Gonorrhea laboratory tests: Difference between revisions
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{{CMG}}; {{AE}} {{SaraM}} | {{CMG}}; {{AE}} {{SaraM}} | ||
==Overview | ==Overview== | ||
==Laboratory tests== | ==Laboratory tests== | ||
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===Gram stain=== | ===Gram stain=== | ||
*Gram stain is highly sensitive and specific in men with symptomatic [[urethritis]]. However, because of lower sensitivity, detection of infection using Gram stain of endocervical, pharyngeal, and rectal specimens also is insufficient and is not recommended. | *Gram stain is highly sensitive and specific in men with symptomatic [[urethritis]]. However, because of lower sensitivity, detection of infection using Gram stain of endocervical, pharyngeal, and rectal specimens also is insufficient and is not recommended. | ||
*In symptomatic men, [[Polymorphonuclear leukocytes|polymorphonuclear leukocytes (PMNs)]] with intracellular [[Gram-negative diplococci]] can be considered diagnostic for infection with ''[[Neisseria gonorrhea]]''. | |||
*Common anatomic sites for taking samples include: | *Common anatomic sites for taking samples include: | ||
**[[Cervical]] | **[[Cervical]] Gram stain in women | ||
**[[Urethral|urethral discharge]] Gram stain in men | **[[Urethral|urethral discharge]] Gram stain in men | ||
** | **[[Synovial fluid]] Gram stain | ||
===Cultures=== | ===Cultures=== | ||
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Cultures provide absolute proof of [[infection]]. Generally, samples for a culture are taken from the [[cervix]], [[vagina]], [[urethra]], [[anus]], or [[throat]]. Cultures can provide a preliminary [[diagnosis]] often within 24 hours and a confirmed [[diagnosis]] within 72 hours. | Cultures provide absolute proof of [[infection]]. Generally, samples for a culture are taken from the [[cervix]], [[vagina]], [[urethra]], [[anus]], or [[throat]]. Cultures can provide a preliminary [[diagnosis]] often within 24 hours and a confirmed [[diagnosis]] within 72 hours. | ||
Common anatomic sites for taking samples include: | Common anatomic sites for taking samples include: | ||
*Endocervical culture in women | *[[Endocervical]] culture in women | ||
*[[Urethral]] discharge culture in men | *[[Urethral]] discharge culture in men | ||
** | ** | ||
Revision as of 20:45, 25 September 2016
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Gonorrhea Microchapters |
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Gonorrhea laboratory tests On the Web |
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American Roentgen Ray Society Images of Gonorrhea laboratory tests |
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Risk calculators and risk factors for Gonorrhea laboratory tests |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [2]
Overview
Laboratory tests
Several laboratory tests are available to diagnose gonorrhea. A doctor or nurse can obtain a sample for testing from the parts of the body likely to be infected (cervix, urethra, rectum, or throat) and send the sample to a laboratory for analysis. Gonorrhea that is present in the cervix or urethra can be diagnosed in a laboratory by testing a urine sample.
Gram stain
- Gram stain is highly sensitive and specific in men with symptomatic urethritis. However, because of lower sensitivity, detection of infection using Gram stain of endocervical, pharyngeal, and rectal specimens also is insufficient and is not recommended.
- In symptomatic men, polymorphonuclear leukocytes (PMNs) with intracellular Gram-negative diplococci can be considered diagnostic for infection with Neisseria gonorrhea.
- Common anatomic sites for taking samples include:
- Cervical Gram stain in women
- urethral discharge Gram stain in men
- Synovial fluid Gram stain
Cultures
Culture is the historical standard for detection of N. gonorrhoeae. Culture test dvantages over non-culture tests include:
- Low cost
- Suitable for a variety of specimen sites
- Antimicrobial susceptibility testing can be performed
Thayer-Martin medium is one example of a medium used for N. gonorrhoeae culture. Direct inoculation of culture plates with swab specimens is best. The inoculated culture plate should be promptly placed into a CO2-enriched (3%- 10%) environment and incubated at 35º-37º C. Cultures provide absolute proof of infection. Generally, samples for a culture are taken from the cervix, vagina, urethra, anus, or throat. Cultures can provide a preliminary diagnosis often within 24 hours and a confirmed diagnosis within 72 hours. Common anatomic sites for taking samples include:
- Endocervical culture in women
- Urethral discharge culture in men
- Throat swab culture in both men and women
- Rectal culture in both men and women
- Culture of joint fluid
- Blood cultures
DNA tests are especially useful as a screening test. They included the ligase chain reaction (LCR) test. DNA tests are quicker than cultures. Such tests can be performed on urine samples, which are a lot easier to collect than samples from the genital area.
Gallery
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![Image depicts the morphologic appearance of Neisseria gonorrhoeae colonies after having grown for a period of 24 hours on GC media base agar supplemented with IsoVitaleX (50X mag). GC media base agar is used in the isolation of N. gonorrhoeae bacteria, and is often used in conjunction with various antibiotics, in order to determine N. gonorrhoeae antimicrobial sensitivity/selectivity. From Public Health Image Library (PHIL). [1]](/images/0/03/Gonorrhea08.jpeg)
Image depicts the morphologic appearance of Neisseria gonorrhoeae colonies after having grown for a period of 24 hours on GC media base agar supplemented with IsoVitaleX (50X mag). GC media base agar is used in the isolation of N. gonorrhoeae bacteria, and is often used in conjunction with various antibiotics, in order to determine N. gonorrhoeae antimicrobial sensitivity/selectivity. From Public Health Image Library (PHIL). [1]
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![Photomicrograph of Neisseria gonorrhoeae in cervical smear using the Gram-stain technique. From Public Health Image Library (PHIL). [1]](/images/0/0c/Gonorrhea14.jpeg)
Photomicrograph of Neisseria gonorrhoeae in cervical smear using the Gram-stain technique. From Public Health Image Library (PHIL). [1]
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![Urethral discharge for Neisseria gonorrhea revealed Gram-negative intracellular rods, NOT diplococci. From Public Health Image Library (PHIL). [1]](/images/a/a2/Gonorrhea13.jpeg)
Urethral discharge for Neisseria gonorrhea revealed Gram-negative intracellular rods, NOT diplococci. From Public Health Image Library (PHIL). [1]
-
![Photomicrograph reveals presence of intracellular Gram-negative, Neisseria gonorrhoeae diplococcal bacteria. From Public Health Image Library (PHIL). [1]](/images/a/aa/Gonorrhea05.jpeg)
Photomicrograph reveals presence of intracellular Gram-negative, Neisseria gonorrhoeae diplococcal bacteria. From Public Health Image Library (PHIL). [1]
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![This Gram-stained photomicrograph revealed the presence of what was termed as “deceptive” extracellular diplococcal bacteria. From Public Health Image Library (PHIL). [1]](/images/f/f8/Gonorrhea04.jpeg)
This Gram-stained photomicrograph revealed the presence of what was termed as “deceptive” extracellular diplococcal bacteria. From Public Health Image Library (PHIL). [1]
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![Photomicrograph reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]](/images/9/91/Gonorrhea03.jpeg)
Photomicrograph reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]
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![Photomicrograph (1000X mag) reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]](/images/8/8d/Gonorrhea01.jpeg)
Photomicrograph (1000X mag) reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]
![Image depicts the morphologic appearance of Neisseria gonorrhoeae colonies after having grown for a period of 24 hours on GC media base agar supplemented with IsoVitaleX (50X mag). GC media base agar is used in the isolation of N. gonorrhoeae bacteria, and is often used in conjunction with various antibiotics, in order to determine N. gonorrhoeae antimicrobial sensitivity/selectivity. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea08.jpeg)
![Photomicrograph of Neisseria gonorrhoeae in cervical smear using the Gram-stain technique. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea14.jpeg)
![Urethral discharge for Neisseria gonorrhea revealed Gram-negative intracellular rods, NOT diplococci. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea13.jpeg)
![Photomicrograph reveals presence of intracellular Gram-negative, Neisseria gonorrhoeae diplococcal bacteria. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea05.jpeg)
![This Gram-stained photomicrograph revealed the presence of what was termed as “deceptive” extracellular diplococcal bacteria. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea04.jpeg)
![Photomicrograph reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea03.jpeg)
![Photomicrograph (1000X mag) reveals Gram-negative rods, and Gram-negative cocci, which were determined to be Haemophilus influenzae, and non-meningococcal Neisseria sp. organisms respectively. From Public Health Image Library (PHIL). [1]](/index.php/File:Gonorrhea01.jpeg)