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 hp
Sign In
Advertise with Us

Download Mobile App




Unique Barcoding System Tracks Pneumonia-Causing Bacteria as They Infect Blood Stream

By LabMedica International staff writers
Posted on 28 Feb 2025

Bacteremia, also known as blood poisoning, occurs when bacteria manage to overcome the body's immune defenses. More...

This condition can progress into sepsis, a serious illness that is responsible for over a third of hospital-related deaths each year. While individuals are frequently exposed to bacteria from the environment, they often fight off these infections without experiencing this deadly progression. Scientists are working to understand how bacteria spread throughout the body to cause systemic infections, with the ultimate goal of halting this process before it escalates.

Researchers at U-M Medical School (Ann Arbor, MI, USA) have been investigating this issue, focusing on gram-negative bacteria such as Klebsiella pneumoniae, a common cause of pneumonia-related bacteremia. In their previous studies, they identified three stages in the spread of bacteria: initial infection at a site like the lungs, entry into the bloodstream, and replication while avoiding filtration by the liver and spleen. Traditionally, bacterial infections are analyzed by culturing tissue and counting the resulting bacteria. While it’s easy to measure the initial infection phase by observing how bacteria invade the lungs, and similarly, the third phase by assessing how bacteria survive in the liver and spleen, the transition from the lungs into the bloodstream has been difficult to track.

Using an innovative barcoding system, the researchers labeled bacteria with short DNA sequences in mouse models and employed computer analysis to track the movement of K. pneumoniae throughout the body. They initially hypothesized that the bacteria would replicate in the lungs until they overwhelmed the local immune defenses, eventually spilling into the bloodstream. This type of spread, which they called metastatic dissemination, was observed in some mice. However, they also uncovered an unexpected pattern. About half of the mice showed this metastatic pattern, while the other half exhibited a form of bacterial spread where the bacteria entered the bloodstream on their own without first replicating in large numbers, a process they termed direct dissemination.

The findings, published in Nature Communications, revealed that the metastatic pathway was associated with a more severe infection compared to the direct dissemination route. Moreover, over time, the infection tended to follow the metastatic pattern. The discovery of the direct route suggests that bacteria might be establishing low-level reservoirs in other parts of the body, which could offer new targets for treating blood infections. Additionally, the researchers introduced mutations in both the K. pneumoniae bacteria and the mice, which affected the mode of bacterial dissemination. This hinted that the interaction between the bacteria and the host’s immune system could play a key role in determining the course of the infection.

“The project began with a very basic question—how does bacteria leave the lungs—that we have now provided some insight into, closing a significant gap in our knowledge,” said Michael Bachman, M.D., Ph.D., clinical associate professor of pathology and microbiology and immunology at U-M Medical School.


Gold Member
Quantitative POC Immunoassay Analyzer
EASY READER+
POC Helicobacter Pylori Test Kit
Hepy Urease Test
New
HBV DNA Test
GENERIC HBV VIRAL LOAD VER 2.0
New
Automatic Hematology Analyzer
DH-800 Series
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Hematology

view channel
Image: Platelets sequester cfDNA during circulation (Murphy L. et al., Science, 2025; DOI: 10.1126/science.adp3971)

Platelets Could Improve Early and Minimally Invasive Detection of Cancer

Platelets are widely recognized for their role in blood clotting and scab formation, but they also play a crucial role in immune defense by detecting pathogens and recruiting immune cells.... Read more

Immunology

view channel
Image: The test could streamline clinical decision-making by identifying ideal candidates for immunotherapy upfront (Xiao, Y. et al. Cancer Biology & Medicine July 2025, 20250038)

Blood Test Predicts Immunotherapy Efficacy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking targeted therapies, making immunotherapy a promising yet unpredictable option. Current biomarkers such as PD-L1 expression or tumor... Read more

Pathology

view channel
image: Researchers Marco Gustav (right) and MD Nic G. Reitsam (left) discuss the study data (Photo courtesy of Anja Stübner/EKFZ)

AI Model Simultaneously Detects Multiple Genetic Colorectal Cancer Markers in Tissue Samples

Colorectal cancer is a complex disease influenced by multiple genetic alterations. Traditionally, studies and diagnostic tools have focused on predicting only one mutation at a time, overlooking the interplay... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.