CLSI Blog Articles

Read the latest articles about CLSI and laboratory standards in the official CLSI Blog. Browse our most recent blog articles below.

Chloride Sweat Testing for Cystic Fibrosis

Chloride sweat testing is used to help diagnose cystic fibrosis (CF), an inherited disorder that disrupts the normal function of epithelial cells found in the sweat glands and lining of passageways in the lungs, liver, pancreas, and digestive and reproductive systems. According to the Cystic Fibrosis Foundation, the sweat test is considered the gold standard for diagnosing cystic fibrosis. Sweat testing should be done at a CF Foundation-accredited care center.

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Patient Safety Through Process Management

The Joint Commission’s 2019 National Patient Safety Goals for laboratory services is a patient safety guideline that sets goals the laboratory must achieve to satisfy accreditation requirements.

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The Cefazolin Inoculum Effect for MSSA

Infections due to methicillin-sensitive Staphylococcus aureus (MSSA) continue to be a significant source of morbidity and mortality. While antistaphylococcal penicillins, such as nafcillin, have been the mainstay of therapy for MSSA, the use of cefazolin has grown increasingly popular. Indeed, recent data from observational clinical studies suggest that cefazolin is as efficacious as nafcillin, with less toxicity, has a more favorable dosing schedule, and possibly improves survival. Thus, cefazolin has become first line therapy for the treatment of MSSA infections.

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Differences in Disk Content Recommended by CLSI and EUCAST for Disk Diffusion Testing

Disk diffusion testing is used by a variety of laboratories throughout the world. Disk diffusion breakpoints are dependent on the concentration of antimicrobial impregnated into the disk, otherwise known as the disk content. This disk content in microgram concentrations is printed on each disk and is listed in both CLSI’s M100 and M45 and European Committee on Antimicrobial Susceptibility Testing (EUCAST ) breakpoint tables.

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CLSI's Guidelines on Clinical Method Validation & Verification

Interferents in medical laboratory measurement pose a danger to patients. Although performance is routinely monitored by internal QC and external quality assessment procedures, laboratories cannot easily detect error caused by interferents. Therefore, manufacturers of in vitro diagnostic measuring systems need to include evaluation of potential interferents’ effects in their risk analyses at the product design stage.

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Automation Advances within the Clinical Microbiology Laboratory

Microbiology specimen processing and culture workup remain mostly manual tasks with few recent changes to methods used. However, automation in the microbiology laboratory through the use of antimicrobial susceptibility testing systems is becoming more prevalent in the lab. Automated microbial identification is performed with MALDI-TOF MS, which stands for matrix-assisted laser de-ionization time-of-flight mass spectrometry.

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PK/PD Workshop Presented at CLSI Committees Week

Last week at CLSI’s first 2019 Committees Week in St. Augustine, Florida, we presented an education session on Recent Advances in Pharmacokinetics/Pharmacodynamics (PK/PD) and Its Use in Setting Breakpoints. Participants in the education session earned continuing education credits.

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Digging Deeper into Understanding Cefazolin Reporting for Enterobacteriaceae

In the Spring 2018 CLSI AST News Update, we provided a case study illustrating various ways by which to report cefazolin as a surrogate for oral cephalosporins for applicable Gram-negative organisms isolated from the urine. The cases concentrated solely on testing and reporting of cefazolin as a surrogate. However, cefazolin, which is administered intramuscularly (IM) or intravenously (IV) may also be used itself for the treatment of complicated urinary tract infections. Additionally, cefazolin may be used in treatment of systemic infections due to susceptible isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis.

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