The diverse alleles of the katG gene associated with INH resistance are present in the M. tuberculosis isolates in Taiwan. These data may be applied to develop new probes for various alleles associated with INH resistance in order to increase the sensitivity for the detection of genetically diverse M. tuberculosis isolates in different geographic areas. The diversity of mutations can also provide information for investigating the evolutional lineages of M. tuberculosis isolates.

The most prevalent mutations of the rpoB gene were missense mutations in the critical codons, encoding Ser-531, Gln-513, Leu-533, Asp-516, and His-526. These mutations had high sensitivity and specificity for predicting the rifampicin-resistance of M. tuberculosis isolates. The resistance profiles and the frequencies of mutated codons of the rpoB gene varied in different geographic regions, indicating that resistance evolved under the selective pressure of the therapeutic regimens and the spread of different genetic clones.

The clonal spread of K. pneumoniae ST11 expressing OXA-48, KPC-2 and CTX-M-14 β-lactamases was the cause of an outbreak of CRKP. To the best of our knowledge, a single strain harbouring A-, B- and D-class carbapenemase genes has not previously been identified. There is a high prevalence of plasmid-encoded KPC-2- and OXA-48-producing CRKP in our hospital; most isolates were members of ST11, which may be representative of a high-risk CRKP clone disseminating in central Taiwan.