Cefazolin effectiveness when Staphylococcus aureus is present in large amounts
Clinical Impact of the Cefazolin Inoculum Effect
This project looks at whether cefazolin, an antibiotic often used for serious Staphylococcus aureus infections, works less well when very large numbers of bacteria are present.
Quick facts
| Grant type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | Methodist Hospital Research Institute NIH-funded |
| Lab location | 1 site (Houston, United States) |
| Project ID | NIH-11086794 on NIH RePORTER |
What this research studies
If you have a serious MSSA infection, such as a bloodstream or bone infection, researchers will collect information about your infection and the bacteria causing it. They will test bacterial samples in the lab to see if cefazolin's ability to stop growth drops when very high amounts of bacteria are present (the cefazolin inoculum effect). The lab results will be linked to patients' treatments and outcomes to see whether this effect predicts treatment failure with cefazolin compared with other antibiotics like nafcillin. The combined lab-and-clinical approach is intended to guide safer antibiotic choices for deep-seated MSSA infections.
Who could benefit from this research
Good fit: Ideal participants are people with methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream or deep bone infections who are being treated with cefazolin or a comparator antibiotic.
Not a fit: People without MSSA infections, those with methicillin-resistant S. aureus (MRSA), or anyone not treated with beta-lactam antibiotics are unlikely to benefit directly from this project.
Why it matters
Potential benefit: If successful, this work could help doctors pick antibiotics that lower the chance of treatment failure and reduce harmful side effects for people with deep Staphylococcus aureus infections.
How similar studies have performed: Prior clinical and laboratory work suggests cefazolin performs similarly to nafcillin for many MSSA infections, but the inoculum effect has been linked to failures in deep infections and needs clearer confirmation in patient outcomes.
Where this research is happening
Houston, United States
- Methodist Hospital Research Institute — Houston, United States (Active)
Researchers
- Principal investigator: Arias, Cesar Augusto — Methodist Hospital Research Institute
- Study coordinator: Arias, Cesar Augusto
About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page below.