title: Detection and molecular characterization of Mycobacterium microti isolates in wild boar from northern Italy.
abstract: Approximately 23,000 hunter-harvested wild boars from the pre-Alpine area of northern Italy were examined for tuberculosis over a 9-year period (2003 to 2011). Retropharyngeal and mandibular lymph nodes from the wild boars were examined grossly, and 1,151 of the lymph nodes were analyzed in our laboratory by histology (728 samples) and culture isolation (819 samples). Mycobacterium tuberculosis complex (MTBC)-specific PCR (1,142 samples) was used for molecular-level detection in tissue samples, as was a gyrB restriction fragment length polymorphism (RFLP) assay (322 samples). Lesions compatible with tuberculosis and indistinguishable from those described in cases of Mycobacterium bovis infection had been observed since 2003. Mycobacterium microti was identified directly in 256 tissue samples by the adopted molecular approaches. However, only 26 M. microti strains were obtained by culture isolation due to the well-known difficulties in isolating this slow-growing mycobacterium. During 2006, a prevalence study was performed in two provinces of the area, and the diffusion of M. microti was calculated to be 5.8% (95% confidence intervals surrounding the estimated prevalences [CIP95%], 3.94 to 7.68%). Over the following years (2007 to 2011), the presence of M. microti appeared to be stable. All isolates were genotyped by spoligotyping and exact tandem repeat analysis (ETR types A to F). In addition to the typical vole type (SB0118), a new spoligotype lacking the 43 spacers was found. Spoligotyping was also applied directly to tissue samples, and a geographical cluster distribution of the two spoligotypes was observed. This is the first report studying the diffusion and genetic variability of M. microti in wild boar.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy mariabeatrice.boniotti@izsler.it.
authors.forename: M Beatrice
authors.initials: MB
authors.lastname: Boniotti
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Gaffuri
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Gelmetti
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Tagliabue
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Chiari
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Mangeli
authors.affiliation: Azienda Sanitaria Locale della Provincia di Brescia, Brescia, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Spisani
authors.affiliation: Unità Organizzativa Veterinaria, Direzione Generale Salute, Regione Lombardia, Piazza Città di Lombardia, Milan, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Nassuato
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Gibelli
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sacchi
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Zanoni
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna: Centro Nazionale di Referenza per la Tubercolosi Bovina, Brescia, Italy.
authors.forename: M Lodovica
authors.initials: ML
authors.lastname: Pacciarini
mesh_terms: D000818:Animals; D005838:Genotype; D007558:Italy / Q000453:epidemiology; D008198:Lymph Nodes / Q000382:microbiology; D058889:Molecular Typing; D009161:Mycobacterium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D034421:Sus scrofa / Q000382:microbiology*; D014376:Tuberculosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*