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JAAD Case Reports Jul 2023
PubMed: 37492428
DOI: 10.1016/j.jdcr.2023.06.013 -
Journal of Microbiological Methods Aug 2023There is an unmet need for tools that permit diagnosis of Tuberculosis (TB) that are affordable, low-tech, and can differentiate Mycobacterium tuberculosis (M.tb) from...
There is an unmet need for tools that permit diagnosis of Tuberculosis (TB) that are affordable, low-tech, and can differentiate Mycobacterium tuberculosis (M.tb) from non-tuberculous mycobacteria (NTM). In this study, we have developed a strip-based assay to detect the activity of a unique Carbapenem Resistance Factor A (CrfA) enzyme present only in M.tb. The strip comprises of PVDF (Polyvinylidene fluoride) membrane that has an immobilized anti-CrfA antibody to capture the CrfA enzyme from M.tb lysate. Lysate of mycobacteria is applied to the strip, washed, and incubated in the presence of chromogenic reporter dye which is a substrate for CrfA. A change in the color of the dye that is readily visible to the naked eye is the readout. We evaluated lysates from M.tb and various NTMs namely, M. abscessus, M. chelonae, M. avium, M. obuense, M. paraintracellulare, M. kansasi, including the patient-derived sputum samples. The strip assay selectively identified only those samples containing M.tb. Based on this evidence, this new assay enables the identification and differentiation of M.tb from NTMs in patient sputum samples. As this tool can be simple to use, therefore has the potential to serve the unmet need for diagnosis of TB and NTM infections in resource-limited settings.
Topics: Humans; Mycobacterium tuberculosis; Nontuberculous Mycobacteria; Tuberculosis; Mycobacterium Infections, Nontuberculous; Sputum
PubMed: 37437716
DOI: 10.1016/j.mimet.2023.106781 -
Anais Brasileiros de Dermatologia 2023
PubMed: 37407333
DOI: 10.1016/j.abd.2022.12.005 -
Surgical Case Reports Jul 2023Mycobacterium chelonae, a nontuberculous mycobacterium, commonly causes skin, soft tissue, eye, pulmonary, catheter-related, and post-surgical infections in patients...
BACKGROUND
Mycobacterium chelonae, a nontuberculous mycobacterium, commonly causes skin, soft tissue, eye, pulmonary, catheter-related, and post-surgical infections in patients with immunosuppression or trauma. M. chelonae breast infections are rare, and most cases occur following cosmetic surgery. Here, we report the first case of spontaneous breast abscess due to M. chelonae.
CASE PRESENTATION
A 22-year-old Japanese woman presented at our hospital with swelling and pain in the right breast for the past 2 weeks without any fever. She had a 19-month-old child and stopped breastfeeding 1 month after giving birth. The patient had no history of trauma or breast surgeries, no family history of breast cancer, and was not immunocompromised. Breast ultrasonography revealed a heterogeneous hypoechoic lesion with multiple fluid-filled areas suspected to be abscesses. Dynamic contrast-enhanced magnetic resonance imaging revealed a 64 × 58 × 62 mm, ill-defined, high-signal-intensity lesion with multiple ring enhancements in the upper half of the right breast. The first diagnosis was inflammatory breast cancer or granulomatous mastitis with abscess. A core needle biopsy led to drainage of pus. Gram staining did not reveal any bacteria in the pus, but the colonies from the biopsy grew on blood and chocolate agar cultures. Mass spectrometry detected M. chelonae in these colonies. Histopathological findings revealed mastitis without malignancy. The patient's treatment regimen was oral clarithromycin (CAM) based on susceptibility. Three weeks later, although the pus had reduced, the induration in the breast did not resolve; therefore, multidrug antibiotic treatment was initiated. The patient received amikacin and imipenem infusion therapy for 2 weeks, followed by continuation of CAM. Three weeks later, tenderness in the right breast recurred with slight pus discharge. Hence, minocycline (MINO) was added to the treatment. The patient stopped CAM and MINO treatment 2 weeks later. There was no recurrence 2 years after treatment.
CONCLUSION
We report a case of M. chelonae breast infection and abscess formation in a 22-year-old Japanese woman without obvious risk factors. M. chelonae infection should be considered in cases of intractable breast abscess, even in patients without immunosuppression or trauma.
PubMed: 37405585
DOI: 10.1186/s40792-023-01706-8 -
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 -
Dermatologie (Heidelberg, Germany) Sep 2023We report the case of a healthy young man who presented to our clinic with itchy skin lesions in the area of a tattoo on the back of the left hand. Bioptic and...
We report the case of a healthy young man who presented to our clinic with itchy skin lesions in the area of a tattoo on the back of the left hand. Bioptic and cultural confirmation of the pathogens led to the diagnosis of Mycobacterium chelonae infection. We initiated antibiotic therapy using azithromycin and linezolid with good response. Our case underlines that besides allergic skin reactions, infections as a complication after tattooing should also be included in the differential diagnosis.
Topics: Humans; Male; Adult; Mycobacterium Infections, Nontuberculous; Tattooing; Skin Diseases, Bacterial; Anti-Bacterial Agents; Mycobacterium chelonae; Azithromycin; Linezolid; Biopsy; Skin; Treatment Outcome
PubMed: 37341750
DOI: 10.1007/s00105-023-05173-y -
Annali Dell'Istituto Superiore Di Sanita 2023Nontuberculous mycobacteria (NTM) are environmental mycobacteria which may cause pulmonary and extrapulmonary diseases. These organisms are difficult to treat due to...
INTRODUCTION
Nontuberculous mycobacteria (NTM) are environmental mycobacteria which may cause pulmonary and extrapulmonary diseases. These organisms are difficult to treat due to their intrinsic drug-resistance. In Italy, no major nationwide study on NTM epidemiology and drug susceptibility was performed.
METHODS
Data on the epidemiology of 7,469 NTM clinical isolates identified in Italy in 2016-2020 and on the minimum inhibitory concentrations (MICs) of 1,506 of these strains were analysed.
RESULTS
Overall, 63 species were identified in 42 hospital laboratories located in 16 out of 20 regions, with Mycobacterium avium complex (MAC) being the most frequently isolated, followed by M. gordonae, M. xenopi, M. abscessus. The MICs of 12 drugs for MAC, M. xenopi, M. kansasii, M. abscessus, M. fortuitum and M. chelonae were interpreted for clinical significance (susceptible, intermediate, resistant) based on the guidelines published by the Clinical and Laboratory Standards Institute in November 2018.
CONCLUSIONS
Our data are in line with other nationwide studies and may be of value for further update of microbiological and clinical guidelines.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Microbial Sensitivity Tests; Italy
PubMed: 37337988
DOI: 10.4415/ANN_23_02_06 -
Cureus May 2023Infections due to nontuberculous mycobacteria (NTM) are caused by mycobacterial species other than , , and . Patients who are immunocompromised have increased...
Infections due to nontuberculous mycobacteria (NTM) are caused by mycobacterial species other than , , and . Patients who are immunocompromised have increased susceptibility to pulmonary, lymphatic, and skin infections by these pathogens. We present a case of a 78-year-old male who presented to dermatology with a left dorsolateral hand infection after sustaining cat scratches in the setting of topical steroid therapy for suspected pyoderma gangrenosum. A shave biopsy of the lesion showed granulomatous dermatitis and associated acid-fast bacilli, while tissue culture grew . This case demonstrates cat scratches as an uncommon risk factor for cutaneous NTM disease. Although an association between cat scratches and human NTM infections has only been reported in two previous cases, it must be considered in cases of unusual and persistent cutaneous lesions, especially in immunocompromised patients, even those with only local immunosuppression from topical agents.
PubMed: 37313069
DOI: 10.7759/cureus.38901 -
Infection Control and Hospital... Dec 2023A pseudo-outbreak of bronchoscopy-associated and was traced to contaminated ice machine water and ice. A nonsterile ice bath was used to cool uncapped, sterile, saline...
A pseudo-outbreak of bronchoscopy-associated and was traced to contaminated ice machine water and ice. A nonsterile ice bath was used to cool uncapped, sterile, saline syringes used to slow procedural bleeding. Joining the growing evidence of bronchoscopy pseudo-outbreaks, our investigation describes several lessons for future prevention.
Topics: Humans; Bronchoscopy; Disease Outbreaks; Ice; Mycobacterium chelonae; Mycobacterium Infections, Nontuberculous; Water Microbiology; Cross Infection
PubMed: 37272469
DOI: 10.1017/ice.2023.101