Spoligotyping and Variable Number Tandem Repeats (VNTR) analysis of M. bovis and Mycobacterium caprae strains isolated during the national eradication programme of bovine tuberculosis (bTB) in Italy, has been routinely performed since 2000. VNTR typing includes 5 ETRs and 7 QUBs/MIRU markers (QUB11a, QUB11b, QUB26, QUB1895, QUB15, QUB3232, MIRU26) selected for their high genotypic discriminatory power. This has enabled to obtain a national animal database (ITAN-TB) containing information and genotypes of 4291 M. bovis/M. caprae strains isolated from 2500 TB outbreaks as a supporting tool for epidemiological tracing of TB. In this study a collection of 141 M. bovis and 2 Mycobacterium caprae recovered from human patients in Lombardy, Tuscany, Piedmont and Emilia-Romagna, from 2000 to 2012, were characterized by the same genotyping method. We identified 45 spoligotypes, 9 of which (involving 12 strains) never described in the international website www.M.bovis.org and 14 (involving 17 strains) not reported in the animal database. The remaining 22 spoligotypes, representing 114 out of the 143 human strains, were already present in the ITAN-TB. The most frequent spoligotypes were SB0120, SB0134 and SB0841 found respectively in 41%, 7,9% and 5,9% of the human isolates and described as prevalent also in M. bovis population of animal origin (53,6%, 8,9% and 6,2%). Combination of the 22 spoligotypes present in the ITAN-TB, with VNTR analysis discriminated the 114 strains into 46 different genotypes, 31 of which unique in humans (differ by at least 2 VNTR markers compared to animal genotypes) and 15 identical or almost identical (single locus variation) to genotypes described in TB positive cattle/buffalo herds localized mainly in Southern Italy. In particular two genotypes were widespread both in human patients than in animal database: SB0134-ETR54534-VNTR 10, 4, 5, 4. 3, 5/6, 5 and SB120-ETR45533-VNTR 10, 4, 4, 4, 3, 6, 5/6 (order of markers as described above), found respectively in 4 and 6 patients and in 42 and 97 TB outbreaks. Interestingly most of M. bovis human isolates which showed a correspondence with animal genotype database were recovered from Italian-born patients.
Mycobacterium bovis isolates from humans: genetic profiles comparison with genotype database of animal tuberculosis strains isolated in Italy from 2000 to 2012
DAL MONTE, PAOLA;
2013
Abstract
Spoligotyping and Variable Number Tandem Repeats (VNTR) analysis of M. bovis and Mycobacterium caprae strains isolated during the national eradication programme of bovine tuberculosis (bTB) in Italy, has been routinely performed since 2000. VNTR typing includes 5 ETRs and 7 QUBs/MIRU markers (QUB11a, QUB11b, QUB26, QUB1895, QUB15, QUB3232, MIRU26) selected for their high genotypic discriminatory power. This has enabled to obtain a national animal database (ITAN-TB) containing information and genotypes of 4291 M. bovis/M. caprae strains isolated from 2500 TB outbreaks as a supporting tool for epidemiological tracing of TB. In this study a collection of 141 M. bovis and 2 Mycobacterium caprae recovered from human patients in Lombardy, Tuscany, Piedmont and Emilia-Romagna, from 2000 to 2012, were characterized by the same genotyping method. We identified 45 spoligotypes, 9 of which (involving 12 strains) never described in the international website www.M.bovis.org and 14 (involving 17 strains) not reported in the animal database. The remaining 22 spoligotypes, representing 114 out of the 143 human strains, were already present in the ITAN-TB. The most frequent spoligotypes were SB0120, SB0134 and SB0841 found respectively in 41%, 7,9% and 5,9% of the human isolates and described as prevalent also in M. bovis population of animal origin (53,6%, 8,9% and 6,2%). Combination of the 22 spoligotypes present in the ITAN-TB, with VNTR analysis discriminated the 114 strains into 46 different genotypes, 31 of which unique in humans (differ by at least 2 VNTR markers compared to animal genotypes) and 15 identical or almost identical (single locus variation) to genotypes described in TB positive cattle/buffalo herds localized mainly in Southern Italy. In particular two genotypes were widespread both in human patients than in animal database: SB0134-ETR54534-VNTR 10, 4, 5, 4. 3, 5/6, 5 and SB120-ETR45533-VNTR 10, 4, 4, 4, 3, 6, 5/6 (order of markers as described above), found respectively in 4 and 6 patients and in 42 and 97 TB outbreaks. Interestingly most of M. bovis human isolates which showed a correspondence with animal genotype database were recovered from Italian-born patients.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
