The International Journal of Mycobacteriology

ORIGINAL ARTICLE
Year
: 2021  |  Volume : 10  |  Issue : 4  |  Page : 379--387

Evaluation of drug susceptibility in nontuberculous mycobacteria using the SLOMYCO and RAPMYCO sensititre plates


Natalia Fernandes Garcia Carvalho, Carolina Salgado Pedace, Andreia Ramos Barbosa de Almeida, Fernanda Cristina dos Santos Simeão, Erica Chimara 
 Tuberculosis and Mycobacteriosis Laboratory, Institute Adolfo Lutz, São Paulo, Brazil

Correspondence Address:
Erica Chimara
Tuberculosis Laboratory, Institute Adolfo Lutz, São Paulo
Brazil

Background: Non-tuberculous Mycobacteria (NTM) cause different forms of diseases. According to recent guideline by ATS/ERS/ESCMID/IDSA, drug susceptibility test (DST) is an important requirement to choose adequate treatment. The minimum inhibitory concentration (MIC) test is the recommended method. Sensititre SLOMYCO and RAPMYCO commercial panels were developed to perform mycobacteria DST easier. However, there are only two comparative studies between SLOMYCO and the MIC method and none for the RAPMYCO panel. The present study aimed to evaluate the Sensititre SLOMYCO and RAPMYCO plates in determining drug susceptibility compared to the gold standard method (MIC). Methods: The tests were carried out with clinical isolates received in the diagnostic routine of the Tuberculosis Laboratory at Institute Adolfo Lutz from the most frequent species in the state of São Paulo, Brazil. Reference strains were tested for repeatability and reproducibility analyses. MIC and Sensititre plates readings were compared with and without resazurin stain. Agreement between results was defined as MIC within the same dilution or dilution variation resulting the same category in both tests. Results were classified by categorical errors. Results: The RAPMYCO panel had 100% agreement for the drugs amikacin, doxycycline, ciprofloxacin and trimethoprim/sulfamethoxazole, 83.3% for clarithromycin and moxifloxacin and 60% for cefoxitin. The SLOMYCO panel had 80% agreement for amikacin and moxifloxacin and 60% for clarithromycin, rifabutin, rifampicin and ciprofloxacin. The repeatability and reproducibility with RAPMYCO and SLOMYCO plates showed a high level of agreement for the drugs tested, being higher with the use of resazurin. However, an evaluation on routine condition is needed. Conclusions: The present study found that the fewer steps in the tests with Sensititre plates and reading with resazurin allow its use with greater safety and efficiency in the laboratory routine. The results presented here will facilitate the execution of a validation for complete incorporation of Sensititre plates into a diagnostic routine.


How to cite this article:
Garcia Carvalho NF, Pedace CS, Barbosa de Almeida AR, dos Santos Simeão FC, Chimara E. Evaluation of drug susceptibility in nontuberculous mycobacteria using the SLOMYCO and RAPMYCO sensititre plates.Int J Mycobacteriol 2021;10:379-387


How to cite this URL:
Garcia Carvalho NF, Pedace CS, Barbosa de Almeida AR, dos Santos Simeão FC, Chimara E. Evaluation of drug susceptibility in nontuberculous mycobacteria using the SLOMYCO and RAPMYCO sensititre plates. Int J Mycobacteriol [serial online] 2021 [cited 2022 Jan 25 ];10:379-387
Available from: https://www.ijmyco.org/article.asp?issn=2212-5531;year=2021;volume=10;issue=4;spage=379;epage=387;aulast=Garcia;type=0