The mutations of katG and inhA genes of isoniazid-resistant Mycobacterium tuberculosis isolates in Taiwan.

Background/purpose: The isoniazid (INH) resistance of Mycobacterium tuberculosis is caused by mutations in the katG and inhA genes encoding for catalase-peroxidase and inhA, respectively. Sequences of the katG and inhA gene of 70 isolates were analyzed to identify the mutations and to compare the mutations with their related susceptibilities.

Methods: Sequences of the katG and inhA genes and the resistance profiles were analyzed for the 70 M.

Resistance profiles and rpoB gene mutations of Mycobacterium tuberculosis isolates in Taiwan.

Background/purpose: The rifampicin resistance of Mycobacterium tuberculosis is caused by mutations in the 81-base pair region of the rpoB gene encoding the β-subunit of RNA polymerase. Sequences of the rpoB gene of 68 isolates were analyzed to identify the mutations and to compare the mutations with their related susceptibilities.

Methods: Susceptibility tests of 68 M.

A single amino acid of niapro of papaya ringspot virus determines host specificity for infection of papaya.

Most strains of Papaya ringspot virus (PRSV) belong to type W, causing severe loss on cucurbits worldwide, or type P, devastating papaya in tropical areas. While the host range of PRSV W is limited to plants of the families Chenopodiaceae and Cucuribitaceae, PRSV P, in addition, infects plants of the family Caricaceae (papaya family). To investigate one or more viral genetic determinants for papaya infection, recombinant viruses were constructed between PRSV P-YK and PRSV W-CI.