Clinical manifestations, diagnosis, and treatment of Mycobacterium haemophilum infections

Review of methods for detection and characterization of non-tuberculous mycobacteria in aquatic organisms

Mycobacteriosis is an emerging and often lethal disease of aquatic organisms caused by several non-tuberculous mycobacteria (NTM) species. Early diagnosis of mycobacteriosis in aquaculture and aquatic settings is critical; however, clinical diagnoses and laboratory detection are challenging, and the available literature is scarce. In an attempt to fill the gap, here we review the most relevant approaches to detect and characterize mycobacteria in clinical specimens of aquatic organisms. Emphasis is given to recent advances in molecular methods used to differentiate NTM species spanning from targeted gene sequencing to next-generation sequencing. Further, given that there are major gaps in our understanding of the prevalence of the different NTM species, partially because of their distinct requirements for in vitro growth, we also reviewed the most relevant NTM species reported to cause disease in aquatic organisms and their specific in vitro growth conditions. We also highlight that traditional bacterial culture continues to be relevant for NTM identification, particularly in non-automated laboratories. However, for NTM species discrimination, a high level of accuracy can be achieved with MALDI-TOF MS and molecular approaches, especially targeted gene sequencing applied from clinical specimens or from pure NTM isolates.

Neurological manifestations of nontuberculous mycobacteria in adults: case series and review of the literature

Introduction

Nontuberculous mycobacteria (NTM) mediated infections are important to consider in cases with neuroinflammatory presentations. We aimed to characterize cases of NTM with neurological manifestations at the National Institutes of Health (NIH) Clinical Center and review the relevant literature.

Materials and methods

Between January 1995 and December 2020, six cases were identified. Records were reviewed for demographic, clinical, and radiological characteristics. A MEDLINE search found previously reported cases. Data were extracted, followed by statistical analysis to compare two groups [cases with slow-growing mycobacteria (SGM) vs. those with rapidly growing mycobacteria (RGM)] and evaluate for predictors of survival. NIH cases were evaluated for clinical and radiological characteristics. Cases from the literature were reviewed to determine the differences between SGM and RGM cases and to identify predictors of survival.

Results

Six cases from NIH were identified (age 41 ± 13, 83% male). Five cases were caused by SGM [Mycobacterium avium complex (MAC) n = 4; Mycobacterium haemophilum n = 1] and one due to RGM (Mycobacterium abscessus). Underlying immune disorders were identified only in the SGM cases [genetic (n = 2), HIV (n = 1), sarcoidosis (n = 1), and anti-interferon-gamma antibodies (n = 1)]. All cases were diagnosed using tissue analysis. A literature review found 81 reports on 125 cases (SGM n = 85, RGM n = 38, non-identified n = 2). No immune disorder was reported in 26 cases (21%). Within SGM cases, the most common underlying disease was HIV infection (n = 55, 65%), and seizures and focal lesions were more common. In RGM cases, the most common underlying condition was neurosurgical intervention or implants (55%), and headaches and meningeal signs were common. Tissue-based diagnosis was used more for SGM than RGM (39% vs. 13%, p = 0.04). Survival rates were similar in both groups (48% SGM and 55% in RGM). Factors associated with better survival were a solitary CNS lesion (OR 5.9, p = 0.01) and a diagnosis made by CSF sampling only (OR 9.9, p = 0.04).

Discussion

NTM infections cause diverse neurological manifestations, with some distinctions between SGM and RGM infections. Tissue sampling may be necessary to establish the diagnosis, and an effort should be made to identify an underlying immune disorder.

Mycobacterium haemophilum infection in immunocompetent adults: a literature review and case report

BACKGROUND

Mycobacterium haemophilum has been increasingly found in severely immunocompromised patients but is scarcely reported in immunocompetent adults.

METHODS

We systematically reviewed previous literature to identify studies on infection in immunocompetent adults. Articles reporting at least one case of M. haemophilum infection were included. We excluded articles involving patients who had immunosuppression-related diseases and routinely used glucocorticoids or immunosuppressants. We also reported a case of a young immunocompetent woman infected by M. haemophilum along the eyebrows, which was probably due to the use of an eyebrow pencil retrieved from a sink drain.

RESULTS

Twelve qualifying articles reporting M. haemophilum infection in immunocompetent adults were identified. Among them, most cases report skin lesions along the eyebrows, and the remaining had cervicofacial lymphadenitis, lesions on the arm or fingers, inflammation in the eyeballs, or ulceration in the perineal region. Most cases were caused by tattoos, make-up, injury, or surgical operation. For diagnosis, specialized tissue culture sensitivity was roughly 75%, and polymerase chain reaction (PCR) test sensitivity was approximately 89%. Triple antibiotic therapy for 3 to 24 months, or surgical excision was effective in controlling infection.

CONCLUSION

M. haemophilum infection should be considered if routine antibacterial and glucocorticoid treatments are ineffective against the disease, even in healthy adults. To definitively diagnose this infection, conditioned tissue culture or PCR testing is required. Treatment usually involves a combination of multiple antibiotics and, if necessary, surgical removal of infected tissue.

Current management of cervicofacial nontuberculous mycobacterial infections in the pediatric population

PURPOSE OF REVIEW

The purpose of this review is to analyze and consolidate recently published literature to provide updated guidelines on the diagnosis and management of nontuberculous mycobacterial lymphadenitis (NTM LAD) in the pediatric population and to suggest areas of further research.

RECENT FINDINGS

Diagnosis of NTM LAD relies on a detailed clinical history, physical examination, laboratory tests, and imaging techniques. Treatment strategies vary widely, with a shift towards complete surgical excision being observed due to its higher cure rate, improved aesthetic outcomes, and lower recurrence rates. However, patient-specific factors must be considered. The role of genetic factors, such as Mendelian susceptibility to mycobacterial disease (MSMD), is being increasingly recognized and could lead to targeted therapies.

SUMMARY

Despite strides in the understanding and management of NTM LAD, substantial gaps remain in key areas such as the role of diagnostic imaging, optimal treatment parameters, postoperative care, and surveillance strategies. In this article, we explain our approach to NTM using the most relevant evidence-based medicine while offering directions for future work.

Nonmarinum, Nontuberculous Mycobacterial Infections of the Upper Extremity: A Multi-Institutional Descriptive Report

PURPOSE

We analyzed patient demographic factors involved in the development of nonmarinum, nontuberculous mycobacterial infections (NTMI) involving the upper extremity, and assessed diagnostic and prognostic values of commonly used preoperative laboratory and imaging studies, as well as factors related to recurrence of disease and patient outcomes.

METHODS

Patients from 2 academic, tertiary facilities with culture-proven, nonmarinum NTMI involving the upper extremity were reviewed. Patient-related factors and clinical outcomes were extracted. The analysis was based on pathogen identification (rapid- vs slow-growing subspecies) and immune status.

RESULTS

Our 76 patients had a mean age of 59 years, and 65% were male. Forty-eight percent reported an injury, and hands were frequently involved (58%). Forty-one percent were immunosuppressed (19% organ transplant recipients). The mean symptom duration prior to presentation was 203 days. The culture identification took a mean of 33 days, with 25 different species identified (subcategorized as rapid or slow growers). Seventy-seven percent had solitary lesions, with a cutaneous or subcutaneous location most common. Immunosuppressed patients were treated longer with antibiotics (243 vs 155 days in immunocompetent patients) and experienced higher rates of side effects, complications, and recurrence. All patients underwent debridement to control infection, including 4 individuals who required amputations. One-third experienced complications and/or recurrence, regardless of the organism type.

CONCLUSIONS

Upper-extremity nonmarinum NTMI is often misdiagnosed, causing management delays. Early consideration in differential diagnoses of chronic, painful swelling, nodular or inflammatory lesions, or septic arthritis is crucial. Tissue biopsy with specimens for histopathology and microbiological analysis (mycobacterial smear, cultures, and broad range polymerase chain reaction) and early involvement with an infectious disease specialist are recommended. Empiric antibiotic therapy is not standard. Debridement and prolonged, directed combination antimicrobial therapy is required; however, adverse reactions are commonly encountered.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Mycobacterium haemophilum infection with cutaneous involvement: two case reports and an updated literature review: Mycobacterium haemophilum skin infection

Mycobacterium haemophilum (MH) is a slow-growing, non-tuberculous Mycobacterium that most commonly causes infections in immunocompromised patients. The skin is the most prevalent site of infection and can be an isolated presentation or part of a disseminated disease. Herein, we reported a case of isolated MH infection of the hand and a case of disseminated MH infection with multiple skin lesions. In addition, other MH cases with cutaneous involvement over the last 10 years, from 2011-2022, were reviewed and analyzed. Among the 79 included cases, the common skin findings in MH infections included nodules, ulcers, abscesses, swelling, and pustules. Middle-aged patients with iatrogenic immunosuppression from glucocorticoids, mycophenolate mofetil, cyclosporine, and cyclophosphamide are the most susceptible to MH infection, with a higher risk of dissemination to internal organs. Disseminated MH infections commonly present as tenosynovitis, arthritis/arthralgia, or osteomyelitis. There is a lack of strong evidence for treatment; however, triple therapy of quinolone, macrolides, and rifampicin is most often used in clinical practice. The overall prognosis is good. The presence of iatrogenic immunocompromised diseases, lesions involving the proximal limbs, and dissemination of MH infections are associated with worse clinical outcomes.

Hautbeteiligung bei Infektionen mit Mycobacterium haemophilum: Zwei Fallberichte und eine aktualisierte Literaturübersicht: Mycobacterium haemophilum infection with cutaneous involvement: Two case reports and an updated literature review

Mycobacterium haemophilum (MH) ist ein langsam wachsendes, nicht‐tuberkulöses Mykobakterium. Infektionen treten am häufigsten bei Patienten mit beeinträchtigtem Immunsystem auf; sie manifestieren sich meist an der Haut und kommen isoliert oder bei disseminierten Infektionen vor. Wir berichten hier über einen Fall mit isolierter MH‐Infektion an der Hand sowie über einen weiteren Fall von disseminierter MH‐Infektion mit multiplen Hautläsionen. Zusätzlich haben wir weitere Fallberichte über MH‐Infektionen mit kutaner Beteiligung aus den letzten zehn Jahren (2011–2022) ausgewertet. Die am häufigsten beobachteten Hautmanifestationen der insgesamt 79 Fälle waren Knötchen, Ulzera, Abszesse, Schwellungen und Pusteln. Patienten mittleren Alters mit iatrogener Immunsuppression durch Glucocorticoide, Mycophenolat‐Mofetil, Ciclosporin und Cyclophosphamid scheinen besonders anfällig für MH‐Infektionen zu sein und haben auch ein höheres Risiko für eine Dissemination in die inneren Organe. Disseminierte MH‐Infektionen manifestieren sich gewöhnlich als Tenosynovitis, Arthritis/Arthralgie oder Osteomyelitis. Derzeit gibt es keine starke Evidenz für bestimmte Therapeutika; in der Praxis wird am häufigsten eine Dreifachkombination aus Chinolon, Makroliden und Rifampicin eingesetzt. Die Prognose ist allgemein gut. Iatrogene Immunsuppression, Läsionen im proximalen Bereich der Extremitäten sowie disseminierte Manifestation sind mit schlechteren klinischen Verläufen assoziiert.

A Systemic Lupus Erythematosus Patient with Cutaneous Mycobacterium haemophilum Infection under Belimumab Treatment: A Case Report

A 38-year-old female with systemic lupus erythematosus (SLE) initiated belimumab treatment. One month later, she presented with a reddish painful swelling on her right lower leg. She was treated with ceftriaxone and vancomycin. However, novel erythematous papules and indurated nodules appeared on both her lower legs. Skin biopsy revealed microabscess formation with mixed cell granuloma surrounded by inflammatory cell infiltration within the dermis with subcutaneous fat tissue. A large number of acid-fast bacilli were observed with Ziehl-Neelsen staining. DNA sequencing of both the hsp65 and the 16S rRNA sequences showed a 100% match with the corresponding region of Mycobacterium haemophilum. Mycobacterial culture revealed satellite growth enhancement on Middlebrook 7H11 agar plates around a paper strip containing hemin. She was treated with levofloxacin, rifabutin, and ethambutol. Within 13 months, her cutaneous lesions improved markedly without any side effects. The B cell-targeted biologic belimumab, a fully humanized IgG1γ monoclonal antibody that inactivates B lymphocyte stimulator, has been considered to be beneficial for active SLE. However, this therapy could increase the risk for the development of biologic therapy-associated mycobacterial infections, both tuberculosis and nontuberculous mycobacteria infections.

Ocular Mycobacterium haemophilum infection originating in the cornea: a case report

BACKGROUND

Mycobacterium haemophilum is a slow-growing non-chromogenic nontuberculous Mycobacterium species that can cause skin infection or arthritis in an immunocompromised population or in children. Primary infection of the healthy adult cornea is rare. The special requirements for culture make this pathogen difficult to diagnose. The study aims to report the clinical manifestation and treatment process of corneal infection and notify the awareness of M. Haemophilus keratitis among clinicians. This is the first case report of primary M. haemophilum infection in the cornea of healthy adults reported in the literature.

CASE PRESENTATION

A 53-year-old healthy goldminer presented with left eye redness and a history of vision loss for four months. The patient was misdiagnosed with herpes simplex keratitis until M. haemophilum was detected using high-throughput sequencing. Penetrating keratoplasty was performed, and a large number of mycobacteria were detected by Ziehl-Neelsen staining of the infected tissue. Three months later, the patient developed conjunctival and eyelid skin infections that manifested as caseous necrosis of the conjunctiva and skin nodules. After excision and debridement of the conjunctival lesions and systemic antituberculosis drug treatment for 10 months, the patient was cured.

CONCLUSION

M. haemophilum could cause primary corneal infection in healthy adults, which is an infrequent or rare infection. Owing to the need for special bacterial culture conditions, conventional culture methods do not provide positive results. High-throughput sequencing can rapidly identify the presence of bacteria, which aids in early diagnosis and timely treatment. Prompt surgical intervention is an effective treatment option for severe keratitis. Long-term systemic antimicrobial therapy is crucial.

[Two severe cases of disseminated cutaneous nontuberculous mycobacteriosis due to Mycobacterium haemophilum]

Mycobacterium haemophilum is a rare pathogen belonging to the group of slowly growing nontuberculous mycobacteria (NTM) that can cause infections, especially in immunocompromised patients. Detection by culturing is difficult because M. haemophilum only grows under special cultivation conditions. Therefore, it is believed that the pathogen is too rarely identified as a cause of disease overall. In addition to patients with severe immunodeficiency, e.g. due to acquired immunodeficiency syndrome (AIDS), chemotherapy or immunosuppression after transplantation, patients with underlying rheumatic diseases are increasingly described in the literature, who are at risk due to the immunosuppressive treatment regimen. Clinically, ulcerative skin alterations, lymphadenopathy and arthropathy are in the foreground. In immunosuppressed patients with unclear skin lesions, infections due to M. haemophilum should be considered and specific microbiological diagnostics should be initiated.

Case report: Subcutaneous Mycobacterium haemophilum infection in an immunocompetent patient after lipolysis injections

Mycobacterium haemophilum is a slow-growing, aerobic mycobacterium that acts as a pathogen in immunocompromised adult patients and immunocompetent children. There are only a few rare cases in the literature describing this species as a cause of subcutaneous infections. Here, we describe a subcutaneous infection caused by M. haemophilum in an immunocompetent female after lipolysis injections at an unqualified beauty salon, suggesting that this bacteria can also be a potential causative agent of adverse events in medical aesthetics. In addition, M. haemophilum caused lesions not only at the injection sites and adjacent areas but also invaded distant sections through the subcutaneous sinus tracts. Thus, early diagnosis and appropriate treatment are vital to prevent further deterioration and improve prognosis.

Osteomyelitis due to Mycobacterium haemophilum in an adult renal transplant recipient

Mycobacterium haemophilum is an increasingly recognized pathogen of the non-tuberculous mycobacteria family that largely infects immunocompromised adults and immunocompetent children. M. haemophilum is a fastidious and slow-growing organism that exhibits preferential growth at lower temperature with iron supplemented media, and therefore most clinical manifestations involve cutaneous infection or musculoskeletal infection of the distal extremities. It is believed that opportunistic infection occurs in immunocompromised hosts when the organism is acquired through environmental exposure. We describe the case of a 71-year-old renal transplant recipient who developed acute M. haemophilum osteomyelitis of the left foot, likely contracted from Epsom salt soaks with contaminated tap water. Outcomes of M. haemophilum infection are generally favorable in the literature. Our patient was treated with local debridement and partial amputation followed by a 3-drug anti-mycobacterial regimen until definitive amputation could be completed.

External quality assessment by European mycobacterial laboratories: results of AFB microscopy and identification rounds

We analyzed mycobacterial stain, culture and identification EQA data from altogether 134 laboratories in 15 mainly European countries over a 4-year period. The aim was to get an overview of the performance and methods and identify diagnostic challenges. The overall success rates for staining and identification were 94% and 91%. The false negative rate for staining was significantly higher for the medium positive than the strong positive slides (11% vs 4%). The false positive rate on negative slides was 10%, indicating contamination issues. The overall success of M. tuberculosis detection was high with error rates ranging from 0.7% to 1.2%. Pre- or postanalytical errors accounted for most of the unsuccessful responses. The detection of nontuberculous mycobacteria (NTM) was less consistent; accurate species identification depended on the assays used. Only 19% of participants performed species level identification for NTMs, 47% detected the presence NTMs while 21% focused on ruling out TB.

Dynamics of the Microbial Community and Opportunistic Pathogens after Water Stagnation in the Premise Plumbing of a Building

In premise plumbing, microbial water quality may deteriorate under certain conditions, such as stagnation. Stagnation results in a loss of disinfectant residual, which may lead to the regrowth of microorganisms, including opportunistic pathogens. In the present study, microbial regrowth was investigated at eight faucets in a building over four seasons in one year. Water samples were obtained before and after 24 h of stagnation. In the first 100‍ ‍mL after stagnation, total cell counts measured by flow cytometry increased 14- to 220-fold with a simultaneous decrease in free chlorine from 0.17–0.36‍ ‍mg L^–1 to <0.02‍ ‍mg L^–1. After stagnation, total cell counts were not significantly different among seasons; however, the composition of the microbial community varied seasonally. The relative abundance of Pseudomonas spp. was dominant in winter, whereas Sphingomonas spp. were dominant in most faucets after stagnation in other seasons. Opportunistic pathogens, such as Legionella pneumophila, Mycobacterium avium, Pseudomonas aeruginosa, and Acanthamoeba spp., were below the quantification limit for real-time quantitative PCR in all samples. However, sequences related to other opportunistic pathogens, including L. feeleii, L. maceachernii, L. micdadei, M. paragordonae, M. gordonae, and M. haemophilum, were detected. These results indicate that health risks may increase after stagnation due to the regrowth of opportunistic pathogens.

A cold-blooded tiptoer: non-resolving cellulitis in an immunocompromised patient

Mycobacterium haemophilum is a nontuberculous mycobacteria (NTM) with a predilection for skin and soft tissue infection (SSTI) in the immunocompromised host. We report a case of disseminated M haemophilum infection initially presenting as a nonresolving subacute cellulitis of bilateral lower extremities. Genetic sequencing was used for final identification, while a commercially available polymerase chain reaction test returned a false-positive result for Mycobacterium intracellulare. Consequently, we highlight the importance of M haemophilum as a major differential diagnosis of SSTI in the immunocompromised host and the need for careful interpretation of rapid diagnostic tests.

Disseminated cutaneous Mycobacterium haemophilum infection in a patient on infliximab for rheumatoid arthritis

Mycobacterium haemophilum is a rarely encountered pathogen that is difficult to identify given its unique growth requirements. It is most often seen in adult patients who are immunosuppressed due to advanced HIV or haematological malignancy. Our case highlights a typical presentation of an atypical pathogen in a patient with rheumatoid arthritis receiving anti-tumour necrosis factor therapy. This case represents an important patient population in whom this previously rare infection is increasingly common.

The key factors contributing to the risk, diagnosis and treatment of non-tuberculous mycobacterial opportunistic infections

The incidence and prevalence of diseases caused by non-tuberculous mycobacteria (NTM) have been steadily increasing worldwide. NTM are environmental saprophytic organisms; however, a few strains are known to produce diseases in humans affecting pulmonary and extra-pulmonary sites. Although the environment is a major source of NTM infection, recent studies have shown that person-to-person dissemination could be an important transmission route for these microorganisms. Structural and functional lung defects and immunodeficiency are major risk factors for acquiring NTM infections. Diagnosis of NTM diseases is very complex owing to the necessity of distinguishing between a true pathogen and an environmental contaminant. Identification at the species level is critical due to differences in the antibiotic susceptibility patterns of various NTM strains. Such identification is mainly achieved by molecular methods; additionally, mass spectrometry (e.g., MALDI-TOF) is useful for NTM species determination. Natural resistance of NTM species to a wide spectrum of antibiotics makes prescribing treatment for NTM diseases very difficult. NTM therapy usually takes more than one year and requires multi-drug regimens, yet the outcome often remains poor. Therefore, alternatives to antibiotic therapy treatment methods is an area under active exploration. NTM infections are an active global health problem imposing the necessity for better diagnostic tools and more effective treatment methods.

Long-Term Outcome of Surgical Treatments for Nontuberculous Mycobacterial Cervicofacial Lymphadenitis in Children

PURPOSE

Information on long-term treatment outcome for nontuberculous mycobacterial (NTM) cervicofacial lymphadenitis in children is scarce. The purpose of this study is to evaluate long-term outcome for surgical treatment, which is the mainstay treatment modality.

METHODS

This case series describes recurrence rates of surgically treated NTM cervicofacial lymphadenitis patients with a follow-up of at least 10 years. The current study data were partially collected from a randomized, prospective, multicenter, multidisciplinary trial (CHIMED study), which was conducted between 2000 and 2006 to determine the optimal treatment for NTM cervicofacial lymphadenitis in children. After the CHIMED trial inclusion ended, our institute continued to serve as a referral center. This enabled us to enlarge the surgical CHIMED cohort by adding patients who were treated during 2007 to 2010 in our center and collect the rest of the current study data.

RESULTS

About 427 children with chronic cervicofacial lymphadenopathy were analyzed. Among these, 290 had microbiologically confirmed cervicofacial mycobacterial infections (n = 3 Mycobacterium tuberculosis, n = 1 Mycobacterium bovis, n = 286 NTM). Of these 286 children with NTM cervicofacial lymphadenitis, 189 were treated surgically (median age: 41 months, range: 9-144, 46.0% males). The affected lymph nodes were excised in 151 children (79.9%), and curettage was performed in 38 children (20.1%). One patient (0.07%) experienced a reactivation/recurrence 2 years after surgical excision and required another surgical excision. Three children (7.9%) experienced infection reactivation/recurrences after curettage, confirmed by redness or a draining fistula, within the first year after healing. Two of these 3 patients were treated with additional surgical excisions.

CONCLUSION

The long-term outcome of surgical excision for NTM cervicofacial lymphadenitis is favorable with a low recurrence rate. Curettage or a conservative wait-and-see approach can be considered an alternative in advanced and surgically challenging cases. However, healing will take longer, and late recurrences are possible.

On the Identification of Clinically Relevant Bacterial Amino Acid Changes at the Whole Genome Level Using Auto-PSS-Genome

The identification of clinically relevant bacterial amino acid changes can be performed using different methods aimed at the identification of genes showing positively selected amino acid sites (PSS). Nevertheless, such analyses are time consuming, and the frequency of genes showing evidence for PSS can be low. Therefore, the development of a pipeline that allows the quick and efficient identification of the set of genes that show PSS is of interest. Here, we present Auto-PSS-Genome, a Compi-based pipeline distributed as a Docker image, that automates the process of identifying genes that show PSS using three different methods, namely codeML, FUBAR, and omegaMap. Auto-PSS-Genome accepts as input a set of FASTA files, one per genome, containing all coding sequences, thus minimizing the work needed to conduct positively selected sites analyses. The Auto-PSS-Genome pipeline identifies orthologous gene sets and corrects for multiple possible problems in input FASTA files that may prevent the automated identification of genes showing PSS. A FASTA file containing all coding sequences can also be given as an external global reference, thus easing the comparison of results across species, when gene names are different. In this work, we use Auto-PSS-Genome to analyse Mycobacterium leprae (that causes leprosy), and the closely related species M. haemophilum, that mainly causes ulcerating skin infections and arthritis in persons who are severely immunocompromised, and in children causes cervical and perihilar lymphadenitis. The genes identified in these two species as showing PSS may be those that are partially responsible for virulence and resistance to drugs.

Patient on Immunomodulatory Therapy Experiencing Joint Pain and Skin Lesions: A Case Report

A woman in her late fifties was admitted to the Family Medicine Inpatient Service directly from Rheumatology clinic for polyarticular pain and erythema with concern for infection. She was taking immunosuppressant medications for a history of multiple autoimmune diseases. Examination showed increasing erythema and tenderness on the upper and lower extremity joints. Histologic evaluation, surgical evaluation, and cultures were consistent with mycobacterium haemophilum infection. Mycobacterium haemophilum is an uncommon opportunistic infection that usually affects immunocompromised patients. The patient was treated with a multi-drug antibiotic regimen for several months due to drug resistance. Although this opportunistic infection is not common it should be considered in the differential of immunocompromised patients with skin and articular symptoms. Treatment outcomes are usually favorable if it caught earlier in the course.

Evaluation of a new culture medium for isolation of nontuberculous mycobacteria from environmental water samples

Nontuberculous mycobacteria (NTM) are waterborne pathogens commonly found in building water systems where they are a primary concern to vulnerable patient populations and can cause severe disease. The recovery of NTM from environmental samples can be a laborious undertaking and current pre-treatment methods and selective media lack sensitivity. We explored the use of the highly selective Rapidly Growing Mycobacteria (RGM) medium for culturing NTM from environmental water samples compared to existing methods. In total, 223 environmental water samples, including potable and non-potable water, were cultured for NTM using three culture media. In addition to direct culture on RGM medium, each sample was cultured on Middlebrook 7H10 medium and Mitchison 7H11 medium after pre-treatment with 0.2M KCl-HCl. Additionally, 33 distinct species of NTM were inoculated onto RGM medium and 7H10 medium in parallel to directly compare their growth. The use of RGM medium alone without pre-treatment provided a sensitivity (91%) comparable to that offered by culture on both 7H10 and 7H11 with acid pretreatment (combined sensitivity; 86%) with significantly less overgrowth and interference from other organisms on RGM medium. The average concentration of NTM observed on RGM medium alone was comparable to or greater than the NTM concentration on either medium alone or combined. Thirty-three species were examined in parallel and all tested strains of 27 of these species successfully grew on RGM medium, including 19 of 21 from the CDC’s healthcare-associated infections species list. RGM medium was successful at recovering environmental NTM without a pre-treatment, greatly reducing labor and materials required to process samples. Simplification of culture processing for environmental NTM will allow for a better assessment of their presence in building water systems and the potential for reduced exposure of susceptible populations.

Cryptococcal fungemia and Mycobacterium haemophilum cellulitis in a patient receiving ruxolitinib: a case report and literature review

Background

Ruxolitinib is a novel oral Janus kinase inhibitor that is used for treatment of myeloproliferative diseases. It exhibits potent anti-inflammatory and immunosuppressive effects, and may increase the risk of opportunistic infections. Here, we report a rare case of Cryptococcus neoformans and Mycobacterium haemophilum coinfection in a myelofibrosis patient who was receiving ruxolitinib.

Case presentation

A 70-year-old Thai man who was diagnosed with JAK2V617F-mutation-positive primary myelofibrosis had been treated with ruxolitinib for 4 years. He presented with cellulitis at his left leg for 1 week. Physical examination revealed fever, dyspnea, desaturation, and sign of inflammation on the left leg and ulcers on the right foot. Blood cultures showed positive for C. neoformans. He was prescribed intravenous amphotericin B deoxycholate with a subsequent switch to liposomal amphotericin B due to the development of acute kidney injury. He developed new onset of fever after 1 month of antifungal treatment, and the lesion on his left leg had worsened. Biopsy of that skin lesion was sent for mycobacterial culture, and the result showed M. haemophilum. He was treated with levofloxacin, ethambutol, and rifampicin; however, the patient eventually developed septic shock and expired.

Conclusions

This is the first case of C. neoformans and M. haemophilum coinfection in a patient receiving ruxolitinib treatment. Although uncommon, clinicians should be aware of the potential for multiple opportunistic infections that may be caused by atypical pathogens in patients receiving ruxolitinib.

Long-term outcome of nonsurgical treatment of nontuberculous mycobacterial cervicofacial lymphadenitis in children

OBJECTIVE

Chronic cervicofacial lymphadenitis in children is often caused by nontuberculous mycobacteria (NTM). Children with NTM infection who were not surgically treated were evaluated for long-term outcome with a follow-up of at least 10 years.

RESULTS

Among the 117 nonsurgically treated children, the median age was 46 months (range, 9-155 months), 56 were male (47.9%), and 61 were female (52.1%). Of the overall group, 75 received antibiotic therapy consisting of clarithromycin and rifabutin (64.1%), and for 54, observation (a wait-and-see approach) was chosen (46.2%). In 100 patients, treatment was considered successful (85%), with a median resolution of 24 (range, 11-134) weeks in the antibiotic group compared to 44.5 (range, 18-130) weeks in the wait-and-see group (P < .05). After 6 months, 58 patients in the antibiotic group were successfully treated (77%), whereas 42 patients of the wait-and-see group demonstrated complete resolution after a median observation time of 44.5 weeks (100%). In 10 patients who experienced complete resolution of the lymphadenitis, infection recurrence developed years later (10%).

CONCLUSION

Nonsurgical treatment of NTM infection can be considered an alternative in advanced and surgically challenging cases. However, healing will take months to years, and late recurrences are possible.

Nontuberculous mycobacterial endophthalmitis: case series and review of literature

Background

To report three cases of nontuberculous mycobacterial (NTM) endophthalmitis following multiple ocular surgeries and to review previous literature in order to study the clinical profile, treatment modalities, and visual outcomes among patients with NTM endophthalmitis.

Methods

Clinical manifestation and management of patients with NTM endophthalmitis in the Department of Ophthalmology, Faculty of Medicine, Siriraj hospital, Mahidol University, Bangkok, Thailand were described. In addition, a review of previously reported cases and case series from MEDLINE, EMBASE, and CENTRAL was performed. The clinical information and type of NTM from the previous studies and our cases were summarized.

Results

We reported three cases of NTM endophthalmitis caused by M. haemophilum, M. fortuitum and M. abscessus and a summarized review of 112 additional cases previously published. Of 115 patients, there were 101 exogenous endophthalmitis (87.8%) and 14 endogenous endophthalmitis (12.2%). The patients’ age ranged from 13 to 89 years with mean of 60.5 ± 17.7 years with no gender predominance. Exogenous endophthalmitis occurred in both healthy and immunocompromised hosts, mainly caused by cataract surgery (67.3%). In contrast, almost all endogenous endophthalmitis patients were immunocompromised. Among all patients, previous history of tuberculosis infection was identified in 4 cases (3.5%). Rapid growing NTMs were responsible for exogenous endophthalmitis, while endogenous endophthalmitis were commonly caused by slow growers. Treatment regimens consisted of macrolides, fluoroquinolones or aminoglycosides, which were continued for up to 12 months. Initial and final vision were generally worse than 6/60.

Conclusions

NTM endophthalmitis is a serious intraocular infection that leads to irreversible loss of vision. The presentation can mimic a chronic recurrent or persistent intraocular inflammation. History of multiple intraocular surgeries or immune-deficiency in patient with chronic panuveitis should raise the practioner’s suspicion of NTM endophthalmitis. Appropriate diagnosis and treatment are important to optimize visual outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05606-2.

Fatal disseminated Mycobacterium haemophilum infection involving the central nervous system in a renal transplant recipient

Mycobacterium haemophilum is a slow growing nontuberculous mycobacterium which prefers cooler temperatures and requires iron for growth. It usually causes skin and soft tissue infections in immunocompromised hosts and cervical lymphadenitis in healthy children. We present the case of fatal disseminated M. haemophilum in an immunocompromised host with central nervous system (CNS) involvement. Our case is a 65-year-old Hispanic male with history of end-stage renal disease status post renal transplantation six years prior (on maintenance immunosuppression with mycophenolate, tacrolimus and prednisone), diabetes mellitus type 2, coronary artery disease, ventricular arrhythmias with implantable cardioverter defibrillator, prior stroke and cochlear implant. In the four months preceding admission to our institution he had frequent hospitalizations for altered mental status (AMS), sepsis syndromes and failure to thrive. Two months prior to presentation he developed progressive swelling and redness of the wrists, right third and left fifth digits. Computed tomography (CT) showed extensive cellulitis in distal right forearm and hand with chronic osteomyelitis. Serial incision and drainage (I&D) of right wrist yielded positive AFB stain and growth on AFB culture. PCR was negative for Mycobacterium tuberculosis. Patient was started on rifampin, clarithromycin and ethambutol. Two days later patient developed AMS and severe septic shock requiring transfer to our facility. CT head revealed indeterminate lesion in the left frontal lobe along with nonspecific hypodensities in the pons and thalamus. Repeat CT upper extremities showed osteomyelitis of distal radius and small hand bones with adjacent abscesses. I&D also revealed bilateral tenosynovitis. Cultures were resent. With suspicion for rapidly growing mycobacterial infection, the regimen was changed to linezolid, imipenem and azithromycin. Several changes in antimicrobials were necessary throughout hospitalization due to complicated hospital course. Unfortunately, despite aggressive measures, patient developed multiorgan failure culminating in death 10 days after starting anti-mycobacterial drugs. On the day of death, the organism was identified as M. haemophilum. Susceptibilities were not done as patient had died. On autopsy the brain was noted to have multiple abscesses containing AFB. The organism also grew from the wrists and right finger cultures. M. haemophilum of the CNS is extremely rare and has been reported in HIV or AIDS patients. To our knowledge this is the first reported case of M. haemophilum brain abscesses in a patient without HIV/AIDS. Because of its fastidious growth requirements, M. haemophilum usually shows on acid fast stains but does not grow on routine AFB cultures. Although it prefers lower temperatures for growth and is usually limited to skin and soft tissues, disseminated disease occurs in immunocompromised patients and has high mortality. It is usually treated with a multi drug regimen including clarithromycin, rifampin, ciprofloxacin and amikacin.

Flexor tenosynovitis of the hand due to rare nontuberculous mycobacterium (Mycobacterium haemophilum) in an immunocompromised patient

We report a case of purulent flexor tenosynovitis caused by Mycobacterium haemophilum in an immunosuppressed patient who received renal transplantation. Three synovial debridements and multiple antimicrobial administrations with clarithromycin, rifampicin, and moxifloxacin have been performed. No apparent recurrence has been observed two years after the final operation.

Mycobacterium haemophilum scleritis: two case reports and review of literature

Background

Mycobacterium haemophilum is a rare and emerging nontuberculous mycobacteria (NTM). It normally causes localized or disseminated systemic diseases, particularly skin infections and arthritis in severely immunocompromised patients. There have been 5 cases of M. haemophilum ocular infections reported in the literature. Only 1 case presented with scleritis with keratitis. Here, we reported 2 cases of M. haemophilum scleritis. One of them was immunocompetent host and had keratitis with radial keratoneuritis as a presenting sign.

Case presentation

Case 1: A 52-year-old Thai female with rheumatoid arthritis presented with scleritis. Conjunctival scraping was carried out and the culture result was positive for M. haemophilum. Despite receiving systemic and topical antibiotics, her clinical symptoms and signs worsened. Surgical debridement was performed. After surgery, the lesion was significantly improved and finally turned to conjunctival scarring. Case 2: A 32-year old healthy Thai male without underlying disease presented with nodular scleritis and keratouveitis with multiple radial keratoneuritis. Surgical debridement of the scleral nodule was performed. Initial microbiological investigations were negative. Herpes ocular infections was suspected. Topical antibiotics, oral acyclovir, low-dose topical steroids and systemic steroids were started. The scleral inflammation subsided but later the keratitis relapsed, requiring corneal biopsy. Histopathology of the specimen revealed acid-fast bacteria and M. haemophilum was identified by polymerase chain reaction (PCR) and sequencing. The diagnosis of Mycobacterial keratitis was made. Although using the combination of systemic and topical antibiotics, his clinical status progressively deteriorated. Multiple therapeutic penetrating keratoplasties were required to eradicate the infection. No recurrence was found during the 1-year follow-up in both cases.

Conclusions

M. haemophilum can cause scleritis and keratitis, even in immunocompenent host. Radial keraoneuritis is first described in M. haemophilum keratitis. NTM keratitis should be considered in the differential diagnosis of patients with radial keratoneuritis. Increased awareness and early diagnosis using appropriate culture conditions and molecular techniques are important for the proper treatment of this infection. Prompt surgical intervention appears to be vital for successful management of M. haemophilum scleritis and keratitis.

The Epidemiology of Extrapulmonary Non-tuberculous Mycobacterial Infection in a Pediatric Population

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and a well-known cause of lymphadenitis, skin and soft tissue infections. The aim of this study was to evaluate the epidemiology of extrapulmonary pediatric NTM infections occurring from 2000 to 2017 in Queensland, Australia.

METHODS

All cases of NTM and TB are notifiable under the Queensland Public Health Act (2005) and associated regulations (2005). Data from 2000 to 2017 inclusive was collected from the Notifiable Conditions Database, a laboratory based notification system that covers private and public laboratory systems. Pediatric population demographic data were obtained from the Australian Bureau of Statistics by researching the number of children 0-14 years of age in Queensland from 2000 to 2017; both annual and averaged population was determined. The statistical software SPSS and Tableau was used for analysis.

RESULTS

The mean age of diagnosis was 2.5 years with a majority of the cohort being women. Mycobacterium avium was the most commonly diagnosed pathogen. Geographic regions with the highest numbers of cases were predominantly tropical and coastal areas. M. haemophilum emerged as a more common pathogen from 2011 following a period of major flooding.

CONCLUSION

Characteristics of the cohort of children susceptible to NTM disease appears consistent with previous reports. However, changes in the epidemiology of NTM infection (such as incidence, species, and geographic distribution) in children may be linked to environmental and weather factors.

Mycobacterium haemophilum skin and soft tissue infection in a kidney transplant recipient: A case report and summary of the literature

Non-tuberculous mycobacteria are ubiquitous pathogens causing infections in immunocompromised patients. Here, we describe a kidney transplant recipient who developed skin and soft tissue infection by Mycobacterium haemophilum, complicated by tenosynovitis and fluid collection, following an injury sustained to her right foot. Her immunosuppressant dose was reduced, and she underwent prolonged antimicrobial therapy followed by surgical debridement with a favorable outcome. Non-tuberculous mycobacteria should be considered as a potential etiology of subacute skin and soft tissue infections.

Meningomyeloencephalitis secondary to Mycobacterium haemophilum infection in AIDS

Infections by opportunistic non-tuberculous mycobacteria (NTM) are rising in global incidence. One emerging, slowly growing NTM is Mycobacterium haemophilum, which can cause skin, lung, bone, and soft tissue infections in immunocompromised patients as well as lymphadenitis in immunocompetent individuals. Detection of this microorganism is difficult using conventional culture-based methods and few reports have documented involvement of this pathogen within the central nervous system (CNS).

We describe the neuropathologic autopsy findings of a 39-year-old man with AIDS who died secondary to M. haemophilum CNS infection. He initially presented with repeated bouts of pyrexia, nausea and vomiting, and altered mental status that required numerous hospitalizations. CSF infectious workups were consistently negative. His most recent admission identified hyperintensities within the brainstem by MRI and despite antibiotic therapies for suspected CNS infection, he died. Autopsy revealed a swollen brain with marked widening of the brainstem. Microscopic examination of the brain and spinal cord showed focal lymphohistiocytic infiltrates, gliosis and neuronal loss that were associated with acid-fast bacilli (AFB). The brainstem was the most severely damaged and AFB were found to congregate along arterial territories lending support to the notion of hematogenous spread as a mechanism for the organisms’ dissemination. 16S rRNA sequencing on formalin-fixed paraffin-embedded tissue enabled post-mortem identification of M. haemophilum. This sequencing methodology may permit diagnosis on CSF intra-vitam.

Cervicofacial non-tuberculous mycobacterial lymphadenitis: clinical determinants of incomplete surgical removal

In patients with non-tuberculous mycobacterial cervicofacial lymphadenitis, incomplete surgical removal of infected lymph nodes leads to delayed healing and a higher recurrence rate, with eventual spontaneous drainage through the skin. However, complete surgical removal is not always achievable due to the extent of the infected tissue and proximity to vulnerable structures, such as the facial or accessory nerve. The aim of this study was to identify the clinical determinants of the (in)ability to perform complete surgical removal. The electronic health records of patients aged 0-15 years with bacteriologically proven non-tuberculous mycobacterial cervicofacial lymphadenitis, who underwent surgical treatment and preoperative sonographic imaging, were analysed. This was a case-control study. A total of 103 patients met the inclusion criteria. Most of the infections were unilateral, submandibular, and caused by Mycobacterium avium. Multiple logistic regression analysis revealed that higher age (odds ratio 1.24, 95% confidence interval 1.04-1.47) and fistulization (odds ratio 3.15, 95% confidence interval 1.13-8.75) were significantly associated with a limited ability to surgically remove all infected tissue. However, a larger sonographic lymph node size was not significantly associated. These findings could aid clinicians when informing the parent(s)/guardian(s) of the patient preoperatively and in properly estimating the intraoperative and postoperative course.

Clinical Characteristics and Treatment Outcomes for Patients Infected with Mycobacterium haemophilum

Mycobacterium haemophilum is a nontuberculous mycobacterium that can infect immunocompromised patients. Because of special conditions required for its culture, this bacterium is rarely reported and there are scarce data for long-term outcomes. We conducted a retrospective study at Siriraj Hospital, Bangkok, Thailand, during January 2012–September 2017. We studied 21 patients for which HIV infection was the most common concurrent condition. The most common organ involvement was skin and soft tissue (60%). Combination therapy with macrolides and fluoroquinolones resulted in a 60% cure rate for cutaneous infection; adding rifampin as a third drug for more severe cases resulted in modest (66%) cure rate. Efficacy of medical therapy in cutaneous, musculoskeletal, and ocular diseases was 80%, 50%, and 50%, respectively. All patients with central nervous system involvement showed treatment failures. Infections with M. haemophilum in HIV-infected patients were more likely to have central nervous system involvement and tended to have disseminated infections and less favorable outcomes.

Antiretroviral therapy-induced paradoxical worsening of previously healed Mycobacterium haemophilum cutaneous lesions in advanced HIV infection

Mycobacterium haemophilum is a nontuberculous mycobacterium that causes localized or disseminated disease, mainly in immunocompromised hosts. We report the case of a 35-year-old HIV-infected woman who presented with several enlarging cutaneous lesions over the arms and legs. Histopathological examination revealed the diagnosis of a cutaneous mycobacterial disease. Mycobacterial analyses unveiled M. haemophilum infection. Six months after completion of a successful antimycobacterial treatment, she developed an immune reconstitution inflammatory syndrome (IRIS). This paradoxical relapse presented as tenderness, redness and swelling at the precise sites of the healed lesions and took place in the setting of significant recovery of the CD4 cell count (from 05 to 318 cells/mm 3 ). Microbiological analyses of these worsening lesions were negative, and they spontaneously remitted without the initiation of a novel antimycobacterial treatment cycle. M. haemophilum infection should always be considered as a cause of skin lesions in immunocompromised subjects. Physicians should be aware of the possibility of IRIS as a complication of successful antiretroviral therapy in HIV-infected patients with M. haemophilum infection.

Intramedullary spinal cord lesions in an immunocompromised host due to Mycobacterium haemophilum

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M. haemophilum can produce severe disease in persons living with HIV/AIDS or other immunocompromised patients.

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The spectrum of disease caused by M. haemophilum may produce life-threatening central nervous system disease.

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The treatment of M. haemophilum when involving the CNS is challenging requiring multi-drug therapy.

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Patients with M. haemophilum central nervous system disease, with and without HIV, should be monitored for IRIS.

Mycobacterium haemophilum is a slow growing acid-fast bacillus (AFB) in the nontuberculous mycobacteria (NTM) group. M. haemophilum typically causes cervicofacial lymphadenitis in children, cutaneous diseases, septic arthritis and osteomyelitis. However, it rarely causes isolated spinal cord disease. We report the first case, to our knowledge, of isolated intramedullary spinal lesions secondary to M. haemophilum. This case involved a patient with newly diagnosed human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). He developed significant immune reconstitution inflammatory syndrome (IRIS) during his treatment. M. haemophilum should be on the differential for isolated intramedullary spinal lesions, particularly in immunocompromised patients. Given our patient’s severe IRIS, patients with HIV and M. haemophilum infection should be closely monitored for IRIS and treated aggressively. In high risk circumstances such as M. haemophilum spinal disease in patients with HIV, clinicians should consider pre-emptive treatment for IRIS.

Antimycobacterial Susceptibility Testing of Nontuberculous Mycobacteria

Recommendations for first-line and second-line drug testing and organism group, specific methodologies, and reporting recommendations have been addressed by the Clinical and Laboratory Standards Institute (CLSI) and are important in the selection of appropriate antimicrobial treatment regimens for nontuberculous mycobacteria (NTM) disease. This review also includes recent information on new antimicrobials proposed for the treatment of NTM but not yet addressed by the CLSI and molecular (gene sequencing) methods associated with the detection of antimicrobial resistance of two major therapeutic antimicrobials, clarithromycin and amikacin.

Cutaneous Infections Due to Nontuberculosis Mycobacterium: Recognition and Management

Nontuberculous mycobacteria (NTM) are a diverse group of organisms that are ubiquitous in the environment, and the incidence of cutaneous infections due to NTM has been steadily increasing. Cutaneous infections due to NTM can be difficult to diagnose, due to their wide spectrum of clinical presentations and histopathological findings that are often nonspecific. A variety of modalities including tissue culture and polymerase chain reaction (PCR) assays may be necessary to identify the organism. Treatment can also be challenging, as it can depend on multiple factors, including the causative organism, the patient's immunological status, and the extent of disease involvement. In this review, we discuss the common presentations of cutaneous NTM infections, diagnostic tools, and treatment recommendations. A multi-disciplinary approach that involves good communication between the clinician, the histopathologist, the microbiologist, and infectious disease specialists can help lead to successful diagnosis and management.

Cutaneous Mycobacterial Infections

Humans encounter mycobacterial species due to their ubiquity in different environmental niches. In many individuals, pathogenic mycobacterial species may breach our first-line barrier defenses of the innate immune system and modulate the activation of phagocytes to cause disease of the respiratory tract or the skin and soft tissues, sometimes resulting in disseminated infection. Cutaneous mycobacterial infections may cause a wide range of clinical manifestations, which are divided into four main disease categories: (i) cutaneous manifestations of Mycobacterium tuberculosis infection, (ii) Buruli ulcer caused by Mycobacterium ulcerans and other related slowly growing mycobacteria, (iii) leprosy caused by Mycobacterium leprae and Mycobacterium lepromatosis, and (iv) cutaneous infections caused by rapidly growing mycobacteria. Clinically, cutaneous mycobacterial infections present with widely different clinical presentations, including cellulitis, nonhealing ulcers, subacute or chronic nodular lesions, abscesses, superficial lymphadenitis, verrucous lesions, and other types of findings. Mycobacterial infections of the skin and subcutaneous tissue are associated with important stigma, deformity, and disability. Geography-based environmental exposures influence the epidemiology of cutaneous mycobacterial infections. Cutaneous tuberculosis exhibits different clinical phenotypes acquired through different routes, including via extrinsic inoculation of the tuberculous bacilli and dissemination to the skin from other sites, or represents hypersensitivity reactions to M. tuberculosis infection. In many settings, leprosy remains an important cause of neurological impairment, deformity, limb loss, and stigma. Mycobacterium lepromatosis, a mycobacterial species related to M. leprae, is linked to diffuse lepromatous leprosy of Lucio and Latapí. Mycobacterium ulcerans produces a mycolactone toxin that leads to subcutaneous tissue destruction and immunosuppression, resulting in deep ulcerations that often produce substantial disfigurement and disability. Mycobacterium marinum, a close relative of M. ulcerans, is an important cause of cutaneous sporotrichoid nodular lymphangitic lesions. Among patients with advanced immunosuppression, Mycobacterium kansasii, the Mycobacterium avium-intracellulare complex, and Mycobacterium haemophilum may cause cutaneous or disseminated disease. Rapidly growing mycobacteria, including the Mycobacterium abscessus group, Mycobacterium chelonei, and Mycobacterium fortuitum, are increasingly recognized pathogens in cutaneous infections associated particularly with plastic surgery and cosmetic procedures. Skin biopsies of cutaneous lesions to identify acid-fast staining bacilli and cultures represent the cornerstone of diagnosis. Additionally, histopathological evaluation of skin biopsy specimens may be useful in identifying leprosy, Buruli ulcer, and cutaneous tuberculosis. Molecular assays are useful in some cases. The treatment for cutaneous mycobacterial infections depends on the specific pathogen and therefore requires a careful consideration of antimicrobial choices based on official treatment guidelines.