Background: Colistin is among the last resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. Antimicrobial susceptibility testing of colistin is challenging due to its physicochemical properties. Broth microdilution (BMD) is the recommended method for colistin susceptibility testing. However BMD is not practical for clinical microbiology laboratories as manual preparation of BMD plates is time-consuming and labor intensive. Recently, some more user-friendly BMD products with commercial panels have become available. Our objective was to evaluate the performance of a commercial broth microdilution (BMD) product [Sensititre (Thermo Fisher Scientific)] for colistin MIC determination by comparison with reference BMD method using a collection of E. coli and K. pneumoniae isolates.
Methods: A total of 323 unique patient isolates (102 E. coli, 221 K. pneumoniae) were included in the study. Isolates were stored at -70°C and subcultured twice on sheep blood agar before testing. Colistin MICs of the isolates were determined using Sensititre (a premade BMD product with dried antibiotics) and an 'in-house prepared BMD panel prepared in accordance with CLSI guidelines' (reference method). MIC determination with Sensititre was performed according to manufacturer's instructions. The reference method was performed using untreated 96-well sterile polystyrene plates. Colistin MIC results were interpreted according to EUCAST breakpoints (susceptible, ≤ 2 mg/L; resistant, > 2 mg/L).
Results: Overall susceptibility rate of isolates to colistin by reference BMD was 75.9%. Overall categorical agreement (CA), essential agreement (EA), very major error (VME), and major error (ME) rates for Sensititre were 98.5%, 72.5%, 3.8%, and 0.8%, respectively. The CA and EA between Sensititre and reference BMD for the isolates with reference colistin MICs close to the susceptibility breakpoint (2 - 8 mg/L) was 94.2% and 48.1%, respectively. Sensititre yielded a VME rate of 15% and ME rate of 0%, respectively, for this subset of isolates.
Conclusions: In conclusion, Sensititre showed high CA but low EA with reference BMD for entire collection of isolates. The VME rate was just slightly above 3% and ME rate was acceptable. The rates of CA and EA were decreased and the rate of VME was increased when a subset consisting of more challenging isolates was used.
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http://dx.doi.org/10.7754/Clin.Lab.2020.200822 | DOI Listing |
J Clin Microbiol
January 2025
Department of Pathology, Harbor-UCLA Medical Center, Torrance, California, USA.
The complex (BCC) is a group of Gram-negative bacteria that cause opportunistic infections, most notably in people with cystic fibrosis (CF), and have been associated with outbreaks caused by contaminated medical products. Antimicrobial susceptibility testing (AST) is often used to guide treatment for BCC infections, perhaps most importantly in people with CF who are being considered for lung transplant. However, recent studies have highlighted problems with AST methods.
View Article and Find Full Text PDFFacioscapulohumeral muscular dystrophy type 1 (FSHD1) and Becker muscular dystrophy (BMD) are distinct disorders caused by different genetic variations and exhibiting different inheritance patterns. The co-occurrence of both conditions within the same family is rare. In this case report, the proband was a 10 year-old boy who presented with eye and mouth orbicular muscles, shoulder and proximal upper and lower limbs weakness.
View Article and Find Full Text PDFOsteoporos Sarcopenia
December 2024
Osteoporosis and Bone Metabolism Unit, Department of Endocrinology, Singapore General Hospital, Singapore.
Osteoporosis in men remains a significantly underrecognized condition, with notable differences in bone mineral density (BMD) and fracture risk between Asian and Western populations. Despite 30% of hip fractures globally occurring in men, they are less likely to be diagnosed or treated for osteoporosis, especially in resource-limited settings. Given these disparities, a deeper understanding of osteoporosis epidemiology and treatment efficacy in men is essential, particularly in Asian populations.
View Article and Find Full Text PDFJ Glob Antimicrob Resist
January 2025
Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy; ESCMID Study Group for Legionella Infections (ESGLI), Basel, Switzerland. Electronic address:
Background: Although antimicrobial resistance has not yet emerged as an overarching problem for Legionella pneumophila (Lp) infection, the description of clinical and environmental strains resistant to fluoroquinolones and macrolides is a cause of concern. This study aimed to investigate the antimicrobial susceptibility of Lp human isolates in Italy.
Methods: A total of 204 Lp clinical isolates were tested for sensitivity to nine antibiotics using the broth microdilution assay (BMD).
Eur J Radiol
January 2025
Department of Medicine 3, Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany; Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany. Electronic address:
Objectives: Contrast agents are frequently administered in computed tomography (CT) scans used for opportunistic screening of osteoporosis. The objective of this study is to compare the impact of contrast-related bone mineral density (BMD) increase between phantom-based and internal CT calibration techniques.
Materials And Methods: Phantom-based and internal CT calibration techniques were used to determine trabecular BMD in 93 existing clinical CT scans of the lumbar spine of 34 subjects, scanned before and after administration of contrast agents.
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