Novel Test to Diagnose Bacterial Pneumonia Directly from Whole Blood

By LabMedica International staff writers
Posted on 31 Jan 2025

Image: RNA sequencing directly from whole blood aims to expand access to LRTI testing (Photo courtesy of CARB-X)

Pneumonia and lower-respiratory-tract infections (LRTIs) are among the top causes of illness and death globally, particularly in vulnerable populations such as the elderly, young children, and immunocompromised individuals. One of the major challenges in diagnosing pneumonia is the difficulty in obtaining an appropriate sample, and frequently, no pathogen is identified. Without a clear microbiological diagnosis, broad-spectrum antibiotics are typically administered, which increases the risk of antibiotic resistance and poor patient outcomes if the wrong antibiotics are chosen. The absence of rapid and accurate diagnostic tools only worsens this situation, hindering the ability to provide tailored treatments and leading to the overuse of antibiotics. Researchers are now exploring the possibility of detecting bacterial pneumonia directly from blood samples to improve access to LRTI testing.

Rhode Island Hospital (Providence, RI, USA) has been awarded USD 1 million by Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator, CARB-X, Boston, MA, USA) to develop a polymerase chain reaction (PCR) method informed by RNA sequencing to detect bacterial pneumonia directly from whole blood. CARB-X is a global non-profit collaboration focused on supporting early-stage research and development of antibacterial therapies to combat the growing problem of antibiotic resistance. The aim is to detect pneumonias caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Haemophilus influenzae, using whole blood samples, making it less invasive compared to traditional methods that require samples from the airways, such as bronchoscopy or deep suctioning.

This simplified approach, involving a needle-stick blood collection from the arm, has the potential to expand access to testing and streamline current LRTI testing methods, enabling testing at primary care centers around the world instead of just tertiary care settings. Unlike traditional microbiological tests, this method will not require specimen culturing, providing results in just four hours. Targeting RNA ensures that the infection is active, as RNA degrades much faster than DNA, lasting only minutes to hours when sourced from bacteria. This technique immediately stabilizes the RNA for testing, and because it targets RNA, it identifies bacteria actively producing resistance proteins, rather than simply detecting bacteria that may carry genes for resistance.

“The support from CARB-X to focus on developing a direct from blood diagnostic for lower-respiratory-tract infections expands our current NIH supported work creating a direct from blood, culture independent, diagnostic for pathogens causing sepsis targeting RNA from the bacteria using RNA sequencing data form patients,” said Sean Monaghan, MD, surgeon at Rhode Island Hospital.

“This innovative diagnostic approach holds the potential to improve access to testing for lower-respiratory-tract infections, including pneumonia, enabling clinicians to make faster, more informed decisions and reduce the use of broad-spectrum antibiotics,” added Erin Duffy, PhD, Chief of R&D and CARB-X. “By supporting Rhode Island Hospital’s work, CARB-X is learning whether alternative sample types in detecting LRTIs is promising for future product development.”

Related Links:
Rhode Island Hospital
CARB-X