Why do we use 100†mg of clofazimine in TB and NTM treatment?

Current tuberculosis and non-tuberculous mycobacterial disease guidelines recommend the use of clofazimine in a 100 mg once-daily dose. The rationale behind this exact dose is not provided. I performed a literature review to determine the reasoning behind the current dosing regimen. The current 100 mg once-daily dose of clofazimine stems from a deliberate attempt to find the minimum effective daily dose in leprosy treatment, driven by efficacy, economical and toxicity considerations. While this dose is safe, economical and practical, a higher dose with a loading phase may add relevant efficacy and treatment-shortening potential to both tuberculosis and non-tuberculous mycobacterial disease treatment. We need to revisit dose-response and maximum tolerated dose studies to get the best out of this drug, while continuing efforts to generate more active r-iminophenazine molecules that accumulate less in skin and intestinal tissues and have pharmacokinetic properties that do not require loading doses.

Open-Label Trial of Amikacin Liposome Inhalation Suspension in Mycobacterium abscessus Lung Disease.

BACKGROUND: Mycobacterium abscessus is the second most common nontuberculous mycobacterium respiratory pathogen and shows in vitro resistance to nearly all oral antimicrobials. M abscessus treatment success is low in the presence of macrolide resistance. RESEARCH QUESTION: Does treatment with amikacin liposome inhalation suspension (ALIS) improve culture conversion in patients with M abscessus pulmonary disease who are treatment naive or who have treatment-refractory disease? STUDY DESIGN AND METHODS: In an open-label protocol, patients were given ALIS (590 mg) added to background multidrug therapy for 12 months. The primary outcome was sputum culture conversion defined as three consecutive monthly sputum cultures showing negative results. The secondary end point included development of amikacin resistance. RESULTS: Of 33 patients (36 isolates) who started ALIS with a mean age of 64 years (range, 14-81 years), 24 patients (73%) were female, 10 patients (30%) had cystic fibrosis, and nine patients (27%) had cavitary disease. Three patients (9%) could not be evaluated for the microbiologic end point because of early withdrawal. All pretreatment isolates were amikacin susceptible and only six isolates (17%) were macrolide susceptible. Eleven patients (33%) were given parenteral antibiotics. Twelve patients (40%) received clofazimine with or without azithromycin as companion therapy. Fifteen patients (50%) with evaluable longitudinal microbiologic data demonstrated culture conversion, and 10 patients (67%) sustained conversion through month 12. Six of the 33 patients (18%) demonstrated mutational amikacin resistance. All were patients using clofazimine or clofazimine plus azithromycin as companion medication(s). Few serious adverse events occurred for ALIS users; however, reduction of dosing to three times weekly was common (52%). INTERPRETATION: In a cohort of patients primarily with macrolide-resistant M abscessus, one-half of the patients using ALIS showed sputum culture conversion to negative findings. The emergence of mutational amikacin resistance was not uncommon and occurred with the use of clofazimine monotherapy. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03038178; URL: www. CLINICALTRIALS: gov.

Nontuberculous Mycobacterial Infections in Cystic Fibrosis.

Nontuberculous mycobacteria (NTM) are important pathogens, with a longitudinal prevalence of up to 20% within the cystic fibrosis (CF) population. Diagnosis of NTM pulmonary disease in people with CF (pwCF) is challenging, as a majority have NTM infection that is transient or indolent, without evidence of clinical consequence. In addition, the radiographic and clinical manifestations of chronic coinfections with typical CF pathogens can overlap those of NTM, making diagnosis difficult. Comprehensive care of pwCF must be optimized to assess the true clinical impact of NTM and to improve response to treatment. Treatment requires prolonged, multidrug therapy that varies depending on NTM species, resistance pattern, and extent of disease. With a widespread use of highly effective modulator therapy (HEMT), clinical signs and symptoms of NTM disease may be less apparent, and sensitivity of sputum cultures further reduced. The development of a disease-specific approach to the diagnosis and treatment of NTM infection in pwCF is a research priority, as a lifelong strategy is needed for this high-risk population.

Skin infection by Mycobacterium marinum - diagnostic and therapeutic challenge.

The number of skin infections caused by atypical mycobacteria has increased in recent decades. They usually appear after contact with wounds and interruptions in the integrity of the skin. The present report describes a case of cutaneous infection by Mycobacterium marinum, in a young, immunocompetent patient, with a prolonged evolution, diagnosed through a skin lesion culture (from a spindle biopsy of the skin). The patient was treated with multidrug therapy, including clarithromycin, doxycycline, and rifampicin, due to the lesion extent, with satisfactory results. A brief review of the literature is also provided.

Non-tuberculous cutaneous mycobacterioses

Abstract Non-tuberculous mycobacteriosis, previously known as atypical, anonymous, opportunistic, or unclassified mycobacteriosis, refers to pathogenic mycobacterioses other than those caused by Mycobacterium tuberculosis and Mycobacterium leprae. These mycobacteria are known for their environmental distribution, mainly in water and soil. The incidence of non-tuberculous mycobacteriosis has been increasing in all countries and skin infections are being increasingly studied, mainly with the increase in immunosuppressive conditions and the development of new medications that affect immunological function. In the present article, a detailed narrative review of the literature is carried out to study the main non-tuberculous mycobacteriosis that cause diseases of the skin and appendages. The article also aims to present a historical context, followed by epidemiological, microbiological, and clinical characteristics of these diseases. Practical considerations about the diagnosis and treatment of non-tuberculous mycobacteriosis are detailed.

Non-tuberculous cutaneous mycobacterioses.

Non-tuberculous mycobacteriosis, previously known as atypical, anonymous, opportunistic, or unclassified mycobacteriosis, refers to pathogenic mycobacterioses other than those caused by Mycobacterium tuberculosis and Mycobacterium leprae. These mycobacteria are known for their environmental distribution, mainly in water and soil. The incidence of non-tuberculous mycobacteriosis has been increasing in all countries and skin infections are being increasingly studied, mainly with the increase in immunosuppressive conditions and the development of new medications that affect immunological function. In the present article, a detailed narrative review of the literature is carried out to study the main non-tuberculous mycobacteriosis that cause diseases of the skin and appendages. The article also aims to present a historical context, followed by epidemiological, microbiological, and clinical characteristics of these diseases. Practical considerations about the diagnosis and treatment of non-tuberculous mycobacteriosis are detailed.

Mycobacteria: Selection of Transplant Candidates and Post-lung Transplant Outcomes.

Mycobacterium is a large, clinically relevant bacterial genus made up of the agents of tuberculosis and leprosy and hundreds of species of saprophytic nontuberculous mycobacteria (NTM). Pathogenicity, clinical presentation, epidemiology, and antimicrobial susceptibilities are exceptionally diverse between species. Patients with end-stage lung disease and recipients of lung transplants are at a higher risk of developing NTM colonization and disease and of severe manifestations and outcomes of tuberculosis. Data from the past three decades have increased our knowledge of these infections in lung transplant recipients. Still, there are knowledge gaps to be addressed to further our understanding of risk factors and optimal treatments for mycobacterial infections in this population.

Clofazimine in Mycobacterium abscessus peritonitis: A pediatric case report.

Peritonitis- and catheter-related infections due to nontuberculous mycobacteria (NTM) including Mycobacterium abscessus have been reported among adults on peritoneal dialysis (PD). There is no recommended antimicrobial regimen for the treatment of M. abscessus peritonitis. Clofazimine has emerged as an important adjuvant antimicrobial treatment of M. abscessus lung infection. We report, to our knowledge, the first case of M. abscessus PD peritonitis in a child treated successfully using clofazimine as a novel adjuvant therapy to amikacin and clarithromycin. Her clinical features were similar to those of bacterial peritonitis, but she had persistence of symptoms and high inflammatory markers despite empirical therapy for peritonitis. Bacterial culture of PD effluent became positive for M. abscessus after 5 days. There was complete symptom resolution after 6 days of multidrug therapy. Due to ototoxicity, amikacin was discontinued after 6 weeks, while clarithromycin and clofazimine were continued for 9 months to ensure complete pathogen eradication before a planned renal transplant. A high index of suspicion in refractory or culture-negative cases is important for the diagnosis of NTM peritonitis. Multidrug therapy is recommended for M. abscessus infections. Clofazimine was chosen as a novel adjunct antimicrobial because of its pharmacokinetics, ease of administration, cost-effectiveness, and lack of serious adverse events.

MmpL3 Inhibition: A New Approach to Treat Nontuberculous Mycobacterial Infections.

Outside of Mycobacterium tuberculosis and Mycobacterium leprae, nontuberculous mycobacteria (NTM) are environmental mycobacteria (>190 species) and are classified as slow- or rapid-growing mycobacteria. Infections caused by NTM show an increased incidence in immunocompromised patients and patients with underlying structural lung disease. The true global prevalence of NTM infections remains unknown because many countries do not require mandatory reporting of the infection. This is coupled with a challenging diagnosis and identification of the species. Current therapies for treatment of NTM infections require multidrug regimens for a minimum of 18 months and are associated with serious adverse reactions, infection relapse, and high reinfection rates, necessitating discovery of novel antimycobacterial agents. Robust drug discovery processes have discovered inhibitors targeting mycobacterial membrane protein large 3 (MmpL3), a protein responsible for translocating mycolic acids from the inner membrane to periplasm in the biosynthesis of the mycobacterial cell membrane. This review focuses on promising new chemical scaffolds that inhibit MmpL3 function and represent interesting and promising putative drug candidates for the treatment of NTM infections. Additionally, agents (FS-1, SMARt-420, C10) that promote reversion of drug resistance are also reviewed.

Clofazimine: an old drug for never-ending diseases.

Clofazimine (CFZ), an old hydrophobic riminophenazine, has a wide range of antimycobacterial activity ranging from leprosy to nontuberculous mycobacterial diseases. CFZ has several advantages such as a favorable pharmacokinetic profile, dose-dependent side effects as well as low price. In this narrative review, we have assessed the clinical development of CFZ, starting from the potential in vitro mechanism of actions, to the spectrum of side effects and potential drug-drug interactions, highlighting its current place in therapy and future possible use in leprosy, nontuberculous mycobacterial diseases and drug-resistant tuberculosis.

Disseminated Mycobacterium simiae infection in a patient with adult-onset immunodeficiency due to anti-interferon-gamma antibodies - a case report.

BACKGROUND: Mycobacterial species other than Mycobacterium tuberculosis and Mycobacterium leprae are generally free-living organisms and Mycobacterium simiae is one of the slowest growing Non-tuberculous mycobacteria. This is the first case report of Mycobacterium simiae infection in Sri Lanka and only very few cases with extrapulmonary manifestation reported in the literature. CASE PRESENTATION: A 24-year-old, previously healthy Sri Lankan male presented with generalized lymphadenopathy with discharging sinuses, evening pyrexia, weight loss, poor appetite and splenomegaly. Lymph node biopsies showed sheets of macrophages packed with organisms in the absence of granulomata. Ziehl Neelsen, Wade Fite and Giemsa stains revealed numerous red coloured acid-fast bacilli within foamy histiocytes. Slit skin smear for leprosy was negative and tuberculosis, fungal and bacterial cultures of the lymph node and bone marrow did not reveal any growth. Later he developed watery diarrhea and colonoscopy revealed multiple small polyps and ulcers throughout the colon extending up to the ileum, Which was confirmed to be due to cytomegalovirus confirmed by PCR and successfully treated with ganciclovir. Positron emission tomography scan guided biopsies of the gut and lymph nodes confirmed presence of mycobacterial spindle cell pseudo-tumours and PCR assays revealed positive HSP65. The culture grew Mycobacterium Simiae. Flow cytometry analysis on patient's blood showed extremely low T and B cell counts and immunofixation revealed low immunoglobulin levels. His condition was later diagnosed as adult onset immunodeficiency due to anti- interferon - gamma autoantibodies. He was initially commenced on empirical anti-TB treatment with atypical mycobacterial coverage. He is currently on a combination of daily clarithromycin, ciprofloxacin, linezolid with monthly 2 g/kg/intravenous immunoglobulin to which, he had a remarkable clinical response with complete resolution of lymphadenopathy and healing of sinuses. CONCLUSIONS: This infection is considered to be restricted to certain geographic areas such as mainly Iran, Cuba, Israel and Arizona and this is the first case report from Sri lanka. Even though the infection is mostly seen in the elderly patients, our patient was only 24 years old. In the literature pulmonary involvement was common presentation, but in this case the patient had generalized lymphadenopathy and colonic involvement without pulmonary involvement.

Is there a role for tedizolid in the treatment of non-tuberculous mycobacterial disease?

BACKGROUND: Pulmonary infections caused by non-tuberculous mycobacteria (NTM) are hard to treat and have low cure rates despite intensive multidrug therapy. OBJECTIVES: To assess the feasibility of tedizolid, a new oxazolidinone, for the treatment of Mycobacterium avium and Mycobacterium abscessus. METHODS: We determined MICs of tedizolid for 113 isolates of NTM. Synergy with key antimycobacterial drugs was assessed using the chequerboard method and calculation of the FIC index (FICI). We performed time-kill kinetics assays of tedizolid alone and combined with amikacin for M. abscessus and with ethambutol for M. avium. Human macrophages were infected with M. abscessus and M. avium and subsequently treated with tedizolid; intracellular and extracellular cfu were quantified over time. RESULTS: NTM isolates generally had a lower MIC of tedizolid than of linezolid. FICIs were lowest between tedizolid and amikacin for M. abscessus (FICI = 0.75) and between tedizolid and ethambutol for M. avium (FICI = 0.72). Clarithromycin and tedizolid showed initial synergy, which was abrogated by erm(41)-induced macrolide resistance (FICI = 0.53). Tedizolid had a weak bacteriostatic effect on M. abscessus and combination with amikacin slightly prolonged its effect. Tedizolid had concentration-dependent activity against M. avium and its efficacy was enhanced by ethambutol. Both combinations had a concentration-dependent synergistic effect. Tedizolid could inhibit the intracellular bacterial population of both M. avium and M. abscessus. CONCLUSIONS: Tedizolid should be further investigated in pharmacodynamic studies and clinical trials for M. avium complex pulmonary disease. It is less active against M. abscessus, but still promising.

Mycobacterium chelonae infection complicating traumatic and surgical wounds: A case series.

Mycobacterium chelonae is a rapidly growing non-tuberculous mycobacterium. The skin and soft tissue infections due to this organism are steadily on the rise and need to be delineated specifically as most of these are not responsive to routine antituberculosis treatment. Here, we report 3 different presentations caused by Mycobacterium chelonae in traumatic and surgical wounds. Mycobacterium chelonae can complicate surgical or traumatic wounds.This infection may also present as injection site abscesses. Diabetics on insulin injections are especially at risk. A high index of suspicion is necessary in long standing culture negative lesions for clinching the diagnosis. PCR can be helpful in confirming the diagnosis.

Métodos de determinación de sensibilidad a los antimicrobianos en micobacterias / Methods for determining the antimicrobial susceptibility of mycobacteria

Las micobacterias son un amplio grupo de microorganismos en el que múltiples especies son causa de una importante morbimortalidad, como la tuberculosis y la lepra. La aparición y diseminación de cepas del complejo Mycobacterium tuberculosis resistentes a diversos fármacos constituye en la actualidad uno de los problemas sanitarios de mayor gravedad a nivel mundial. Por otro lado, las micobacterias diferentes de M. tuberculosis y Mycobacterium leprae, denominadas micobacterias no tuberculosas (MNT), son aislamientos cada vez más frecuentes, requiriendo en muchos casos un tratamiento que precisa una orientación sobre la sensibilidad de estos microorganismos a los antimicrobianos. En el presente artículo se revisan los métodos para determinar la sensibilidad in vitro a los antimicobacterianos de los aislamientos del complejo M. tuberculosis y las MNT más relevantes. Además, también se realiza un análisis de las técnicas moleculares de detección rápida de la resistencia a partir de las muestras clínicas (AU)

Mycobacteria are a large group of microorganisms, multiple species of which are major causes of morbidity and mortality, such as tuberculosis and leprosy. At present, the emergence and spread of multidrug-resistant strains of Mycobacterium tuberculosis complex are one of the most serious health problems worldwide. Furthermore, in contrast to M. tuberculosis and Mycobacterium leprae, non-tuberculous mycobacteria (NTM) are more frequently isolated and, in many cases, treatment is based on drug susceptibility testing. This article is a review of the different methods to determine the in vitro drug susceptibility of M. tuberculosis complex and the most relevant NTM isolates. The molecular techniques currently used for rapid detection of resistance of clinical specimens are also analysed (AU)

Non-Tuberculous Mycobacteria: Classification, Diagnostics, and Therapy.

Non-tuberculous mycobacteria (NTM) are species other than those belonging to the Mycobacterium tuberculosis complex and do not cause leprosy. NTM are generally free-living organisms that are ubiquitous in the environment. There have been more than 140 NTM species identified to-date. They can cause a wide range of infections, with pulmonary infections being the most frequent (65-90 %). There is growing evidence that the incidence of NTM lung diseases and associated hospitalizations are on the rise, mainly in regions with a low prevalence of tuberculosis. A crucial clinical problem remains the evaluation of NTM significance in relation to the disease, especially in regard to the colonization of the respiratory tract in patients with residual lesions after tuberculosis or bronchiectasis. Clinical and radiographic pictures of mycobacteriosis, as well as therapy, have often similarities to those of tuberculosis. The treatment regimen should be individualized. In addition to antituberculotics, antibiotics are used more frequently. The most common mycobacteria causing lung disease in Slovakia are Mycobacterium avium and Mycobacterium abscessus.

Minocycline successfully treats exaggerated granulomatous hypersensitivity reaction to Mw immunotherapy.

Mycobacterium W (Mw) vaccine has been found to be effective in the treatment of leprosy and warts. Despite increasing use of Mw immunotherapy, data on its safety is limited. We report a series of eight patients who developed persisting injection site granulomatous reaction following Mw immunotherapy and were successfully treated with minocycline. Eight patients with persistent nodular swelling at the site of Mw injections were identified. Seven of them had received Mw immunotherapy for cutaneous warts and one for verrucous epidermal nevus. The lesions were firm, erythematous, succulent, non-tender nodules confined to the sites of Mw vaccine injections. In 6 of these patients nodules also involved the previously injected areas. Skin biopsy from all patients showed eosinophil rich inflammation admixed with histiocytes and lymphocytes. In addition granulomas were seen in all with septal and nodular panniculitis in four patients. Broken and granular acid-fast bacilli were identified in two cases. All patients were treated with oral minocycline 100 mg/day for a mean of 9 weeks and showed good clinical response. Granulomatous reaction is a rare but significant adverse effect of Mw immunotherapy at cosmetically and functionally imperative sites. Oral minocycline appears to be effective therapy in this situation.

Clinical and therapeutic features of pulmonary nontuberculous mycobacterial disease, Brazil, 1993-2011.

To identify clinical and therapeutic features of pulmonary nontuberculous mycobacterial (PNTM) disease, we conducted a retrospective analysis of patients referred to the Brazilian reference center, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil, who received a diagnosis of PNTM during 1993­2011 with at least 1 respiratory culture positive for NTM. Associated conditions included bronchiectasis (21.8%), chronic obstructive pulmonary disease (20.7%), cardiovascular disease (15.5%), AIDS (9.8%), diabetes (9.8%), and hepatitis C (4.6%).Two patients had Hansen disease; 1 had Marfan syndrome. Four mycobacterial species comprised 85.6% of NTM infections: Mycobacterium kansasii, 59 cases (33.9%); M. avium complex, 53 (30.4%); M. abscessus, 23 (13.2%); and M. fortuitum, 14 (8.0%). A total of 42 (24.1%) cases were associated with rapidly growing mycobacteria. In countries with a high prevalence of tuberculosis, PNTM is likely misdiagnosed as tuberculosis, thus showing the need for improved capacity to diagnose mycobacterial disease as well as greater awareness of PNTM disease prevalence.