Advantages

- A selective medium that can specifically culture only carbapenem-non-susceptible VGS.
- Carbapenem susceptibility can be confirmed when using antibiotics for VGS.
- If nosocomial infection of carbapenem-non-susceptible VGS is suspected, the source can be determined by culturing the collected sample.

Background and Technology

Viridans group streptococci (VGS) are Gram-positive bacteria that can reside in the oral cavity and can be the causative bacteria of infective endocarditis. Among the beta-lactam antibiotics used to treat VGS infections, bacteria resistant to penicillins and cephalosporins have been confirmed, and in such cases, carbapenems are used as a trump card.
We identified for the first time 25 VGS strains that are non-susceptible to carbapenems in the clinic. It was confirmed that these carbapenem-non-susceptible VGS also show reduced susceptibility to many other β-lactam antibiotics. At present, there are few reports of clinical detection of carbapenem- non-susceptible VGS, but there is concern that this will spread and become a problem in the future. Therefore, when using antibiotics for VGS, it is important to confirm carbapenem susceptibility.
We analyzed the susceptibility of the identified carbapenem-non-susceptible VGS strains to various antibacterial drugs using the disk diffusion method and developed a detection method using the disk diffusion method and a selective medium.

Reference and Patent

- Sarangi et al., Antimicrobial Agents and Chemotherapy (2024) 68(4):e0117923.
- Patent pending (unpublished yet)

Principal Investigator

Kouji KIMURA (Nagoya University Graduate School of Medicine)

Current Stage and Next Step

- To date, we have developed a detection method and selection medium composition for carbapenem-non-susceptible VGS.
- The specific detection methods and the selection media details can be disclosed under CDA.
- We are looking for partner companies for collaboration regarding the commercialization of the selective media and the incorporation into automatic antimicrobial susceptibility testing systems.
Project.BK-04591