Minimal Inhibitory Concentration of Clofazimine Among Clinical Isolates of Nontuberculous Mycobacteria and Its Impact on Treatment Outcome.

BACKGROUND: Clofazimine has been regarded as a promising agent for the treatment of nontuberculous mycobacteria pulmonary disease (NTM-PD). However, its overall effectiveness in vitro and in the clinic remains unknown. RESEARCH QUESTION: What is the minimal inhibitory concentration (MIC) of clofazimine in clinical isolates and the association between MICs and treatment outcome? STUDY DESIGN AND METHODS: MICs for clofazimine were measured in clinical isolates from NTM-PD patients who participated in a prospective study at Seoul National University Hospital. The MIC was determined by using the broth microdilution concentration method. Correlation between MIC and conversion to negative of sputum culture with clofazimine was determined. RESULTS: Of a total 189 isolates, 133 strains were Mycobacterium avium complex (MAC) and 40 strains were M abscessus. Although the clofazimine MICs for MAC ranged from 0.031 mg/L to 8 mg/L, the values obtained for M abscessus ranged from 0.031 mg/L to 16 mg/L. Of 20 patients who were treated with a regimen including clofazimine, eight achieved negative conversion of sputum culture. All patients with isolates exhibiting clofazimine MIC values ≤ 0.25 mg/L achieved culture conversion. The likelihood of culture conversion in patients with MIC value ≤ 0.25 mg/L was much higher than that of patients with MIC value > 0.5 mg/L (OR, 39.3; P = .021). INTERPRETATION: The MICs of clofazimine varied widely in clinical isolates from patients with NTM-PD. Negative conversion of sputum culture with clofazimine use was associated with a lower MIC value. Clofazimine use could be considered in patients with NTM-PD when the MIC value is ≤ 0.25 mg/L. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01616745; URL: www.clinicaltrials.gov.

State-of-the-art treatment strategies for nontuberculous mycobacteria infections.

INTRODUCTION: Non-tuberculous Mycobacteria (NTM) are a group of organisms whose importance in medicine seems to be increasing in recent times. The increasing number of patients susceptible to these diseases make it necessary to expand our knowledge of therapeutic options and to explore future possibilities for the development of a therapeutic arsenal. AREAS COVERED: In this review, the authors provide a brief introduction about the present importance of NTM and describe the present recommendations of the available guidelines for their treatment. They include a description of the future options for the management of these patients, especially focusing on new antibiotics. The authors also look at possibilities for future therapeutic options, such as antibiofilm strategies. EXPERT OPINION: No actual changes have been made to the current recommendations for the management of most NTM infections (except perhaps the availability of nebulized amikacin). However, it is also true that we have increased the number of available antibiotic treatment options with good in vitro activity against NTM. The use of these drugs in selected cases could increase the therapeutic possibilities. However, some problems are still present, such as the knowledge of the actual meaning of a NTM isolate, and will probably be a key part of future research.

Trypethelone and phenalenone derivatives isolated from the mycobiont culture of Trypethelium eluteriae Spreng. and their anti-mycobacterial properties.

The metabolites of the mycobiont culture of the lichen Trypethelium eluteriae were isolated by column chromatography and preparative TLC. Nine compounds (1-9) including two new trypethelones, 8-methoxytrypethelone (6) and 5'-hydroxy-8-ethoxytrypethelone (9), together with four known trypethelones (3-4, 7-8), and two known phenalenones (1-2) were characterized. It is the first report of 8-methoxytrypethelone methyl ether (5) purification as a racemic mixture in T. eluteriae. Earlier, 7-hydroxyl-8-methoxyltrypethelone (10) was reported as new compound with erroneous spectroscopic data. This compound was identified later as 8-hydroxytrypethelone methyl ether (4). X-ray crystallographic structures of compounds 5-7 were elucidated for the first time. Phenalenones (1-2) and trypethelones (5-6 and 9) were the additional compounds discovered in the cultured mycobiont of T. eluteriae. Six compounds (1-2, 5-8) were screened against Mycobacterium tuberculosis H37Rv and two compounds (7-8) against non-tuberculosis mycobacteria and other human pathogenic bacteria. Compound (7) inhibited M. tuberculosis H37Rv strain with an MIC of 12.5 µg/mL.

Pharmacotherapy Approaches in Nontuberculous Mycobacteria Infections.

Nontuberculous mycobacteria (NTM) comprise a heterogeneous group of organisms, with only a small subset known to cause disease in humans. Although NTM infection is not a reportable disease, both the increasing clinical recognition and recent advancements in laboratory diagnostic capabilities of NTM infections in immunocompromised and immunocompetent patients are rapidly evolving. We reviewed antimicrobial agents used to treat the most frequently encountered NTM infections and examined optimized drug dosing strategies, toxicity profiles, drug-drug interactions, and the role of therapeutic drug monitoring. Antimicrobial susceptibility testing and patient monitoring on therapy were also examined. We used PubMed to review the published literature on the management of select NTM pathogens, the common syndromes encountered since 2000, and select pharmacokinetic principles of select antimicrobial agents used since 1990. We included select clinical trials, systematic reviews, published guidelines, and observational studies when applicable. The prolonged duration and the necessity for combination therapy for most forms of NTM disease can be problematic for many patients. A multidisciplinary care team that includes pharmacy engagement may help increase rates of optimal patient tolerability and successful treatment completion.

Clofazimine inhalation suspension for the aerosol treatment of pulmonary nontuberculous mycobacterial infections.

BACKGROUND: Nontuberculous mycobacteria are recognized as a concern for cystic fibrosis (CF) patients due to increasing disease prevalence and the potential for detrimental effects on pulmonary function and mortality. Current standard of care involves prolonged systemic antibiotics, which often leads to severe side effects and poor treatment outcomes. In this study, we investigated the tolerability and efficacy of a novel inhaled therapeutic in various mouse models of NTM disease. METHODS: We developed clofazimine inhalation suspension (CIS), a novel formulation of clofazimine developed for inhaled administration. To determine the efficacy, minimum inhibitory concentrations were evaluated in vitro, and tolerability of CIS was determined in naïve mouse models over various durations. After establishing tolerability, CIS efficacy was tested in in vivo infection models of both Mycobacterium avium and M. abscessus. Lung and plasma clofazimine levels after chronic treatments were evaluated. RESULTS: Clofazimine inhalation suspension demonstrated antimycobacterial activity in vitro, with MIC values between 0.125 and 2 µg/ml for M. avium complex and M. abscessus. Administration into naïve mice showed that CIS was well tolerated at doses up to 28 mg/kg over 28 consecutive treatments. In vivo, CIS was shown to significantly improve bacterial elimination from the lungs of both acute and chronic NTM-infected mouse models compared to negative controls and oral clofazimine administration. Clofazimine concentrations in lung tissue were approximately four times higher than the concentrations achieved by oral dosing. CONCLUSION: Clofazimine inhalation suspension is a well tolerated and effective novel therapeutic candidate for the treatment of NTM infections in mouse models.

Synergistic potential of Juniperus communis and Helichrysum italicum essential oils against nontuberculous mycobacteria.

OBJECTIVE: The present study evaluated the possible synergistic antimycobacterial interactions of Juniperus communis and Helichrysum italicum essential oils (EO). METHODS: Antimycobacterial potential was tested against Mycobacterium avium and Mycobacterium intracellulare using broth and water dilution method and checkerboard synergy method. Antiadhesion and antibiofilm effect of EOs was evaluated on biotic (HeLa cells) and abiotic surface (polystyrene). To evaluate the possible mechanisms of action, cellular leakage of proteins and DNA was tested and structural changes were visualized with a transmission electron microscope. RESULTS: MIC, minimum bactericidal concentration (MBC) and minimal effective concentration (MEC) were 1.6 mg ml-1 for J. communis EO and 3.2 mg ml-1 for H. italicum EO against both mycobacteria. All combinations of EOs in checkerboard synergy method produced fractional inhibitory concentration index values ranging from 0.501 to 1.5, corresponding to synergistic, additive or indifferent effects. Mycobacterium avium showed a greater tendency to create biofilm but these EOs at subinhibitory concentrations (sMIC) effectively blocked the adhesion and the establishment of biofilm. The exposure of both mycobacteria to MICs and sMICs lead to significant morphological changes: acquired a swollen form, ghost-like cell, disorganized cytoplasm detached from the cell wall. OD value of supernatant for both mycobacteria exposed to EOs have confirmed that there is a leakage of cellular material. CONCLUSION: The leakage of the cellular material is noticeably higher in sMIC, which is probably due to cell wall damage. sMIC of both EOs have an additive or synergistic effect, reducing MICs, limiting adhesion and preventing the formation of biofilms.

Repurposing disulfiram to target infections caused by non-tuberculous mycobacteria.

BACKGROUND: Non-tuberculous mycobacteria are emerging pathogens of significant worldwide interest because they have inherent drug resistance to a wide variety of FDA-approved drugs and cause a broad range of serious infections. In order to identify new drugs active against non-tuberculous mycobacteria, we identified disulfiram, utilized for treatment of alcohol dependence, as exhibiting potent growth-inhibitory activity against non-tuberculous mycobacteria. METHODS: Whole-cell growth inhibition assays were used to screen and identify novel inhibitors. The hit compounds were tested against Vero cells to determine the selectivity index, and this was followed by determining time-kill kinetics against Mycobacterium fortuitum and Mycobacterium abscessus. Disulfiram's ability to synergize with several approved drugs utilized for the treatment of M. fortuitum and M. abscessus was determined using fractional inhibitory concentration indexes followed by determining its ability to reduce mycobacterial infections ex vivo. Finally, disulfiram's in vivo potential was determined in a neutropenic murine model mimicking mycobacterial infection. RESULTS: We identified disulfiram as possessing potent antimicrobial activity against non-tuberculous mycobacteria. Disulfiram exhibited concentration- and time-dependent bactericidal activity against M. fortuitum as well as against M. abscessus and synergized with all drugs utilized for their treatment. Additionally, disulfiram reduced bacterial load in macrophages in an intracellular killing assay better than amikacin. When tested in a murine neutropenic M. fortuitum infection model, disulfiram caused significant reduction in bacterial load in kidneys. CONCLUSIONS: Disulfiram exhibits all properties required for it to be repositioned as a novel anti-mycobacterial therapy and possesses a potentially new mechanism of action. Thus, it can be considered as a potent structural lead for the treatment of non-tuberculous mycobacterial infections.

Portuguese in vitro antibiotic susceptibilities favor current nontuberculous mycobacteria treatment guidelines.

SETTING: Nontuberculous mycobacteria (NTM) are increasingly recognized as causative agents of opportunistic infections in humans for which effective treatment is challenging. There is, however, very little information on the prevalence of NTM drug resistance in Portugal. OBJECTIVE AND DESIGN: Our aim was to analyze the drug susceptibility testing (DST) performed in NTM at the Portuguese National Health Institute Dr. Ricardo Jorge from February 2003 to February 2016. A total of 262 DST were included in the analysis. RESULTS: Most (94%) M. avium intracellulare complex isolates showed in vitro susceptibility to clarithromycin. All M. kansasii isolates were susceptible to rifampicin and ethambutol and 97.1% were susceptible to isoniazid. The majority of rapidly-growing mycobacteria (RGM) demonstrated in vitro susceptibility to amikacin, clarithromycin and cefoxitin. However, in RGM there was a marked increase on the relative risk of having sulfamethoxazole resistance in isolates resistant to ciprofloxacin compared to susceptible isolates. CONCLUSION: Tested NTM in Portugal revealed in vitro susceptibility to most of the antimicrobials currently recommended for treatment. However, our results also suggest that sulfamethoxazole should be avoided in treatment of RGM resistant to ciprofloxacin (or vice versa). Further trials that correlate the in vitro DST results with the clinical outcome are needed in order to reach conclusions on efficient antimicrobial therapy.

Treatment of Other Nontuberculous Mycobacteria.

Nontuberculous mycobacteria (NTM) are numerous, and for the vast majority of them, randomized studies are lacking and data regarding optimal treatment are limited. When Mycobacterium avium complex (MAC) and M. abscessus are excluded, the main NTM are M. xenopi, M. kansasii, M. malmoense, M. szulgai, and M. simiae. Treatment is long (at least 12 months after culture conversion according to recommendations by scientific societies) and difficult (at least three drugs are required, each of which have potential adverse events). Moreover, optimal treatment is unknown for the vast majority of NTM and efficacy of treatment is not 100%. That is why, balance between benefit and risk is fundamental. For M. xenopi, the second most common NTM isolated in Europe, treatment is classically based on macrolides or fluoroquinolones, associated with ethambutol and rifampicin. For M. kansasii, the cornerstone of treatment is rifampicin, which should be associated with two other drugs: ethambutol plus isoniazid or clarithromycin. M. malmoense, which is common in Northern Europe, can be treated by rifampicin, ethambutol, and clarithromycin and/or fluoroquinolones.

In Vitro Anti-mycobacterial Activity of Three Medicinal Plants of Lamiaceae Family.

BACKGROUND: Mycobacterium tuberculosis as an intracellular pathogen causes Tuberculosis (TB). Due to the long time required for treatment, hepatotoxicity of drugs and also emergence of Multidrug-Resistant (MDR) and Extremely Drug Resistant (XDR) strains, TB is currently a major public health problem. Some medicinal plants possess remarkable activity against Mycobacterium. Among them, Lamiaceae family are of pharmaceutical interest because of their potential antimicrobial properties. The aim of the study was to evaluate the in vitro activities of Satureja rechingeri, Satureja khuzestanica and Zataria multiflora against MDR M. tuberculosis and two Non-Tuberculous Mycobacteria (NTM). METHODS: The essential oils were prepared by the standard method. The confirmed strains were obtained from the microbial collection of Tehran University of Medical Sciences. Minimum Inhibitory Concentrations (MICs) of essential oils of plants against mycobacterial strains were determined using standard broth microdilution method. RESULTS: MDR M. tuberculosis was completely inhibited by Z. multiflora at 78µg/ml concentration. S. rechingeri and S. khuzestanica also showed same anti-mycobacterial activity against MDR M. tuberculosis with MICs of 156 µg/ml. The MICs of the essential oils against M. tuberculosis H37Rv, M. kansasii and M. fortuitum were in the range from 39 to 156 µg/ml. CONCLUSION: The studied medicinal plants showed notable effects against mycobacterial strains. Our results indicated that utilization of Lamiaceae family can be helpful for treatment of mycobacterial infections.

Clinical, Radiological, and Microbiological Characteristics of Mycobacterium simiae Infection in 97 Patients.

Mycobacterium simiae is a rare species of slow-growing nontuberculous mycobacteria (NTM). From 2002 to 2017, we conducted a retrospective study that included all patients with NTM-positive respiratory samples detected in two university hospitals of the French overseas department of Reunion Island. We recorded the prevalence of M. simiae in this cohort, as well as the clinical, radiological, and microbiological features of patients with at least 1 sample positive for M. simiae In our cohort, 97 patients (15.1%) were positive for M. simiae Twenty-one patients (21.6%) met the American Thoracic Society (ATS) criteria for infection. M. simiae infection was associated with bronchiectasis, micronodular lesions, and weight loss. Antibiotic susceptibility testing was performed for 60 patients, and the isolates were found to have low susceptibility to antibiotics, except for amikacin, fluoroquinolones, and clarithromycin. Treatment failed for 4 of the 8 patients treated for M. simiae infection. Here, we describe a specific cluster corresponding to a large cohort of patients with M. simiae, a rare nontuberculous mycobacterium associated with low pathogenicity and poor susceptibility to antibiotics.

Antibiotic resistance in Mycobacterium Abscessus and Mycobacterium Fortuitum isolates from Malaysian patients.

BACKGROUND: Rapidly growing mycobacterial species (RGM) are increasingly being recognized as the cause of various superficial and deep infections in humans. Two of the species most frequently isolated from clinical specimens are Mycobacterium abscessus and Mycobacterium fortuitum. Both species are associated with antibiotic resistances that may complicate therapy. This paper describes the pattern of resistance to five antibiotics commonly prescribed for RGM infections, in M. abscessus and M. fortuitum isolated from Malaysian patients. METHODS: The bacterial strains studied were examined with Etest strips to determine their minimum inhibitory concentrations (MICs) toward amikacin, ciprofloxacin, clarithromycin, imipenem, and linezolid. RESULTS: Among 51 M. abscessus isolates examined by the Etest, the overall MICs of ciprofloxacin, imipenem, amikacin, clarithromycin, and linezolid showed resistance rates of 33.3%, 31.4%, 2.0%, 5.9%, and 21.6%, to the five antibiotics, respectively. M. abscessus subspecies abscessus was more resistant than M. abscessus subsp. massilience to ciprofloxacin, imipenem, and linezolid but was more susceptible to clarithromycin and amikacin. M. fortuitum isolates were significantly less resistant than M. abscessus to ciprofloxacin (3.6%) and imipenem (7.1%) but more resistant to clarithromycin (42.9%) and linezolid (39.3%). CONCLUSION: A suitable combination therapy for Malaysian patients would be amikacin plus clarithromycin and ciprofloxacin, to cover infections by all three M. abscessus subspecies and M. fortuitum.

Antibiofilm activity of nanoemulsions of Cymbopogon flexuosus against rapidly growing mycobacteria.

Rapidly growing mycobacteria (RGM) are opportunistic microorganisms that can cause both local and disseminated infections. When in biofilm, these pathogens become highly resistant to antimicrobials used in clinical practice. Composed abundantly of polymeric substances, biofilms delay the diffusion of antimicrobials, preventing the drug from penetrating the deeper layers and having an effective action. Therefore, the search for new and alternative therapeutic options has become of fundamental importance. Natural products fall into these options, especially essential oils. However, these oils present problems, such as low miscibility in water (which decreases its bioavailability) and degradation by light and temperature. Thus, the objective of this work was to explore the action of free essential oil and nanoemulsions of Cymbopogon flexuosus on strains of RGM, in planktonic and sessile forms. In this work, standard strains of Mycobacterium fortuitum (ATCC 6841), Mycobacterium massiliense (ATCC 48898) and Mycobacterium abscessus (ATCC 19977) were used. The susceptibility of the microorganisms in planktonic form was obtained by conventional microdilution techniques and by cell viability curve. The analysis of the antibiofilm activity was performed by a semi-quantitative macrotechnique. The nanoemulsion exhibited significant antimicrobial activity, with minimum inhibitory concentration values lower than those presented by the free essential oil, against strains in the planktonic state. However, both were efficient in destroying the already formed biofilm, whereas only the free oil inhibited the formation of mycobacterial biofilm. This study demonstrated the therapeutic potential of C. flexuosus essential oil, especially in its nanostructured form, which can be demonstrated against infections caused by rapidly growing mycobacteria.

Biological evaluation of diphenyleneiodonium chloride (DPIC) as a potential drug candidate for treatment of non-tuberculous mycobacterial infections.

BACKGROUND: Novel drug discovery against non-tuberculous mycobacteria is beset with a large number of challenges including the existence of myriad innate drug resistance mechanisms as well as a lack of suitable animal models, which hinders effective translation. In order to identify molecules acting via novel mechanisms of action, we screened the Library of Pharmacologically Active Compounds against non-tuberculous mycobacteria to identify such compounds. METHODS: Whole-cell growth inhibition assays were used to screen and identify novel inhibitors. The hit compounds were tested for cytotoxicity against Vero cells to determine the selectivity index, and time-kill kinetics were determined against Mycobacterium fortuitum. The compound's ability to synergize with amikacin, ceftriaxone, ceftazidime and meropenem was determined using fractional inhibitory concentration indexes followed by its ability to decimate mycobacterial infections ex vivo. Finally, the in vivo potential was determined in a neutropenic murine model mimicking mycobacterial infection. RESULTS: We have identified diphenyleneiodonium chloride (DPIC), an NADPH/NADH oxidase inhibitor, as possessing potent antimicrobial activity against non-tuberculous mycobacteria. DPIC exhibited concentration-dependent bactericidal activity against M. fortuitum and synergized with amikacin, ceftriaxone, ceftazidime and meropenem. When tested in a murine neutropenic M. fortuitum infection model, DPIC caused a significant reduction in bacterial load in kidney and spleen. The reduction in bacterial count is comparable to amikacin at a 100-fold lower concentration. CONCLUSIONS: DPIC exhibits all properties to be repositioned as a novel anti-mycobacterial therapy and possesses a potentially new mechanism of action. Thus, it can be projected as a potential new therapeutic against ever-increasing non-tuberculous mycobacterial infections.

Clofazimine-Containing Regimen for the Treatment of Mycobacterium abscessus Lung Disease.

Patients with lung disease caused by Mycobacterium abscessus subsp. abscessus (here M. abscessus) typically have poor treatment outcomes. Although clofazimine (CFZ) has been increasingly used in the treatment of M. abscessus lung disease in clinical practice, there are no reported data on its effectiveness for this disease. This study sought to evaluate the clinical efficacy of a CFZ-containing regimen for the treatment of M. abscessus lung disease. We performed a retrospective review of the medical records of 42 patients with M. abscessus lung disease who were treated with CFZ-containing regimens between November 2013 and January 2015. CFZ was administered in combination with other antibiotics as an initial antibiotic regimen in 15 (36%) patients (initial treatment group), and it was added to an existing antibiotic regimen for refractory M. abscessus lung disease in 27 (64%) patients (salvage treatment group). Overall, there was an 81% treatment response rate based on symptoms and a 31% response rate based on radiographic findings. Conversion to culture-negative sputum samples was achieved in 10 (24%) patients after CFZ-containing antibiotic treatment, and during treatment, there were significant decreases in the positivity of semiquantitative sputum cultures for acid-fast bacilli in both the initial (P = 0.018) and salvage (P = 0.001) treatment groups. Our study suggests that CFZ-containing regimens may improve treatment outcomes in patients with M. abscessus lung disease and that a prospective evaluation of CFZ in M. abscessus lung disease is warranted.

Progression and Treatment Outcomes of Lung Disease Caused by Mycobacterium abscessus and Mycobacterium massiliense.

BACKGROUND: Mycobacterium abscessus and Mycobacterium massiliense are grouped as the Mycobacterium abscessus complex. The aim of this study was to elucidate the differences between M. abscessus and M. massiliense lung diseases in terms of progression rate, treatment outcome, and the predictors thereof. METHODS: Between 1 January 2006 and 30 June 2015, 56 patients and 54 patients were diagnosed with M. abscessus and M. massiliense lung diseases, respectively. The time to progression requiring treatment and treatment outcomes were compared between the 2 groups of patients, and predictors of progression and sustained culture conversion with treatment were analyzed. In addition, mediation analysis was performed to evaluate the effect of susceptibility to clarithromycin on treatment outcomes. RESULTS: During follow-up, 21 of 56 patients with M. abscessus lung diseases and 21 of 54 patients with M. massiliense lung diseases progressed, requiring treatment. No difference was detected in the time to progression between the 2 patient groups. Lower body mass index, bilateral lung involvement, and fibrocavitary-type disease were identified as predictors of disease progression. Among the patients who began treatment, infection with M. massiliense rather than M. abscessus and the use of azithromycin rather than clarithromycin were associated with sustained culture conversion. The difference in treatment outcomes was partly mediated by the organism's susceptibility to clarithromycin. CONCLUSIONS: Progression rates were similar but treatment outcomes differed significantly between patients with lung disease caused by M. abscessus and M. massiliense. This difference in treatment outcomes was partly explained by the susceptibility of these organisms to clarithromycin.

High correlation of clinical criteria in the diagnosis of drug-resistant TB and prevalence of ofloxacin resistance.

OBJECTIVE: To study the drug resistance profile of patients with suspected multidrug-resistant tuberculosis (MDR-TB). MATERIAL AND METHODS: This was a prospective study conducted among patients with suspected MDR-TB attending the Department of Respiratory Medicine, King George's Medical University, Lucknow, India, from August 2014 to April 2015. Sputum samples obtained from 50 such patients were subjected to drug susceptibility testing against first- and second-line drugs. Data on baseline characteristics were obtained from the patients and their previous medical records. RESULTS: Mycobacterium tuberculosis was detected in 47/50 (94%) and non-tuberculous mycobacteria (NTM) in 3/50 (6%). Of the 47 patients with M. tuberculosis, 36 (76.6%) had MDR-TB: 24 (66.7%) of these had pre-extensively drug-resistant TB (pre-XDR-TB) and 4 (11.1%) had XDR-TB. CONCLUSIONS: Among proven MDR-TB cases, approximately two thirds were pre-XDR-TB cases and more than 10% were XDR-TB cases. These form a sizeable proportion and may result in the failure of second-line treatment.

Antibiofilm effect of antimicrobials used in the therapy of mycobacteriosis.

Rapidly growing mycobacteria (RGM) are opportunistic pathogens found in the environment. When in biofilms, mycobacteria is highly resistant to antibacterial treatments. The purpose of this study is to evaluate the antibiofilm activity of antimicrobials commonly used in therapy against mycobacteria. The antimicrobial susceptibility of Mycobacterium abscessus, Mycobacterium fortuitum and Mycobacterium massiliense was determined in planktonic and sessile populations. The antimicrobials amikacin, ciprofloxacin, clarithromycin, doxycycline, imipenem and sulfamethoxazole were tested. For each drug, it was evaluated the susceptibility of the pathogen, the ability to inhibit biofilm formation and the resistance of biofilms to antimicrobial activity. Results showed although, the antimicrobials tested are used as an alternative therapy for RGM, M. abscessus proved to be resistant to clarithromycin, beside that, M. massiliense showed a resistant profile to clarithromycin and sulfamethoxazole. Moreover, the inhibition of biofilm formation and its destruction have not been fully met. Considering that the biofilms are a known form of bacterial resistance, the failure of alternatives to inhibit or destroy biofilms can trigger the recurrence of infections. In RGM, besides causing treatment failures, biofilms are a factor of pathogenic risk, since these microorganisms are found in environmental sources and can cause infections easily.