Neisseria gonorrhoeae (pathogenic gonorrhea)

2021-08-20 11:50 PM

Gonorrhea has poor resistance and dies quickly when it leaves the body. In the specimen, the bacteria die at room temperature for 1 to 2 hours

Pathogenic bacteria include Staphylococci, Streptococcus, Pneumococcus, and Neisseria. These are spherical bacteria and are collectively known as pyogenic cocci. Except for Neisseria, all pyogenic cocci are Gram-positive.

Biological characteristics

Shape

Like meningococcal, gonococci are coffee bean-shaped Gram-negative cocci, measuring 0.8 x m0.6 mm, often arranged in pairs. In acute gonorrhea, gonococci are often numerous and located in polymorphonuclear leukocytes. In chronic gonorrhea, gonococcal cysts are less often extracellular.

Viral Culture properties

Culture is difficult because when outside the body the bacteria are easy to die, need to be cultured immediately. Gonorrhea only grows in nutrient-rich media such as chocolate agar, Thayer-Martin agar. Bacteria grow well under aerobic conditions at pH 7.2-7.6, temperature 35-360C and atmosphere with 5-10% CO2. Colonies after 48 hours are small, round, flattened, light gray in color.

Biochemical properties

Oxidase positive, catalase-positive, glucose positive non-vapor, maltose negative, saccharose negative.

Resistance abilities

Gonorrhea has poor resistance and dries quickly when it leaves the body. In specimens, bacteria die at room temperature for 1-2 hours, at 580C for 1 hour. A 1% silver nitrate solution kills gonorrhea within 2 minutes.

Antigen structure

Gonorrhea has many group and type-specific antigens. In practice, those antigens are of no help in identifying the bacteria.

Possibility to cause disease

Gonorrhea is found only in humans, not in nature. People are infected by direct transmission through the genital tract, through the skin, mucous membranes, cornea. It causes urethritis (gonorrhea) in both men and women. It also causes infections in different parts of the genital tract: in men, it causes prostatitis, epididymitis, and in women, cervicitis, metritis, and salpingitis. In addition, gonorrhea can cause infections in other organs such as sepsis leading to infections in joints, endocarditis, conjunctivitis.

In newborns, gonococcal conjunctivitis can occur when passing through the genital tract of an infected mother, which if not treated promptly can cause blindness.

Microbiological diagnosis

Direct diagnosis

In men, collect urethral pus early in the morning before urinating for the first time of the day.

In women, collect pus from the urethral orifice, the cervix, and the openings of the vaginal glands.

Gram staining

Diagnosis of acute gonorrhea: Gram-stained microscopy, if there are many neutrophils and many intracellular Gram-negative leukocytes, it is possible to identify the patient with gonorrhea.

Diagnosis of chronic gonorrhea: on Gram-stained specimens, gonococcal and gonococcal infections are rarely seen outside of polymorphonuclear leukocytes.

Diagnosis by PCR technique

Viral Culture

In both acute and chronic cases, it is necessary to inoculate the specimen in a suitable medium, isolate and identify the bacteria based on their culturing and biochemical properties.

Serological diagnosis

Detection of antibodies to gonorrhea by fluorescently bound monoclonal antibodies.

IgM detection by ELISA for the diagnosis of extra-genital gonorrhea.

Prevention and treatment

Prevention

Gonorrhea does not confer protective immunity after recovery. Mainly disease detection and thorough treatment, improving the social situation. For newborns to prevent gonococcal conjunctivitis, one drop of 1% silver nitrate after birth.

Treatment

Currently, there have appeared strains of gonorrhea resistant to penicillin G, so it is necessary to do an antibiogram to select an appropriate antibiotic for the treatment of the disease. However, in practice, penicillin G is still a commonly used antibiotic and, in many cases, gives good results. In addition, antibiotics such as ampicillin, oxacillin, spectinomycin, cefoxitin, rifamycin are also used to treat gonorrhea. It is necessary to treat thoroughly to avoid turning to chronic gonorrhea. For chronic gonorrhea, the diagnosis is difficult, and the treatment is complicated and expensive.