Correction to: Molecular characterization of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) isolates identifies local transmission of infection in Kuwait, a country with a low incidence of TB and MDR-TB.

The original publication of this article [1] contained few erroneous paragraphs and errors in Table 1 and Table 2. The first four paragraphs are in the 'Results' section while the last four paragraphs are in the 'Discussion' section. The errors in Table 1 involve the number of isolates tested for pyrazinamide and pyrazinamide susceptible isolates, ethambutol-susceptible isolates with a mutation and number of resistant isolates with a mutation for streptomycin. The error in Table 2 involves wrong codon number for a mutation in isolate KM17-01 in Cluster XII for gidB gene. The updated informations have been indicated in bold and also refer corrected Tables 1 and 2.

The original publication of this article [1] contained few erroneous paragraphs and errors in Table 1 and Table 2.
The first four paragraphs are in the 'Results' section while the last four paragraphs are in the 'Discussion' section. The errors in Table 1 involve the number of isolates tested for pyrazinamide and pyrazinamide susceptible isolates, ethambutol-susceptible isolates with a mutation and number of resistant isolates with a mutation for streptomycin. The error in Table 2 involves wrong codon number for a mutation in isolate KM17-01 in Cluster XII for gidB gene. The updated informations have been indicated in bold and also refer corrected Tables 1 and 2. Incorrect: Although all 93 MDR-TB isolates were tested for susceptibility to pyrazinamide, only 47 isolates yielded interpretable results; 11 isolates were susceptible and 36 were resistant to this drug including 15 isolates that were resistant to all five drugs. The remaining 46 MDR-TB strains failed to grow at the reduced pH in the absence of the drug.
Correct: Although all 93 MDR-TB isolates were tested for susceptibility to pyrazinamide, only 46 isolates yielded interpretable results; 10 isolates were susceptible and 36 were resistant to this drug including 15 isolates that were resistant to all five drugs. The remaining 47 MDR-TB strains failed to grow at the reduced pH in the absence of the drug.
Incorrect: The proportion of MDR-TB isolates exhibiting resistance conferring mutations in target genes varied for different anti-TB drugs, being highest for rifampicin and lowest for streptomycin (Table 1).
Correct: The proportion of MDR-TB isolates exhibiting resistance conferring mutations in target genes varied for different anti-TB drugs, being highest for rifampicin and lowest for streptomycin among SIRE drugs (Table 1).
Incorrect: PCR-sequencing of pncA identified mutations in 30 of 36 MDR-TB strains phenotypically resistant to pyrazinamide and 23 of 46 isolates for which phenotypic DST data for pyrazinamide was not available while all 11 isolates phenotypically susceptible to pyrazinamide contained wild-type sequence for pncA.
Correct: PCR-sequencing of pncA identified mutations in 30 of 36 MDR-TB strains phenotypically resistant to pyrazinamide and 23 of 47 isolates for which phenotypic DST data for pyrazinamide was not available while all 10 isolates phenotypically susceptible to pyrazinamide contained wild-type sequence for pncA.
Incorrect: Resistance conferring mutations in rpsL and/or rrs gene were detected in majority (49 of 59, 83%) of streptomycin-resistant but not in any streptomycinsusceptible MDR-TB strain while mutations in embB gene were detected in both ethambutol-resistant and -susceptible MDR-TB strains, as described in our previous studies [23,28].
Correct: Resistance conferring mutations in rpsL and/ or rrs gene were detected in majority (51 of 59, 86.4%) of streptomycin-resistant but not in any streptomycin-susceptible MDR-TB strain while mutations in embB gene were detected in both ethambutol-resistant and -susceptible MDR-TB strains, as described in our previous studies [23,28].
Incorrect: Phenotypic DST results for pyrazinamide were available for only 47 of 93 MDR-TB strains while the remaining 46 isolates failed to grow at lower pH. No pncA mutation was detected in 50 pansusceptible strains. Analysis of 93 MDR-TB strains showed that 30 of 36 MDR-TB strains phenotypically resistant to pyrazinamide and 23 of 46 isolates for which DST data for pyrazinamide was not available contained a mutation in pncA while all 11 MDR-TB strains phenotypically susceptible to pyrazinamide contained wild-type sequence for pncA.
Correct: Phenotypic DST results for pyrazinamide were available for only 46 of 93 MDR-TB strains while the remaining 47 isolates failed to grow at lower pH. No pncA mutation was detected in 50 pansusceptible strains. Analysis of 93 MDR-TB strains showed that 30 of 36 MDR-TB strains phenotypically resistant to pyrazinamide and 23 of 47 isolates for which DST data for pyrazinamide was not available contained a mutation in pncA while all 10 MDR-TB strains phenotypically susceptible to pyrazinamide contained wild-type sequence for pncA.
Incorrect: The two isolates in Cluster XII were also very closely related, with the second isolate (KM17-01) displaying an additional mutation (L95F) in gidB which is considered as a hot-spot for mutations in the M. tuberculosis genome [21,57].
Correct: The two isolates in Cluster XII were also very closely related, with the second isolate (KM17-01) ( Table 2) displaying an additional mutation (L59F) in