| Reported in | Status | Registered by | ||
|---|---|---|---|---|
| Aadella | ||||
| Aadella gelida Ts | ||||
| Aalborgicola | ||||
| Aalborgicola bjergmarkensis | ||||
| Aalborgicola danicus | ||||
| Aalborgicola defluviihabitans Ts | ||||
| Aalborgicola lynettensis | ||||
| Aalborgiella | ||||
| Aalborgiella aggregata Ts | ||||
| Abditibacteriaceae | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abditibacteriales | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abditibacteriia | ||||
| Abditibacteriota | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abditibacterium | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abditibacterium utsteinense T | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abiotrophia | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abiotrophia adiacens | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Abiotrophia balaenopterae | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Abiotrophia defectiva T | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abiotrophia elegans | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Absicoccus | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Absicoccus intestinalis | ||||
| Absicoccus porci T | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Absiella | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Absiella argi T | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abyssalbus | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Abyssalbus ytuae T | Unknown | Valid (ICNP) | Excubia bot about 3 years ago | |
| Abyssibacter | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abyssibacter profundi T | Unknown | Valid (ICNP) | Excubia bot over 4 years ago | |
| Abyssibius | Unknown | Valid (ICNP) | Excubia bot about 3 years ago |