title: Mycobacterium tuberculosis population structure shift in a 5-year molecular epidemiology surveillance follow-up study in a low endemic agro-industrial setting in São Paulo, Brazil.
abstract: Starting with 257 outpatients attending the specialized health service for tuberculosis (TB) between 2002 and 2006 in Araraquara, an agro-industrial area with low tuberculosis (TB) incidence in São Paulo state, Brazil, positive mycobacterial cultures were obtained in 130 cases, of which 121 were confirmed as Mycobacterium tuberculosis complex. This report assesses the genetic diversity observed on 69.42% (n=84) of the clinical isolates, for which both spoligotyping and 12-loci MIRU typing data were fully interpretable. In order to monitor changes in the population dynamics of circulating M. tuberculosis strains over time, spoligotypes were compared from this study (n=84) with an earlier study from 1998 to 2001 (n=70 strains); and these two datasets from low-incidence Araraquara area were also compared with a 2-year cohort in the nearby higher-incidence São Paulo city area from 2006 to 2008 (n=93). The results obtained showed that with 58.3% (49/84) of the strains, the Latin-American-Mediterranean (LAM) was the predominant lineage in the present follow-up study; major patterns being SIT42/LAM9 11.9% (10/84), and SIT20/LAM1 10.7% (9/84). As compared with the 1998-2001 period when 40% (28/70) of the isolates belonged to the ill-defined T family, it was replaced by LAM strains between 2002 and 2006 with a visible shift to a population structure characteristic of the metropolitan São Paulo city. Further typing of the follow-up isolates from 2002 to 2006 using 12 loci MIRUs in conjunction with conventional epidemiology did not link this population structure shift to an increase in ongoing transmission or drug-resistance. Instead, it is most probably linked to movements of the important migrant community of Araraquara to higher TB incidence metropolitan areas such as São Paulo city. This is of particular concern owing to the increment in the global burden of LAM strains and the recent association of certain LAM sublineages with multidrug- and extensively drug-resistant TB. These observations suggest the need for further molecular monitoring of the TB population structure and the evaluation of transmission trends amongst migrant workers and other risk groups, such as persons in homeless shelters, in correctional facilities, drug users, and those with HIV infection, etc.
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: Adolfo Carlos Barreto
authors.initials: AC
authors.lastname: Santos
authors.affiliation: Special Health Service of Araraquara - SESA, Araraquara, SP, Brazil.
authors.forename: Rosângela Maria
authors.initials: RM
authors.lastname: Gaspareto
authors.affiliation: Special Health Service of Araraquara - SESA, Araraquara, SP, Brazil.
authors.forename: Brunilde Helena Jung
authors.initials: BH
authors.lastname: Viana
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: Natália Helena
authors.initials: NH
authors.lastname: Mendes
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: José Rodrigo Cláudio
authors.initials: JR
authors.lastname: Pandolfi
authors.affiliation: Department of Clinical Analysis, State University of Maringá - UEM, Maringá, Paraná, Brazil.
authors.forename: Rosilene Fressatti
authors.initials: RF
authors.lastname: Cardoso
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: Daisy Nakamura
authors.initials: DN
authors.lastname: Sato
authors.affiliation: Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal.
authors.forename: Susana Correia de Matos
authors.initials: SC
authors.lastname: David
authors.affiliation: Cellular Microbiology Laboratory, IOC, FIOCRUZ, Rio de Janeiro, RJ, Brazil.
authors.forename: Maria Helena Feres
authors.initials: MH
authors.lastname: Saad
authors.affiliation: WHO Supranational TB Reference Laboratory, TB & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, F97183 Abymes, Guadeloupe, France. Electronic address: nrastogi@pasteur-guadeloupe.fr.
authors.forename: Nalin
authors.initials: N
authors.lastname: Rastogi
authors.affiliation: Department of Biological Sciences, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, SP, Brazil.
authors.forename: Clarice Queico Fujimura
authors.initials: CQ
authors.lastname: Leite
keywords: Brazil; Epidemiology; MIRU-VNTRs; Mycobacterium tuberculosis; Population-structure; Spoligotyping; Tuberculosis