Aminoglycoside Resistance in Mycobacterium kansasii, Mycobacterium avium-M. intracellulare, and Mycobacterium fortuitum: Are Aminoglycoside-Modifying Enzymes Responsible?
AUTOR(ES)
Ho, I. I. Y.
FONTE
American Society for Microbiology
RESUMO
Aminoglycoside acetyltransferase was detected in Mycobacterium kansasii and M. fortuitum but not in M. avium-M. intracellulare when they were screened by a radioassay. Aminoglycoside phosphotransferase and nucleotidyltransferase activities were absent from all three species tested. Acetyltransferases from both M. kansasii and M. fortuitum displayed relatively high Kms, all at the millimolar level, for substrates including tobramycin, neomycin, and kanamycin A. The Km of each substrate was well above the corresponding maximum achievable level in serum. The low affinities of these enzymes for their substrates suggested that drug modification in vivo was very unlikely. Among the various substrates tested, no apparent positive correlation was found between substrate affinity and resistance level. The presence of aminoglycoside-modifying enzymes in these mycobacterial species was therefore not shown to confer resistance to aminoglycosides.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=89625Documentos Relacionados
- Mycobacterium avium-M. intracellulare and Acquired Immunodeficiency Syndrome
- Isolator component responsible for inhibition of Mycobacterium avium-M. intracellulare in BACTEC 12B medium.
- Nomenclature of Genes Encoding Aminoglycoside-Modifying Enzymes
- Molecular genetics of aminoglycoside resistance genes and familial relationships of the aminoglycoside-modifying enzymes.
- Microplate phosphocellulose binding assay for aminoglycoside-modifying enzymes.
