Neisseriaceae and Moraxella catarrhalis Flashcards
(70 cards)
For detection of Neisseria gonorrhoeae:
Pus/secretions from:
- Genital sites (male urethra, female cervix, or vagina in prepubertal girls)
- Extragenital sites (conjunctiva, throat, rectum)
- Blood, synovial fluid, or joint fluid in systemic illness
For detection of Neisseria meningitidis:
- Blood
- CSF
- Puncture material from petechiae
- Nasopharyngeal swab for carrier surveys
Direct inoculation of blood culture bottles is preferred over SPS Vacutainer tubes owing to the recognized [?] of SPS on gonococci or meningococci.
If blood is first collected in Vacutainer
tubes containing SPS, the specimen must be transferred to the broth culture system within 1 hour of collection.
inhibitory effects
Should be inoculated into aerobic blood culture bottles.
Joint /synovial fluids
Any specimens or cultures in which N. meningitidis is a consideration should be handled in a [?] to prevent laboratory-acquired infections.
biologic safety cabinet
of the specimen reveals gram-negative kidney or coffee-bean-shaped diplococci found intracellularly within polymorphonuclear leukocytes (PMNs) or extracellularly.
Direct gram-stained smear
Diagnostic of gonococcal infection with sensitivity of about 90% and a specificity of 99%.
In urethral specimen from males
Only presumptive evidence of gonococcal infection, because the normal vaginal and rectal flora are composed of gram-negative coccobacilli, which can resemble Neisseria spp. Diagnosis must be confirmed by culture and additional testing.
In endocervical specimen in females or in rectal specimen
Can also be diagnostic
In conjunctival exudates
NOT diagnostic of gonococcal infection, because nonpathogenic, commensal Neisseria spp. may be present. Diagnosis must be confirmed by culture and additional testing.
In pharyngeal specimens
Direct gram-stained smear of [?] or other specimen reveals gram-negative kidney or coffeebean-shaped diplococci found intracellularly within polymorphonuclear leukocytes (PMNs) or extracellularly.
blood, CSF
Heavily encapsulated strains may have a [?] around the cells.
distinct pink halo
A [?] is a critical result that must be reported to the requesting physician immediately.
positive blood or CSF gram stain
Is preferred over BAM for isolation because heating the blood to 80 oC inactivates fatty acids and trace metals in blood which are inhibitory to the pathogenic Neisseria.
Chocolate agar medium
Contain antimicrobial agents that inhibit other microorganisms and allow the selective recovery of pathogenic N. gonorrhoeae and N. meningitidis
Selective Media
very rarely causes disease but is important because it grows in the selective media used for cultures of gonococci and meningococci from clinical specimens.
N. lactamica
N .lactamica can be cultured from the [?] of 3–40% of persons and most often is found in children.
nasopharynx
Enriched chocolate agar-based media that are prepared with nitrogenous GC agar base, hemoglobin , and enrichment
Thayer-Martin (TM), Modified Thayer Martin (MTM), Martin-Lewis (ML), and GC-Lect
chemically defined supplement that
provide vitamins, amino acids cystine and cysteine), coenzymes, dextrose, ferric ions and other factors
IsoVitaleX
A clear peptone-corn starch agar-based medium containing yeast dialysate, citrated horse plasma, and lysed horse erythrocytes.
New York City (NYC) medium
Consists of selective medium (MTM, ML, or GC-Lect) in a self-contained CO2 environment
Culture Media Transport System
Intended for transport and primary isolation of pathogenic Neisseria
Culture Media Transport System
Agar slant in a bottle has a formulation similar to MTM but has a higher dextrose to promote growth of Neisseria and a high agar to provide a more rigid medium suitable for mailing.
Transgrow Medium
Adequate CO2 is incorporated within the media bottle.
Transgrow Medium
