Early and accurate diagnosis is one of the greatest challenges in the management of sepsis. Despite advances in medicine, identifying the causative pathogen quickly enough to guide targeted therapy remains difficult in most healthcare settings.
At Microbio, we’re often asked about how our InfectID™-BSI test fits into this diagnostic landscape — and how molecular testing compares to traditional methods. Below, we’ve compiled answers to some of the most common questions.
What is sepsis?
Sepsis is a life-threatening organ dysfunction caused by a dis response to infection[1]. When pathogens enter the bloodstream, the body’s immune system can go into overdrive, leading to widespread inflammation, tissue damage, and potentially multi-organ failure.
Sepsis can result from a wide variety of infections — including pneumonia, urinary tract infections, abdominal infections, or skin infections — that spread to the bloodstream.
Globally, sepsis affects around 49 million people each year and is responsible for 11 million deaths, accounting for nearly one in five deaths worldwide[2].
Although sepsis can affect anyone, certain groups are at higher risk:
- Newborns and infants
- Pregnant women
- Elderly individuals
- People with weakened immune systems or chronic illnesses
The key to improving outcomes is early recognition and rapid initiation of appropriate antimicrobial therapy — both of which depend on diagnostic speed and accuracy.
How is sepsis diagnosed?
Sepsis diagnosis typically begins with clinical evaluation, supported by laboratory tests that look for signs of infection and organ dysfunction.
Common diagnostic components include:
- Vital signs and clinical scoring systems, such as SOFA (Sequential Organ Failure Assessment) or qSOFA, to assess organ dysfunction.
- Biomarkers, such as C-reactive protein (CRP), procalcitonin (PCT), and lactate, which can indicate inflammation, tissue hypoperfusion, or metabolic stress, though they do not identify the specific pathogen.
- Microbiological testing, primarily through blood cultures, to detect pathogens responsible for bloodstream infections.
- Artificial intelligence (AI) tools, which are increasingly used in triage and early warning systems to help identify patients at risk of sepsis sooner and support timely clinical intervention.
The role of blood cultures
Blood culture remains the standard of care for pathogen identification and antimicrobial susceptibility testing. However, this method relies on the growth of microorganisms in the lab, which can take 10 to 72 hours or longer[3].
Additionally, up to 30–50% of sepsis cases yield negative blood cultures, often due to:
- Low bacterial load in the bloodstream
- Prior antibiotic treatment before sampling
- Fastidious or slow-growing organisms
These limitations mean clinicians must often start empirical broad-spectrum antibiotics, adjusting therapy only once laboratory results are available. This delay can impact outcomes and contribute to antimicrobial resistance (AMR).
What is molecular testing?
Molecular diagnostics represent a major advance in sepsis detection by targeting the genetic material (DNA or RNA) of pathogens rather than completely relying on growth in culture.
Using technologies such as real-time quantitative PCR (qPCR), molecular tests can detect and quantify microbial DNA directly from a blood sample.
How “real-time” PCR works
In real-time PCR, the amplification of DNA is monitored as it happens — cycle by cycle — using fluorescent markers. This provides both qualitative (presence or absence) and quantitative (amount of DNA detected) results, without post-PCR processing.
Advantages of molecular testing
- Speed: Results in hours instead of days.
- Sensitivity: Detects pathogens at very low concentrations, even before they are culturable.
- Specificity: Precisely identifies the genetic signatures of different microorganisms.
- Multiplexing capability: Some assays can detect multiple pathogens in a single run.
Together, these advantages enable earlier and more targeted treatment decisions — a key factor in reducing mortality and improving patient outcomes.
How fast is InfectID™-BSI?
Microbio’s InfectID™-BSI test is designed to detect 26 pathogens commonly associated with bloodstream infections (BSIs) — directly from whole blood — in just three hours.
Unlike culture-based methods, InfectID™-BSI doesn’t require waiting for pathogen growth. The test amplifies and identifies genetic targets of key sepsis-associated bacteria and fungi directly from the sample, providing faster diagnostic insights.
By accelerating time to result, InfectID™-BSI helps clinicians:
- Identify pathogens earlier, allowing for more precise antimicrobial selection.
- Reduce reliance on empirical broad-spectrum antibiotics.
- Support antimicrobial stewardship efforts through earlier, targeted therapy.
- Use negative results to rule out the 26 pathogens included in the panel, which may help guide de-escalation of antibiotics when appropriate, based on the patient’s overall clinical presentation.
Faster identification and clearer diagnostic insight support more confident, timely clinical decision-making — and ultimately, better patient outcomes.
How does InfectID™-BSI fit into existing laboratory workflows?
InfectID™-BSI is designed to complement, not replace, existing laboratory testing. It can be integrated alongside routine blood cultures, providing an early identification layer while awaiting culture confirmation and susceptibility testing.
Laboratories benefit from:
- Streamlined workflows using existing laboratory equipment.
- Minimal hands-on time using a semi-automated workflow. Compatibility with existing quality and regulatory frameworks.
For hospitals, the clinical value lies in earlier actionable information, even before blood cultures become positive.
What support does Microbio provide?
Microbio partners with laboratories, distributors, and clinicians to ensure that implementation of InfectID™-BSI is seamless and effective. Our support includes:
- Technical training for laboratory teams, including assay setup, run protocols, and data interpretation.
- Scientific and clinical education to assist clinicians integrate results into patient management decisions.
- Ongoing distributor support, with materials and updates to help partners communicate the test’s benefits accurately.
- Regulatory and documentation assistance, ensuring compliance across different markets.
Our goal is not only to deliver an innovative diagnostic solution but also to empower healthcare teams to use it confidently in clinical practice.
Still have questions?
We’re here to help.
Click here to contact our medical team to learn more about InfectID™-BSI, technical support, or partnership opportunities.
References- Gray AP, Chung E, et al. Global, regional, and national sepsis incidence and mortality, 1990–2021: a systematic analysis. Lancet Glob Health. 2025;13(11):e1914-e1923. doi:10.1016/S2214-109X(25)00356-0.[↩]
- World Health Organization. Sepsis. Updated 2023. https://www.who.int/news-room/fact-sheets/detail/sepsis[↩]
- Opota O, Croxatto A, Prod’hom G, Greub G. Blood culture-based diagnosis of bacteraemia: state of the art. Clin Microbiol Infect. 2015;21(4):313–322.[↩]