We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Technopath Clinical Diagnostics - An LGC Company

Download Mobile App




Events

ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

Microbes Identified In Leukemic Febrile Neutropenia

By LabMedica International staff writers
Posted on 28 Jun 2022
Print article
Image: BD Bactec Media: Plus Aerobic/F were used to culture blood from Leukemic Febrile Neutropenia patients and compared to metagenomic shotgun sequencing (Photo courtesy of Fisher Scientific)
Image: BD Bactec Media: Plus Aerobic/F were used to culture blood from Leukemic Febrile Neutropenia patients and compared to metagenomic shotgun sequencing (Photo courtesy of Fisher Scientific)

Despite diagnostic advances in microbiology, the etiology of neutropenic fever remains elusive in most cases. Infectious complications of neutropenia occur in more than 80% of patients who undergo chemotherapy for hematological malignancy and 10% to 50% of those with visceral malignancies.

Bacteria are the most commonly detected microorganisms (10%–25%), followed by fungi (4%), with viruses being least commonly documented. Metagenomic shotgun sequencing is a blanket sequencing technique that has the potential to analyze all genetic material present in a sample. Over the last few years, metagenomic shotgun sequencing has been applied in clinical practice, and enabling detection of microorganisms not detected by conventional tests and even previously unrecognized human pathogens.

Infectious Disease Specialists at the Mayo Clinic College of Medicine and Science (Rochester, MN, USA) and their colleagues prospectively enrolled 20 acute leukemia patients and obtained blood from these patients at three time points: 1) anytime from onset of neutropenia until before development of neutropenic fever; 2) within 24 hours of onset of neutropenic fever; and 3) 5–7 days after onset of neutropenic fever.

Whole blood (5 mL) was collected in EDTA tubes (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) from each subject at the three time points. Blood cultures were performed using the Becton Dickinson BD BACTEC FX platform. A typical set consisted of two BD BACTEC Plus Aerobic/F bottles and one BD BACTEC Lytic Anaerobic/F bottle. Routinely, at least two blood culture sets are drawn per patient. Samples underwent nucleic acid extraction within four days of collection. Bacterial and viral fractions were spiked with internal controls (DNA phages for bacterial, and DNA and RNA phages for viral fractions) to assess assay quality. Sample preparation and nucleic acid extraction were performed using the iDTECT® Dx Blood test (PathoQuest, Paris, France).

The scientists reported that blood cultures grew a bacterium in three cases: Streptococcus mitis group in two and Leptotrichia species in one. Clinically relevant viruses or bacteria (CRVB) were present in three cases by metagenomic shotgun sequencing: rhinovirus in a subject with respiratory tract infection, Staphylococcus aureus in a subject with peri-anal cellulitis and Staphylococcus epidermidis in a subject with a potential bloodstream infection. Results of blood culture and metagenomic shotgun sequencing were discordant in all cases.

Besides blood culture results, three other subjects had positive microbiological laboratory tests, all from the respiratory tract. These included, respectively, rhinovirus and influenza A/respiratory syncytial virus infections in two subjects with upper respiratory tract infection, and a sputum culture for Pseudomonas aeruginosa in a subject with pneumonia.

The authors concluded that metagenomic shotgun sequencing could potentially be used as a supplement to standard tests to increase the yield of microbiological diagnosis. However, improvements in and optimization of sample preparation methods and sequencing platforms will be needed for widespread adoption of this approach into clinical practice. The study was published on June 16, 2022, in the journal PLOS ONE.

Related Links:
Mayo Clinic College of Medicine and Science 
Becton, Dickinson and Company 
PathoQuest 

New
Gold Supplier
POC Test Reader
NycoCard READER II
New
Albumin Urine Test
Micro-Albumin ELISA
New
Automated Clinical Chemistry Analyzer
DRI-CHEM NX600
New
Hemolysing Reagent
Dialyse-BA 5D

Print article

Channels

Microbiology

view channel
Image: Trichinella sp. found in muscle tissue (Photo courtesy of McGill University)

Laboratory Features of Trichinellosis and Eosinophilia Threshold Determined

Trichinella nativa is a nematode worm, one of the species of the genus Trichinella, found in arctic and subarctic regions. It is highly pathogenic and has a high resistance to freezing. It is encapsulated,... Read more

Industry

view channel
Image: With Cell IDx’s acquisition, Leica Biosystems will be moving its multiplexing menu forward (Photo courtesy of Leica Biosystems)

Leica Biosystems Acquires Cell IDx, Expanding Offerings in Multiplexed Tissue Profiling

Leica Biosystems, a technology leader in automated staining and brightfield and fluorescent imaging (Nussloch, Germany), has acquired Cell IDx, Inc. (San Diego, CA, USA), which provides multiplex staining... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.