This note revives the bacterial name Pseudomonas maltophilia, originally described by Hugh and Ryschenkow in 1961, which had lost standing in bacterial nomenclature because it was not included on the Approved Lists of Bacterial Names that took effect January 1, 1980. The author argues that P. maltophilia should be reinstated because it represents a distinct, well-characterized bacterial species that is clinically important as the second most frequently isolated Pseudomonas species in human specimens. The organism causes infections in immunocompromised hosts and is commonly found in soil and water. The species can be distinguished from other Pseudomonas species by uniform morphological and biochemical characteristics: it is a gram-negative, motile rod with polar flagella that produces catalase and extracellular deoxyribonuclease, and oxidatively ferments glucose and maltose. The type strain is ATCC 13637. The author formally revives the name P. maltophilia in accordance with bacterial nomenclature rules 24a and 28a, noting there is clinical need for this established name in healthcare delivery.

Key findings

• Pseudomonas maltophilia is revived as a valid species name after losing standing when not included on the 1980 Approved Lists of Bacterial Names
• P. maltophilia is the second most frequently isolated Pseudomonas species in clinical specimens and causes infections in compromised hosts
• The species is reliably distinguished from other Pseudomonas species by gram-negative morphology, polar flagella, catalase and deoxyribonuclease production, and oxidative fermentation of glucose and maltose
• Type strain ATCC 13637 represents the species, with confirmed strain identifications preventing taxonomic confusion