Clinical and genomic features of Mycobacterium avium complex: a multi-national European study.

BACKGROUND: The Mycobacterium avium complex (MAC) comprises the most frequent non-tuberculous mycobacteria (NTM) in Central Europe and currently includes twelve species. M. avium (MAV), M. intracellulare subsp. intracellulare (MINT), and M. intracellulare subsp. chimaera (MCH) are clinically most relevant. However, the population structure and genomic landscape of MAC linked with potential pathobiological differences remain little investigated. METHODS: Whole genome sequencing (WGS) was performed on a multi-national set of MAC isolates from Germany, France, and Switzerland. Phylogenetic analysis was conducted, as well as plasmids, resistance, and virulence genes predicted from WGS data. Data was set into a global context with publicly available sequences. Finally, detailed clinical characteristics were associated with genomic data in a subset of the cohort. RESULTS: Overall, 610 isolates from 465 patients were included. The majority could be assigned to MAV (n = 386), MCH (n = 111), and MINT (n = 77). We demonstrate clustering with less than 12 SNPs distance of isolates obtained from different patients in all major MAC species and the identification of trans-European or even trans-continental clusters when set into relation with 1307 public sequences. However, none of our MCH isolates clustered closely with the heater-cooler unit outbreak strain Zuerich-1. Known plasmids were detected in MAV (325/1076, 30.2%), MINT (62/327, 19.0%), and almost all MCH-isolates (457/463, 98.7%). Predicted resistance to aminoglycosides or macrolides was rare. Overall, there was no direct link between phylogenomic grouping and clinical manifestations, but MCH and MINT were rarely found in patients with extra-pulmonary disease (OR 0.12 95% CI 0.04-0.28, p < 0.001 and OR 0.11 95% CI 0.02-0.4, p = 0.004, respectively) and MCH was negatively associated with fulfillment of the ATS criteria when isolated from respiratory samples (OR 0.28 95% CI 0.09-0.7, p = 0.011). With 14 out of 43 patients with available serial isolates, co-infections or co-colonizations with different strains or even species of the MAC were frequent (32.6%). CONCLUSIONS: This study demonstrates clustering and the presence of plasmids in a large proportion of MAC isolates in Europe and in a global context. Future studies need to urgently define potential ways of transmission of MAC isolates and the potential involvement of plasmids in virulence.

Fracture-associated infection with Mycobacterium smegmatis in a 16-year old patient.

We present a patient who suffered an agricultural rollover trauma and developed a fracture-associated tissue infection caused by Mycobacterium smegmatis. Since cases are rare, treatment of infections with M. smegmatis requires an interprofessional approach and the combination of surgery and adjunctive antimicrobial treatment.

Treatment of MDR, Pre-XDR, XDR, and Rifampicin-Resistant Tuberculosis or in Case of Intolerance to at Least Rifampicin in Austria, Germany, and Switzerland.

Based on the assessment of new evidence, the World Health Organization (WHO) updated its guidelines for the treatment of drug-resistant tuberculosis (TB) in December 2022. The new recommendations and the latest study data made it necessary to update the existing guideline on the treatment of at least rifampicin-resistant TB (RR-TB) for the German-speaking countries, replacing the respective chapters of the treatment guidelines published in 2022. A shortened treatment of proven RR-TB and multidrug-resistant TB for at least 6 months using the fixed and non-modifiable drug combination of bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM) is now also recommended for Austria, Germany, and Switzerland under certain conditions considering the existing barriers for the implementation of the new treatment regimen. For the treatment of pre-extensively drug-resistant (pre-XDR-) TB, an individualized treatment for 18 months continues to be the primary recommendation. The non-modifiable drug combination of bedaquiline, pretomanid, and linezolid (BPaL) may be used alternatively in selected pre-XDR-TB cases, provided that all prerequisites are met. The necessary requirements for using BPaLM and BPaL are presented in detail in this amendment to the consensus-based TB treatment guideline for adult patients.

Dual-centre evaluation of the FluoroType MTBDR version 2 assay for detection of Mycobacterium tuberculosis complex and resistance-conferring mutations in pulmonary and extrapulmonary samples from Denmark, Germany and Sierra Leone.

OBJECTIVES: We evaluated the ability of FluoroType MTBDR version 2 (FTv2; Hain Lifescience), a second-step real-time PCR assay, to simultaneously detect Mycobacterium tuberculosis complex (MTBC) DNA and mutations conferring resistance to rifampicin (RIF) and isoniazid (INH), in pulmonary and extrapulmonary samples from patients and compared them with corresponding cultures. METHODS: FTv2 MTBC was evaluated on 1815 and 432 samples from Denmark (DK) and Germany (DE), respectively. RIF and INH resistance mutations were assessed in the German samples and 110 samples from Sierra Leone and subsequently compared to phenotypic antimicrobial susceptibility testing and a composite reference DNA (CRD) based on the GenoType MTBDR line-probe assay and Sanger sequencing or whole-genome sequencing. RESULTS: Of the 584 (557 smear-negative) Danish and 277 (85 smear-negative) German sputum samples, 42 (16) and 246 (54) were culture positive, and 44 (18) and 222 (35) were FTv2 positive, providing an FTv2 sensitivity and specificity of 0.86 (0.63) and 0.98 (DK), 0.90 (0.65) and 1.00 (DE), respectively. The count, sensitivities, and specificities for all pulmonary samples were 1434, 0.79, and 0.99 (DK) and 347, 0.86, and 1.00 (DE), respectively; for extrapulmonary samples, 381, 0.33, 0.99 (DK) and 83, 0.50, and 1.00 (DE). The valid count, sensitivity, and specificity compared with CRD for detecting resistance mutations were RIF 355, 0.99, 0.96, and INH 340, 1.00, and 0.98, respectively. DISCUSSION: FTv2 reliably detects MTBC DNA in pulmonary and extrapulmonary samples and detects resistance mutations for INH and RIF resistance in inhA promoter, katG, and rpoB genes.

Genomic diversity and clinical relevance of Mycobacterium simiae.

Introduction: Mycobacterium simiae is a slow-growing non-tuberculous mycobacterium that can cause non-tuberculous mycobacterium (NTM) pulmonary disease and extrapulmonary infections. Until now, detailed genomic and clinical characteristics, as well as possible transmission routes of this rare pathogen remain largely unknown. Methods: We conducted whole genome sequencing of available M. simiae isolates collected at a tertiary care centre in Central Germany from 2006 to 2020 and set them into context with publicly available M. simiae complex sequences through phylogenetic analysis. Resistance, virulence and stress genes, as well as known Mycobacteriaceae plasmid sequences were detected in whole genome raw reads. Clinical data and course were retrieved and correlated with genomic data. Results: We included 33 M. simiae sensu stricto isolates from seven patients. M. simiae showed low clinical relevance with only two patients fulfilling American Thoracic Society (ATS) criteria in our cohort and three receiving NTM-effective therapy. The bacterial populations were highly stable over time periods of up to 14 years, and no instances of mixed or re-infections with other strains of M. simiae were observed. Clustering with <12 single nucleotide polymorphisms distance was evident among isolates from different patients; however, proof for human-to-human transmission could not be established from epidemiological data. Conclusion: Overall, the available sequence data for M. simiae complex was significantly extended and new insights into its pathogenomic traits were obtained. We demonstrate high longitudinal genomic stability within single patients. Although we cannot exclude human-to-human transmission, we consider it unlikely in the light of available epidemiological data.