Identification and analysis of two Mycobacterium abscess with different morphology / 中华检验医学杂志

ABSTRACT

Two types of Mycobacterium abscesses (Mab) were found in sputum from a patient with severe pneumonia in May 2020. One was Mycobacteriumabscessus with smooth morphology (Mab S), the other was Mycobacteriumabscessus with rough morphology (Mab R). Both of them were compared and drug susceptibility testing were performed to provide clinical scientific diagnosis and treatment. Morphology, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA were used to analyze Mab S and Mab R, phylogenetic evolution tree was constructed by gene sequence alignment for homology, proportion and broth drug test were used for in vitro drug sensitivity test. There were morphological differences between Mab S and Mab R. MALDI-TOF MS analysis showed that there were 223 protein peaks in Mab R and 147 protein peaks in Mab S. Mab S contained 1 397 bp and Mab R contained 1 402 bp as 16s rRNA gene sequencing revealed. Drug susceptibility testing showed that both of them were almost resistant to all antituberculosis drugs, but sensitive to most of antibiotics. Mab S and Mab R were not only different in manifestations, but also in protein and gene comparison. Both of them were generally resistant to antituberculosis drugs. Antibiotic combined therapy has been confirmed to be an effective treatment in clinic.