User:Awil236/Neisseria cinerea
| Neisseria cinerea | |
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| Genus: | Neisseria
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| Species: | N. cinerea
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Neisseria cinerea is a commensal species grouped with the Gram-negative, oxidase-positive, and catalase-positive diplococci.[1] It was first classified as Micrococcus cinereus by von Lingelsheim in 1906.[2] Using DNA hybridization, N. cinerea exhibits 50% similarity to Neisseria gonorrhoeae and this is distinct from it.[3]
Classification
[edit]N. cinerea has been formerly classified as many other organisms, including Moraxella catarrhalis and Neisseria pseudocatarrhalis.[4] It is often mistaken for N. gonorrhoeae as they are morphologically and biochemically very similar.[5] They are isolated from similar infections, including endocervical and rectal infections, neonatal conjunctivitis, and lymphadenitis.[6] N. cinerea has even been isolated on gonococcal selective media specifically made to isolate N. gonorrhoeae.[7]
Colony Morphology
[edit]One important difference between N. cinerea and N. gonorrhoeae is that N. cinerea is slightly more pigmented and exhibits a golden-brown rather than a pinkish-brown pigmentation.[8] The average diameter of N. cinerea colonies varies but stays around 1-2 mm.[9] The colonies are convex, translucent, and glistening.[10] There is no change in the color of the media used to isolate N. cinerea before or after staining with Lugol's iodine.[11]
Biochemical Processes
[edit]N. cinerea can produce acid from glucose like N. gonorrhoeae but it will then oxidize the acid to carbon dioxide.[12] Although it can break down glucose, it is unable to use glucose or other carbohydrates for energy, making it asaccharolytic.[13] In addition, N. cinerea will react in coagglutination serologic tests and, like N. gonorrhoeae, it produces the enzyme hydroxyprolylaminopeptidase.[14] N. cinerea does not reduce nitrate, but it does reduce nitrite.[15] Proline, arginine, cystine, and cysteine are required for its growth.[16] N. cinerea does not react with antigonococcal protein I monoclonal antibodies and does not produce immunoglobulin A protease, unlike N. gonorrhoeae.[17] Also unlike N. gonorrhoeae, N. cinerea is not resistant to the antibiotic colistin and it can grow on Mueller-Hinton agar and trypticase soy agar.[18]
Disease
[edit]Neisseria cinerea is classified as a non-pathogenic bacterium, but has been isolated from numerous infections including acute meningitis.[19] Many studies indicate that N. cinerea colonizes the oropharynx and sometimes the genital tract.[20] A few infections which could possibly be caused by N. cinerea have been reported.[21] However, in each case the organism was misidentified as N. flavescens, N. gonorrhoeae, or M. catarrhalis.[22]
See Also
[edit]- Branhamella catarrhalis
- Neisseria
- Sexually Transmitted Disease
- Oxidase Test
Notes
[edit]References
[edit]- Centers for Disease Control and Prevention (2008). "Neisseria cinerea"
- Knapp, J. S. et al. (1984). "Characterization of Neisseria cinerea, a nonpathogenic species isolated on Martin-Lewis medium selective for pathogenic Neisseria spp."
- Boyce, J. M., et al. "Nosocomial pneumonia caused by a glucose-metabolizing strain of Neisseria cinerea." Journal of clinical microbiology 21.1 (1985): 1-3.
- Knapp, J. S., and E. W. Hook. "Prevalence and persistence of Neisseria cinerea and other Neisseria spp. in adults." Journal of clinical microbiology 26.5 (1988): 896-900.