In this report, we describe the first case of infective endocarditis caused by Mycobacterium kansasii in a 45-year-old male patient who presented with a 10-day fever and decompensated cirrhosis. Despite negative results in blood culture and pathology, we employed metagenomic next-generation sequencing (mNGS) to analyze the genome sequences of both the host and microbe. The copy number variation (CNV) indicated a high risk of liver disease in the patient, which correlated with biochemical examination findings. Notably, M. kansasii sequences were detected in peripheral blood samples and confirmed through Sanger sequencing. Unfortunately, the patient\'s condition deteriorated, leading to his demise prior to heart surgery. Nevertheless, we propose that mNGS could be a novel approach for diagnosing M. kansasii infection, particularly in cases where blood culture and pathology results are unavailable. It is important to consider M. kansasii infection as a potential cause of endocarditis and initiate appropriate anti-infection treatment.

Nontuberculous mycobacteria (NTM) refer to a large group of mycobacteria other than Mycobacterium tuberculosis complex and Mycobacterium leprae. Mycobacterium szulgai (M. szulgai) is a slow growing species of nontuberculous mycobacteria (NTM), which can cause infection in multiple organs, including the lungs. Using the technique of next-generation sequencing (NGS), we diagnosed disseminated M. szulgai infection in a patient with no obvious immunodeficiency. We report on a 66-year-old female patient who presented with enlarged cervical lymph nodes and an intermittent fever. Imaging showed multiple, enlarged, abnormal lymph nodes, a pulmonary mass and rib lesions that strongly suggested neoplasia. There was no significant improvement in symptoms after intermittent antibiotic treatment. The pathological results of multiple biopsies did not support the diagnosis of tumors. The diagnosis of M. szulgai infection was confirmed by NGS. The patient started standard treatment with clarithromycin, ethambutol, and moxifloxacin in July 2020. Since then and over the 10-month follow-up period, there has been a progressive reduction in the size of the enlarged lymph nodes and lung lesions, and no recurrence of fever or other symptoms. M. szulgai is a potential cause of infection (including of disseminated disease) even in patients with no obvious immunosuppression. The potential usefulness of the NGS of clinical samples should be highlighted.

BACKGROUND: Nontuberculous mycobacteria (NTM) and pulmonary tuberculosis (PTB) are difficult to distinguish in initial acid-fast bacilli (AFB) smear-positive patients.
OBJECTIVE: Establish a predictive model to identify more effectively NTM infections in initial AFB patients.
METHODS: Consecutive AFB smear-positive patients in the Respiratory Department of Shanghai Pulmonary Hospital from January 2019 to February 2020 were retrospectively analysed. A multivariate regression was used to determine the independent risk factors for NTM. A receiver operating characteristic (ROC) curve was used to determine the model\'s predictive discrimination. The model was validated internally by a calibration curve and externally for consecutive AFB smear-positive patients from March to June 2020 in this institution.
RESULTS: Presenting with haemoptysis, bronchiectasis, a negative QuantiFERON tuberculosis (QFT) test and being female were characteristics significantly more common in patients with NTM (P ≤ 0.001), when compared with PTB. The involvement of right middle lobe, left lingual lobe and cystic change was more commonly seen on chest high-resolution computed tomography (HRCT) in patients with NTM (P < 0.05), compared with PTB. Multivariate regression showed female, bronchiectasis, negative test for QFT and right middle lobe lesion were independent risk factors for NTM (P < 0.05). A ROC curve showed a sensitivity and specificity of 85.9% and 93.4%, respectively, and the area under the curve (AUC) was 0.963. Moreover, internal and external validation both confirmed the effectiveness of the model.
CONCLUSIONS: The predictive model would be useful for early differential diagnosis of NTM in initial AFB smear-positive patients.

BACKGROUND: Nontuberculous mycobacteria (NTM) are mycobacteria other than mycobacterium tuberculosis complex (MTBC) and mycobacterium leprae. NTM can cause infection in many human tissues and organs and is most commonly seen in the lungs. Clinically, the symptoms and signs of nontuberculous mycobacteria lung disease (NMLD) are very similar to those of tuberculosis (TB). Because most NTMs are resistant to conventional anti-TB drugs, the rapid diagnosis of NMLD is the key to treatment. This study aimed to use gene chip technology to examine bronchoalveolar lavage fluid (BALF) from NMLD patients to explore the value of this technique for the rapid diagnosis of NMLD in BALF.
METHODS: A retrospective analysis of 308 patients with NMLD treated at Fuzhou Pulmonary Hospital from January 2018 to June 2020 was performed. BALF was collected from the patients. Gene chip detection (Capital Bio Corporation, Chengdu, China) and BACTEC MGIT960 (Becton, Dickinson and Company, MD, USA) liquid culture were performed to compare the NTM positive detection rates between the two methods. The NTM strain isolated from liquid culture were identified by rDNA sequencing and the results of identification were compared with those of gene chip detection using BALF specimens.
RESULTS: A total of 221 cases of NTM were detected in 308 BALF specimens by the gene chip method; the positive rate was 71.75% (221/308). A total of 218 cases of NTM were detected by the liquid culture method, and the positive rate was 70.78% (218/308). There was no significant difference in the positive rate of NTM detected in BALF specimens between the two methods (χ2=0.138 P=0.804>0.05); 187 cases were detected with both sequencing and gene chip detection, and the coincidence rate of strain identification with the two methods reached 96.79% (181/187). Sequencing of 218 strains of NTM was carried out; eight species were identified, and the top four species were M. intracellulare (131/218, 60.09%), M. avium (48/218, 22.02%), M. abscessus (27/218, 12.38%), and M. kansasii (5/218, 2.29%).
CONCLUSIONS: Gene chip technology can rapidly detect NTM in BALF and accurately identify bacterial species. It has important clinical value in the early diagnosis and treatment of NMLD.

BACKGROUND: Rapid identification of pathogenic Mycobacterium species is critical for a successful treatment. However, traditional method is time-consuming and cannot discriminate isolated non-tuberculosis mycobacteria (NTM) at species level. In the retrospective study, we evaluated the clinical applicability of PCR-reverse blot hybridization assay (PCR-REBA Myco-ID) with clinical specimens for rapid detection and differentiation of mycobacterial species.
METHODS: A total of 334 sputum and 362 bronchial alveolar lavage fluids (BALF) from 696 patients with mycobacterium pulmonary disease (MPD) and 210 patients with non-mycobacterium pulmonary disease used as controls were analyzed. Sputum or BALF were obtained for MGIT 960-TBc ID test and PCR-REBA Myco-ID assay. High resolution melt analysis (HRM) was used to resolve inconsistent results of MGIT 960-TBc ID test and PCR-REBA Myco-ID assay.
RESULTS: A total of 334 sputum and 362 BALF specimens from 696 MPD patients (292 MTB and 404 NTM) were eventually analyzed. In total, 292 MTBC and 436 NTM isolates (mixed infection of two species in 32 specimens) across 10 Mycobacterium species were identified. The most frequently isolated NTM species were M. intracellulare (n = 236, 54.1%), followed by M. abscessus (n = 106, 24.3%), M. kansasii (n = 46, 10.6%), M. avium (n = 36, 8.3%). Twenty-two cases had M. intracellulare and M. abscessus mixed infection and ten cases had M. avium and M. abscessus mixed infection. A high level of agreement (n = 696; 94.5%) was found between MGIT 960-TBc ID and PCR-REBA Myco-ID (k = 0.845, P = 0.000). PCR-REBA Myco-ID assay had higher AUC for both MTBC and NTM than MGIT 960-TBc ID test.
CONCLUSIONS: PCR-REBA Myco-ID has the advantages of rapid, comparatively easy to perform, relatively low cost and superior accuracy in mycobacterial species identification compared with MGIT 960-TBc ID. We recommend it into workflow of mycobacterial laboratories especially in source-limited countries.

Mycobacterial infections are a resurgent and increasingly relevant problem. Within these, tuberculosis (TB) is particularly worrying as it is one of the top ten causes of death in the world and is the infectious disease that causes the highest number of deaths. A further concern is the on-going emergence of antimicrobial resistance, which seriously limits treatment. The COVID-19 pandemic has worsened current circumstances and future infections will be more incident. It is urgent to plan, draw solutions, and act to mitigate these issues, namely by exploring new approaches. The aims of this review are to showcase the extensive research and application of silver nanoparticles (AgNPs) and other metal nanoparticles (MNPs) as antimicrobial agents. We highlight the advantages of mycogenic synthesis, and report on their underexplored potential as agents in the fight against all mycobacterioses (non-tuberculous mycobacterial infections as well as TB). We propose further exploration of this field.

Hepatic granulomas caused by nontuberculous mycobacteria (NTM) are an uncommon, insidious, and indolent disease. Making an accurate diagnosis of a hepatic nontuberculous granuloma is challenging because of nonspecific clinical presentations and radiological appearances, especially in patients with a history of malignant tumors, as these lesions may mimic metastases and make a dilemma for decision-making in treatment. Herein, we report three cases of hepatic nontuberculous granulomas following operations for malignant tumors, including colon cancer, ovarian adenocarcinoma, and both rectal and renal carcinoma, respectively. Two patients presented with multiple hepatic lesions and the third had a solitary nodule in the liver. Computed tomography (CT) showed low attenuating nodules without early enhancement in the arterial phase but a slight peripheral enhancement in the portal venous phase after the intravenous administration of contrast agent. Magnetic resonance imaging (MRI) showed high signal intensity on T2-weighted image, rim enhancement in the venous phase and no contrast agent of Gd-EOB-DTPA uptake in the hepatobiliary phase. The biopsy was performed, and histopathological examinations revealed the chronic granulomas composed of epithelioid histiocytes, inflammatory cells, and Langhans giant cells. The results of nested polymerase chain reaction (PCR) were positive for NTM.