This study is a prospective, multicenter, integrated trial designed to evaluate, from the perspectives of diagnostic performance and clinical utility, whether a diagnostic and treatment strategy based on the NuRapid-CRISPR rapid pathogen detection technology can reduce the 28-day all-cause mortality rate in patients with sepsis or septic shock in the ICU, compared to traditional pathogen culture.

The study consists of two parts:

1. Diagnostic Accuracy Study: For all enrolled sepsis patients, microbiological specimens will undergo concurrent blinded testing, with NuRapid-CRISPR serving as the test of interest and traditional pathogen culture as the reference standard. A prospective comparison will evaluate differences between the two methods in key metrics such as pathogen detection rate, sensitivity, specificity, and turnaround time.
2. Clinical Utility Cohort Study: All patients will undergo NuRapid-CRISPR testing as part of routine clinical care. Based on whether the rapid results are adopted clinically to guide early antimicrobial therapy decisions, the cohort will naturally form an exposure group (early treatment adjustments based on NuRapid-CRISPR results) and a control group (treatment primarily based on traditional culture results or empirical therapy). The study will prospectively compare the two groups in terms of the time to optimize antimicrobial therapy, coverage of the initial treatment spectrum, and infection-related clinical outcomes.

Inclusion Criteria:

• Age ≥ 18 years, length of stay in the ICU ≤ 24 hours;
• Meets the Sepsis-3.0 diagnostic criteria (an increase in SOFA score of ≥2 points from baseline, and evidence of infection);
• Clinically suspected sepsis or septic shock; the pathogen is unknown; the clinical plan is to collect sterile or suitable specimens, such as blood, respiratory specimens, cerebrospinal fluid, and ascites, for microbiological testing;
• Expected ICU stay of ≥48 hours and ability to complete at least 28 days of clinical follow-up;
• A written informed consent form signed by the patient or their legally authorized representative;

Exclusion Criteria:

• At the time of admission, the patient had already received a definitive pathogen diagnosis (based on microbiological culture, reliable molecular testing, or serological evidence), and targeted antimicrobial therapy against that pathogen had been initiated for more than 48 hours;
• Vital signs are extremely unstable; death is expected within 24 hours;
• Patients with severe primary immunodeficiency (e.g., AIDS, active hematologic malignancies, post-transplantation of solid organs or hematopoietic stem cells, or long-term use of high-dose glucocorticoids [prednisone ≥ 20 mg/day or equivalent dose for more than 4 weeks] or other potent immunosuppressants);
• Women who are pregnant or breastfeeding;
• The patient or their authorized representative has expressly refused to undergo any pathogen testing;
• It is not possible to obtain a suitable specimen for testing due to anatomical, physiological, or technical reasons;
• The patient is currently participating in another interventional clinical trial that may interfere with the assessment of the primary outcome of this study;
• The patient or their authorized representative has declined to participate in this study;