Gonorrhea, Diagnosis of Neisseria Gonorrhoeae

Neisseria Gonorrhoeae

Sample

1. The best sample for men is the urethral discharge smear.
2. Females can make a smear from the vagina.
3. In females, a cervical smear can also be taken.
4. An anal canal smear can be taken.
5. Smears are made from prostatic secretions, urethra, cervix, and pelvic inflammatory disease.

Indications

1. A urethral smear is stained to diagnose gonorrhea.
2. A cervical smear is stained to diagnose gonorrhea.
3. It is advised to diagnose sexually transmitted diseases.

Introduction of Neisseria gonorrhoeae

1. Neisseria gonorrhoeae causes contagious disease and is usually sexually transmitted.
2. Mother can transmit the disease to the newborn.

Bacteriology of Neisseria Gonorrhoeae

1. N.Gonorrhoeae can infect any epithelium lined by columnar cells with cilia-like:
   1. Urethra.
   2. Cervix.
   3. Rectum.
   4. Pharynx.
   5. conjunctiva.
      1. But cannot vagina which is the squamous epithelium.
2. There are two pathogenic Neisseria:
   1. N. Gonorrhoeae (Gonococcus).
   2. N. Meningitides (Meningococcus).
      1. These are obligate parasites of the human urogenital area.
      2. These are characteristically seen in pairs with adjacent side concave.
      3. In the purulent material, these are seen intracellularly and as well outside the cells.
   3. The incubation period is 2 to 10 days.
      

      Neisseria Gonorrhoeae stained smear

3. These bacteria grow in enriched media (Chocolate agar).
   1. Incubation is done in a moist atmosphere containing 5 to 10% CO2.
   2. The optimal temperature is 35 to 37 C.
   3. These media may contain antibiotics (Lincomycin) to inhibit the growth of other bacteria.
   4. There are small gray glistening colonies after 24 hours of incubation and may become larger after 48 hours.
   5. The identification test is carbohydrate utilization where it will produce acid only from the glucose.
4. N.Gonorrhoeae is gram-negative bacteria that can grow in the body like the urethra, cervix, uterus, fallopian tubes in females, and urethra in males.
5. It grows in the warm, moist area of the female reproductive system.
6. It can also grow in the mouth, throat, and anus.

Signs and symptoms of Neisseria Gonorrhoeae (Gonorrhea):

1. This is more symptomatic in men than in women.
2. In the male:
   1. There is urethral purulent discharge.
   2. There is dysuria.
   3. There may be proctitis and tenesmus.
   4. There is pelvic pain.
3. In the female:
   1. Females are usually asymptomatic.
   2. Gonorrhea in females is symptomatic in about 75% to 80% and 19% to 15% in males.
   3. There is mucopurulent cervicitis.
   4. There is vaginal discharge.
   5. There may be dysuria.
   6. There may be proctitis.
   7. N. gonorrhea causes gonorrheal urethritis and initiates the majority of the case of acute salpingitis, a so-called pelvic inflammatory disease.
4. Transmission from male to female is very efficient than from female to male.
5. While pharyngeal infections are asymptomatic.
6. Ascending pelvic infection occurs in 10 to 20% of the cases and it leads to infertility and ectopic pregnancy.
7. This may involve the rectum and oropharynx.
8. Oropharyngeal infection is present in 10% of females and 20% of homosexual men.
   1. Pharyngeal gonorrhea is usually asymptomatic, self-limited in 10 to 12 weeks, and visible in <50% of the cases.
   2. For the diagnosis, culture is needed and the smear is not diagnostic because of the nonpathogenic Neisseria species.
9. Gonococcal arthritis is diagnosed by the presence of gonococci in 1/3 of the cases.
   1. A variable number of WBCs are found or synovial fluid may be purulent.

Gonorrhea disease In females:

1. Urethritis
2. Conjunctivitis
3. Vulvitis.
4. Vaginal discharge.
5. Swollen lymph nodes.
6. Bleeding after intercourse.

Gonorrhea disease in males:

1. Urethritis (burning micturition).
2. Swollen, painful testes.
3. Enlarged lymph nodes in the throat.

Complications of Gonorrhea:

1. In females ascending pelvic infection.
   1. There is salpingitis which leads to infertility.
   2. There may be gonococcal vulvovaginitis.
   3. There may be bartholinitis.
2. In male:
   1. Epididymis-orchitis.
   2. There may be cystitis.
   3. There may be prostatitis.
   4. There may be a urethral stricture.
3. In the untreated mother, newborn babies can have Ophthalmia neonatorum (gonococcal conjunctivitis).
4. There may be septicemia, arthritis, and meningitis due to the spread through the blood.

Diagnosis of Neisseria Gonorrhoeae

1. In males in the case of urethritis, there is urethral discharge. Make the smear from the urethral discharge.
   1. Now stain with gram stain which will show gram-negative diplococci and these are intracellular.
2. The urethral smear is diagnostic and very specific.
   1. In the male ask the patient to squeeze the penis to get a good amount of material.
   2. The patient can apply directly the material on the slide.
3. Females can make a cervical smear and do the culture.
4. Swab smears are taken from:
   1. Urethra.
   2. Endocervical canal.
   3. Anal canal.
   4. Pharynx.
5. Smears may be tested by a fluorescent antibody test.
6. When there is no discharge then insert the swab into the urethra up to 2 cms and gently rotate.
7. Can take endocervical specimen under direct vision using a speculum.
8. Other sites for the swab are the pharynx, anorectal area, blood, CSF, and synovial fluid.
9. Ultimately can confirm the diagnosis by culture and these bacteria need nutrient-rich selective agar media (Thayer-Martin).
   1. Culture needs 48 hours to form colonies.
10. It can take conjunctival swabs in infants who have conjunctivitis.
11. Blood and synovial fluid may be taken in case of arthritis.
12. Gram-stained smears:
    1. Smear is positive when you find intracellular gram-negative diplococci.
    2. Extracellular gram-negative diplococci are not confirmatory.
    3. Smears are only 50% positive in asymptomatic patients. These patients must have the culture of the sample.
    4. Smear becomes negative within the start of the antibiotics in a few hours.
    5. In females, gram stain smears of the endocervical site are 45% to 65% are positive.
    6. Smears from the vagina, oropharynx, and anal canal are not recommended.
    7. Urethral smears are >95% positive in symptomatic males.

13. DNA probe tests are highly sensitive and specific.
14. DNA amplification by PCR is good to test. It can be done on urine and swab specimen.

Treatment of Neisseria Gonorrhoeae

1. Sensitivity to antibiotics:

2. These bacteria are sensitive to penicillin, ampicillin, tetracycline, macrolides, cefuroxime, and ciprofloxacin.
3. Give a single oral dose of Amoxycillin or ampicillin.
4. In 2% of the cases, gonorrhea is resistant to pencillin.
5. Give probenecid to delay the excretion of medicine.
6. Or a single dose of Ceftriaxone 250 mg I/M.
   1. Or a single dose of Norfloxacin 800 mg.
7. Ciprofloxacin is given when an infection is complicated with Chlamydia infection.
8. Erythromycin is given to pregnant ladies and children.
9. The extragenital infection needs treatment for 5 to 7 days.
10. Penicillin-resistant gonorrhea is treated with cefuroxime, cefotaxime, erythromycin, ciprofloxacin, tetracycline, or aztreonam.

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