In:
Journal of Clinical Microbiology, American Society for Microbiology, Vol. 50, No. 4 ( 2012-04), p. 1390-1396
Kurzfassung:
Fluoroquinolone resistance in Mycobacterium tuberculosis can be conferred by mutations in gyrA or gyrB . The prevalence of resistance mutations outside the quinolone resistance-determining region (QRDR) of gyrA or gyrB is unclear, since such regions are rarely sequenced. M. tuberculosis isolates from 1,111 patients with newly diagnosed culture-confirmed tuberculosis diagnosed in Tennessee from 2002 to 2009 were screened for phenotypic ofloxacin resistance ( 〉 2 μg/ml). For each resistant isolate, two ofloxacin-susceptible isolates were selected: one with antecedent fluoroquinolone exposure and one without. The complete gyrA and gyrB genes were sequenced and compared with M. tuberculosis H37Rv. Of 25 ofloxacin-resistant isolates, 11 (44%) did not have previously reported resistance mutations. Of these, 10 had novel polymorphisms: 3 in the QRDR of gyrA , 1 in the QRDR of gyrB , and 6 outside the QRDR of gyrA or gyrB ; 1 did not have any gyrase polymorphisms. Polymorphisms in gyrA codons 1 to 73 were more common in fluoroquinolone-susceptible than in fluoroquinolone-resistant strains (20% versus 0%; P = 0.016). In summary, almost half of fluoroquinolone-resistant M. tuberculosis isolates did not have previously described resistance mutations, which has implications for genotypic diagnostic tests.
Materialart:
Online-Ressource
ISSN:
0095-1137
,
1098-660X
DOI:
10.1128/JCM.05286-11
Sprache:
Englisch
Verlag:
American Society for Microbiology
Publikationsdatum:
2012
ZDB Id:
1498353-9
SSG:
12
