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Epidemiology of Nontuberculous Mycobacteria in Tuberculosis suspects, Southwest of China, 2017-2022.Frontiers in Cellular and Infection... 2023This study summarizes the epidemiological characteristics, species distribution, and drug sensitivity of clinical nontuberculous mycobacteria (NTM) isolates at the...
OBJECTIVES
This study summarizes the epidemiological characteristics, species distribution, and drug sensitivity of clinical nontuberculous mycobacteria (NTM) isolates at the Public Health Clinical Center of Chengdu, China, from January 2017 to December 2022.
METHODS
We retrospectively analyzed data from patients with clinically isolated NTM strains. Chi-square analysis assessed the rate of strain isolation over 6 years.
RESULTS
The number of samples tested for (MTB) and/or NTM increased each year, while MTB detection decreased and NTM detection rose significantly each year (P=0.03). The average age of NTM patients was 51 ± 17.53 years, with a 14.1% HIV infection rate. The predominant isolates were (MAC) and /, with 96.4% of cases being of Han ethnicity. Amikacin, moxifloxacin, and clarithromycin were effective against and ; linezolid, amikacin, and cefoxitin were effective against /. Over 90% of NTM cases originated from the respiratory tract.
CONCLUSION
The NTM isolation rate in Southwest China has risen in recent years, primarily among elderly patients with a high HIV co-infection rate. The main NTM isolates were MAC and /. Amikacin, moxifloxacin, clarithromycin, and linezolid exhibited strong antibacterial activity against SGM, while amikacin and linezolid displayed relatively better antibacterial activity against RGM. The prevalence of NTM infection may be positively associated with regional economic development and health conditions.
Topics: Humans; Aged; Adult; Middle Aged; Nontuberculous Mycobacteria; Clarithromycin; Amikacin; Linezolid; HIV Infections; Moxifloxacin; Retrospective Studies; Anti-Bacterial Agents; Mycobacterium Infections, Nontuberculous; Tuberculosis; China; Microbial Sensitivity Tests
PubMed: 38029240
DOI: 10.3389/fcimb.2023.1282902 -
Journal of Clinical Microbiology Oct 2023Macrolides, such as clarithromycin, are crucial in the treatment of nontuberculous mycobacteria (NTM). NTM are notoriously innately drug resistant, which has made the...
Macrolides, such as clarithromycin, are crucial in the treatment of nontuberculous mycobacteria (NTM). NTM are notoriously innately drug resistant, which has made the dependence on macrolides for their treatment even more important. Not surprisingly, resistance to macrolides has been documented in some NTM, including and , which are the two NTM species most often identified in clinical isolates. Resistance is mediated by point mutations in the 23S ribosomal RNA or by methylation of the rRNA by a methylase (encoded by an gene). Chromosomally encoded genes have been identified in many of the macrolide-resistant isolates, but not in . Now, Brown-Elliott et al. (J Clin Microbiol 61:e00428-23, 2023, https://doi.org/10.1128/JCM.00428-23) describe the identification of a new variant, (55) which was found either on the chromosome or on a plasmid in highly macrolide-resistant clinical isolates of . The chromosomal (55) gene appears to be associated with mobile elements; one gene is within a putative transposon and the second is in a large (37 kb) insertion/deletion. The plasmid carrying (55) also encodes type IV and type VII secretion systems, which are often linked on large mycobacterial plasmids and are hypothesized to mediate plasmid transfer. While the conjugative transfer of the (55)-containing plasmid between NTM has yet to be demonstrated, the inferences are clear, as evidenced by the dissemination of plasmid-mediated drug resistance in other medically important bacteria. Here, we discuss the findings of Brown-Elliott et al. and the potential ramifications on treatment of NTM infections.
Topics: Humans; Anti-Bacterial Agents; Mycobacterium chelonae; Macrolides; Drug Resistance, Bacterial; Clarithromycin; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Chromosomes
PubMed: 37724858
DOI: 10.1128/jcm.00628-23 -
Microbial Drug Resistance (Larchmont,... Jul 2023There is a scarcity of data regarding the antimicrobial susceptibility testing profiles of nontuberculous mycobacterial (NTM) in Israel and other Middle Eastern...
There is a scarcity of data regarding the antimicrobial susceptibility testing profiles of nontuberculous mycobacterial (NTM) in Israel and other Middle Eastern countries. We aimed to describe the antimicrobial susceptibility profiles of NTM in Israel. A total of 410 clinical isolates of NTM, identified to the species level using matrix-assisted laser desorption ionization-time of flight mass spectrometry or gene sequencing, were included. Minimum inhibitory concentrations for slowly growing mycobacteria (SGM) and rapidly growing mycobacteria (RGM) for 12 and 11 drugs were determined using the Sensititre SLOMYCOI and RAPMYCOI broth microdilution plates, respectively. complex (MAC) was the most frequently isolated species ( = 148; 36%), followed by ( = 93; 23%), group ( = 62; 15%), ( = 27; 7%), and ( = 22; 5%) accounting together for 86% of isolates. The most active agents against SGM were amikacin (98%/85%/100%) and clarithromycin (97%/99%/100%), followed by moxifloxacin (25%/10%/100%) and linezolid (3%/6%/100%) for MAC, , and , respectively. For RGM, the most active agents were amikacin (98%/100%/88%) followed by linezolid (48%/80%/100%) and clarithromycin (39%/28%/94%) for group, , and , respectively. These findings can assist in guiding the treatment of NTM infections.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Linezolid; Anti-Bacterial Agents; Amikacin; Clarithromycin; Israel; Microbial Sensitivity Tests
PubMed: 37219996
DOI: 10.1089/mdr.2023.0024 -
Journal of Clinical Microbiology Jul 2023Macrolides are a mainstay of therapy for infections due to nontuberculous mycobacteria (NTM). Among rapidly growing mycobacteria (RGM), inducible macrolide resistance is...
Macrolides are a mainstay of therapy for infections due to nontuberculous mycobacteria (NTM). Among rapidly growing mycobacteria (RGM), inducible macrolide resistance is associated with four chromosomal 23S rRNA methylase () genes. Beginning in 2018, we detected high-level inducible clarithromycin resistance (MICs of ≥16μg/mL) in clinical isolates of Mycobacterium chelonae, an RGM species not previously known to contain genes. Using whole-genome sequencing, we identified a novel plasmid-mediated gene. This gene, designated (55), exhibits <65% amino acid identity to previously described RGM genes. Two additional chromosomal (55) alleles, with sequence identities of 81% to 86% to (55), were also identified and designated (55) and (55). The (55) is part of a transposon. The (55) allele variant is located on a putative 137-kb conjugative plasmid, pMchErm55. Evaluation of 133 consecutive isolates from 2020 to 2022 revealed 5 (3.8%) with (55). The e(55) gene was also identified in public data sets of two emerging pathogenic pigmented RGM species: Mycobacterium iranicum and Mycobacterium obuense, dating back to 2008. In both species, the gene appeared to be present on plasmids homologous to pMchErm55. Plasmid-mediated macrolide resistance, not described previously for any NTM species, appears to have spread to multiple RGM species. This has important implications for antimicrobial susceptibility guidelines and treatment of RGM infections. Further spread could present serious consequences for treatment of other macrolide-susceptible RGM. Additional studies are needed to determine the transmissibility of pMchErm55 and the distribution of (55) among other RGM species.
Topics: Humans; Anti-Bacterial Agents; Macrolides; Mycobacterium chelonae; Drug Resistance, Bacterial; Clarithromycin; Nontuberculous Mycobacteria; Mycobacterium; Plasmids; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous
PubMed: 37347171
DOI: 10.1128/jcm.00428-23 -
International Journal of Systematic and... Apr 2024As required by Rule 54 of the International Code of Nomenclature of Prokaryotes, the authors propose the replacement specific epithet '' for the illegitimate prokaryotic...
Proposal of nom. nov., subsp. nom. nov. and subsp. nom. nov. as new names with replacement specific or subspecific epithets, respectively, for three illegitimate prokaryotic names Yoo . 2007, subsp. Kim . 2017 and subsp. Kudo . 2012; proposal of comb. nov. and comb. nov. as replacement...
As required by Rule 54 of the International Code of Nomenclature of Prokaryotes, the authors propose the replacement specific epithet '' for the illegitimate prokaryotic name Yoo . 2007, the replacement subspecific epithet '' for subsp. Kim 2017 and the replacement subspecific epithet '' for subsp. Kudo . 2012. Meanwhile, new combinations and are also proposed as replacements for the illegitimate prokaryotic names Yang . 2023 and Zhang . 2023, respectively.
Topics: Mycobacterium chelonae; Lactobacillus delbrueckii; Sphingobacterium; Sequence Analysis, DNA; DNA, Bacterial; Phylogeny; Bacterial Typing Techniques; RNA, Ribosomal, 16S; Base Composition; Fatty Acids; Lactobacillus; Mycobacteriaceae
PubMed: 38578275
DOI: 10.1099/ijsem.0.006319 -
Journal of Infection and Chemotherapy :... Sep 2023The prevalence of nontuberculous mycobacteria (NTM) infections is increasing worldwide. Although NTM can affect extrapulmonary organs, studies on the clinical...
INTRODUCTION
The prevalence of nontuberculous mycobacteria (NTM) infections is increasing worldwide. Although NTM can affect extrapulmonary organs, studies on the clinical characteristics of extrapulmonary NTM are rare.
METHODS
We retrospectively analyzed patients who were newly diagnosed with NTM infections at Hiroshima University Hospital between 2001 and 2021 to investigate species distribution, infected sites, and risk factors of extrapulmonary NTM compared to pulmonary NTM.
RESULTS
Of the 261 NTM infections, 9.6% and 90.4% had extrapulmonary and pulmonary NTM, respectively. The mean ages of patients with extrapulmonary and pulmonary NTM were 53.4 and 69.3 years, 64.0% and 42.8% were male, 36.0% and 9.3% received corticosteroids, 20.0% and 0% had acquired immune deficiency syndrome (AIDS), and 56.0% and 16.1% had any immunosuppressive conditions, respectively. Younger age, corticosteroid use, and AIDS were associated with extrapulmonary NTM. In pulmonary NTM, Mycobacterium avium complex (MAC) accounted for 86.4% of NTM species, followed by M. abscessus complex (4.2%), whereas in extrapulmonary NTM, M. abscessus complex, MAC, M. chelonae, and M. fortuitum accounted for 36.0%, 28.0%, 12.0%, and 8.0%, respectively. Compared to pulmonary NTM, extrapulmonary NTM were significantly more likely to be rapid-growing mycobacteria (RGM) (56.0% vs. 5.5%). The most common sites of infection were the skin and soft tissues (44.0%), followed by the blood (20.0%), tenosynovium, and lymph nodes (12.0%).
CONCLUSION
Younger age and immunosuppressive conditions are associated with extrapulmonary NTM, with a higher prevalence of RGM in extrapulmonary NTM than in pulmonary NTM. These results provide a better understanding of extrapulmonary NTM.
Topics: Humans; Male; Middle Aged; Aged; Female; Retrospective Studies; Acquired Immunodeficiency Syndrome; Japan; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Mycobacterium avium Complex; Pneumonia
PubMed: 37209842
DOI: 10.1016/j.jiac.2023.05.013 -
Journal of Infection in Developing... Jul 2023Although non-tuberculous mycobacterium (NTM) infection accounts for only a small proportion of fever of unknown origin (FUO) cases, it has become a more common etiology... (Review)
Review
INTRODUCTION
Although non-tuberculous mycobacterium (NTM) infection accounts for only a small proportion of fever of unknown origin (FUO) cases, it has become a more common etiology in recent years. Therefore, we reviewed FUO patients with underlying NTM infection to better understand its clinical features.
METHODOLOGY
The medical records of patients presenting with FUO and diagnosed with NTM infection admitted to Peking Union Medical College Hospital between January 2016 and June 2021 were reviewed. The clinical information of patients whose follow-up data were available were summarized. Specimens submitted for pathogenic identification were processed by mycobacterial culture, acid-fast staining, and mycobacterial nucleic acid detection. IBM SPSS Statistics v22.0 (SPSS, Inc., Chicago, IL, USA) was used for data analysis.
RESULTS
Fifty-five FUO patients were diagnosed with NTM infection (55/785; 7.0% of FUO cases). Patients were mostly middle-aged men and had a relatively long disease course. Seven, 29, and 54 patients had previously no respondence to glucocorticoids, immunosuppressants, and multiple antibiotics, respectively; their inflammatory indexes were significantly increased; and there was no obvious risk of immunosuppression in this group, who were likely to be T.SPOT-TB negative (33/41; 80.5%). The most commonly identified NTM was Mycobacterium intracellulare followed by Mycobacterium chelonae/abscessus, Mycobacterium kansasii, and Mycobacterium avium.
CONCLUSIONS
Microbiological investigations including culture, acid-fast staining, NTM nucleic acid examination, and next-generation sequencing were performed to confirm the diagnosis of NTM in FUO patients. FUO patients should screen for NTM infections so that this important etiology can be recognized, targeted treatments administered early, and outcomes improved.
Topics: Male; Middle Aged; Humans; Mycobacterium Infections, Nontuberculous; Fever of Unknown Origin; Mycobacterium avium Complex; Mycobacterium; Tuberculosis; Nontuberculous Mycobacteria; Retrospective Studies
PubMed: 37515806
DOI: 10.3855/jidc.17610