Disease caused by non-tuberculous mycobacteria species alone or in association with M. tuberculosis

B R IMPERIALE; A B DI GIULIO; NIEVES C; TARTARA S; MOYANO RD; M P SANTANGELO; M I ROMANO; MORCILLO N

Congreso; 37° Congreso Anual de la Sociedad Europea de Micobacteriología (ESM).; 2016

The non tuberculosis mycobacteria (NTM) term includes almost 170 species, all of them exerting a wide pathogenic spectrum from both humans? beings and animals.Objectives. To estimate the burden of NTM causing human disease (from 2006 to 2015) alone and in association with M. tuberculosis; to determine the proportion of cases due to rapid and slowly growers mycobacteria (RGM, SGM), the genetic diversity of Mycobacterium avium complex (MAC) causing disease, and also exploring the occurrence of cases infected by both NTM and M. tuberculosis(TB). Materials and Methods. Data collected from patients were: age; gender; disease localization; HIV infection; co-morbidities, previous tuberculosis and bacteriological results. Mycobacteria species were determined by the GenoType CMTM. M. abscessus ß?lactamases activity was explored by the iodine and the nitrocephine hydrolysis methods. Members of MAC were identified by IS1311-PCR and the IS901-PCR was specifically used to differentiate M. avium avium (MAA) from M. avium hominissuis (MAH). Genetic diversity of MAC was explored by the polymorphism presented in 8 MIRU-VNTR loci.Results. There were diagnosed 2,785 (7.8%) cases: 281 (10.1%) due to NTM and 2,504 (89.9%) to M. tuberculosis Complex (MTBC); 23 different NTM species were recovered. MAC was found in 139 cases, 85 cases due to MAH and 54 to M. intracellulare. RGM were isolated from 66 (23.5%) patients: M. abscessus ß?-lactamases positive, 30 cases, and M. fortuitum 10. The SGM showed a small decreasing trend while RGM showed a clear increasing trend albeit still with a low number of cases. The RGM figures (years 2009, 2011 and 2014) were mostly due to M. abscessus from surgical or cosmetic wounds. Until now, almost 30% of MAH were genotyped, 5 known patterns were found among 14 isolates (INMV 121, n: 4; INMV 92, n: 4; INMV 97, n: 2; INMV 103, n: 2; INMV 50, n: 2) and other 7 no previously reported patterns were also identified among other 8 isolates. The loci 292 and X3 had the highest D for MAH (0.658 and 0.5931) and the global discriminatory power (HGDI) was 0.9307. Mixed infections of MTBC associated to MAH were found in 4 cases, and in 3, 2 and 1 combined to M. intracellulare, M. abscessus and M. fortuitum respectively. MAC species with highly genetic diversity and M. abscessus were the most frequent pathogens after MTBC. Disease caused by mixed infections should be thought before making a right diagnosis and prescribing an appropriated treatment.