Haemophilus influenzae
Haemophilus influenzae (formerly called Pfeiffer's bacillus or Bacillus influenzae) is a Gram-negative, coccobacillary, facultatively anaerobic capnophilic pathogenic bacterium of the family Pasteurellaceae. H. influenzae was first described in 1892 by Richard Pfeiffer during an influenza pandemic.[1] He incorrectly described Haemophilus influenzae as the causative microbe, which retains "influenza" in its name.[2][3]
| Haemophilus influenzae | |
|---|---|
 | |
| H. influenzae on a chocolate agar plate | |
Scientific classification  | |
| Domain: | Bacteria |
| Phylum: | Pseudomonadota |
| Class: | Gammaproteobacteria |
| Order: | Pasteurellales |
| Family: | Pasteurellaceae |
| Genus: | Haemophilus |
| Species: | H. influenzae |
| Binomial name | |
| Haemophilus influenzae (Lehmann & Neumann 1896) Winslow et al. 1917 | |
| Haemophilus influenzae infection | |
|---|---|
 | |
| Haemophilus influenzae satellite colonies (pin points) near Staphylococcus aureus (yellow) on blood agar plate | |
| Specialty | Infectious disease |
The bacterium was argued by some to be the cause of influenza[4] as bacterial influenza. H. influenzae is responsible for a wide range of localized and invasive infections, but influenza is caused by viruses.
This species was the first free-living organism to have its entire genome sequenced.[5]