Case report of the first cured patient with Mycobacterium Chimaera infection following cardiac valve replacement in the mainland of China.

BACKGROUND: Mycobacterium chimaera infections subsequent to cardiac surgery are related to contaminated heater-cooler devices, with high mortality. Nevertheless, few studies have been reported in Asia. CASE PRESENTATION: We described the case of a 55-year-old man with Mycobacterium chimaera infection following cardiac surgery in the mainland of China. He was diagnosed with endocarditis caused by Mycobacterium chimaera subsequent to open heart surgery. Metagenomic next-generation sequencing (mNGS) and 16S rRNA gene PCR analysis were used to identify potential pathogens. The patient underwent redo valve replacement surgery and received combination therapy with azithromycin, ethambutol, linezolid, and amikacin. No signs of relapse were observed during the 11-month follow-up visit. CONCLUSIONS: This is the first documented case of Mycobacterium chimaera infection following cardiac surgery in the mainland of China and the first documented transnational imported case worldwide. Moreover, mNGS is a novel diagnostic technology that can guide antimicrobial therapy prior to obtaining fluid/tissue culture results for Mycobacterium chimaera, providing a new approach for the detection of potential Mycobacterium chimaera infection.

Pineal Region Tuberculoma Caused by Mycobacterium bovis as a Complication of Bacille Calmette-Guérin Vaccine: Case Report and Review of the Literature.

BACKGROUND: Brain tuberculoma is a rare manifestation of tuberculosis especially in immunosuppressed patients. The definitive diagnosis may be difficult owing to mimicking brain tumors and the absence of the common presentation. Bacille Calmette-Guérin (BCG) vaccine is used for protection against tuberculous meningitis and miliary disease, more so in children, and also for the treatment of bladder cancer. CASE DESCRIPTION: The following case of brain tuberculoma is a boy aged 6 months who was presented to our hospital with poor feeding, nausea and vomiting, and confusion lasting 1 month. A brain magnetic resonance imaging scan showed a large mass lesion in the pineal region with generalized hydrocephaly in which polymerase chain reaction assays of the tissue was positive for Mycobacterium bovis and had a good response to antituberculosis drugs and surgery. CONCLUSIONS: We present a case of brain tuberculoma as the complication of BCG vaccine. To our knowledge, this case is the first case of brain tuberculoma after BCG vaccination. We should consider brain tuberculoma that presents with a similar presentation in any infants with a history of BCG vaccination.

Rare infection in patient with rheumatoid arthritis treated with adalimumab.

Mycobacterium haemophilum is a rare pathogen, predominately present in the immunocompromised population. It is especially studied in HIV and haematological malignancy patients. Given its unique living conditions, it is often difficult to establish its diagnosis, but it is often suspected by its classic association with ulcerating skin findings. Our case is unique in that our patient is immunocompromised by his rheumatoid arthritis treatment, and presented without any skin lesions, but was found to have this rare pathogen causing a constellation of unusual symptoms.

Role of CT-guided transthoracic biopsy in the diagnosis of mycobacterial infection.

Mycobacterial infection(MI) is sometimes diagnosed using CT-guided transthoracic needle biopsy (TNB). However, the exact role of CT-guided TNB in this diagnostic process is not clearly known. The purpose of this study is to analyze the role of CT-guided TNB in patients with MI who present with a focal lung lesion. Of 1233 patients who underwent CT-guided TNB from January 2010 through February 2016 at our institution, patients with a final diagnosis of MI were included for analysis. Clinical characteristics and biopsy-related factors were compared between patients whose diagnosis could be established using TNB samples alone (group 1) and those whose samples from additional tests were necessary for diagnosis (group 2). We also analyzed the possible benefit of CT-guided TNB as compared with bronchoscopy in a subgroup who underwent both procedures. 47 patients with MI were included in the study, with 37 patients (78.7%) in group 1 and 10 patients (21.2%) in group 2. There was no statistically significant difference in clinical characteristics or biopsy-related factors between the two groups. Of 41 patients with MI who underwent both bronchoscopy and TNB, success in diagnosis was solely attributable to TNB in 16 (39.0%) patients; in 19 (46.0%) patients, diagnosis could be made based on bronchoscopy results alone. MI can be successfully diagnosed by CT-guided TNB in about 80% of patients with MI who underwent TNB, but 46% of the patients could have been diagnosed with bronchoscopy results alone. CT-guided TNB is inferior to bronchoscopy in the differentiation of Mycobacterium species even in peripheral lung lesions.

Emergence of Mycobacterium simiae: A retrospective study from a tertiary care center in Lebanon.

OBJECTIVE: The objective of this study is to describe the clinical significance of Mycobacterium simiae at a major tertiary care center in Lebanon. METHODS: This is a retrospective study of patients with positive cultures for M. simiae isolated between 2004 and 2016 at the American University of Beirut Medical Center. RESULTS: This study included 103 M. simiae isolates recovered from 51 patients. Their mean age was 62.7 years. The majority were males and smokers. Specimens were mostly from respiratory sources (97%). Common comorbidities included chronic lung disease (such as chronic obstructive pulmonary disease), solid tumor, systemic disease, and diabetes mellitus. Productive cough and dyspnea were the most common symptoms. Frequent radiographic findings were infiltrates and nodules on chest X-ray and nodules, infiltrates, and bronchiectasis on chest computed tomography scan. Among 18 tested isolates, 5.8% were resistant to clarithromycin, 11.7% to amikacin, and 70-100% to other antimicrobials. Out of 13 patients receiving early treatment, 5 noted improvement, one had recurrence of symptoms, two received alternative diagnosis, and five died. Two of those deaths were related to M. simiae. Common treatment regimens included clarithromycin in different combinations with trimethoprim-sulfamethoxazole, moxifloxacin, and amikacin. Moreover, clofazimine was used in only two patients whose isolates were resistant to all but one agent. Duration of treatment ranged from 6-24 months. CONCLUSION: In Lebanon, M. simiae is increasingly encountered with true infection rates of at least 47%. Furthermore, the prevalence of multidrug resistance among the Lebanese M. simiae isolates is very high limiting the treatment options.

Pulmonary Mycobacterium heckeshornense infection in a healthy woman.

Pulmonary infection due to Mycobacterium heckeshornense (M. heckeshornense) in healthy adults without underlying diseases is very rare and optimal treatments have not yet been established. A 39-year-old woman was admitted to our hospital for further examinations following the identification of a pulmonary cavitary nodule. Acid-fast bacilli were cultured from specimens obtained by bronchofiberscopy, and identified with M. heckeshornense using nucleotide sequencing. Antimycobacterial chemotherapy was effective temporarily, while the nodular lesion subsequently worsened. The patient underwent lobectomy and has not relapsed thus far. A lung specimen showed marked granulomatous inflammation with extensive caseous necrosis and the preservation of some parts of alveolar septa within caseous necrosis, indicating an exudative process and resistance to chemotherapy. M. heckeshornense is strongly pathogenic and switching to surgical intervention needs to be considered when chemotherapy is insufficient.

Mycobacterium malmoense pulmonary infection in France: a case report.

BACKGROUND: Mycobacterium malmoense infections have frequently been reported in northern Europe since the late 1970s. Factors accounting for this geographically localized epidemiology remain poorly understood. CASE PRESENTATION: We report the case of a 54-year old man concomitantly diagnosed with non-small cell lung carcinoma and M. malmoense pulmonary infection. We present detailed clinical, microbiological and radiological elements strongly arguing for M. malmoense true pathogenicity. Since M. malmoense infection has rarely been reported in France, we also provide elements of the epidemiological investigation and a literature review of potential acquisition and transmission pathways of M. malmoense. We detail therapeutic interventions and subsequent favorable evolution. CONCLUSION: Mycobacterium malmoense is a recognized respiratory pathogen for which routes of infection need to be better investigated.

Radiopathological Features and Identification of Mycobacterial Infections in Granulomatous Nodules Resected from the Lung.

BACKGROUND: Pulmonary granulomas are sometimes resected because they resemble lung cancer and false-positive findings come through from positron emission tomography (PET) using 18fluorine-fluorodeoxyglucose (18F-FDG). Mycobacterial infection is a common cause of granulomas. OBJECTIVE: The purpose of this study was to evaluate the radiopathological features and the methods for identifying mycobacterial infections in granulomatous nodules resected from the lung. METHODS: Thirty-five solitary lesions resected because of suspected lung cancer were enrolled, including 22 nonfungal granulomatous lesions and 13 benign lesions as controls. The radiological, microbiological, and histological findings were reviewed. To identify mycobacterial infection, immunohistochemical (IHC) staining, IS6110 polymerase chain reaction (PCR), and real-time PCR for the detection of Mycobacterium tuberculosis (TB) were performed using formalin-fixed and paraffin-embedded tissue specimens. The correlations between the radiopathological features and the median maximum standardized uptake value (SUVmax) of 18F-FDG PET were also evaluated. RESULTS: Mycobacteria were isolated from the cultures of 10 of the granulomatous lesions, including TB from 2 and Mycobacterium avium complex from 8. The mean size of the nodules in the culture-positive group was significantly larger than that of those in the culture-negative group (30.5 ± 13.1 vs. 15.1 ± 6.3 mm, p = 0.003). IHC stainings were positive in 15 granulomas. Eight granulomas were positive in IS6110 PCR, and 7 of them were also positive in real-time PCR. SUVmax was ≥2.5 in all of the PCR-positive granulomas. CONCLUSION: The most frequent cause of granulomatous lesions was mycobacterial infection. It seemed that the culture result was associated with nodule size and that the results of IS6110 were associated with 18F-FDG-uptake.

Computed tomographic findings in cats with mycobacterial infection.

OBJECTIVES: The objective of this study was to describe the CT imaging findings associated with confirmed mycobacterial infection in cats. METHODS: CT images from 20 cats with confirmed mycobacterial disease were retrospectively reviewed. Five cats underwent conscious full-body CT in a VetMouseTrap device. All other cats had thoracic CT performed under general anaesthesia, with the addition of CT investigation of the head/neck, abdomen and limbs in some cases. RESULTS: Mycobacterial infection was seen most frequently in adult (mean age 7.4 years; range 0.6-14 years) neutered male cats (11/20). The most common infections were Mycobacterium microti (6/20) and Mycobacterium bovis (6/20). CT abnormalities were most commonly seen in the thorax, consisting of bronchial (9/20), alveolar (8/20), ground glass (6/20) or structured interstitial (15/20) lung patterns, which were often mixed. Tracheobronchial, sternal and cranial mediastinal lymphadenomegaly were common (16/20). Other abnormalities included abdominal (8/13) or peripheral (10/18) lymphadenomegaly, hepatosplenomegaly (7/13), mixed osteolytic/osteoproliferative skeletal lesions (7/20) and cutaneous or subcutaneous soft tissue masses/nodules (4/20). CONCLUSIONS AND RELEVANCE: CT of feline mycobacteriosis shows a wide range of abnormalities, often involving multiple organ systems and mimicking many other feline diseases. Mycobacteriosis should be considered in the differential diagnosis of thoracic, abdominal and skeletal disorders in cats.

Clinical and radiographic differentiation of lung nodules caused by mycobacteria and lung cancer: a case-control study.

BACKGROUND: Lung nodules caused by mycobacteria can resemble lung cancer on chest imaging. The advent of lung cancer screening with low-dose Computed Tomography is accompanied by high false-positive rates, making it necessary to establish criteria to differentiate malignant from benign nodules. METHODS: We conducted a retrospective case-control study of 52 patients with mycobacterial lung nodules and 139 patients with lung cancer, diagnosed between 2010 and 2012. We compared clinical and radiographic characteristics to identify predictors of disease by univariate and multivariate analysis. The discriminatory power of maximum Standardized Uptake Values from Positron-Emission-Tomography was also evaluated. RESULTS: Several variables were correlated with a diagnosis of mycobacterial infection or lung cancer on univariate analysis. Such variable include smoking status and history, lesion size and imaging evidence of tree-in-bud opacities, lymphadenopathy or emphysema on computed tomography. Upon author consensus, the most clinically-relevant variables were selected to undergo multivariate analysis. A history of current or former smoking [OR 4.4 (95 % CI 1.2-15.6) and 2.7 (95 % CI 1.1-6.8), respectively P = 0.04] was correlated with diagnoses of lung cancer. Contrarily, the presence of tree-in-bud opacities was less likely to be correlated with a diagnosis of malignancy [OR 0.04 (95 % CI 0.0-1.0), P = 0.05]. Additionally, higher maximum standardized uptake values from positron emission tomography were associated with malignancy on multivariate analysis [OR 1.1 (95 % CI 1.0-1.2), P = 0.04]; but the accuracy of the values in differentiating between diseases was only 0.67 as measured by the area under the curve. Lesion size was not independently associated with diagnosis [OR 0.5 (95 % CI 0.2-1.2), (P = 0.12)]. CONCLUSIONS: Establishing the likelihood of malignancy for lung nodules based on isolated clinical or radiographic criteria is difficult. Using the variables found in this study may allow clinicians to stratify patients into groups of high and low risk for malignancy, and therefore establish efficient diagnostic strategies.

Causes and imaging patterns of tree-in-bud opacities.

BACKGROUND: Multiple causes for tree-in-bud (TIB) opacities have been reported. However, to our knowledge the relative frequencies of the causes have not been evaluated. The purpose of this study was to determine the relative frequency of causes of TIB opacities and identify patterns of disease associated with TIB opacities. METHODS: Cases with TIB opacities in the radiology report in 2010 were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of TIB opacities. Patterns of disease associated with TIB opacities were evaluated. RESULTS: Causes for TIB opacities were established in 166 of 406 (40.9%) cases. Respiratory infections (119 of 166, 72%) with mycobacteria (65 of 166, 39%), bacteria (44 of 166, 27%), viruses (four of 166, 3%), or multiple organisms (six of 166, 4%) were most common. Aspiration was the cause in 42 of 166 (25%). Alternating areas of normal lung with regions of small airways disease (TIB opacities, bronchiectasis) (random small airways pattern) was specific (0.92) for Mycobacterium avium complex infection. Nearly uniform distribution of bronchiectasis (widespread bronchiectasis pattern) was specific for "diseases predisposing to airway infection" (specificity 0.92), such as cystic fibrosis, primary ciliary dyskinesia, allergic bronchopulmonary aspergillosis, and immunodeficiency states. Consolidation and TIB opacities (bronchopneumonia pattern) were usually due to bacterial infection or aspiration. Dependent distribution (specificity 0.79) and esophageal abnormality (specificity 0.86) with TIB opacities were associated with aspiration. Chronicity of findings was associated with mycobacterial infection (P < .0001, sensitivity 0.96). Acuteness of findings was associated with bacterial infection (P < .001, specificity 0.87). CONCLUSIONS: TIB opacities are most often a manifestation of infections or aspiration. Patterns of disease can provide clues to the most likely diagnosis.

Relationship between radiographic evidence of tracheobronchial lymph node enlargement and definitive or presumptive diagnosis.

Tracheobronchial lymphadenomegaly is commonly associated with lymphosarcoma and disseminated mycotic infection. Available data also suggest other pathologic causes of enlarged tracheobronchial lymph nodes. Our objective was to establish the distribution and prevalence of diseases that cause radiographically evident tracheobronchial lymphadenomegaly in a large population of dogs. Patients were divided into groups based on the methods of diagnoses with 25 having confirmed diagnoses and 85 with presumptive diagnoses. Of the 110 dogs in the study, 92 (84%) had neoplasia and 18 (16%) had infectious diseases. Infections were attributed to Coccidioides (12, 67%), Aspergillus (3, 17%), and 1 each (6%) to Nocardia, Penicillium, and Mycobacteriosis. Tumors were characterized as lymphoma (66, 60%) or nonlymphoid (26, 23.6%). Nonlymphomas in Group 1 included histiocytic sarcoma complex (16%), carcinoma (12%), adenocarcinoma (8%), osteosarcoma (8%), chemodectoma (4%), ganglioneuroblastoma (4%), and neuroendocrine (4%). The number of dogs with tracheobronchial lymphadenomegaly scores 1, 2, 3, 4, or 5 (with 5 being the greatest) was 8 (7%), 15 (14%), 30 (27%), 15 (14%), and 44 (38%), respectively. The results suggest that in addition to diagnoses of lymphoma and fungal infections, other neoplasms and in particular histiocytic sarcoma and metastatic adenocarcinoma, should be considered when tracheobronchial lymphadenomegaly is identified radiographically in dogs. When comparing the degree of tracheobronchial lymphadenopathy by disease category, there was no significant affiliation (P = 0.33).

Radiographic findings in cats with mycobacterial infections.

This study describes radiographic changes associated with mycobacterial infection in 33 domestic cats confirmed by culture or interferon-gamma testing. Infection was seen most frequently in adult (average age 5.7 years; range 1.5-12 years), non-pedigree (87%; 27/31), neutered male cats (69%; 22/32). The most common infections were Mycobacterium microti (60%; 18/30) and Mycobacterium bovis (37%; 11/30); Mycobacterium avium and Mycobacterium malmoense were infrequently cultured (3% of each; 1/30). Radiographs were available for the thorax (24 cats), abdomen (eight), appendicular skeleton (11) and head (three). Radiographic changes affected the thorax most commonly, consisting of bronchial (46%; 11/24), alveolar (38%; 9/24), nodular unstructured interstitial (38%; 9/24) or unstructured interstitial (25%; 6/24) lung patterns, which were often mixed. Perihilar or sternal lymphadenopathy were common (42%; 10/24), particularly perihilar lymphadenopathy (25%; 6/24). Skeletal changes were found in the distal antebrachium (three), pes (two), maxilla, scapula, spine, manus, femur, and tarsus (one each). Changes were typically osteolytic (73%; 8/11), often permeative osteolytic (64%; 7/11). Osteoproliferative changes were seen in three cats and soft tissue swelling in five cats, which were adjacent to the bony abnormality in four cats. Other changes included submandibular soft tissue swelling, marked aortic, aortic root and brachiocephalic trunk calcification, and soft tissue swelling with calcification in the distal antebranchium which was not involving bone. Abdominal changes were uncommon (seen in 2/8 cats) and consisted of hepatomegaly and hepatosplenomegaly. In summary, radiographic changes were varied, no lesion was pathognomic for mycobacterial infection, and pathology was seen most commonly in the thorax.

Is there a role for fluorine 18 fluorodeoxyglucose-positron emission tomography and positron emission tomography/computed tomography in evaluating patients with mycobacteriosis? A systematic review.

OBJECTIVE: This study was designed to review the emerging role of fluorine 18 fluorodeoxyglucose (¹8F-FDG)-positron emission tomography (PET) CT/computed tomography (PET/CT) in patients with mycobacteriosis. METHODS: A comprehensive literature search of published studies through October 2010 in PubMed/MEDLINE database regarding ¹8F-FDG-PET and PET/CT in patients with mycobacteriosis was performed. RESULTS: Ultimately, we identified 16 studies comprising a total of 220 patients with mycobacteriosis. Main findings of the included studies are presented. CONCLUSIONS: (1) Mycobacteriosis commonly causes increased ¹8F-FDG uptake; therefore, positive ¹8F-FDG-PET results should be interpreted with caution in differentiating benign from malignant abnormalities. (2) ¹8F-FDG-PET and PET/CT are potentially useful in detecting sites of Mycobacterium infection. (3) Dual-phase ¹8F-FDG-PET is not useful for the differential diagnosis between malignant lesions and sites of Mycobacterium infection. (4) ¹8F-FDG-PET and PET/CT are useful for the evaluation of disease activity and in monitoring response to therapy in patients with mycobacteriosis. (5) Dual-tracer PET and PET/CT are potentially useful for presumptive diagnosis of solitary pulmonary nodules.

Disseminated Mycobacterium genavense with pulmonary nodules in a kidney transplant recipient: case report and review of the literature.

We report a case of disseminated Mycobacterium genavense with pulmonary nodules in a kidney transplant recipient and review the associated literature. Disease caused by M. genavense has been recognized in acquired immunodeficiency syndrome (AIDS) patients since 1990, with subsequent case reports in other immunocompromised host populations. In AIDS patients, pulmonary lesions are an uncommon finding. This is the first report to our knowledge of a human immunodeficiency virus (HIV)-negative patient with pulmonary nodules as a feature of disseminated M. genavense. Diagnosis of M. genavense is often challenging and frequently requires nucleic acid-based identification techniques. Because of limitations in culture and drug susceptibility testing, treatment regimens rely on reported clinical experience. This case report and literature review illustrates a successful approach to the diagnosis and treatment of disseminated M. genavense and summarizes the reports of M. genavense infection in HIV-negative patients.

Mycobacterium bovis infection of total hip arthroplasty after intravesicular bacille Calmette-Guérin therapy.

Bacille Calmette-Guérin (BCG) is a live, attenuated strain of Mycobacterium bovis. Intravesicular BCG therapy is the most effective treatment for superficial bladder cancer. The most common complication of this treatment is cystitis; there is a wide range of other complications. The English-language literature includes reports of 3 total hip arthroplasty infections and 1 total knee arthroplasty infection with M bovis after BCG therapy. These secondary infections may present either acutely during the therapy, months, or even years later. In this article, we report the case of a patient who presented with a painful right hip 6 years after successful total hip arthroplasty and 3 years after treatment for bladder cancer. Left total hip arthroplasty was performed 2 years after right hip arthroplasty. Surgeons examining a painful joint arthroplasty should be particularly suspicious of infection if the patient has a history of BCG therapy.

Mycobacterial infection of the musculoskeletal tissues: the use of pathological specimens for identification of causative species by PCR-direct sequencing of 16S rDNA.

Mycobacterial infection of musculoskeletal tissue is a rare disease that may cause destruction of the tissues. Both Mycobacterium tuberculosis and non-tuberculous mycobacteria affect the tissues. Although surgical debridement and antibiotic therapy are required for the treatment, it is necessary to identify the causative species before selecting the antibiotics. However, it is difficult to identify the species in clinical samples from musculoskeletal tissue. In the current study, using pathological specimens, the causative species was identified by PCR amplification and direct sequencing of mycobacterial 16S rDNA containing a hypervariable region. Twelve cases of chronic granulomatous inflammation of musculoskeletal tissues were used for the study. DNA was extracted from paraffin sections, and mycobacterial 16S rDNA was amplified by PCR. The amplicons were obtained in 5 of 12 cases (41%), even in specimens in which the microorganism was only scarcely detected by using special stains. Direct sequencing of the amplified products presented high homology with M. tuberculosis in four cases and M. avium in one. Therefore, PCR-direct sequencing of 16S rDNA containing hypervariable region using pathological specimens is useful for the diagnosis and identification of causative species in mycobacterial infection of musculoskeletal tissues.

Femoropopliteal prosthetic bypass graft infection due to Mycobacterium abscessus localized by FDG-PET/CT scan.

A patient with postvascular graft placement presented with bacteremia but no localizing symptoms. Our standard infected graft workup of computed tomography (CT) scan, ultrasound scan, magnetic resonance imaging (MRI) scan, and additional laboratory tests did not localize the infection source. Nuclear medicine had three options including white blood cell (WBC) scan, gallium scan, and the fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan. FDG-PET/CT imaging alone demonstrated the location. We present an unusual case of Mycobacterium abscessus in a vascular graft not localized with CT scan, ultrasound scan, or MRI scan and could only be localized with FDG-PET/CT scan.

Comparison of clinical and radiographic characteristics between nodular bronchiectatic form of nontuberculous mycobacterial lung disease and diffuse panbronchiolitis.

The nodular bronchiectatic form of nontuberculous mycobacterial (NTM) lung disease and diffuse panbronchiolits (DPB) show similar clinical and radiographic findings. The present study was performed to clarify the clinicoradiographic similarities as well as the differences between NTM lung disease and DPB. The initial clinicoradiographic features of 78 patients with the nodular bronchiectatic form of NTM lung disease (41 patients with Mycobacterium avium complex infection and 37 patients with Mycobacterium abscessus infection) were compared with those of 35 patients with DPB. Old age, female sex, a history of tuberculosis treatment, and hemoptysis were related to NTM lung disease while exertional dyspnea, coarse crackles, history of sinusitis, obstructive abnormalities in pulmonary function tests, and hypoxemia were related to DPB. The number of lobes involved with bronchiolitis and bronchiectasis on chest computed tomography were more numerous in DPB patients. There is considerable overlap in the clinical and radiographic appearances of the nodular bronchiectatic form of NTM lung disease and DPB, although some clinicoradiographic features differ between two diseases. The correct diagnosis, including aggressive microbiologic evaluation, should be made for the appropriate management of patients presenting with bilateral bronchiectasis and bronchiolitis.