Sitafloxacin-Containing Regimen for the Treatment of Refractory Mycobacterium avium Complex Lung Disease

Clinical Outcome with Standard Regimen plus Clofazimine or Moxifloxacin in Cavitary Mycobacterium avium Complex Pulmonary Disease

In this retrospective analysis including 173 patients in a tertiary referral center in South Korea, compared with the standard therapeutic regimen, clofazimine or moxifloxacin plus standard treatment regimen potentially did not induce a higher 1-year culture conversion rate in patients with Mycobacterium avium complex pulmonary disease who present with cavitary lesions (fibrocavitary or cavitary nodular bronchiectatic type).

Treatment strategies with alternative treatment options for patients with Mycobacterium avium complex pulmonary disease

Diseases caused by Mycobacterium avium complex (MAC) infection in the lungs are increasing worldwide. The recurrence rate of MAC-pulmonary disease (PD) has been reported to be as high as 25-45%. A significant percentage of recurrences occurs because of reinfection with a new genotype from the environment. A focus on reducing exposure to MAC organisms from the environment is therefore an essential component of the management of this disease as well as standard MAC-PD treatment. A macrolide-containing three-drug regimen is recommended over a two-drug regimen as a standard treatment, and azithromycin is recommended rather than clarithromycin. Both the 2007 and 2020 guidelines recommend a treatment duration of MAC-PD of at least one year after the culture conversion. Previous clinical studies have reported that ethambutol could prevent macrolide resistance. Furthermore, the concomitant use of aminoglycoside, amikacin liposomal inhalation, clofazimine, linezolid, bedaquiline, and fluoroquinolone with modification of guideline-based therapy has been studied. Long-term management of MAC-PD remains challenging because of the discontinuation of multi-drug regimens and the acquisition of macrolide resistance. Moreover, the poor compliance of guideline-based therapy for MAC-PD treatment worldwide is concerning since it causes macrolide resistance. Therefore, in this review, we focus on MAC-PD treatment and summarize various treatment options when standard treatment cannot be maintained, with reference to the latest ATS/ERS/ESCMID/IDSA clinical practice guidelines revised in 2020.

Sitafloxacin Expresses Potent Anti-Mycobacterium abscessus Activity

Therapeutic options for treating Mycobacterium abscessus infections are extremely limited; quinolones are important. The in vitro anti-M. abscessus activities of nine quinolones, emphasizing sitafloxacin, were investigated. Antimicrobial susceptibility testing was performed on 10 non-tuberculous mycobacterium reference strains and 194 clinical, M. abscessus isolates. The activity of sitafloxacin against intracellular M. abscessus residing within macrophages was also evaluated. A checkerboard assay was conducted to determine synergy between sitafloxacin and 10 clinically important antibiotics. Among the nine quinolones tested, sitafloxacin exhibited the greatest anti-M. abscessus activity with MIC₅₀ and MIC₉₀ of 1 and 2 mg/L, respectively. Sitafloxacin exerted a bacteriostatic effect on M. abscessus and inhibited the intracellular growth of M. abscessus at concentrations equivalent to clarithromycin. No antagonism between sitafloxacin and 10 clinically important anti-M. abscessus antibiotics was evident. In summary, sitafloxacin exhibited a significant advantage relative to other quinolones in inhibiting the growth of M. abscessus in vitro, suggesting the potential inclusion of sitafloxacin in new strategies to treat M. abscessus infections.

Anti-Mycobacterial Drug Resistance in Japan: How to Approach This Problem?

Mycobacteriosis is mainly caused by two groups of species: Mycobacterium tuberculosis and non-tuberculosis mycobacteria (NTM). The pathogens cause not only respiratory infections, but also general diseases. The common problem in these pathogens as of today is drug resistance. Tuberculosis (TB) is a major public health concern. A major challenge in the treatment of TB is anti-mycobacterial drug resistance (AMR), including multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. Recently, the success rate of the treatment of drug-resistant tuberculosis (DR-TB) has improved significantly with the introduction of new and repurposed drugs, especially in industrialized countries such as Japan. However, long-term treatment and the adverse events associated with the treatment of DR-TB are still problematic. To solve these problems, optimal treatment regimens designed/tailor-made for each patient are necessary, regardless of the location in the world. In contrast to TB, NTM infections are environmentally oriented. Mycobacterium avium-intracellulare complex (MAC) and Mycobacterium abscessus species (MABS) are the major causes of NTM infections in Japan. These bacteria are naturally resistant to a wide variation of antimicrobial agents. Macrolides, represented by clarithromycin (CLR) and amikacin (AMK), show relatively good correlation with treatment success. However, the efficacies of potential drugs for the treatment of macrolide-resistant MAC and MABS are currently under evaluation. Thus, it is particularly difficult to construct an effective treatment regimen for macrolide-resistant MAC and MABS. AMR in NTM infections are rather serious in Japan, even when compared with challenges associated with DR-TB. Given the AMR problems in TB and NTM, the appropriate use of drugs based on accurate drug susceptibility testing and the development of new compounds/regimens that are strongly bactericidal in a short-time course will be highly expected.

Minimum Inhibitory Concentrations before and after Antibacterial Treatment in Patients with Mycobacterium abscessus Pulmonary Disease

The clinical importance of Mycobacterium abscessus (MABS) pulmonary disease has been increasing. However, there is still a lack of information about MIC distribution patterns and changes in clinical practice settings. The MIC results of rapidly growing mycobacteria isolated from 92 patients with nontuberculous mycobacterial pulmonary disease diagnosed from May 2019 to March 2021 were retrospectively analyzed. Most of the patients (86 patients; 93.5%) were infected with MABS; 46 with Mycobacterium abscessus subsp. abscessus (Mab), and 40 with Mycobacterium abscessus subsp. massiliense (Mma). Significant differences in susceptibility to clarithromycin (15.2% versus 80.0%, P < 0.001) and azithromycin (8.7% versus 62.5%, P < 0.001) were observed between Mab and Mma. Most isolates were susceptible to amikacin (80; 93.0%), and over half were susceptible to linezolid (48; 55.8%). Only one-quarter of isolates (22, 25.6%) were susceptible to imipenem, while more than half (56; 65.1%) had intermediate susceptibility. Fifty-one isolates (59.3%) had MIC values of less than 1 μg/mL for sitafloxacin, which were significantly higher than isolates for moxifloxacin (5; 5.8%), especially in Mab. Sixty-five (75.6%) isolates had MICs of less than 0.5 μg/mL to clofazimine. Two patients showed obvious MIC result changes: from susceptible to resistant to clarithromycin and from resistant to susceptible to amikacin and imipenem. In conclusion, MABS isolates were relatively susceptible to amikacin and linezolid, and clarithromycin and azithromycin were especially effective against Mma. In addition, sitafloxacin and clofazimine had low MICs and might be effective treatment agents. IMPORTANCE The MICs of isolates from 86 patients with Mycobacterium abscessus (MABS); 46 with Mycobacterium abscessus subsp. abscessus (Mab), and 40 with Mycobacterium abscessus subsp. massiliense (Mma) were retrospectively analyzed. The main findings are as follows: (i) Mma were significantly more susceptible to clarithromycin and azithromycin than Mab, and both subspecies tended to be more susceptible to clarithromycin than azithromycin. (ii) Most isolates were susceptible to amikacin (93.0%), and over half to linezolid (55.8%). (iii) Fifty-one isolates (59.3%) had MIC values of less than 1 μg/mL for sitafloxacin, and 65 (75.6%) had less than 0.5 μg/mL for clofazimine, which seems worth clinical investigating. (iv) Among nine cases analyzed chronological changes, only two patients showed obvious MIC result changes even after the long-term multidrug treatment. The present study revealed MICs of MABS clinical isolates before and after treatment in clinical settings, which could help develop future MABS treatments strategies.

Efficacy of fluoroquinolones as substitutes for ethambutol or rifampin in the treatment of Mycobacterium avium complex pulmonary disease according to radiologic types

Objective: During the treatment of Mycobacterium avium complex pulmonary disease (MAC-PD), ethambutol or rifampin is often discontinued because of adverse events. This study investigated the treatment outcomes when later-generation fluoroquinolones substitute ethambutol or rifampin in MAC-PD treatment based on the radiologic type. Methods: Between 2006 and 2019, patients who initiated standard treatment and whose treatment duration was ≥1 year were retrospectively identified at a tertiary referral center in South Korea, including 178 patients with cavitary disease (fibrocavitary and cavitary nodular bronchiectatic types) and 256 patients with noncavitary nodular bronchiectatic (NC-NB) type. We compared the microbiologic cure at 1 year between the patients who maintained the initial regimen and those who replaced ethambutol or rifampin with fluoroquinolones (moxifloxacin or levofloxacin). Results: The overall microbiologic cure rate of the 178 patients with cavitary disease was 71.3%. Among these, the microbiologic cure rates of the 16 patients who substituted fluoroquinolones for ethambutol were lower than those of the 156 patients who maintained three-drug oral antibiotics with aminoglycoside (37.5% vs. 74.4%, respectively; P = 0.007), which was statistically significant in multivariate analysis. The outcomes of the six patients receiving fluoroquinolones as an alternative to rifampin were similar to that of those continuing the initial regimen. The microbiologic cure rate of the patients with the NC-NB type receiving daily or intermittent oral three-drug therapy was similar regardless of maintaining the initial therapy or replacing ethambutol or rifampin with fluoroquinolones. Conclusions: In cavitary MAC-PD, substituting ethambutol with fluoroquinolones resulted in inferior patient outcomes.

Vertebral osteomyelitis caused by Mycobacteroides abscessus subsp. abscessus resulting in spinal cord injury due to vertebral body fractures

Nontuberculous mycobacteria (NTM) rarely cause vertebral osteomyelitis; however, the clinical characteristics of vertebral osteomyelitis caused by NTM are poorly understood due to its rarity. A 74-year-old man with lung cancer was treated with prednisolone for immune checkpoint inhibitor-associated immune-related adverse events. He had been experiencing mild back pain without febrile episodes for five months, and was admitted to the hospital for worsening back pain and progressive paraplegia. Magnetic resonance imaging showed spinal cord compression at T4-5 due to fractures of the T5 and T7 vertebral bodies. The culture of a sample of pus from the T7 vertebral body obtained at the time of spinal fusion surgery yielded the Mycobacteroides abscessus (M. abscessus) complex. The patient was diagnosed with vertebral osteomyelitis caused by M. abscessus complex and treated with clarithromycin, amikacin, and imipenem; clarithromycin was later replaced by sitafloxacin because of inducible macrolide resistance. However, his neurologic deficits were irreversible, and he died due to a deteriorating general condition. The strain was identified up to subspecies level as M. abscessus subsp. abscessus by hsp65 and rpoB sequencing and nucleic acid chromatography. Although vertebral osteomyelitis due to NTM is rare, delayed diagnosis can lead to serious complications or poor outcomes. A prolonged clinical course, less frequent fever, vertebral destruction or spinal deformity, neurological deficits, or immunosuppressed conditions might be suggestive of NTM vertebral osteomyelitis.

Comparison of Rifabutin-Based Versus Rifampin-Based Regimens for the Treatment of Mycobacterium avium Complex: A meta-Analysis Study

Background: The incidence of Mycobacterium avium complex (MAC) increases as immunosuppressed conditions become more common. MAC's standard treatment regimen includes a macrolide, ethambutol, and a rifamycin, among which rifampin and rifabutin are the most commonly used. Although current guidelines recommend initial therapy for MAC with rifampin, it has been theorized to be less efficacious than rifabutin.

Methods: We reviewed the relevant scientific literature published up to February 18, 2020. Statistical analyses were performed with Comprehensive Meta-Analysis Software Version 2.0 (Biostat, Englewood, NJ). The pooled frequency with 95% confidence intervals (CI) was assessed using a random-effect model. We considered P <0.05 as statistically significant for publication bias.

Results: After reviewing 3665 records, we identified 24 studies that satisfied the inclusion criteria. Among these studies, 8 had rifabutin in their regimens (rifabutin group) and 16 had rifampin in their regimens (rifampin group). The estimated pooled treatment success rate was found to be 54.7% (95% CI 41.0-67.0%) in rifabutin groups and 67.5% (95% CI 55.7-77.4%) in rifampin groups. There was no evidence of publication bias among the included studies (Egger’s test p-value was 0.7).

Conclusion: In this study, it was shown that in comparison to Rifabutin, rifampin has similar treatment success rates in treating MAC. In order to determine the exact preference of each of these drugs, double-blind clinical trial studies are recommended.

Comparative activities of sitafloxacin against recent clinical isolates in hospitals across China

Sitafloxacin is one of the newer generation fluoroquinolones. Considering the ever-changing antimicrobial resistance, it is necessary to monitor the activities of sitafloxacin against recent pathogenic isolates. Therefore, we determined the minimum inhibitory concentrations (MICs) of sitafloxacin and comparators by broth microdilution or agar dilution method against 1101 clinical isolates collected from 2017 to 2019 in 31 hospitals across China. Sitafloxacin was highly active against gram-positive isolates evidenced by the MICs required to inhibit the growth of 50%/90% isolates (MIC_50/90): ≤ 0.03/0.25, ≤ 0.03/0.125, ≤ 0.03/2, 0.125/0.25, 0.25/2, and 0.125/0.125 mg/L for methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-susceptible coagulase-negative Staphylococcus (MSCNS), methicillin-resistant S. aureus (MRSA), methicillin-resistant CNS, Enterococcus faecalis, and Streptococcus pneumoniae, respectively. Sitafloxacin inhibited 82.8% of the MRSA strains and 97.5% of MRCNS strains. Sitafloxacin was also potent against ciprofloxacin-susceptible Escherichia coli (MIC_50/90: ≤ 0.03/0.06 mg/L) and Klebsiella pneumoniae (MIC_50/90: ≤ 0.03/0.125 mg/L), non-ESBL-producing E. coli (MIC_50/90: ≤ 0.03/1 mg/L) and K. pneumoniae (MIC_50/90: ≤ 0.03/0.5 mg/L), Haemophilus influenzae (MIC_50/90: ≤0.015/0.06 mg/L), Haemophilus parainfluenzae (MIC_50/90: 0.125/0.5 mg/L), Moraxella catarrhalis (MIC_50/90: ≤ 0.015/≤ 0.015 mg/L), Bacteroides fragilis (MIC_50/90: 0.06/2 mg/L), Peptostreptococcus (MIC_50/90: 0.125/4 mg/L), and Mycoplasma pneumoniae (≤ 0.03/≤ 0.03 mg/L). However, sitafloxacin was less active for Enterococcus faecium, ciprofloxacin-resistant and/or ESBL-producing E. coli, and K. pneumoniae strains. Sitafloxacin was superior or comparable to most of the comparators in activities against the abovementioned isolates, so sitafloxacin is still highly active against most of the clinical isolates in hospitals across China, proving its utility in treatment of the abovementioned susceptible strains.

Role of Clofazimine in Treatment of Mycobacterium avium Complex

Background: Non-tuberculous mycobacteria (NTM), specifically Mycobacterium avium complex (MAC), is an increasingly prevalent cause of pulmonary dysfunction. Clofazimine has been shown to be effective for the treatment of M. avium complex, but there were no published large-scale analyses comparing clofazimine to non-clofazimine regimens in MAC treatment. The objective of this large-scale meta-analysis was to evaluate patient characteristics and treatment outcomes of individuals diagnosed with MAC and treated with a clofazimine-based regimen.

Methods: We used Pubmed/Medline, Embase, Web of Science, and the Cochrane Library to search for studies published from January 1, 1990 to February 9, 2020. Two reviewers (SSH and NY) extracted the data from all eligible studies and differences were resolved by consensus. Statistical analyses were performed with STATA (version 14, IC; Stata Corporation, College Station, TX, USA).

Results: The pooled success treatment rate with 95% confidence intervals (CI) was assessed using random effect model. The estimated pooled treatment success rates were 56.8% in clofazimine and 67.9% in non-clofazimine groups. Notably, success rates were higher (58.7%) in treatment of HIV patients with disseminated infection.

Conclusions: Treatment was more successful in the non-clofazimine group overall. However, HIV patients with disseminated infection had higher treatment response rates than non-HIV patients within the clofazimine group.

Efficacy estimation of a combination of triple antimicrobial agents against clinical isolates of Mycobacterium abscessus subsp. abscessus in vitro

Background

Mycobacterium abscessus subsp. abscessus (M. abscessus) is a rapidly growing mycobacterium that is resistant to most antibiotics. The number of patients with pulmonary disease caused by M. abscessus is increasing in several regions, and therapy involves long-term antibiotic combination treatments, although no standard treatment regimen has been established.

Objectives

To examine candidate regimens for maintenance of antimicrobial treatment against M. abscessus by measuring MIC using the three-drug chequerboard method.

Methods

We evaluated the drug susceptibility of 70 clinical isolates of M. abscessus using the three-drug chequerboard method. We tested the antimycobacterial agents bedaquiline, clofazimine, amikacin, and sitafloxacin (which showed a relatively low MIC range when used as single agents) alone and in combinations.

Results

The three-drug combinations of bedaquiline/clofazimine/amikacin, and bedaquiline/clofazimine/sitafloxacin were studied. Among isolates for which the fractional inhibitory concentration index (FICI) could be calculated, 29/70 isolates (41%) and 11/70 isolates (16%) showed a synergistic response (FICI ≤0.75) with combined use of bedaquiline/clofazimine/amikacin, or with bedaquiline/clofazimine/sitafloxacin, respectively.

Conclusions

The combination of bedaquiline with clofazimine plus either amikacin or sitafloxacin may be useful as maintenance regimens when treating pulmonary disease caused by M. abscessus.

Resumption/efficacy and safety of an azithromycin-containing regimen against Mycobacterium avium complex lung disease in patients who experienced adverse effects with a clarithromycin-containing regimen

BACKGROUND

Antibiotic therapy, including clarithromycin (CLR), has been widely used for the management of Mycobacterium avium complex (MAC) lung disease in clinical settings. When patients develop adverse events (AEs) during CLR-based treatment, the treatment regimen is modified or chemotherapy itself is discontinued. The need for alternative macrolide treatment strategies is emphasized due to the high rate of AEs possibly caused by CLR. Thus, the current study aimed to examine the efficacy and safety of azithromycin (AZM) in patients with MAC lung disease whose treatment was switched from CLR to AZM.

METHODS

We performed a retrospective study of patients with MAC lung disease. The inclusion criteria were as follows: (1) patients who experienced AEs during treatment with antibiotics, including CLR, between December 2012 and November 2017, and (2) those who had antimicrobial therapy that was switched from CLR to AZM. The efficacy and safety of AZM during the clinical course of the disease after switching the regimen from CLR to AZM were investigated.

RESULTS

Antibiotic therapy was switched in 31 patients who presented with AEs including drug-induced fever, rash, dysgeusia, liver dysfunction, and neutropenia during treatment with CLR-containing regimens. After switching to AZM, the median duration of treatment was 1286 (364-4615) days. During follow-up, 13 patients had a negative conversion of sputum culture.

CONCLUSIONS

AZM may be safe and effective for patients with MAC lung disease who have difficulty tolerating CLR. In patients who experienced AEs possibly caused by CLR, switching from CLR to AZM might be an appropriate strategy.

Pulmonary infection due to fluoroquinolone-resistant Mycolicibacterium fortuitum: a case report

Background

Mycolicibacterium fortuitum is a species of the rapidly growing mycobacteria that can cause pulmonary infection. It is susceptible to multiple antibiotics both in vitro and in clinical practice, so that any combination of susceptible drugs is effective. However, we encountered a case of infection due to fluoroquinolone-resistant M. fortuitum. In this study, we report the case and describe the mechanism of resistance.

Case presentation

A 65-year-old man with a history of total gastrectomy and immunosuppressant treatment for rheumatoid arthritis developed a recurrence of pulmonary infection caused by M. fortuitum. He was treated with clarithromycin and levofloxacin as a first-line treatment, based on the favorable susceptibility at that time. After recurrence, a high minimum inhibitory concentration to fluoroquinolones was detected. DNA sequencing of the pathogen showed the substitution of serine for tryptophan at residue 83 in the gyrA gene. He was successfully treated with a combination of other antibiotics.

Conclusion

This is the first report on the treatment of fluoroquinolone-resistant M. fortuitum and investigation of the mechanism of resistance. We suggest that the susceptibility test remains effective for determining the next line of treatment after a pathogen has acquired resistance, and resistance to fluoroquinolones in M. fortuitum can be attributed to a single change of amino acid.

Efficacy and safety of fluoroquinolone-containing regimens in treating pulmonary Mycobacterium avium complex disease: A propensity score analysis

Background

Although combination therapy using clarithromycin, rifampicin, and ethambutol is recommended for patients with pulmonary Mycobacterium avium complex (MAC) disease, some patients do not tolerate it because of adverse effects or underlying diseases. The efficacy and safety of fluoroquinolone-containing combination regimens as an alternative remain uncertain. This study aimed to compare the efficacy and safety of fluoroquinolone-containing regimens with those of the standard regimens for treating pulmonary MAC disease.

Methods

We retrospectively included consecutive MAC patients who were treated in our hospital between January 2011 and May 2019. Patients treated with fluoroquinolone-containing regimens who had relapsed after treatment with standard regimens were excluded. A propensity score analysis was conducted to reduce selection bias, and the proportions of clinical improvement, defined by chest imaging findings and sputum conversion, were compared between the fluoroquinolone-containing regimen and standard regimen groups.

Results

We analyzed 28 patients who received fluoroquinolone-containing regimens and 46 who received the standard regimen. Fluoroquinolone-containing regimens were more likely selected for patients with cavitary lesions, diabetes mellitus, culture negativity, a low daily physical activity level, a decreased lymphocyte count and an increased CRP level. The propensity score was calculated using these variables (C-statistic of the area under the receiver operating characteristic curve of the propensity score: 0.807, p < 0.0001). The fluoroquinolone-containing regimens were significantly inferior to the standard regimen in clinical improvements (p = 0.002, Log-rank test) in the univariate analysis, but the significance was lost after adjusting for the propensity score (HR 0.553, 95% CI 0.285–1.074, p = 0.080). Six (21%) patients in the fluoroquinolone-containing regimen group and ten (22%) patients in the standard regimen group experienced low-grade adverse effects.

Conclusions

There was no significant difference in clinical improvement between these regimens after propensity score adjustment. A large-scale prospective study is required to validate these results.

Antibiotic therapy success rate in pulmonary Mycobacterium avium complex: a systematic review and meta-analysis

Objectives: The incidence of Mycobacterium avium complex (MAC) pulmonary disease is increasing worldwide. We conducted a systematic review and meta-analysis to determine the treatment success rate of antibiotic therapy in MAC pulmonary disease and evaluate the effectiveness of aminoglycoside-containing regimens.Methods: We searched literature between 1 January 1980 to 19 June 2019. Studies with diagnosis criteria based on the current guidelines that reported treatment outcomes were included. We defined treatment success as the achievement of culture conversion and completion of the planned treatment without relapse while on treatment.Results: We retrieved 45 studies including 3862 patients. The estimated pooled treatment success rate was 68.1% [95% confidence interval (CI) 64.7-71.4%]. Based on the Cochrane tool, the included studies had a low risk of bias. Forty-two studies reported macrolide-containing regimens, while 6 studies included aminoglycoside-containing regimens. Macrolide-containing regimens led to better treatment success rates comparing to non-macrolide-containing regimens; 69% vs 58.5%, respectively. Treatment duration of 12 months or more showed better results.Conclusion: Poor treatment success rate of MAC pulmonary disease calls for more randomized clinical trials designed based on consensus definitions of the disease diagnosis and treatment. New drugs with a better adherence rate need to be developed.Systematic Review Registration: PROSPERO (pending registration ID: 151674).

Clinical characteristics and treatment outcomes of patients with macrolide-resistant Mycobacterium avium complex pulmonary disease: a systematic review and meta-analysis

Background

Macrolide is a key drug in the treatment of Mycobacterium avium complex pulmonary disease (MAC-PD). Macrolide-resistant MAC is gaining importance, but there are little data in clinical characteristics and treatment outcomes of macrolide-resistant MAC-PD (MR-MAC-PD).

Methods

We performed a systematic review and meta-analysis of published studies reporting clinical characteristics and treatment outcomes of patients with MR-MAC-PD. Risk of bias was assessed using the modified Newcastle-Ottawa Scale.

Results

Nine studies (seven retrospective and two prospective) comprising 319 patients were identified through a database search. Around 73% were women, and 52% had the fibrocavitary form. Pooled sputum culture conversion rate after combined multiple antibiotics or surgical resection was 21% (95% confidence interval [CI], 14–30%), and the one-year all-cause mortality was 10% (95% CI, 5–20%). There was no significant difference in treatment outcomes between nodular bronchiectatic and fibrocavitary types.

Conclusions

Even combination therapy with fluoroquinolone, aminoglycoside, and surgical resection, the treatment outcomes of MR-MAC-PD were poor. The investigation of new treatment modalities is urgent.