Neisseria flavescens

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Neisseria flavescens
A gram stain of Neisseria flavescens provided by CDC/Dr. W. A. Clark
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Pseudomonadota
Class: Betaproteobacteria
Order: Neisseriales
Family: Neisseriaceae
Genus: Neisseria
Species:
N. flavescens
Binomial name
Neisseria flavescens
Branham 1930[1]

Neisseria flavescens was first isolated from cerebrospinal fluid in the midst of an epidemic meningitis outbreak in Chicago.

commensals.[3] However, this species can also play a pathogenic role in immunocompromised and diabetic individuals.[4] In rare cases, it has been linked to meningitis, pneumonia, empyema, endocarditis, and sepsis
.

Morphology

These bacteria are

gram-negative and diplococcus, rendering them virtually indistinguishable from the other Neisseria species.[2] Yet, Neisseria flavescens remains distinct due to its signature pigmented colonies, yellow-gold in color.[5] And it is through this yellow-gold color that this bacteria earned its name, with flavescens precisely translating as "becoming a golden yellow."[2] This pigmentation also indicates N. flavescens' similarity to saccharolytic Neisseria species, which also exhibit pigmentation.[6] In addition, these pigmented species differ from meningococcus, which lack pigmentation.[2]

Biochemical processes

Similar to saccharolytic species, N. flavescens strains are capable of producing polysaccharides from sucrose and are colistin-susceptible.

diplococci, with N. flavescens being DNase negative, weakly positive to Superoxol, and capable of prolyl aminopeptidase production in an enzyme-substrate test.[5]

Molecular biology

Though it shares many similarities with the saccharolytic species, Neisseria flavescens has a greater genetic relation to pathogenic Neisseria species,

β-lactam portion of penicillin
.

Disease

Typically serving as a commensal, Neisseria flavescens has also played a pathogenic role, ever since its origin. Arising from an epidemic meningitis outbreak in Chicago, N. flavescens was isolated from the cerebrospinal fluid of infected individuals. In particular, out of forty-seven total cases of meningitis, fourteen individuals were found to carry N. flavescens, in contrast to carrying one of the typical four meningococci.[2] Additionally, the mortality rate among these fourteen individuals was close to thirty percent, indicating that this bacterium's role as a possible causative agent for meningitis should not be overlooked.[2] Since then, four other cases of meningitis have also found Neisseria flavescens to be the causative agent.[9]

Along with

diplococci were present in the smear, narrowing the organism down to a Neisseria species. Ultimately, blood cultures revealed N. flavescens to be the culprit, due to observation of yellow-gold colony formation and no sugar fermentation.[9]

In addition to blood and CSF, Neisseria flavescens can also act as a pathogen in the lower respiratory tract.[4] Isolation via a transthoracic pulmonary fine-needle aspiration identified N. flavescens as the cause of pneumonia and empyema in a diabetic patient.[4] More specifically, the aspirate was sent off to the respiration department, where it underwent acid fast and gram staining, inoculation, and biochemical testing to identify N. flavescens.[4] Next, 16S rRNA sequencing was done, further confirming that Neisseria flavescens was indeed the causative agent.[4]

Lastly, this bacteria has also been the pathogen behind a case of endocarditis. Testing β-lactamase positive, Neisseria flavescens rendered penicillin an ineffective treatment for the patient and, instead, was targeted by cefotaxime.[10]

See also

References

  1. ^ LPSN lpsn.dsmz.de
  2. ^
    JSTOR 4579618
    .
  3. ^ a b "What does Neisseria flavescens mean? Definition, meaning and sense (The Titi Tudorancea Encyclopedia)". www.tititudorancea.com. Retrieved 2015-11-17.
  4. ^
    PMID 24822118
    .
  5. ^ a b "Neisseria flavescens - Gonorrhea - STD Information from CDC". www.cdc.gov. Retrieved 2015-11-17.
  6. ^
    PMID 3069201
    .
  7. doi:10.1099/00207713-32-1-57
    .
  8. PMID 2510173
    .
  9. ^
    PMID 4972296
    .
  10. PMID 3799678
    . Retrieved 2015-11-28.

External links
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