analyzed by conventional and molecular speciation methods. Also, bacillary DNA present on 454 sputum smears from 223 TB patients were OxyR genotyped and none was recognized as M. bovis. Our data indicate that M. bovis importance on the burden of human TB in Brazil is marginal.
authors.affiliation: Laboratory of Molecular Biology Applied to Mycobacteria, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil. adsrocha@hotmail.com
authors.forename: Adalgiza
authors.initials: A
authors.lastname: Rocha
authors.forename: Atina R
authors.initials: AR
authors.lastname: Elias
authors.forename: Luciana F
authors.initials: LF
authors.lastname: Sobral
authors.forename: Diego F
authors.initials: DF
authors.lastname: Soares
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Santos
authors.forename: Ana-Grazia
authors.initials: AG
authors.lastname: Marsico
authors.forename: Mariana A
authors.initials: MA
authors.lastname: Hacker
authors.forename: Paulo C
authors.initials: PC
authors.lastname: Caldas
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Parente
authors.forename: Marcio R
authors.initials: MR
authors.lastname: Silva
authors.forename: Leila
authors.initials: L
authors.lastname: Fonseca
authors.forename: Philip
authors.initials: P
authors.lastname: Suffys
authors.forename: Neio
authors.initials: N
authors.lastname: Boéchat
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D019411:Clinical Laboratory Techniques; D003611:Dairy Products / Q000009:adverse effects / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D015994:Incidence; D009163:Mycobacterium bovis / Q000235:genetics / Q000302:isolation & purification*; D011159:Population Surveillance; D012307:Risk Factors; D014376:Tuberculosis / Q000453:epidemiology* / Q000235:genetics / Q000635:transmission