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ABSTRACTThe genetic diversity of 829 strains of Mycobacterium tuberculosisisolated during a 3-year period in Tuscany, Italy, a country with a low prevalence of tuberculosis, from 480 Italian-born and 349 foreign-born patients was determined by spoligotyping. The predominant spoligotype families were T (30.2% of isolates), Haarlem (19.9%), and the Latino-American and Mediterranean family (LAM) (11.2%); the remaining isolates were distributed among the Beijing (6.5%), S (4.2%), East Africa-India (EAI) (3.0%), Bovis (2.3%), Central Asia (CAS) (2.1%), Africanum (1.3%), and X (1.2%) families or were undefined (2.7%) or orphan (14.1%) isolates. Isolates of the families T, Haarlem, Bovis, and X were distributed among Italian- and foreign-born patients almost proportionally to the patients' numbers. Isolates of the LAM family were prevalent in foreign-born people (13.5%, versus 9.6% in Italian-born patients). Isolates of the S family were found almost exclusively in Italian-born patients, while strains of families EAI and CAS were isolated almost exclusively from foreign-born patients; Africanum isolates were all from African-born patients. The isolates of the Beijing family showed a trend to a steady increase during the survey. The prevalence of Beijing strains was 11.7% among foreign-born people and 2.7% among Italian-born patients. The Beijing strains were typed by the standardized IS6110restriction fragment length polymorphism assay, which yielded a total of 38 distinct IS6110patterns; 21 isolates (39.6%) occurred in six distinct clusters; of these, three contained two isolates and the other three contained four, five and six isolates, thus demonstrating that Beijing strains caused several tuberculosis outbreaks in the region. These findings indicate that transmission of Beijing strains between immigrants and the autochthonous population has occurred frequently and suggests an ongoing active transmission of the Beijing genotype in the region.

ABSTRACTIn order to achieve a better knowledge of Mycobacterium bovisepidemiology in Italy, 42 clinical isolates from humans were genotyped. Predominant molecular patterns were found in one cluster of 15 isolates sharing spoligotype (ST482), variable-number tandem repeat (VNTR), and IS6110-based restriction fragment length polymorphism (one 1.9-kb band) profiles and in two clusters of 6 and 3 Mycobacterium bovisBCG isolates differing by one VNTR character. The remaining 18 isolates yielded unique profiles. Our results confirm the potential utility of spoligotyping and VNTR typing as a major typing system of M. bovisisolates.

ABSTRACTMycobacterium tuberculosiscomplex isolates (n= 248) collected during a 1-year period in Tuscany, Italy, were genotyped for the katG463and gyrA95polymorphisms and by standard spacer oligonucleotide typing (spoligotyping) and IS6110restriction fragment length polymorphism (RFLP) assays. Most of the isolates (n= 212; 85.5%) belonged to genotypic groups 2 and 3, which included most isolates from Italian-born patients. The remaining isolates were genotypic group 1 organisms, which were prevalent among foreign-born patients (29 of 36; 80.6%). Spoligotype analysis detected 116 unique patterns and 34 clusters including 166 isolates. The combination of spoligotyping and IS6110RFLP analyses yielded 28 distinct clusters including 65 identical isolates (26.2%)—22 clusters with 2 isolates, 4 clusters with 3 isolates, 1 cluster with 4 isolates, and 1 cluster with 5 isolates—thus proving a low transmission rate in the community. Predominant spoligotypes representing 50% of clustered isolates were found in six clusters that included widespread type ST53 (clade T1) with 29 isolates (11.7% of total isolates); types ST50 and ST47 (Haarlem family) with 18 isolates (7.3%) and 8 isolates (3.2%), respectively; type ST42 (Latino-American and Mediterranean clade) with 13 isolates (5.2%); new type ST1737 (named “Tuscany”) with 8 isolates (3.2%); and type ST1 (W-Beijing family) with 7 isolates (2.8%). Other spoligotype families, such as the Mycobacterium africanum, East African-Indian (EAI2/Manila), and central Asia 1 (CAS1/Delhi) families (all including organisms of genotypic group 1) and the Cameroun family (genotypic group 2), were detected especially among immigrant patients. The occurrence of genotypes originally found in distant geographic areas with a high prevalence of tuberculosis may represent a hallmark for changes in the dynamics of transmission of tuberculosis in the region in the near future.

ABSTRACTHemolysin was quantified in 58 isolates of Mycobacterium aviumfrom human, animal, and environmental sources. Human Mav-A and Mav-B isolates were the strongest producers; in contrast, animal and environmental Mav-A isolates and human, animal, and environmental Mav-C organisms were low-level producers. Hemolysin production was not restricted to isolates causing invasive infections.