Evaluation of the SLOMYCO Sensititre® panel for testing the antimicrobial susceptibility of Mycobacterium marinum isolates

Abstract

BackgroundThe agar dilution method is currently considered as the reference method for Mycobacterium marinum drug susceptibility testing (DST). As it is time-consuming, alternative methods, such as the E-test, were evaluated for M.marinum DST, but without success. The SLOMYCO Sensititre® panel, recently commercialized by TREK Diagnostic Systems (Cleveland, OH), can be used for DST in slow-growing mycobacteria and for antimicrobial agents recommended by the Clinical and Laboratory Standards Institute (CLSI) for M.marinum DST. The main goal of this work was to evaluate the SLOMYCO Sensititre® panel method for DST in M.marinum isolates from human patients and fish relative to the reference agar dilution method.Methods/ResultsThe reproducibility of the minimum inhibitory concentration (MIC) determination (±1 log2 dilution) was very good for both the agar dilution method and SLOMYCO Sensititre® panel (>90 % agreement). The percentage essential agreement between methods varied, depending on the drug: between 97 and 75 % for ciprofloxacin, moxifloxacin, linezolid, isoniazid, clarithromycin, amikacin, rifabutin and rifampin, 74 % for trimethoprim, 72 % for doxycycline, 70 % for sulfamethoxazole, 59 % for streptomycin, 33 % for ethambutol and only 2.2 % for ethionamide. When the agar dilution and SLOMYCO Sensititre® panel results were converted into interpretive criteria, the category agreement was 100 % for amikacin, ciprofloxacin, clarithromycin, moxifloxacin, rifabutin, sulfamethoxazole and trimethoprim, 98 % for ethambutol and 96 % for rifampin and no agreement for doxycycline.ConclusionsThe SLOMYCO Sensititre® panel method could provide a potential alternative to the reference agar dilution method, when DST in M.marinum is required, except for doxycycline.

Mandibular Nodule Caused by <i>Mycobacterium marinum</i> with False Positive Interferon-γ Release Assay

“…Mycobacterium marinum is a slow-growing nontuberculous photochromogenic mycobacteria. It is a ubiquitous waterborne organism, inhabiting fresh and saltwater and causes disease in many fish species and occasionally in humans ( 1 , 2 ). It is also known to cause a false positive reaction to interferon-γ (IFN-γ) release assay (IGRA) for the diagnosis of latent tuberculosis infection (LTBI) ( 3 , 4 ).…”

Heterologous Expression of ethA and katG in Mycobacterium marinum Enables the Rapid Identification of New Prodrugs Active against Mycobacterium tuberculosis

“…In addition, M. marinum has been proven to be a useful model for the identification of potential antimycobacterial compounds (7)(8)(9)(10). However, M. marinum and M. tuberculosis possess distinct susceptibility levels to a number of antimycobacterial drugs, notably, ethionamide (ETH) and isoniazid (INH) (7,11,12). These observations indicate that there are significant differences between M. tuberculosis and M. marinum, which may hinder the efficacy of antimycobacterial drug discovery when using M. marinum as a screening model.…”

“…The converted metabolites form adducts with NAD 1 and subsequently bind to inhibit InhA, which is essential for mycolic acid synthesis (16). In several studies, the MICs of ETH and INH were observed to be among the most contrasting between M. tuberculosis and M. marinum (11,12). For the activation of INH, this could be attributed to small differences between the KatG structures of M. marinum and M. tuberculosis (17).…”