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Microbiology Spectrum Jan 2017Rapidly growing mycobacteria (RGM) compose approximately one-half of the currently validated mycobacterial species and are divided into six major groups, including the... (Review)
Review
Rapidly growing mycobacteria (RGM) compose approximately one-half of the currently validated mycobacterial species and are divided into six major groups, including the Mycobacterium fortuitum group, M. chelonae/M. abscessus complex, M. smegmatis group, M. mucogenicum group, M. mageritense/M. wolinskyi, and the pigmented RGM. This review discusses each group and highlights the major types of infections associated with each group. Additionally, phenotypic and molecular laboratory identification methods, including gene sequencing, mass spectrometry, and the newly emerging whole-genome sequencing, are detailed, along with a discussion of the current antimicrobial susceptibility methods and patterns of the most common pathogenic species.
Topics: Bacteriological Techniques; Diagnostic Tests, Routine; Humans; Molecular Diagnostic Techniques; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 28084211
DOI: 10.1128/microbiolspec.TNMI7-0027-2016 -
Clinics in Chest Medicine Mar 2015Diseases and therapies that reduce cell-mediated immunity increase the risk of nontuberculous mycobacterial (NTM) disease. Extrapulmonary NTM disease, including... (Review)
Review
Diseases and therapies that reduce cell-mediated immunity increase the risk of nontuberculous mycobacterial (NTM) disease. Extrapulmonary NTM disease, including disseminated, skin, and catheter-related disease, is more common in immunosuppressed than immunocompetent patients. Mycobacterium avium complex remains the most common cause of NTM infection, but rapid growers including Mycobacterium abscessus, Mycobacterium chelonae, and Mycobacterium fortuitum play an important role in skin and catheter-related infections. With the exception of antibiotic prophylaxis for AIDS patients, the prevention of NTM remains difficult. Management is complicated, involving restoration of immune function and removal of catheters in addition to treatment with species-specific antibiotics per current guidelines.
Topics: Anti-Bacterial Agents; Drug Administration Schedule; Humans; Immunocompromised Host; Immunosuppressive Agents; Lung Diseases; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 25676522
DOI: 10.1016/j.ccm.2014.11.002 -
Journal of Veterinary Diagnostic... Jan 2022Two aborted Chester White pig fetuses were presented to a veterinary diagnostic laboratory in Illinois. Postmortem examination identified no gross abnormalities....
Two aborted Chester White pig fetuses were presented to a veterinary diagnostic laboratory in Illinois. Postmortem examination identified no gross abnormalities. Histologic evaluation revealed multifocal necrosis of chorionic epithelial cells, coalescing areas of mineralization in the placenta, and focal accumulations of viable and degenerate neutrophils in the lung. Intra- and extracellular acid-fast bacilli were identified in the lesions in both the placenta and lungs. Bacterial culture of stomach contents yielded heavy growth of , a rapidly growing nontuberculous mycobacterium (NTM), which was further confirmed through whole-genome sequencing. NTM are opportunistic pathogens commonly found in the soil and in contaminated water supplies. In animals, is typically introduced through cutaneous wounds leading to infections limited to the skin, with systemic infection being uncommon. To our knowledge, abortion caused by has not been reported previously.
Topics: Animals; Calcinosis; Cell Count; Epithelial Cells; Female; Mycobacterium fortuitum; Nontuberculous Mycobacteria; Swine; Swine Diseases
PubMed: 34448422
DOI: 10.1177/10406387211042289 -
Antimicrobial Agents and Chemotherapy Feb 2021Infections caused by nontuberculous mycobacteria (NTM) are increasing globally. complex (MAC) and complex are the most frequently encountered NTM, and oral treatment...
Infections caused by nontuberculous mycobacteria (NTM) are increasing globally. complex (MAC) and complex are the most frequently encountered NTM, and oral treatment options are extremely limited for these pathogens, especially for the complex. In this study, the potency of omadacycline, a new tetracycline derivative, was tested against 111 isolates of NTM. MIC testing was performed as recommended by the Clinical and Laboratory Standards Institute against 70 isolates of rapidly growing mycobacteria (RGM), of which >90% were tetracycline resistant. These included subsp. (20 isolates), subsp. (3), (15 isolates), (7 isolates), the group, including six doxycycline-resistant isolates (12 isolates), and the group, including four doxycycline-resistant isolates (10 isolates). Forty-one isolates of slowly growing mycobacteria (SGM), including 16 isolates of MAC, were also tested. Omadacycline was active against all RGM species, with MIC ranges of 0.004 to 0.25 and 0.06 to 1 μg/ml for 80% and 100% inhibition, respectively. For subsp. , MICs were 0.06 and 0.12 μg/ml with 80% and 100% inhibition, respectively. There was considerable trailing of the omadacycline endpoint with the RGM. MICs of tigecycline exhibited no trailing and were generally within 1 to 2 dilutions of the 100% inhibition omadacycline MICs. While there was no trailing observed in SGM, omadacycline MICs were higher (MIC range, 8 to >16 μg/ml; = 41), as previously noted with tigecycline. This study supports further research of omadacycline, including clinical trials, for the treatment of RGM infections, especially .
Topics: Anti-Bacterial Agents; Humans; Microbial Sensitivity Tests; Mycobacteriaceae; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Tetracyclines
PubMed: 33288634
DOI: 10.1128/AAC.01947-20 -
Microbiology Spectrum Aug 2023We evaluated the clinical characteristics and treatment outcomes of 35 patients diagnosed with Mycobacterium fortuitum-pulmonary disease (M. fortuitum-PD). Prior to...
We evaluated the clinical characteristics and treatment outcomes of 35 patients diagnosed with Mycobacterium fortuitum-pulmonary disease (M. fortuitum-PD). Prior to treatment, all isolates were sensitive to amikacin and 73% and 90% were sensitive to imipenem and moxifloxacin, respectively. Approximately two-thirds of the patients (24 of 35) remained stable without antibiotic treatment. Of 11 patients requiring antibiotic treatment, the majority (81%, 9 of 11) achieved a microbiological cure with susceptible antibiotics. Mycobacterium fortuitum (M. fortuitum) is a rapidly growing mycobacterium that causes M. fortuitum-pulmonary disease (PD). It is common among individuals with preexisting lung conditions. Limited data exist regarding treatment and prognosis. Our study examined patients with M. fortuitum-PD. Two-thirds of them remained stable without antibiotics. Among those requiring treatment, 81% achieved a microbiological cure with suitable antibiotics. In many cases, M. fortuitum-PD follows a stable course without antibiotics, and when necessary, a favorable treatment response can be achieved with the appropriate antibiotics.
Topics: Humans; Mycobacterium fortuitum; Mycobacterium Infections, Nontuberculous; Anti-Bacterial Agents; Treatment Outcome; Microbial Sensitivity Tests; Lung Diseases
PubMed: 37428038
DOI: 10.1128/spectrum.02051-23 -
Antimicrobial Agents and Chemotherapy Apr 2023Mycobacterium fortuitum represents one of the most clinically relevant rapid-growing mycobacterial species. Treatments are complex due to antibiotic resistance and to...
Mycobacterium fortuitum represents one of the most clinically relevant rapid-growing mycobacterial species. Treatments are complex due to antibiotic resistance and to severe side effects of effective drugs, prolonged time of treatment, and co-infection with other pathogens. Herein, we explored the activity of NITD-916, a direct inhibitor of the enoyl-ACP reductase InhA of the type II fatty acid synthase in Mycobacterium tuberculosis. We found that this compound displayed very low MIC values against a panel of M. fortuitum clinical strains and exerted potent antimicrobial activity against M. fortuitum in macrophages. Remarkably, the compound was also highly efficacious in a zebrafish model of infection. Short duration treatments were sufficient to significantly protect the infected larvae from M. fortuitum-induced killing, which correlated with reduced bacterial burdens and abscesses. Biochemical analyses demonstrated an inhibition of synthesis of mycolic acids. Resolving the crystal structure of the InhA in complex with NAD and NITD-916 confirmed that NITD-916 is a direct inhibitor of InhA. Importantly, single nucleotide polymorphism leading to a G96S substitution in InhA conferred high resistance levels to NITD-916, thus resolving its target in M. fortuitum. Overall, these findings indicate that NITD-916 is highly active against M. fortuitum both and and should be considered in future preclinical evaluations for the treatment of M. fortuitum pulmonary diseases.
Topics: Animals; Mycobacterium fortuitum; Zebrafish; Mycobacterium tuberculosis; Mycolic Acids; Oxidoreductases
PubMed: 36920188
DOI: 10.1128/aac.01607-22 -
Journal of the Association of Medical... Mar 2022is a rapidly growing mycobacterium, ubiquitous in soil and water, but it is an uncommon cause of infections in immunocompetent hosts. Cardiac device infections and...
BACKGROUND
is a rapidly growing mycobacterium, ubiquitous in soil and water, but it is an uncommon cause of infections in immunocompetent hosts. Cardiac device infections and bloodstream infections due to non-tuberculous mycobacteria are rare.
CASE PRESENTATION
We present the case of an 85-year-old patient with infective endocarditis and pacemaker lead infection secondary to .
PubMed: 36340848
DOI: 10.3138/jammi-2021-0003 -
Frontiers in Cellular and Infection... 2023We aimed to evaluate the activity of PBTZ169 and pretomanid against non-tuberculous mycobacteriosis (NTM) and .
OBJECTIVES
We aimed to evaluate the activity of PBTZ169 and pretomanid against non-tuberculous mycobacteriosis (NTM) and .
METHODS
The minimum inhibitory concentrations (MICs) of 11 antibiotics, against slow-growing mycobacteria (SGMs) and rapid-growing mycobacteria (RGMs) were tested using the microplate alamarBlue assay. The activities of bedaquiline, clofazimine, moxifloxacin, rifabutin, PBTZ169 and pretomanid against four common NTMs were assessed in murine models.
RESULTS
PBTZ169 and pretomanid had MICs of >32 μg/mL against most NTM reference and clinical strains. However, PBTZ169 was bactericidal against (3.33 and 1.49 log10 CFU reductions in the lungs and spleen, respectively) and (2.29 and 2.24 CFU reductions in the lungs and spleen, respectively) in mice, and bacteriostatic against Mycobacterium avium and . Pretomanid dramatically decreased the CFU counts of (3.12 and 2.30 log10 CFU reductions in the lungs and spleen, respectively), whereas it showed moderate inhibition of and . Bedaquiline, clofazimine, and moxifloxacin showed good activities against four NTMs and . Rifabutin did not inhibit and in mice.
CONCLUSION
PBTZ169 appears to be a candidate for treating four common NTM infections. Pretomanid was more active against , and than against .
Topics: Animals; Mice; Mycobacterium abscessus; Mycobacterium avium; Mycobacterium fortuitum; Mycobacterium chelonae; Clofazimine; Moxifloxacin; Mice, Inbred BALB C; Anti-Bacterial Agents; Nontuberculous Mycobacteria; Mycobacterium Infections; Rifabutin; Mycobacterium Infections, Nontuberculous; Microbial Sensitivity Tests
PubMed: 37077530
DOI: 10.3389/fcimb.2023.1115530