Cell Wall Mycolic Acids Research Articles

Characterization of an Isolate of the Newly Described Species Mycobacterium interiectum

The phenotypic features of a clinical isolate of the new species Mycobacterium interjectum, identified on the basis of its 16S rRNA gene sequence, are compared with those of the type strain. The differentiation of M. interjectum from Mycobacterium gordonae or Mycobacterium scrofulaceum is not achievable on the basis of phenotypic traits usually tested for mycobacterial speciation, but it can be reached by 16S rRNA gene sequencing or by high performance liquid chromatography (HPLC) of cell wall mycolic acids. The former reveals sequence identity with the signature region of the type species, and the latter yields a profile which is easily differentiated from those of the other two species. The unique HPLC profile of M. interjectum is reported here for the first time and so are the MICs of a wide spectrum of drugs.

Identification of the newly described Mycobacterium poriferae from tuberculous lesions of snakehead fish ( Channa striatus)

A mycobacterium isolated form a cultured snakehead with nodular lesions was identified on the basis of high performance liquid chromatography (HPLC) profile of cell wall mycolic acids, and confirmed by conventional tests, as Mycobacterium poriferae, a species previously isolated only from a marine sponge. The profiles of M. poriferae, Mycobacterium aurum and Mycobacterium parafortuitum are here reported for the first time.

Characterization of Mycobacteria Species by HPLC and Pattern Recognition

Multivariate methods of analysis are used to characterize 36 mycobacteria species following high-performance liquid chromatography (HPLC) of extracts of mycolic acids. After growth of the bacterial cultures, cell wall mycolic acids are saponified, extracted, then derivatized to the p-bromophenacyl esters. Reversed-phase HPLC with gradient elution separates 38 peaks in 10 min, plus an internal standard. A training set of 276 samples is composed and classification models are developed to predict the mycobacteria species. Classifications during the training phase are 91 and 95% accurate for single-pass and multilevel approaches, respectively. Validation is performed with a 549-sample set; successful classifications of known species are 87 and 92%, respectively. Bunching the predictions of MAIS complex species into one category improves the latter result to 97% correctly classified species. Fourteen of the 27 species (including M. tuberculosis) are classified without error in the validation data set.

Biosynthesis and regulation of cell wall mycolic acid in mycobacteria

Biosynthesis and regulation of cell wall mycolic acid in mycobacteria