Septicemia Models for Preclinical Research

Septicemia, also known as bloodstream infection or sepsis, is one of the leading causes of mortality worldwide and a major clinical challenge. It results from the systemic spread of pathogens and triggers a dysregulated immune response, often leading to septic shock and multi-organ failure. The increasing incidence of multidrug-resistant bacteria and the high mortality associated with fungal sepsis underscore the urgent need for novel therapeutic approaches.

At Vibiosphen, we provide robust and translational septicemia models in rodents to support the development of new antibiotics, antifungals, and immunomodulatory therapies. These models are designed to generate clinically relevant data that help pharmaceutical and biotechnology companies accelerate their infectious disease programs.
 

Background of Septicemia

Bloodstream infections arise when pathogens invade the circulatory system, spreading rapidly throughout the body. They can originate from lung infections, gastrointestinal translocation, urinary tract infections, or catheter-related infections. Their global burden is amplified by:

• The rise of multidrug-resistant Gram-negative and Gram-positive bacteria
• The high mortality rates associated with fungal sepsis
• The lack of effective treatments beyond supportive care in severe sepsis
• The urgent need for new drugs targeting both infection and host inflammatory responses
   

Preclinical septicemia models are therefore essential for evaluating the efficacy, safety, and mechanism of action of therapeutic candidates before clinical development.

Rodent Models of Septicemia

Mouse lineages

• The primary mouse lineages used in preclinical studies are inbred strains known for their genetic uniformity, which minimizes experimental variability.
  • C57BL/6 mice have a T-helper type 1 (Th1) biased immune response, which is a cellular immune response important for fighting intracellular pathogens.
  • BALB/c mice have a T-helper type 2 (Th2) biased immune response. A Th2 response is a humoral immune response that relies on antibodies and is essential for combatting extracellular parasites.

• Outbred mice, unlike their inbred counterparts, are maintained in large, randomly bred colonies to maximize genetic variation. This heterogeneity makes each mouse genetically unique.
  • Swiss mice, OF1 and CD1

The decision to use an inbred or outbred strain depends on the specific research question. Inbred mice are for when you want to minimize all genetic variables and pinpoint the effect of a single factor. Outbred mice are for when you want to see how a factor affects a genetically varied population.

Rat lineages

• Inbred strain, meaning they are genetically uniform, and provide a consistent baseline for preclinical studies, which is essential for reproducibility.
  • Fischer 344 (F344) rats

• Outbred rats. They have a wide range of genetic variability, which better represents the genetic diversity found in the human population 
  • Sprague Dawley rats 
  • Wistar rats 

The decision to use an inbred or outbred strain depends on the specific research question. Inbred rats are for when you want to minimize all genetic variables and pinpoint the effect of a single factor. Outbred rats are for when you want to see how a factor affects a genetically varied population.

Routes of Administration

Compounds under evaluation can be administered through several routes to reflect clinical usage and pharmacological profiles:

• Oral gavage 
• Intraperitoneal route
• Intravenous route
• Subcutaneous route
• Intramuscular route
• Intranasal route
• Inhalation / aerosolization route

• Intratracheal route

   

This versatility allows us to design tailored studies that align both the infection route and the therapeutic administration route with the intended clinical application.

Pathogens Studied in Vibiosphen Septicemia Models

Vibiosphen has access to validated bacterial and fungal strains, and can also adapt models to client-specific isolates.

Bacterial Septicemia

• Escherichia coli
• Klebsiella pneumoniae
• Pseudomonas aeruginosa
• Staphylococcus aureus (including MRSA)
• Enterococcus faecium (VRE)
• Acinetobacter baumannii
• And further strains available (please ask for specific pathogens including BSL3)
   

These models are especially valuable for evaluating new antibiotics and tackling the global issue of antimicrobial resistance.

Fungal Pulmonary Infections

• Candida albicans
• Candida auris
• Candida tropicalis
• And further strains available (please ask for specific pathogens)

These models are particularly useful for evaluating novel antimicrobials, antifungals, and adjunctive immunotherapies in the context of bloodstream infection.

Readouts in Septicemia Models

To ensure robust and translational outcomes, Vibiosphen applies a wide range of validated readouts:

• Microbiological burden: CFU quantification in blood, spleen, liver, and other organs
• Survival and clinical scoring: Comprehensive monitoring of mouse welfare and clinical signs (Body weight, temperature, mobility, and signs of septic shock)
• Blood biomarkers: Cytokine profiling (IL-6, TNF-α, IL-10), organ dysfunction markers (ALT, AST, creatinine)
• Histopathology: Assessment of organ damage (liver, spleen, kidney, lung) and immune cell infiltration
• Immunomodulation endpoints: Evaluation of host immune responses and inflammation control
   

Applications of Vibiosphen’s Septicemia Models

Our septicemia models are applied in a broad range of preclinical studies:

• Efficacy testing of novel antibiotics, antifungals, and immunomodulatory drugs
• Pharmacodynamics (PD) studies to establish optimal dosing
• Host–pathogen interaction and immune response analysis
• Comparative studies against standard-of-care therapies
   

Why Choose Vibiosphen?

• Proven expertise in infectious disease research
• Flexible and customized study designs adapted to sponsor requirements (see downloads available as example) 
• Advanced facilities to ensure reliable and reproducible results (BSL2 and BSL3) 
• Strong collaborations with pharmaceutical companies, biotech firms, and academic partners

Vibiosphen combines scientific excellence with industry know-how to deliver actionable preclinical data that drive innovation in infectious disease therapeutics.

Contact Us

If you are developing new treatments or vaccines against pulmonary infections, Vibiosphen can help accelerate your research.

Contact us today to discuss your project and explore how our pulmonary infection models can support your development strategy. 

We will be pleased to facilitate your project by providing a customized study design to your project objectives.