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Emerging Infectious Diseases Aug 2022In mid-2014, Public Health Ontario Laboratories identified coincident increasing Mycobacterium avium isolation and falling M. xenopi isolation in the Toronto, Ontario,...
In mid-2014, Public Health Ontario Laboratories identified coincident increasing Mycobacterium avium isolation and falling M. xenopi isolation in the Toronto, Ontario, Canada, area. We performed a retrospective cohort of all patients in a Toronto clinic who began treatment for either M. avium or M. xenopi pulmonary disease during 2009-2012 (early period) or 2015-2018 (late period), studying their relative proportions and sputum culture conversion. We conducted a subgroup analysis among patients who lived in the Toronto-York region. The proportion of patients with M. avium was higher in the late period (138/146 [94.5%] vs. 82/106 [77.4%]; p<0.001). Among M. avium patients, conversion was lower in the late period (26.1% vs. 39.0%; p = 0.05). The increase in the proportion of patients with M. avium pulmonary disease and the reduction in the frequency of sputum culture conversion is unexplained but could suggest an increase in environmental M. avium exposure.
Topics: Humans; Lung Diseases; Mycobacterium Infections, Nontuberculous; Mycobacterium avium; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Nontuberculous Mycobacteria; Ontario; Retrospective Studies
PubMed: 35876492
DOI: 10.3201/eid2808.220464 -
Journal of Global Antimicrobial... Mar 2024Genetic changes in Mycobacterium abscessus during antibiotic treatment are not fully understood. This study aimed to investigate the genetic changes in M. abscessus in...
OBJECTIVES
Genetic changes in Mycobacterium abscessus during antibiotic treatment are not fully understood. This study aimed to investigate the genetic changes in M. abscessus in patients receiving antibiotic treatment, and their clinical implications.
METHODS
Pretreatment and 12-month post-treatment M. abscessus isolates were obtained from patients with M. abscessus pulmonary disease. Isolates from each time point were separated into six groups based on their distinctive morphological characteristics. Twenty-four isolates, comprising 12 from patient A exhibiting progressive disease and 12 from patient B demonstrating stable disease, underwent sequencing. Subsequently, minimal inhibitory concentrations (MICs) for the administered antibiotics were measured.
RESULTS
Persistent infection with a single strain was observed in patients A and B. During 12 months of treatment, MICs for administered drugs did not generally change over time in either patient and single nucleotide variations (SNV) associated with antimicrobial resistance (rrl, rrs, erm(41), gyrA, gyrB, whiB7 and hflX) were not mutated. Although not significant, 47 and 52 non-synonymous SNVs occurred in M. abscessus from patients A and B, respectively, and the accumulation of these SNVs differed in patients A and B, except for five SNVs. The most variable positions were within a probable NADH-dependent glutamate synthase gene and a putative YrbE family protein gene in patients A and B, respectively.
CONCLUSIONS
Persistent infections by a single strain of M. abscessus were observed in two patients with different clinical courses. Genetic changes in M. abscessus during antibiotic treatment were relatively stable in these patients.
CLINICAL TRIALS IDENTIFIER
NCT01616745 (ClinicalTrials.gov ID).
Topics: Humans; Anti-Bacterial Agents; Lung Diseases; Microbial Sensitivity Tests; Mycobacterium abscessus
PubMed: 38128724
DOI: 10.1016/j.jgar.2023.12.004 -
International Journal of Infectious... Mar 2020Non-tuberculous mycobacteria (NTM) are ubiquitous dwellers of environmental niches and are an established cause of natural and nosocomial infections. The incidence of...
Non-tuberculous mycobacteria (NTM) are ubiquitous dwellers of environmental niches and are an established cause of natural and nosocomial infections. The incidence of NTM infections is rising owing to a growing population of immunocompromised and vulnerable individuals, complex medical and surgical procedures, as well as increased awareness and diagnostic capabilities. The prevalence of different NTM varies between continents, regions, and countries. The true global burden of pulmonary and extrapulmonary disease is unknown and estimates are subject to under and/or over-estimation. Diagnosis requires confirmation by isolation of NTM along with clinical and radiological criteria, which may be suboptimal at all levels. Susceptibility testing is complex and clinical breakpoints are not available for many of the drugs. Frequently, NTM infections are not considered until late in the course of disease. Improved and rapid detection of tuberculosis cases in high-burden countries has, however, also brought NTM infections into the limelight, and has identified a need for research efforts towards rapid diagnostic tests and the identification of biomarkers to monitor the treatment response in patients with NTM infections.
Topics: Biomarkers; Communicable Diseases, Emerging; Humans; Incidence; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Prevalence
PubMed: 32114200
DOI: 10.1016/j.ijid.2020.02.022 -
HIV Medicine Mar 2022In this study, the distribution of nontuberculous mycobacteria (NTM) strains in patients with and without HIV/AIDS in Chongqing, China was evaluated.
INTRODUCTION
In this study, the distribution of nontuberculous mycobacteria (NTM) strains in patients with and without HIV/AIDS in Chongqing, China was evaluated.
METHODS
A retrospective study was performed in January-December 2020 at Chongqing Public Health Medical Center. NTM strains were assessed by a multi locus phylogenetic analysis. The distribution of NTM strains in HIV/AIDS and non-HIV/AIDS groups was compared. CD4+ cell counts, imaging changes, and characteristics of mycobacterial species were determined.
RESULTS
In total, 324 patients with NTM infection (50 patients with HIV/AIDS and 274 patients without HIV/AIDS) were included. The most common etiological agent was M. abscessus (29%), followed by M. paraintracellulare (12%) and M. colombiense (11%). Predominant NTM species were M. avium (26%), M. colombiense (24%), and M. kansasii (18%) in patients with HIV/AIDS and were M. abscessus (32%), M. paraintracellulare (13%), M. fortuitum (10%), and M. intracellulare (10%) in patients without HIV/AIDS. For a CD4+ cell count of <200/μl, the predominant species were M. aviumin the HIV/AIDS group and M. abscessus in the non-HIV/AIDS group. With respect to radiologic characteristics, different NTM strains were associated with distinct imaging manifestations; for example, M. marseillense, M. kansasii, and M. parasenchytosis were more likely to induce cavities. Imaging cavities, bronchiectasis, and acinar-like changes were more common in the non-HIV/AIDS groups.
CONCLUSIONS
The infection rates of HIV and NTM in Chongqing are high, while M. abscessus, M. paraintracellulare, and M. colombiense are the main pathogens causing NTM diseases in Chongqing, and NTM strains differed significantly between patients with and without HIV/AIDS. Monitoring these indicators can help develop prevention strategies.
Topics: Acquired Immunodeficiency Syndrome; HIV Infections; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Phylogeny; Retrospective Studies
PubMed: 35293104
DOI: 10.1111/hiv.13249 -
Journal of Infection and Public Health Mar 2021Non tuberculous mycobacteria (NTM) is an emerging opportunistic pathogen increasing globally and indistinguishable from tuberculosis (TB), which remains a challenge...
BACKGROUND AND OBJECTIVES
Non tuberculous mycobacteria (NTM) is an emerging opportunistic pathogen increasing globally and indistinguishable from tuberculosis (TB), which remains a challenge particularly in developing countries. This study aimed to identify the prevalence and diversity of NTM among both pulmonary TB (PTB) and extrpulmonary TB (EPTB) clinical isolates from south India.
METHODOLOGY
A total of 7633 specimens from TB suspects (PTB, n = 4327 and EPTB, n = 3306) were collected during the study period (July 2018-March 2020) in a tertiary care hospital. The study specimens were subjected to Ziehl Neelsen (ZN) staining and Auramine phenol (AP) staining followed by Lowenstein-Jensen (LJ) and mycobacteria growth indicator tube (MGIT) culture. The MPT64 immunochromatographic test (ICT) was performed among mycobacterial cultures and ICT negative isolates were subjected to Line Probe Assay (LPA). In addition, 53 (PTB, 48 and EPTB, 5) NTM MGIT positive cultures were collected from Intermediate Reference Laboratory (IRL), Puducherry and subjected to LPA for speciation.
RESULTS
Of the 7633 TB suspects, 0.6% were diagnosed as NTM diseases and 5.5% with Mycobacterium tuberculosis (MTBC). NTM infection was observed among 0.7% (31/4327) of PTB and 0.4% (14/3306) of EPTB. MTBC was detected among 6.1% (264/4327) of PTB and 4.6% (153/3306) of EPTB. Among 98 NTM cultures, 80.6% of isolates were recovered from PTB and 19.4% from EPTB specimens. Among pulmonary specimens, Mycobacterium intracellulare (26.6%), Mycobacterium abscessus (17.7%) and Mycobacterium kansasii (12.7%) were the most frequently detected species, while Mycobacterium intracellulare (21.1%), Mycobacterium scrofulaceum (15.8%) and Mycobacterium fortuitum (10.5%) were common in extrapulmonary specimens.
CONCLUSION
The frequency of NTM infection among TB suspects was low at a South Indian tertiary care hospital. The most predominant NTM species isolated from both pulmonary and extrapulmonary specimens was M. intracellulare.
Topics: Adult; Aged; Bacterial Typing Techniques; Female; Humans; India; Male; Middle Aged; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Prevalence; Prospective Studies; Species Specificity; Tuberculosis, Pulmonary
PubMed: 33618276
DOI: 10.1016/j.jiph.2020.12.027 -
Emerging Infectious Diseases Sep 2020We studied 31 US healthcare facilities to characterize trends in mycobacterial testing. During 2009-2015, testing for acid-fast bacilli increased 3.2% annually, and...
We studied 31 US healthcare facilities to characterize trends in mycobacterial testing. During 2009-2015, testing for acid-fast bacilli increased 3.2% annually, and prevalence of pathogenic nontuberculous mycobacteria increased 4.5% annually. These increases were highest for subpopulations at high risk of infection, including older women, Asians, and patients with concurrent conditions.
Topics: Aged; Diagnostic Tests, Routine; Female; Humans; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Prevalence; United States
PubMed: 32818422
DOI: 10.3201/eid2609.200749 -
Biometals : An International Journal on... Aug 2023Skin and soft tissue infection (SSTI) caused by atypical mycobacteria such as Mycobacterium abscessus and Mycobacterium avium intracellulare complex (MAIC) have...
Skin and soft tissue infection (SSTI) caused by atypical mycobacteria such as Mycobacterium abscessus and Mycobacterium avium intracellulare complex (MAIC) have increased in recent years. Current therapeutic options are limited, and hence new and better therapies are urgently required. Colloidal Silver (CS) has been identified for its widespread antibacterial properties and silver-impregnated dressings have been used for SSTIs caused by various pathogens. The efficacy of Green Synthesized Colloidal Silver (GSCS) was investigated for bacterial growth inhibition (BGI) using a microdilution method and minimum biofilm eradication concentration (MBEC) using resazurin assay and confocal scanning laser microscopy (CSLM) of M. abscessus (n = 5) and MAIC (n = 5). The antibacterial effect of GSCS against M. abscessus infected macrophages was also evaluated. The in vitro cytotoxicity of GSCS on a human keratinocyte cell line (HaCaT) and neonatal foreskin fibroblasts was analyzed by the crystal violet proliferation assay. Average BGI and MBEC of GSCS varied between 0.7 and 22 ppm for M. abscessus and MAIC. The concentration of 3 ppm reduced M. abscessus-infection in macrophages significantly. GSCS was not cytotoxic to HaCaT and neonatal foreskin fibroblast cells at concentrations < 3 ppm up to 2 h exposure time. GSCS therefore, has the potential for topical application against atypical mycobacterial SSTI.
Topics: Infant, Newborn; Humans; Nontuberculous Mycobacteria; Silver; Anti-Bacterial Agents; Biofilms; Macrophages
PubMed: 36729280
DOI: 10.1007/s10534-023-00494-w -
Frontiers in Immunology 2022Non-tuberculous mycobacterial pulmonary disease (NTM-PD) is a chronic, progressive, and growing worldwide health burden associated with mounting morbidity, mortality,...
Non-tuberculous mycobacterial pulmonary disease (NTM-PD) is a chronic, progressive, and growing worldwide health burden associated with mounting morbidity, mortality, and economic costs. Improvements in NTM-PD management are urgently needed, which requires a better understanding of fundamental immunopathology. Here, we examine temporal dynamics of the immune compartment during NTM-PD caused by complex (MAC) and complex (MABS). We show that active MAC infection is characterized by elevated T cell immunoglobulin and mucin-domain containing-3 expression across multiple T cell subsets. In contrast, active MABS infection was characterized by increased expression of cytotoxic T-lymphocyte-associated protein 4. Patients who failed therapy closely mirrored the healthy individual immune phenotype, with circulating immune network appearing to 'ignore' infection in the lung. Interestingly, immune biosignatures were identified that could inform disease stage and infecting species with high accuracy. Additionally, programmed cell death protein 1 blockade rescued antigen-specific IFN-γ secretion in all disease stages except persistent infection, suggesting the potential to redeploy checkpoint blockade inhibitors for NTM-PD. Collectively, our results provide new insight into species-specific 'immune chatter' occurring during NTM-PD and provide new targets, processes and pathways for diagnostics, prognostics, and treatments needed for this emerging and difficult to treat disease.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Lung Diseases; Immune System Diseases
PubMed: 36439147
DOI: 10.3389/fimmu.2022.1047781 -
Annals of the American Thoracic Society Aug 2023
Topics: Adult; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Wisconsin; Anti-Bacterial Agents
PubMed: 37526483
DOI: 10.1513/AnnalsATS.202305-420ED -
Antimicrobial Agents and Chemotherapy Jan 2022Cyclohexyl-griselimycin is a preclinical candidate for use against tuberculosis (TB). Here, we show that this oral cyclodepsipeptide is also active against the...
Cyclohexyl-griselimycin is a preclinical candidate for use against tuberculosis (TB). Here, we show that this oral cyclodepsipeptide is also active against the intrinsically drug-resistant nontuberculous mycobacterium Mycobacterium abscessus and in a mouse model of infection. This adds a novel advanced lead compound to the M. abscessus drug pipeline and supports a strategy of screening chemical matter generated in TB drug discovery efforts to fast-track the discovery of novel antibiotics against M. abscessus.
Topics: Animals; Anti-Bacterial Agents; Mice; Microbial Sensitivity Tests; Mycobacterium Infections, Nontuberculous; Mycobacterium abscessus; Nontuberculous Mycobacteria; Peptides, Cyclic
PubMed: 34723632
DOI: 10.1128/AAC.01400-21