Nontuberculous Mycobacterial Musculoskeletal Infection Cases from a Tertiary Referral Center, Colorado, USA

Non-tuberculous mycobacterial bone and joint infections - a case series from a tertiary referral centre in Australia

BACKGROUND

Non-tuberculous mycobacteria (NTM) are rare causes of bone and joint infection (BJI) and there is limited evidence on which to base management decisions. This study describes 1 year of experience from a multi-disciplinary BJI team which collects data on all cases reviewed at a tertiary referral centre in Queensland, Australia.

METHODS

The database was interrogated for all cases in which NTM were recovered from operative samples. Individual chart review was performed to collect the details of each case.

RESULTS

A total of seven cases were managed between 1st February 2021 and 28th February 2022, comprising one patient with chronic osteomyelitis, three with fracture-related infections, two with prosthetic joint infections, and one with infection of a synthetic ligament graft. In contrast to pulmonary NTM infections, most patients were clinically well and immunocompetent, and most infections were propagated by direct inoculation. Time to diagnosis was unknown in three patients, with 1, 2, 2, and 5 months for the remaining four. Rapid growing NTM were diagnosed on routine cultures and specific mycobacterial cultures were confirmatory. Management was characterized by multiple stage surgical procedures and prolonged antimicrobial regimens.

CONCLUSIONS

Antimicrobial complications were common; however, all patients were infection free at their latest follow up. Despite the inherent limitations, these results suggest that routinely ordering mycobacterial culture is of low yield. There is potential for shorter-term oral antimicrobial treatments. Prospective research is required to optimize treatment regimens and durations.

Clinical features and treatment outcomes of bone and joint nontuberculous mycobacterial infections according to immune status: a 9-year retrospective observational cohort

OBJECTIVES

Nontuberculous mycobacteria (NTM) bone and joint infections (BJIs) are uncommon. We evaluated the characteristics of BJIs and identified differences according to immune status.

METHODS

We performed a multicenter retrospective study in France involving patients with documented NTM BJI over a 9-year period. We collected the clinical and microbiological characteristics, management, and clinical outcomes of the patients.

RESULTS

Overall, 95 patients were included, of whom 50.5% (48/95) were immunosuppressed. Tenosynovitis was more frequent in the immunocompetent group, and native arthritis more common in the immunosuppressed group. Mycobacerium marinum and M. abscessus complex were significantly more frequent in the immunocompetent group, and M. avium and M. xenopi were significantly more frequent in the immunosuppressed group. The combination of antibiotherapy with surgery tended to be more frequent in the immunocompetent than the immunosuppressed group (63.8% (30/47) vs 47.8% (22/46), respectively); of the latter, 45.7% (21/46) received antimicrobial therapy alone, a higher frequency than in the immunocompetent group (23.4%, 11/47). The median duration of antimicrobial treatment was similar in the two groups (11 months). Mortality was significantly higher in the immunosuppressed group.

CONCLUSIONS

Although the clinical presentations and the NTM species involved in BJI differed according to immune status, most recovered completely after treatment.

Management of M. abscessus subsp. abscessus early-onset prosthetic joint infection: Case report and literature review

Nontuberculous mycobacteria are a rare but still emerging cause of difficult-to-treat prosthetic joint infection. To our knowledge only 17 cases of M. abscessus complex prosthetic joint infection are reported in literature, of which only 1 is by M. abscessus subps. abscessus. No guidelines are available for this clinical scenario. We describe a 68-years-old female patient with an early-onset M. abscessus subsp. abscessus prosthetic joint infection, successfully treated with a tailored medical-surgical strategy, and present an overview of cases currently available in the literature to assist physicians in the management of these uncommon infections.

Mycobacterium flavescens Infection - An Unusual Case of Prosthetic Joint Infection

INTRODUCTION

The onset of prosthetic joint infections (PJIs) is characterized by early onset defined as within 90 days of the procedure, delayed onset defined as within 3 to 12 months, and late onset defined as over 12 months. In only a scant number of case reports, Mycobacterium flavescens associated infections are typically found in sputum cultures and associated with various forms of penetrating joint traumas, particularly post-surgical interventions. Due to its rarity in presentation among cases of PJIs, we have presented a case of PJI caused by Mycobacterium flavescens.

CASE PRESENTATION

We have, herein, reported a case of a 70-year-old male presenting with stabbing left knee pain over the past several months along with accompanying erythema and swelling with the presence of purulent discharge. Outpatient cultures have shown the growth of Mycobacterium flavescent; subsequently, the patient underwent a 2-stage revision arthroplasty and was treated with a three-drug regimen and implant 5 months later. Although being an atypical cause of PJIs, we emphasize the importance of considering NTM as a differential for immunocompromised patients, especially those with prior surgical intervention.

DISCUSSION

Mycobacterium spp. related PJIs manifest clinical features similar to other bacteriacausing PJIs, such as warm, indurated edema at the surgical site resulting in wound dehiscence and joint effusion. Diagnosis of Mycobacterium spp. related PJIs includes history and physical examination findings, serum inflammatory markers, synovial fluid analysis, and culture. Concurrently with surgical interventions, utilization of antimicrobial agents provides additional control in Mycobacterium- related PJI. Mycobacterium flavescens should be included among other NTMs as a possible cause of PJIs.

Atypical mycobacterium infection following anterior cruciate ligament reconstruction

A man in his 20s presented with instability of the right knee following an incident of fall from a height. He was clinicoradiologically diagnosed to have an anterior cruciate ligament (ACL) tear for which he underwent ACL reconstruction. Postoperatively, he was started on an accelerated ACL rehabilitation protocol. Six weeks postoperatively, he developed features of subclinical septic arthritis for which he underwent arthroscopic debridement. Intraoperative samples cultured Mycobacterium abscessus complex on MGIT 960 system. The patient subsequently had to undergo another debridement after 1 month as there were clinical signs of persisting infection. The graft was intact even on the second debridement and after removing the implants. This case reports a rare complication of ACL reconstruction with infection by atypical mycobacterium and the clinical outcome. It also emphasises that prompt surgical intervention can save the graft.

Mycobacterium avium complex prosthetic joint infection: A systematic review of the literature and pooled analysis

BACKGROUND

Mycobacterium avium complex (MAC) prosthetic joint infection (PJI) has been rarely reported.

METHODS

This study aimed to investigate the epidemiology and outcomes of MAC PJI. A systematic review of the literature regarding the MAC infection following total joint arthroplasty including hip and knee joint was performed. Multiple databases were searched for published English-written articles up to May 2023. Studies that reported cases of PJI by MAC were reviewed.

RESULTS

A total of 17 patients were identified and analyzed from 11 published studies. All patients presented with joint symptom of pain or swelling prior to the diagnosis and MAC was confirmed by culture. The most of the patients (16/17 patients, 94.1%) were noted to have underlying medical condition(s) that might have affected immunity. Treatment consisted of anti-MAC medication therapy only in two patients and anti-MAC medication therapy plus surgery in 15 patients. Among the patients who underwent surgery, 14 patients (82.3%) had removal of the prosthesis including seven patients who had two-stage surgery to have reimplantation of the prosthesis. No relapse of MAC infection was reported despite of one case of relapse of infection caused by different pyogenic bacteria. The rate of overall mortality was 29.4%, however, identified attributable mortality due to MAC infection was low (5.9%).

CONCLUSION

PJI by MAC is a rare disease. However, MAC needs to be considered in the differential diagnosis in immunocompromised patients presenting with symptoms of PJI. Two-stage exchange arthroplasty may result in successful treatment outcomes without higher risks of relapse of infection if undertaken in association with appropriate active anti-MAC antibiotic therapy.

Nontuberculous Mycobacteria in Horses: A Narrative Review

Nontuberculous mycobacteria (NTM) infections are increasing in human and veterinary medicine. Although horses were initially thought to be resistant to NTM infection, reports of horses suffering from gastrointestinal, respiratory, and reproductive diseases associated with NTM have increased in the last few decades. The aim of this literature review is to summarize the mycobacteria species found in horses, describe clinical manifestations, diagnostic and treatment approaches, and public health concerns of NTM infection in horses. Clinical manifestations of NTM in horses include pulmonary disease, lymphadenitis, soft tissue, bone infections, and disseminated disease. NTM are also linked to granulomatous enteritis, placentitis, and abortions. Currently, diagnostic methods for NTM are limited and include acid-fast microscopy, bacterial cultures, species-specific PCR assays, and gene sequencing. In humans, NTM treatment guidelines are available, but their application appears inadequate and inconsistent. In horses, treatment guidelines for NTM infections are not available. NTM are a serious public health threat as 70% of people with untreated acquired immunodeficiency syndrome (AIDS) have a chronic pulmonary disease caused by NTM. Thus, it is essential that we gain a better understanding of NTM infections in horses and their zoonotic potential.

Non-Tuberculosis Mycobacterium Periprosthetic Joint Infections Following Total Hip and Knee Arthroplasty: Case Series and Review of the Literature

OBJECTIVE

Periprosthetic joint infection (PJI) caused by non-tubercular mycobacteria (NTM) is uncommon but catastrophic. However, conclusive clinical data on PJI caused by NTM are lacking. In this case series and systematic review, the clinical manifestations, diagnosis, and management of NTM PJI are summarized and analyzed.

METHODS

From 2012 to 2020, we retrospectively analyzed consecutive PJI cases caused by NTM in our institution. A literature review was also conducted from January 2000 to December 2021, utilizing the PubMed, MEDLINE, Cochrane Library, and EMBASE databases to identify all reported NTM-induced PJI cases. The clinical characteristics, demographics, pathogen identification, treatment protocols, and prognosis of NTM PJI were summarized and analyzed.

RESULTS

In this retrospective analysis, seven patients infected with NTM following total joint arthroplasty at our institution were included, including six cases of PJI caused by NTM and one case of septic arthritis (SA) caused by NTM. There were six men and one woman, and their average age was 62.3 years. The average interval between TJA and PJI onset was 4 months. The preoperative serological markers, including the mean ESR (51 mm/h), CRP (4.0 mg/dL), fibrinogen (5.7 g/L), and D-dimer (1.1 g/L), were increased. Six patients underwent staged revision surgery, and one patient with SA received antibiotic-loaded bone cement beads to treat the infection. After an average of 33 months of observation following surgical intervention, none of the patients showed any symptoms of infection recurrence. From 2000 to 2021, 68 patients with NTM PJI were found in 39 studies in the published literature. Reinfections occurred within 1 year after arthroplasty in more than half (53.2%) of the patients. M. fortuitum and M. abscesses were the most prevalent rapidly growing mycobacteria (RGM) in all PJI patients, whereas Mycobacterium avium intracellulare (MAC) was the most prevalent slowly growing mycobacterium (SGM). The corresponding antibiotics were amikacin and ethambutol. The rate of culture-negative without specific clinical symptoms was as high as 36.4% (12/33), while 45% (18/40) utilized additional diagnostic techniques such as NGS. A final clinical follow-up record was available for 59 patients (86.7%; mean follow-up period, 29 months), and 10.1% of patients failed to respond to treatment.

CONCLUSION

Orthopaedic surgeons should consider NTM in patients with negative routine cultures who are at risk for Mycobacterium infection. Treatment options rely on the accurate result of microbiologic identification and drug sensitivity testing, and to achieve this, it may be necessary to send multiple culture specimens, extend the culture time, and change the culture medium. Every effort should be made to identify NTM and its various subtypes through modern diagnostic tools if necessary.

A Systematic Review of Nontuberculous Mycobacterium Infection Following Anterior Cruciate Ligament Reconstruction

Although infection following anterior cruciate ligament (ACL) reconstruction is rare, these cases have potentially catastrophic ramifications. Nontuberculous mycobacteria (NTM) are ubiquitous, located in the water supply and soil. Our objective was to review the literature to characterize NTM infection following ACL reconstruction.

Methods

A database search was performed for arthroscopic ACL reconstructions that resulted in a postoperative diagnosis of NTM infection.

Results

The literature search returned 6 case reports that met the inclusion criteria. The initial postoperative presentation occurred after 3 to 52 weeks, which is consistent with reports of postoperative NTM infection.

Conclusions

The common indolent course of NTM infection hinders prompt diagnosis and treatment. Organism susceptibility testing is crucial for effective treatment and limiting unnecessary antibiotic exposure.

Clinical Relevance

The duration of medical treatment for NTM infection is 4 to 6 months, depending on the severity of disease and species. Based on the aggregate literature, we recommend removal of local implants if the infection is localized and without articular involvement. However, in cases of articular involvement, all fixation and graft material should be removed.

A Rare Case of Osteomyelitis of an Ankle Caused by Mycobacterium chelonae

Mycobacterium chelonae, a rapidly growing nontuberculous mycobacterium, is usually described as a causative agent of soft tissue infections (postsurgical, posttraumatic, posttransplantation, postinjection, catheter infection, etc.), but only rarely as a cause of osteomyelitis. The authors describe a case report of a 72-year-old man with osteomyelitis of the talus. Initially, the infection was assessed as a soft tissue infection, without any osteolytic changes on the X-ray. After cultivation with subsequent targeted molecular typing of the rpoB gene, M. chelonae was identified from the affected tissue. The bone involvement was subsequently detected on MRI and confirmed histologically with findings of the granulomatous tissue and acid-fast bacilli. The patient was initially treated intravenously with a combination of tigecycline, amikacin, and moxifloxacin for 4 weeks, after which the oral combination of doxycycline and moxifloxacin continued. Identification of the infecting pathogen using molecular typing thus helped to establish the correct diagnosis and represents a rarely described case of osteomyelitis caused by M. chelonae.

Opportunistic etiological agents causing lung infections: emerging need to transform lung-targeted delivery

Lung diseases continue to draw considerable attention from biomedical and public health care agencies. The lung with the largest epithelial surface area is continuously exposed to the external environment during exchanging gas. Therefore, the chances of respiratory disorders and lung infections are overgrowing. This review has covered promising and opportunistic etiologic agents responsible for lung infections. These pathogens infect the lungs either directly or indirectly. However, it is difficult to intervene in lung diseases using available oral or parenteral antimicrobial formulations. Many pieces of research have been done in the last two decades to improve inhalable antimicrobial formulations. However, very few have been approved for human use. This review article discusses the approved inhalable antimicrobial agents (AMAs) and identifies why pulmonary delivery is explored. Additionally, the basic anatomy of the respiratory system linked with barriers to AMA delivery has been discussed here. This review opens several new scopes for researchers to work on pulmonary medicines for specific diseases and bring more respiratory medication to market.

Multidisciplinary Treatment of Persistent Nontuberculous Mycobacterial Spinal Hardware Infection with a Pedicled Superior Gluteal Artery Perforator Flap

Nontuberculous mycobacterial hardware infections are extremely challenging to treat. Multidisciplinary care involving removal of infected hardware, thorough debridement, and durable soft tissue coverage in conjunction with antibiotic therapy is essential for successful management. This case report presents a patient with chronic mycobacterial spinal hardware infection that underwent successful treatment with aggressive serial debridements and reconstruction with a large pedicled superior gluteal artery perforator flap coverage.

Rare Case of Non-tuberculous Mycobacterial Infection following Repair of Pectoralis Major Avulsion: Case Report and Review of Literature

Introduction

Non-tuberculous mycobacteria (NTM) infections of the musculoskeletal system are commonly missed due to their rarity and the absence of systemic symptoms. Here, we present a rare case of NTM infection following repair of an avulsed pectoralis major tendon in an immunocompetent host managed by a multi-disciplinary team specializing in musculoskeletal infections.

Case Report

A 23-year-old male patient presented with discharging sinus in the right axilla for 6 months. He sustained the right pectoralis major muscle avulsion following an accident which was surgically repaired using FiberWire® and endo buttons. He developed a discharging sinus 4-month post-surgery. He presented with persistent infection in spite of empirical antibiotics elsewhere. Radiographs and MRI sonogram showed intra-medullar endo buttons in the proximal humerus with marginal pus collection in the axillary region with minimal medial extension into pectoralis major and minor muscles along the superior aspect. A detailed plan was made with inputs from a multidisciplinary bone infection team. Wound was radically debrided, implants and sutures removed, humerus scraped, and tissues sent for microbiology and histopathology. Extended incubation of deep tissue culture as suggested by ID specialists grew Rapidly growing mycobacteria, a type of NTM 3 weeks after surgery. Patient was started on intravenous amikacin along with oral clarithromycin and linezolid based on antibiotic susceptibility. Wound discharge persisted for almost 5-week post-surgery and stopped 2 weeks after initiation of appropriate antibiotics. Amikacin was given for 1 month and oral antibiotics were continued for 6 months. The pectoralis major function was unaffected after surgery and patient returned to normal activities 3 months after debridement. Patient has an infection free follow-up of 4 years.

Conclusion

This case outlines the importance of having a high degree of suspicion for the diagnosing orthopedic NTM infections. In addition, it showcases the advantages of having good communication between surgeons, infectious disease specialist, and microbiologist for achieving good functional outcomes.

Difficulty in Diagnosis and Management of Musculoskeletal Nontuberculous Mycobacterial Infections

We describe two cases of musculoskeletal nontuberculous mycobacterial (NTM) infection resulting in undesirable outcomes. These organisms can be difficult to identify and treat, potentially leading to significant morbidity. NTM should remain on the differential for culture negative bone and joint infections, especially with a prior surgical history or environmentally-acquired injuries.

•

There is considerable difficulty in diagnosing NTM orthopedic infections.

•

These infections can be prolonged and progressive.

•

Consider NTM infection with negative cultures and failure of routine antibacterials.

•

Surgical debridement is essential in combination with antimycobacterials.

•

Treatment should be determined after culture results yield drug susceptibilities.

Non-tuberculous Mycobacterial Infection of the Musculoskeletal System Detected at Two Tertiary Medical Centres in Henan, China, 2016-2020

Non-tuberculous mycobacterial (NTM) infection of the musculoskeletal system is rare but poses a grave threat to public health. These infections yield non-specific symptoms that remain undetected until the development of the later stages of the disease. In this study, we performed a retrospective review of 25 cases of musculoskeletal NTM infection at two tertiary medical centres over a 5-year period to determine the clinical features and improve the current clinical diagnosis and treatment. The most common mycobacterial species detected were Mycobacterium fortuitum in eleven patients, Mycobacterium abscessus in eight patients, Mycobacterium houstonense in three patients, Mycobacterium avium in two patients, and Mycobacterium smegmatis in one patient. The sites of infection included the limbs and joints, most commonly the knee (ten patients) and foot (six patients). The median duration from the onset of symptoms to diagnosis was 2.5 months (0.8-13.5 months). Deep sinus tracts extending to the surgical site were observed in 60% of the patients (15/25), and granulomatous inflammation and granulomatous inflammation with necrosis occurred in 60% of the patients (15/25). All patients underwent surgical treatment for infection control, and all patients, except one, received antimycobacterial therapy based on drug sensitivity assays. The median duration of the antimicrobial chemotherapy was 5 months (range: 3-20 months). At the final follow-up, 24 patients presented with absence of recurrence and one patient succumbed owing to heart failure after debridement. Our findings highlight the importance of vigilance and improvements in the diagnostic methods for musculoskeletal NTM infection. Aggressive surgical treatment and antimycobacterial drug treatment can help achieve satisfactory results.

Mycobacterium abscessus Periprosthetic Hip Infection Complicated by Superimposed Polymicrobial Infection: A Case Report

CASE

A 79-year-old man developed Mycobacterium abscessus prosthetic joint infection (PJI) after hip hemiarthroplasty that was complicated by polymicrobial infection. He was ultimately treated with resection arthroplasty and chronic suppressive therapy. He has had no evidence of recurrent infection after 2 years of follow-up.

CONCLUSION

As far as we know, this is the first reported case of M. abscessus hip PJI complicated by superimposed polymicrobial infection. This case demonstrates the challenge of treating M. abscessus infection, the need for a multidisciplinary approach with aggressive surgical intervention, and prolonged combination antimicrobial therapy for a successful outcome.

Septic arthritis of native joints due to Mycobacterium avium complex: A systematic review of case reports

INTRODUCTION

While MAC native joint septic arthritis is historically considered a rare entity, the number of reported cases have increased in recent decades. However, no comprehensive review of this topic has been conducted.

OBJECTIVES

To conduct a systematic review of cases of MAC native joint septic arthritis reported in the literature and summarize the presentations, baseline characteristics, risk factors, diagnosis, treatment, and treatment outcomes.

METHODS

A systematic review was conducted by performing an extensive literature search through Medline, Google Scholar, and Web of Science, starting from their inception. Screening of articles, assessment of eligibility, and data synthesis from eligible articles were independently performed by two reviewers with input from a third reviewer to achieve consensus. Inclusion criteria to determine eligibility included articles in English, case reports/case series, adult patients who presented with MAC/MA/MI septic arthritis of a native joint. Statistical analyses were performed using Statistical Package for the Social Sciences.

RESULTS

Thirty-three cases of MAC native joint septic arthritis were reported since 1976. MAC septic arthritis affects immunocompetent and immunocompromised patients, most frequently as a monoarthritis involving the knees and wrist. MAC septic arthritis may present in the context of disseminated MAC infection and primary MAC septic arthritis. The average time to diagnosis from onset of symptoms was 20 months, where the majority of cases were initially misdiagnosed. Although arthrocentesis can be used to make the diagnosis, a synovial biopsy is necessary in many cases to confirm the diagnosis. A combination of surgery and antimycobacterial drug treatment has the highest chance of achieving complete resolution.

CONCLUSION

The diagnosis of septic arthritis of native joints due to MAC can be challenging and/or delayed. A high level of suspicion is needed in high-risk patients and also when atypical presentations occur. Therefore, understanding the presentation, risk factors, and pitfalls in diagnosing MAC septic arthritis are essential. MAC septic arthritis literature is scarce, necessitating further research of this rare condition to increase awareness, diagnostic accuracy and determine the optimal treatment strategy to improve patient outcomes.

Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Management of refractory Mycobacterium abscessus sternal infection following reoperative cardiac surgery

Mycobacterium abscessus surgical site infections are rare, but notoriously difficult to treat. Eradication requires aggressive surgical resection, removal of foreign material, prolonged antibiotics, and consideration of delayed reconstruction.

Septic arthritis due to non-tuberculous mycobacterium without effusion

Septic arthritis is an important but difficult to make diagnosis that leads to significant morbidity and mortality. Joint effusion is generally accepted to be a highly sensitive finding in septic arthritis; however, final diagnosis requires synovial fluid studies. Without a significant joint effusion, it is difficult to obtain synovial fluid. In this case report, we describe the presentation and diagnosis of septic arthritis in the first MTP due to mycobacterium chelonae in a 69 year old man with a history of gout and immunosuppression due to a heart transplant. There was notably no significant effusion in the joint on clinical examination or bedside ultrasound. As the patient was immunosuppressed, arthrocentesis was performed under ultrasound guidance. A needle was clearly visualized in the joint; however, minimal synovial fluid was obtained. The fluid grew Mycobacterium chelonae in culture. Subsequent joint washout revealed purulent synovial fluid that grew out the same bacteria. This case emphasizes the importance of obtaining synovial fluid to evaluate for septic arthritis, even when joint effusion is absent. Ultrasound guidance can facilitate this.

Mycobacterium chelonae bloodstream infection induced by osteomyelitis of toe: A case report

Mycobacterium chelonae is a rapidly growing mycobacterium that has the potential to cause refractory infections in humans. Mycobacteremia resulting from the organism is extremely rare, and its clinical features are yet to be uncovered. We herein present a case of M. chelonae bloodstream infection involving an immunocompromised older patient. A 79-year-old woman, on a long-term treatment with prednisolone plus tacrolimus for rheumatoid arthritis, visited our outpatient department complaining of deteriorating pain and swelling at her right 1st toe. Laboratory parameters showed elevated C-reactive protein and leukocytosis, and magnetic resonance imaging indicated osteomyelitis at the proximal phalanx of her right 1st toe. Considering the refractory course, the infected toe was immediately amputated. M. chelonae was isolated from bacterial cultures of the resected tissue and blood (BD BACTEC™ FX blood culture system, Becton Dickinson, Sparks, MD, USA), leading to a diagnosis of disseminated M. chelonae infection. We treated the patient with an antibiotic combination of clarithromycin, minocycline, and imipenem (2 weeks), which was converted to oral therapy of clarithromycin, doxycycline, and levofloxacin. This case highlighted the potential pathogenesis of M. chelonae to cause mycobacteremia in an immunocompromised patient.

Treatment of Extrapulmonary Nontuberculous Mycobacterial Diseases

Nontuberculous mycobacteria (NTM) diseases mainly manifest as pulmonary illnesses, but 20 -30% of NTM isolates originate from extrapulmonary diseases. These diseases cause a variety of clinical syndromes, including skin and soft-tissue infections, musculoskeletal infections, lymphadenitis, and disseminated disease. In skin and soft-tissue infections, musculoskeletal infections, prolonged treatment with combinations of antibiotics is effective in the treatment of NTM diseases, with surgery as an important complementary tool. The recommended duration of therapy for skin and soft-tissue infection is usually 2 – 4 months for mild disease and 6 months for severe disease, while treatment of musculoskeletal NTM disease usually requires at least 6 - 12 months. Management options of NTM lymphadenitis include surgical intervention, medical therapy, or observation. Treatment of disseminated NTM disease generally requires 6 to 12 months after immune restoration. However, despite a considerable increase in knowledge about NTM diseases, determining optimal treatment approaches remains a complex and challenging task.