Colonies on Blood agar are small, circular, raised, smooth, glistening, yellowish.
Chromogenesis best seen on Loeffler's serum medium; greenish yellow.
Haemolysis is not produced. Optimum temperature, 37 ºC. Can grow at 22 ºC.
Phylum Proteobacteria, Class Betaproteobacteria, Order Neisseriales, Family Neisseriaceae, Genus Neisseria, Neisseria flava
Bergey et al. 1923.
According to Bergey’s Manual of Systematic Bacteriology, Second edition, 2005, Neisseria subﬂava contains the previous species N.
ﬂava, N. perﬂava, and N. subﬂava, resulting 3 biovars: N. subﬂava biovar ﬂava, N. subﬂava biovar perﬂava, N. subﬂava biovar
subﬂava. However, it seems that Bergey's consolidation of the species was not official and in the Approved Lists of Bacterial Names
(Amended) 1989, they are distinct species.
Gram-negative cocci, 0.5-1.0 μm in diameter, occurring singly and in pairs with
adjacent sides flattened. Nonmotile. Not capsulated. Endospores are not produced.
Isolated from the nasopharynx of humans and rarely in cerebrospinal ﬂuid. Susceptible to colistin.
Isolated from cerebrospinal ﬂuid in cases of meningitis.
- Tone Tonjum, 2005. Order IV. Neisseriales ord. nov. In: Bergey’s Manual of Systematic Bacteriology, Second edition, Vol two, part C
The Alpha-, Beta-, Delta-, and Epsilonproteobacteria, George M. Garrity (Editor-in-Chief), pp 774-863.
- Euzeby (J.P.): List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet. Int. J. Syst. Bacteriol., 1997,
47, 590-592. (List of Prokaryotic names with Standing in Nomenclature. http://www.bacterio.net).
- Magnus Unemo (Editor-in-Chief), 2013. Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency
virus, pp 44-45. World Health Organization, ISBN 978 92 4 150584 0.
- Daniel C. Stein, 2006. The Neisseria. In: The Prokaryotes Third Edition, Volume 5: Proteobacteria: Alpha and Beta Subclasses,
Martin Dworkin (Editor-in-Chief), pp 602–647.
- Skerman (V.B.D.), McGowan (V.) and Sneath (P.H.A.) (editors): Approved Lists of Bacterial Names. Int. J. Syst. Bacteriol., 1980, 30,
- Robert S. Breed, E. G. D. Murray, Nathan R. Smith, 1957. Family VIII. Neisseriaceae Prevot, 1933. In: Bergey’s Manual of
Determinative Bacteriology, 7th edition, 480-485.
Positive results for carbonic anhydrase, catalase, nitrite reduction (with production of
gas), oxidase, acid production from: fructose, glucose & maltose.
Negative results for beta-galactosidase (ONPG), DN-ase, gamma-glutamyl
transferase, iodine test (polysaccharide production), nitrate reduction, tributyrin
hydrolysis, acid production from: lactose, mannose & sucrose.
(c) Costin Stoica