Prevalence and Species Spectrum of Pulmonary Nontuberculous Mycobacteria Isolates at a Tertiary Care Center / 대한임상미생물학회지

BACKGROUND: Pulmonary infection with nontuberculous mycobacteria (NTM) is increasing in South Korea. Since treatment strategy differs by NTM species, accurate identification is necessary. In this study, using Mycobacterium pulmonary isolates recently recovered from a general hospital in Seoul, the prevalence of NTM isolates was investigated. METHODS: A total of 483 Mycobacterium pulmonary strains isolated between May and November 2018 from an 814-bed general hospital in South Korea were analyzed. Bacterial species were identified based on nucleotide sequences of the 16S–23S rDNA internal transcribed spacer and the rpoB gene. RESULTS: From a total of 1,209 pulmonary specimens from patients suspected to be infected with mycobacteria, 324 deduplicate strains were isolated, comprising 90 Mycobacterium tuberculosis and 229 NTM strains. Among the NTM isolates, 61.5% (n=144) were Mycobacterium avium complex (MAC), including 92 M. avium and 52 Mycobacterium intracellulare, while 8.1% (n=19) represented Mycobacterium abscessus, including 10 M. abscessus subsp. abscessus and 9 M. abscessus subsp. massiliense. In addition, 12 (5.1%) Mycobacterium lentiflavum, 12 (5.1%) Mycobacterium gordonae, 6 (2.6%) Mycobacterium kansasii, and 5 (2.1%) Mycobacterium fortuitum were identified. In addition, Mycobacterium mucogenicum (n=2), Mycobacterium septicum (n=1), Mycobacterium colombiens (n=1), Mycobacterium asiaticum (n=1), and Mycobacterium celatum (n=1) were identified. CONCLUSION: Among the recently recovered Mycobacterium pulmonary strains, more than half were identified as NTM, and MAC was the most prevalent NTM, followed by M. abcessuss.

Coinfección por Mycobacterium fortuitum y Mycobacterium tuberculosis en abscesos esplénicos en un paciente con VIH / Co-infection by Mycobacterium fortuitum and Mycobacterium tuberculosis in splenic abscesses in a patient with HIV

RESUMEN Los pacientes con VIH son susceptibles a la infección por micobacterias. En el caso de las micobacterias de crecimiento rápido, grupo al que pertenece el Mycobacterium fortuitum (M. fortuitum), se han descrito infecciones en la piel, pulmones, ganglios linfáticos y enfermedad diseminada. Presentamos el caso de un paciente varón de 43 años, con diagnóstico previo de VIH en tratamiento antirretroviral, que acude por fiebre, astenia, pérdida de peso y diarrea crónica. Se realiza tomografía abdominal y se evidencia hepatoesplenomegalia con lesiones nodulares en el bazo. El cultivo esplénico, finalmente, fue positivo para M. fortuitum, con PCR positivo a Mycobacterium tuberculosis. Los protocolos actuales de tratamiento para este tipo de infecciones se basan en la susceptibilidad mostrada en los cultivos realizados. En lo que respecta a coinfecciones entre M. fortuitum y Mycobacterium tuberculosis, en pacientes VIH positivos, la información es aun menor.

ABSTRACT Patients with HIV are susceptible to mycobacterium infection. In the case of fast-growing mycobacteria, the group to which Mycobacterium fortuitum (M. fortuitum) belongs, infections have been described in the skin, lungs, lymph nodes and disseminated disease. We present the case of a 43-year-old male patient with pre-diagnosis of HIV in antiretroviral therapy, which comes as a fever, asthenia, weight loss and chronic diarrhea. Abdominal tomography is performed and hepatosplenomegaly is evidenced with nodular lesions in the spleen. The splenic culture was finally positive for M. Fortuitum, with positive PCR to Mycobacterium tuberculosis. The current treatment protocols for this type of infection are based on the susceptibility shown in the cultures performed. With regard to coinfections between M. Fortuitum and Mycobacterium tuberculosis, in HIV positive patients, there are even less information.

Antimicrobial Susceptibility Testing and Molecular Characterization of Mycobacterium fortuitum Isolates in China / 生物医学与环境科学（英文）

We performed molecular identification of clinical isolates of Mycobacterium fortuitum (M. fortuitum) and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates and potential molecular mechanism conferring resistance to fluoroquinolone and macrolide drugs. The results showed that moxifloxacin had the highest in vitro activity against M. fortuitum, and most M. fortuitum isolates were resistant to clarithromycin and linezolid in China. The loss of genetic mutation in clarithromycin- and amikacin-resistant isolates indicates that some other intrinsic mechanism conferring clarithromycin and amikacin resistance plays an essential role in M. fortuitum infection.

Cutaneous Mixed Infection of Mycobacterium fortuitum and Mycobacterium intracellulare after a Fat Graft / 대한피부과학회지

Atypical mycobacteria, widely distributed in nature, are opportunistic infection strain, rare pathogen in immunocompetent patients. Recently, the increase of invasive cosmetic treatment and surgery has increased the infection of atypical mycobacteria. We report a case of cutaneous infection by Mycobacterium fortuitum and Mycobacterium intracellulare that occurred after a fat graft. A 62-year-old female patient presented painful, erythematous nodules and purulent discharge on her face after a fat graft. A skin biopsy and culture were performed. Polymerase chain reaction-hybridization to identify mycobacterium other than tuberculosis revealed M. fortuitum and M. intracellulare. The patient was treated with clarithromycin, rifampicin, and ethambutol for 1 month after excision and drainage of pus, after which the skin lesions improved. In cases of refractory cutaneous infection after an invasive cosmetic procedure, atypical mycobacterial infection should be suspected.

Disseminated Mycobacterium fortuitum Infection Associated with Venous Access Device.

Mycobacterium fortuitum is an important opportunistic pathogen among the rapidly growing Mycobacteria. Disseminated disease occurs as a consequence of bacteremia linked to vascular catheters, which carry high morbidity and mortality when they occur in immuno-compromised patients. Conventional culture methods often miss these organisms since they may grow more slowly (after 48 h) and are dismissed as skin contaminants because of their morphological resemblance to diphtheroids on grams staining. We report a case of 10 months old child with primitive neuroectodermal tumor who developed disseminated disease with M. fortuitum that was related to an indwelling intravascular device. The isolates were confirmed as M. fortuitum by polymerase chain reaction based DNA sequencing targeting heat shock protein 65 gene. The child was treated with, rifampicin, ethambutol and azithromycin. The patient improved remarkably and became afebrile 2 days after institution of therapy and removal of the catheter. The treatment was given for 3 months.

Spondylitis with an Epidural Abscess due to Mycobacterium fortuitum: A Case Report / 대한내과학회지

Mycobacterium fortuitum is a rapidly growing mycobacteria that causes skin and soft tissue infection, pulmonary infection, and occasionally disseminated disease in severely immunocompromised patients. While three cases of spondylitis caused by M. fortuitum have been reported, no case has been reported in Korea. We describe the first reported case of M. fortuitum spondylitis and an epidural abscess after lumbar acupuncture, and a surgical procedure to treat spinal stenosis.

Evaluation of Peptide Nucleic Acid Probe-Based Fluorescence In Situ Hybridization for the Detection of Mycobacterium tuberculosis Complex and Nontuberculous Mycobacteria in Clinical Respiratory Specimens / 대한임상미생물학회지

BACKGROUND: Tuberculosis is globally the most important cause of death from single pathogen. Rapid and accurate identification of mycobacteria is essential for the control of tuberculosis. We evaluated a fluorescence in situ hybridization (FISH) method using peptide nucleic acid (PNA) probes for the differentiation of Mycobacterium tuberculosis complex (MTB) and nontuberculous mycobacteria (NTM) in direct smears of sputum specimens. METHODS: The cross-reactivity of MTB- and NTM-specific PNA probes was examined with reference strains of M. tuberculosis ATCC 13950, Mycobacterium kansasii ATCC 12479, Mycobacterium fortuitum ATCC 6841, several clinical isolates of mycobacteria (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium gordonae and Mycobacterium chelonae), and 11 frequently isolated respiratory bacterial species other than mycobacteria. A series of 128 sputa (89 MTB culture positive, 29 NTM culture positive, and 10 under treatment culture negative) with grades of trace to 4+ were used to evaluate the performance of the method. RESULTS: The MTB- and NTM-specific PNA probes showed specific reactions with the reference strains of MTB and M. kansasii and clinical isolates of mycobacteria except M. fortuitum ATCC 6841, and no cross-reactivity with other tested bacteria. The PNA probe-based FISH assay for detection of MTB had a sensitivity and specificity of 100%, respectively. The sensitivity and specificity of the NTM-specific PNA probe was 100%. The smear grades of the PNA FISH test were same as with those of the fluorescence AFB stain in 2+ or higher grade. CONCLUSION: Detection and differentiation based on PNA FISH is sensitive and accurate for detecting mycobacteria and for differentiating MTB from NTM in clinical sputum smears.

Mycobacterium fortuitum-related lymphadenitis associated with the varicella-zoster virus

Lymphadenitis caused by non-tuberculous mycobacteria is an uncommon manifestation in immunocompetent individuals. Here, we report a case of Mycobacterium fortuitum infection in a previously healthy 9-year-old patient who developed cervical lymphadenitis evolving to a suppurative ulcer associated with a varicella-zoster virus infection. We discuss the relationship between the varicella-zoster virus and the immune response of the host as an explanation for the unusual progression of the case.

Isolation of Mycobacterium fortuitum in sputum specimens of a patient with chronic cough: Is it clinically significant?

Managing chronic cough is diagnostically challenging especially in primary care. This case report highlights the difficulties experienced in approaching a case of chronic cough from a primary care perspective. The discussion also involves the clinical significance and treatment dilemma of M. fortuitum chelonae complex that was isolated from the sputum cultures of an elderly woman who presented with chronic cough for more than a year.

Postsurgical Wound Infection Caused by Mycobacterium conceptionense Identified by Sequencing of 16S rRNA, hsp65, and rpoB Genes in an Immunocompetent Patient / 대한임상미생물학회지

Rapidly growing mycobacteria are ubiquitous in the environment and are increasingly being recognized as opportunistic pathogens. Recently, a new species, Mycobacteium conceptionense, has been validated from the Mycobacterium fortuitum third biovariant complex by molecular analysis. However, there are few reports, and postsurgical wound infection by this species is rare. We report a case of postsurgical wound infection caused by M. conceptionense in an immunocompetent patient that was identified by a sequencing analysis of 16S rRNA, hps65, and rpoB genes.

A Clinical, Microbiological, and Pathological Study of Cutaneous Nontuberculous Mycobacterial Infection / 대한피부과학회지

BACKGROUND: As the immunocompromised population has increased in recent years, the number of cutaneous nontuberculous mycobacterial (NTM) infections has also risen. However, since this affliction has no pathognomonic clinical or histological features, the diagnosis and treatment of cutaneous NTM infections are often delayed. OBJECTIVE: The aim of this study was to investigate the microbiological, clinical, and histological findings of cutaneous NTM infections. METHODS: We reviewed medical records and histologic slides of 10 patients diagnosed with cutaneous NTM infections confirmed by culture or polymerase chain reaction. RESULTS: All patients except one were immunocompetent, and 5 of 10 patients had preceding factors including trauma, liposuction, and intralesional triamcinolone injection. Microbiologically, of the 10 infections, 5 were caused by Mycobacterium marinum, 3 by Mycobacterium fortuitum, and 1 each by Mycobacterium chelonae and Mycobacterium ulcerans, respectively. Of the 5 patients with M. marinum, 2 had a fish-related job and 1 reared fish at a home aquarium. The most common clinical presentation was erythematous nodules (7/10). Histologically, irregular acanthosis (4/10), mixed cell infiltrate of lymphocytes, histiocytes, neutrophils (9/10), suppurative granuloma (7/10), microcysts lined by neutrophils (5/10), fibrosis (4/10), and panniculitis (7/10) were identified. CONCLUSION: We found microcysts lined by neutrophils in 50% of the samples and considered this finding to be a diagnostic marker of NTM infection. These clinicopathologic features will assist clinicians in diagnosing NTM infection more rapidly and accurately.

Properties of catechol 1, 2 dioxygenase in the cell free extract and immobilized extract of Mycobacterium fortuitum

Polycyclic aromatic hydrocarbons (PAH) are carcinogenic compounds which contaminate water and soil, and the enzymes can be used for bioremediation of these environments. This study aimed to evaluate some environmental conditions that affect the production and activity of the catechol 1,2-dioxygenase (C12O) by Mycobacterium fortuitum in the cell free and immobilized extract in sodium alginate. The bacterium was grown in mineral medium and LB broth containing 250 mg L-1 of anthracene (PAH). The optimum conditions of pH (4.0-9.0), temperature (5-70 ºC), reaction time (10-90 min) and the effect of ions in the enzyme activity were determined. The Mycobacterium cultivated in LB shown higher growth and the C12O activity was two-fold higher to that in the mineral medium. To both extracts the highest enzyme activity was at pH 8.0, however, the immobilized extract promoted the increase in the C12O activity in a pH range between 4.0 and 8.5. The immobilized extract increased the enzymatic activity time and showed the highest C12O activity at 45 ºC, 20 ºC higher than the greatest temperature in the cell free extract. The enzyme activity in both extracts was stimulated by Fe3+, Hg2+ and Mn2+ and inhibited by NH4+ and Cu2+, but the immobilization protected the enzyme against the deleterious effects of K+ and Mg2+ in tested concentrations. The catechol 1,2-dioxygenase of Mycobacterium fortuitum in the immobilized extract has greater stability to the variations of pH, temperature and reaction time, and show higher activity in presence of ions, comparing to the cell free extract

Skin and Soft Tissue Infection due to Rapidly Growing Mycobacteria: Case Series and Literature Review

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous in soil and water. Most NTM cause disease in humans only rarely unless some aspect of host defense is impaired. Recently, rapidly growing mycobacteria (RGM) is not uncommon, and the prevalence of RGM infection has been increasing. RGM causes a wide spectrum of pulmonary and extrapulmonary diseases and has been shown as an important source for opportunistic infection. MATERIALS AND METHODS: We report 5 patients of skin and soft tissue infection due to RGM in tertiary medical center in Jeju Island and analyzed 21 patients of skin and soft tissue infection due to RGM in Republic of Korea. Clinical, microbiological and epidemiological data were collected from each patient. NTM isolates were identified using conventional and molecular methods including 16S rDNA gene sequencing. RESULTS: The mean age of the RGM patients (n=26) was 54.9 +/- 15.9 years and 73% were women. Mycobacterium fortuitum complex was the most common (12/26). Antimicrobial resistance for clarithromycin and quinolone were 12% and 60%, respectively. Clarithromycin based therapy was done in 46%. The mean duration of treatment was 21.2 +/- 8.7 weeks. CONCLUSIONS: Many cases can be cured after therapy for 4-7 month with at least 2 or 3 antibiotics according to in vitro susceptibility. Recent increasing of NTM cases suggests that species and subspecies identification is epidemiologically important, especially related to medical procedure, and surgery.

Molecular characterization of environmental non-Tuberculous mycobacteria using PCR- RFLP analysis of 441 Bp heat shock protein 65 fragments

Non- Tuberculous Mycobacteria are environmental opportunistic pathogens that can be found in various terrestrial and aquatic habitats. There are an epidemiological links between species isolated in tap water and those isolated from patients. hsp65 gene has more variability in its sequences, compared to the some more conserved genes in NTM, for identification of mycobacteria to species level. In this study, the prevalence of NTM in Isfahan City water samples was determined using culture, biochemical tests and PCR-RFLP analyses of hsp65 gene. Eighty-five water samples were collected and cultured. The mycobacterial isolates were identified by conventional biochemical tests. A 441 bp fragment of hsp65 genes was amplified and digested by two restriction enzymes, BstEII and HaeII. Digested products were analyzed using polyacrilamid gel electrophoresis [PAGE]. 25.9% of the water samples contained different species of NTM. Dominant isolates were M. fortuitum [26.7%], M. chelonae like organism [13.3%] and M. mucogenicum [13.3%]. Nineteen isolates of Mycobacteria were differentiated using hsp65 genes PCR-RFLP. Three isolates could not be identified at the species level because their RFLP patterns were different from other known PCR-RFLP profiles. There were different hsp65 gene PCR-RFLP profiles produced by digestion with BstEII and HaeIII. This study showed that PCR-RFLP of hsp65 gene in mycobacteria is more reliable method for identification of NTM at the specie level than conventional phenotypic methods [P<0.05]. In comparing of RFLP patterns of this study to other investigation, some minor differences were negligible

Mycobacterium fortuitum Infection after Footbath / 대한피부과학회지

Mycobacterium fortuitum is one of the rapidly-growing atypical mycobacteria, belonging to Runyon group IV. M. fortuitum infection is usually related to trauma, injections and surgical procedures, and is resistant to treatment with anti-tuberculous agents. Herein, we report on a case of M. fortuitum infection after footbath. A 51-year-old male presented with painful, erythematous nodules and plaques with crust and purulent discharge on the lower legs for 3 months. The skin lesion occurred after two herb and aroma footbaths and leg massage. He went to the massage shop again, and received the footbath one more time. The skin lesion aggravated and he visited a hospital, then the skin biopsy was performed but the result was unremarkable. He was treated with antihistamine and antibiotics but there was no improvement. So he visited our hospital, and culture demonstrated atypical mycobacterium, which was identified as M. fortuitum by polymerase chain reaction. He was treated with oral clarythromycin for 5 months, and the skin lesions have improved.

Breast Abscess due to Mycobacterium Fortuitum: A Case Report / 대한내과학회지

The rapidly growing nontuberculous mycobacterium, Mycobacterium fortuitum, is of increasing clinical importance. The ubiquitous M. fortuitum has been isolated from water, soil, and dust. M. fortuitum usually causes skin or soft-tissue infection following trauma or surgery, but may also infect a wide variety of tissues, including the lungs, lymph nodes, bones, joints, and meninges. We believe this is the first report of a breast abscess due to M. fortuitum, which presented in an immunocompetent woman in Korea after nipple piercing. A 26-year-old non-pregnant female presented with a 5-month history of a tender right breast lump that gradually increased in size. Pus from the right breast supported the growth of M. fortuitum. Mycobacterial infection should be considered in cases of recurrent breast abscess with sterile bacterial cultures, particularly when there is a history of nipple piercing procedures.

Mycobacterium fortuitum Infection Associated with Facial Fat Grafting: Simultaneous Infection of Liposuction and Liposculpture Site

We report a case of Mycobacterium fortuitum infection of the face and abdomen in a 25 years old man following cosmetic autologous fat injection. The goal of this manuscript is to increase awareness and suspicion of such as atypical mycobacterial infections complicating liposuction and fat injection. The clinical presentation, laboratory studies utilizing acid-fast stains and cultures, prevention and treatment including surgical debridement, and pharmacologic regimens in the ultimate diagnosis for Mycobacterium fortuitum infections are discussed.

Infección protésica mamaria por Mycobacteriumfortuitum en una paciente con lupus eritematoso sistémico / Breast implant infection by Mycobacterium fortuitum in a patient with systemic lupus erythematosus

In recent decades there has been an increase in the number of breast implants for reconstruction and cosmetic purposes. Infection is a severe complication mostly caused by Staphylococcus aureus or coagulase-negative staphylococci. Mycobacteria are an infrequent cause of infection in this type of surgery. We describe a case of Mycobacterium fortuitum infection in a patient with lupus, subjected to a prosthetic replacement. These patients are more prone to unusual opportunistic infections. Treatment always requires both removal of prosthetic material and antibiotic therapy.

En las últimas décadas se ha producido un incremento en el número de colocaciones de implantes mamarios para reconstrucciones y fines estéticos. La infección es una complicación seria y en su mayoría es producida por Staphylococcus aureus o Staphylococcus coagulasa-negativa. Las micobacterias son una causa infrecuente de infección en este tipo de cirugías. Describimos el caso de una infección de un implante mamario por Mycobacterium fortuitum en una paciente lúpica sometida a un recambio protésico. Este tipo de pacientes es más propenso a padecer infecciones oportunistas. El tratamiento siempre requiere retiro del material asociado a antibioterapia.