TY - JOUR
T1 - Identification and genotyping of Mycobacterium tuberculosis isolated from water and soil samples of a metropolitan city
AU - Velayati, Ali Akbar
AU - Farnia, Parissa
AU - Mozafari, Mohadese
AU - Malekshahian, Donya
AU - Farahbod, Amir Masoud
AU - Seif, Shima
AU - Rahideh, Snaz
AU - Mirsaeidi, Mehdi
N1 - Publisher Copyright:
© 2015 American College of Chest Physicians.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - BACKGROUND: The potential role ofenvironmental Mycobacterium tuberculosis in the epidemiology of TB remains unknown. We investigated the transmission of M tuberculosis from humans to the environment and the possible transmission of M tuberculosis from the environment to humans. METHODS: A total of 1,500 samples were collected from three counties of the Tehran, Iran metropolitan area from February 2012 to January 2014. A total of 700 water samples (47%) and 800 soil samples (53%) were collected. Spoligotyping and the mycobacterial interspersed repetitive units-variable number of tandem repeats typing method were performed on DNA extracted from single colonies. Genotypes of M tuberculosis strains isolated from the environment were compared with the genotypes obtained from 55 patients with confirmed pulmonary TB diagnosed during the study period in the same three counties. RESULTS: M tuberculosis was isolated from 11 of 800 soil samples (1%) and 71 of 700 water samples (10%). T family (56 of 82, 68%) followed by Delhi/CAS (11 of 82, 13.4%) were the most frequent M tuberculosis superfamilies in both water and soil samples. Overall, 27.7% of isolates in clusters were related. No related typing patterns were detected between soil, water, and clinical isolates. The most frequent superfamily of M tuberculosis in clinical isolates was Delhi/CAS (142, 30.3%) followed by NEW-1 (127, 27%). The bacilli in contaminated soil (36%) and damp water (8.4%) remained reculturable in some samples up to 9 months. CONCLUSIONS: Although the dominant M tuberculosis superfamilies in soil and water did not correspond to the dominant M tuberculosis family in patients, the presence of circulating genotypes of M tuberculosis in soil and water highlight the risk of transmission.
AB - BACKGROUND: The potential role ofenvironmental Mycobacterium tuberculosis in the epidemiology of TB remains unknown. We investigated the transmission of M tuberculosis from humans to the environment and the possible transmission of M tuberculosis from the environment to humans. METHODS: A total of 1,500 samples were collected from three counties of the Tehran, Iran metropolitan area from February 2012 to January 2014. A total of 700 water samples (47%) and 800 soil samples (53%) were collected. Spoligotyping and the mycobacterial interspersed repetitive units-variable number of tandem repeats typing method were performed on DNA extracted from single colonies. Genotypes of M tuberculosis strains isolated from the environment were compared with the genotypes obtained from 55 patients with confirmed pulmonary TB diagnosed during the study period in the same three counties. RESULTS: M tuberculosis was isolated from 11 of 800 soil samples (1%) and 71 of 700 water samples (10%). T family (56 of 82, 68%) followed by Delhi/CAS (11 of 82, 13.4%) were the most frequent M tuberculosis superfamilies in both water and soil samples. Overall, 27.7% of isolates in clusters were related. No related typing patterns were detected between soil, water, and clinical isolates. The most frequent superfamily of M tuberculosis in clinical isolates was Delhi/CAS (142, 30.3%) followed by NEW-1 (127, 27%). The bacilli in contaminated soil (36%) and damp water (8.4%) remained reculturable in some samples up to 9 months. CONCLUSIONS: Although the dominant M tuberculosis superfamilies in soil and water did not correspond to the dominant M tuberculosis family in patients, the presence of circulating genotypes of M tuberculosis in soil and water highlight the risk of transmission.
UR - http://www.scopus.com/inward/record.url?scp=84927126678&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84927126678&partnerID=8YFLogxK
U2 - 10.1378/chest.14-0960
DO - 10.1378/chest.14-0960
M3 - Article
C2 - 25340935
AN - SCOPUS:84927126678
VL - 147
SP - 1094
EP - 1102
JO - Diseases of the chest
JF - Diseases of the chest
SN - 0012-3692
IS - 4
ER -