Microbiology: lecture notes Ksenia Viktorovna Tkachenko

4. Gonococci

4. Gonococci

They belong to the genus Neisseria, species N. gonorrhoeae.

These are bean-shaped diplococci, in smears they are located intracellularly in the protoplasm of leukocytes, and have the appearance of coffee beans.

They do not form spores, are immobile, form a microcapsule, and are gram-negative. They are obligate aerobes.

Gonococci are extremely demanding of nutrient media; they grow only on media containing human proteins (serum agar, ascites agar, etc.). On serum agar they form small shiny colonies in the form of droplets.

Biochemically inactive, they break down only glucose (to acid).

Gonococcal antigens:

1) protein antigens of the outer membrane;

2) lipopolysaccharide cell wall antigens.

There is no generally accepted division into serogroups and serovars.

Virulence factors:

1) adhesins – fimbriae (pili);

2) endotoxin; suppresses phagocytosis, ensuring the intracellular location of gonococci;

3) aggression enzymes – hyaluronidase, neuraminidase.

Pathogenic only for humans. They cause only specific nosological forms of purulent-inflammatory diseases.

Gonococcal infection is an anthroponotic infection, the source of infection is a sick person, there is no carriage. The route of transmission is sexual, it is possible that a newborn can become infected when passing through the birth canal of a sick mother.

Clinical forms of gonococcal infection:

1) gonorrhea (urogenital, extragenital);

2) gonococcal septicopyemia;

3) specific conjunctivitis of newborns (occurs only when a mother with gonorrhea passes through the birth canal).

Based on the duration of gonorrhea and the severity of clinical signs, they are distinguished:

1) fresh gonorrhea (duration of no more than 2 months):

a) acute;

b) subacute;

c) torpid;

2) chronic gonorrhea (sluggish disease lasting more than 2 months or with an unknown duration).

According to the clinical course, they are distinguished:

1) uncomplicated gonorrhea (purulent inflammation of the lower parts of the urogenital tract);

2) complicated gonorrhea (the process extends to the upper parts of the genitourinary system).

The disease does not leave lasting immunity.

Diagnostics:

1) in acute form:

a) bacterioscopy of a smear of discharge from the urethra and cervix;

2) in the chronic form:

a) bacterioscopy;

b) bacteriological examination;

c) serodiagnosis - RSC;

d) immunoindication.

Feature of serodiagnosis: the diagnosis is made qualitatively (by detecting antibodies in the serum of the patient) based on the results of a single reaction (without paired sera). This is explained by the fact that post-infectious immunity is not formed in gonorrhea (there are no post-infectious antibodies).

Treatment: etiotropic antibiotic therapy.

Gonococci are bean-shaped, arranged in the form of diplococci, surrounded by a microcapsule, do not have flagella, and do not form spores, similar to meningocci. The cell wall has an outer membrane, the proteins of which are divided into three groups according to their functional significance. Gonococci are characterized by the presence of pili, which differ from each other in their antigenic properties (16 antigenic variants). Gonococci are cultivated on nutrient media containing native protein(blood serum, ascitic fluid). They grow better at 3-5% CO2. On ascitagara they form transparent colonies with smooth edges. Of carbohydrates, only glucose is fermented, catalase and cytochrome oxidase are formed - enzymes typical of Neisseria.

Antigens

The antigenic structure of gonococci is variable. This is due to the presence of numerous antigenic variants of pili, which are formed during the development of infection.

Pathogenicity and pathogenesis

Gonococci attach to the cylindrical epithelium of the urethra, the vaginal part of the cervix, rectum, conjunctiva of the eye, as well as sperm and protozoa (Trichomonas, amoeba). Adhesion occurs due to pili and proteins of the outer membrane of the cell wall. Characteristic feature gonococci is their ability to penetrate leukocytes and multiply in them. The lipooligosaccharide part of the cell wall has a toxic effect. Capsular polysaccharides inhibit phagocytosis. Connecting with the villi of the cylindrical epithelium of the urethral mucosa, and in women, the endocervical canal, gonococci penetrate into the cells with the participation of proteins of the outer membrane of the cell wall. This leads to the development of acute urethritis, cervicitis and damage to the cervix, appendages (tubes, ovaries) in women, seminal vesicles, and prostate gland in men. With extragenital localization, gonococci can damage the rectum and tonsils, and also cause blenorrhea (conjunctivitis) in newborns. Infection occurs during the passage of the birth canal of a mother with gonorrhea.

Immunity

With gonorrhea, a humoral immune response occurs. However, the resulting antibacterial antibodies do not have protective properties. During the course of the disease, IgA is formed, which suppresses the attachment of the pathogen's pili to the cells of the urethral mucosa. However, they are not able to protect the mucosa from subsequent infection by other generations of gonococci, which is associated with a change in their antigenic structure. This leads to reinfections and relapses, as well as the disease becoming chronic.

Gonococcal infections

The causative agent of gonorrhea and blenorrhea N.gonorrhoeae (preliminarily classified as gonococcus) belongs to the family Neisseriaceae, genus Neisseria. In smears from patient secretions, gonococci have the shape of coffee beans, are gram-negative, and are located in pairs both inside leukocytes (incomplete phagocytosis) and outside the cells. According to their own morphological characteristics they are very similar to meningococci. Gonococci are characterized by polymorphism - there are small and large cells, rarely rod-shaped. They are very picky about nutrient media. They grow better on media containing blood, serum, and ascitic fluid. Gonococci contain protein and polysaccharide antigens, according to which they are divided into 16 serovars, but they are not yet determined in routine bacteriological laboratories. For microbiological diagnostics Gonococcal infections use bacterioscopic, bacteriological, serological and allergic methods.

Taking material for research

In order to carry out bacteriological and bacterioscopic diagnostics with dignity and good quality, it is important to correctly take clinical material. As a rule, it should be carried out by a doctor. In men, the secretions of the urethra, paraurethral ducts, rectum are examined, and, if indicated, material from the oropharynx, as well as the secretion of the prostate gland after its massage. You can also examine sediment and “threads” of urine, but gonococci are detected much less frequently in them. Before taking material from the urethra, the patient should not urinate for 4-5 hours and not use antimicrobial drugs and disinfectant solutions. The external opening of the urethra is first wiped with a sterile cotton swab moistened with a 0.85% sodium chloride solution, then with a dry swab. Smears are made not from manure, which flows freely, but from material taken by scraping from the urethral mucosa with a bacteriological loop or a special Volkmann spoon. For minor discharge, it is necessary to perform a preliminary urethral massage. In women, material is taken from the urethra, paraurethral passages, cervix, rectum, and, if indicated, from the oropharynx. First, the vagina is cleaned of secretions, the urethra is massaged, and the material is removed by scraping with a bacteriological loop or a Volkmann spoon. The cervix is ​​first wiped with a sterile cotton swab to remove the mucus plug. Discharge from the cervical canal is taken with a bacteriological loop or tweezers. Material from the distal rectum is taken using a Volkmann spoon in a blind manner, i.e. without any preparation of the patient, or using a recoscope or rectal speculum. In this case, the material being studied is taken directly from the visible site of the lesion. With oropharyngeal gonorrhea, mucus They are taken from the oropharynx with sterile cotton swabs on special steel wire holders. To diagnose lenorrhea, the conjunctival secretion is removed with a bacteriological loop. Rarely, gonorrhea is complicated by gonosepsis, endocarditis, or arthritis. Then the material for juslidzhenya is blood or synovial fluid. Taking into account the high sensitivity of gonococci to temperature fluctuations, the materials under study are delivered to the laboratory in special thermoses or bags with a heating pad.

Bacterioscopic examination

Bacterioscopic examination is the most common, although less sensitive method laboratory diagnostics gonorrhea and blenorrhea compared with the selection of true cultures. This is especially true for the chronic course of the disease, when the test material contains a small amount of gonococci. However, with the correct collection of material, repeated examinations of patients, the use of provocation methods, and qualified assessment of smears, bacterioscopic examination quite often makes it possible to quickly and correctly diagnose the disease. Two thin, uniform smear preparations are made from the material being studied. One is stained with methylene blue, the second is stained using the Gram method. In the absence of methylene blue, one smear can be stained with a 1% aqueous solution of crystal violet or 0.5% solution of brilliant green for 1 minute. A conclusion about the presence of gonococci is made based on their properties: gram-negative color, diplococcal structure, shape of coffee beans, location inside leukocytes. Under the influence of antibiotics and other chemotherapy drugs, as well as in chronic gonorrhea, the morphology and color of gonococci can change. Individual cells acquire different shapes and sizes (the so-called Asch forms). In addition, the test material may contain gram-negative cocci similar to gonococci from the genus Veillonella. This to some extent limits the diagnostic value of the primary microscopy method. The best and most reliable results are obtained by the immunofluorescence method. Thin smears from the patient's secretions are fixed in the burner flame. Fluorescein isothiocyanate-labeled anti-gonococcal serum is applied to them for 1 hour at 35 ° C in a humid chamber. After this, the smears are washed twice with a buffer solution, buffered with glycerol are applied and covered with coverslips. When gonococci interact with labeled antibodies, a characteristic glow around the bacterial cells is visible under a fluorescent microscope.

Bacteriological research

Indications for isolating pure cultures of gonococci are repeated negative bacterioscopy results, the presence of microorganisms suspicious for gonococci, but not morphologically identified, as well as for reliably establishing the cure of the disease. It is very important to place the crops in the thermostat immediately. If it is impossible to carry out cultures at the site of collection of the material, you can hang a cotton swab in a test tube with Stewart's transport medium, which ensures the preservation of the viability of gonococci during delivery to the laboratory. Cultures are carried out according to standard scheme into one of the special nutrient media in test tubes or Petri dishes (CDS, Bailey, blood or serum agar, dry nutrient medium of the Kharkov enterprise "Biolek" for the production of bacterial and medicines). For diagnostic cultivation of gonococci in many countries, “chocolate” agar is also used. The best media are those based on rabbit meat agar or fresh bovine hearts. Adding 20 units/ml of polymyxin and 2 μg/ml of lincomycin to them significantly increases the frequency of inoculation of gonococci, since these drugs inhibit the growth of other bacteria. Before sowing, all media are heated in a thermostat for 15-20 minutes. Dishes and test tubes with cultures are placed in desiccators, where an atmosphere of 20% CO2 is created. Colonies usually grow within 18-24 hours, but late growth is also possible. Then the crops are kept in a thermostat (in a desiccator!) for up to 8 days, checking the appearance of growth daily. The grown colonies of gonococci have a round, slightly convex shape, smooth edges, a shiny surface, and a mucous consistency. They are transparent, like drops of dew, almost colorless, although whitish variants can also occur. The resulting colonies are examined macroscopically and microscopically. In smears, gonococci are located in pairs, tetrads and clusters. Typical colonies are subcultured onto serum agar slants to isolate a pure culture. The final identification is carried out taking into account the morphological, cultural, enzymatic and antigenic properties. Biochemically, gonococci are little active. On whey media with 1.5% of various carbohydrates, they decompose only glucose, but not maltose and sucrose. The oxidase activity of isolated cultures is determined by applying a 1% solution of dimethylparaphenylenediamine to the colonies (after microscopy). Oxidase-positive colonies first turn red and later turn black. Differentiation of gonococci from other species of the genus Neisseria is of particular importance in the diagnosis of oropharyngeal gonorrhea. As is known, on the mucous membrane of the tonsils, oropharynx and nasopharynx there is constantly a large number of gram-negative Neisseria - representatives of normal human microflora. Reliable methods for identifying gonococci are immunofluorescence, latex and coaglutination reactions, as well as determination of enzymatic properties. It is imperative to carry out a qualitative determination of the sensitivity or resistance of microorganisms to antibiotics using the agar diffusion method using disks. In order to increase the frequency of finding gonococci in smears during primary microscopy and more reliable isolation of pure cultures, especially in cases of sluggish, chronic course of the disease, methods of provoking gonorrhea are used , that is, an artificial exacerbation of the pathological process, as a result of which a larger number of gonococci appear in the secretions. The main of these methods are: a) chemical - instillation of a 0.5% solution of silver nitrate into the urethra in men, lubrication of the cervical canal with a 2-5% solution of silver nitrate; b) mechanical - insertion of a direct bougie into the urethra for 10 minutes, or anterior urethroscopy; c) biological - intramuscular injection of gonovaccine in an amount of 500 million microbial bodies or pyrogenal 200 MTD; d) nutritional - consumption of salty, spicy foods; e) thermal - warming the genitals with an inductothermic current; f) physiological - taking smears during menstruation. It is even better to combine several methods of provocation, for example, chemical, nutritional and biological. Lately To more reliably identify the causative agent of gonorrhea, polymerase chain reaction is used. It allows you to identify the pathogen in cases of chronic gonorrhea, when bacterioscopic and bacteriological examination does not give positive results.

Serological diagnosis

Serological diagnosis of gonorrhea is carried out relatively rarely, mainly in its chronic course, when bacterioscopic and bacteriological studies do not give positive results. IN modern conditions carry out enzyme immunoassay, RNGA and Bordet-Gengou reactions (BRS). The antigens for these reactions are: heat-killed polyvalent gonococcal vaccine, ultrasound-inactivated vaccine, protein and polysaccharide fractions of gonococci, as well as pyridine antigen. ELISA and RNGA are highly specific and reliable serological reactions. Compared to the past, RSK has somewhat lost its role. It has no practical value in the diagnosis of acute gonorrhea, since it is treated before the formation of a significant amount of antibodies. It is generally unsuitable for establishing the reliability of a cure. The Bordet-Gengou reaction is important in the serodiagnosis of chronic gonorrhea, especially in its complicated forms (gonosepsis, metritis, arthritis, prostatitis, etc.). The diagnostic value of allergy tests is somewhat devalued by the fact that they are positive for many years after gonorrhea. To set them up, 0.1 ml of fresh gonococcal vaccine (100 million microbial cells in 1 ml) is injected intradermally. After 24 hours, hyperemia is observed, sometimes with swelling in the center.

Treatment and prevention

For chemotherapy of gonorrhea, antibiotics are used: beta-lactams (penicillins, cephalosporins) and other antibiotics. Vaccinal prevention of gonorrhea is not carried out due to the lack of effective vaccines. To prevent blenorrhea, all newborns are given a solution of one of the listed antibiotics instilled onto the conjunctiva of the eye.

Gonococci - These are gram-negative, non-motile, non-capsular, non-spore-forming diplococci. In smears, the cocci are adjacent to each other with flat surfaces and are similar in outline to coffee beans. It has a cellular structure characteristic of gram-negative microorganisms, and can multiply outside and inside host cells. Has no intraspecific variants.

Neisseriae gonorrhoeae (gonococcus) is the causative agent of gonorrhea, a widespread contagious sexually transmitted infection. The disease was known to the ancient Chinese, Egyptians, and Jews. It got its name from two Greek words gone - seed and rhein - expiration, that is, a disease transmitted by seminal fluid. That's what Galen called her in the beginning new era. Gonococci also called diplococci - this name was given to it by the German doctor Albert Neisser, who in 1879 discovered it in the purulent discharge of the urethra, cervix and conjunctiva of the eyes. The pathogen was named after Neisseriae gonorrhoeae.

Gonococci. general characteristics

Gonorrhea is a disease accompanied by discharge from the urogenital tract, initially liquid, watery, and then purulent. The incubation period is short - 3-5 days. In the first days of the disease, gonococci are found freely lying in the serous exudate or attached to epithelial cells. When the discharge becomes purulent, the cocci are phagocytosed and can be seen in the cytoplasm of the pus cells (dolimorphonuclear neutrophilic leukocytes). One cell can contain from 20 to 100 gonococci, which, being absorbed, do not die and remain virulent. In the late stage of the disease, they can be found outside the cells; in the stage of formation of a chronic process, they are often not detected at all.

Gonococci - very fastidious microbes, they do not grow on ordinary nutrient media; it is difficult to cultivate them on enriched media specially prepared for them. They grow better at slightly lower temperatures (up to 35.5°C) in the presence of oxygen and 10% CO 2 .

4 types of colonies have been described:
– gonococci types 1 and 2 are formed by virulent gonococci;
– gonococci types 3 and 4 – non-virulent.
Cocci that form ears of types 1 and 2 have pili - an adhesion factor. It is with pili that the bacterium attaches to the cells of the cylindrical epithelium of the urethra, uterine leukemia, and rectum and is not phagocytosed, but colonizes the cells of these sections (colonization). Attachment – necessary condition infections, only bacteria that have pili are considered pathogenic.

Gonococci produce the enzyme indophenol oxidase, which catalyzes the reduction of molecular oxygen independently of hydrogen peroxide. The oxidase test is used to identify colonies in laboratory cultures. Gonococci , belonging to all types, produce an enzyme that breaks down secretory IgA, located in the secretions of the mucosa.

Despite the fact that gonococci are difficult to destroy in the patient’s body, they are extremely unstable in the external environment. They die very quickly in sunlight and when dried. In pus or on linen in a dark, damp place, it can persist for 18 to 24 hours. Very sensitive to disinfectants, especially silver salts. Temperature +60°C kills them in 10 minutes.

Although gonococci sensitive to the effects of modern antibiotics, drug resistance is becoming an increasingly serious problem, especially in the case of penicillinase-producing strains of N.gonorrhoeae. These strains were first discovered in the United States in early 1976, and were imported from Southeast Asia and the Philippines. The gene producing penicillinase (β-lactamase) in gonococci is located in plasmids with nucleotide sequences similar to those that determine resistance to penicillin in some gram-negative enterobacteria. Some gonococci can transmit their 3-lactamase plasmids by the “sexual” (conjugative) route.

Gonococci. Pathogenicity

Gonococci damage the columnar epithelium lining the cervix and rectum, as well as the intermediate (urogenital) epithelium lining the urinary tract. Vaginal infection is not detected because the epithelium lining the vagina adult woman is a keratinizing stratified squamous epithelium resistant to gonococci. Before puberty, the vagina is lined with softer, especially receptive epithelium. Gonorrheal vulvovaginitis in prepubertal girls can be epidemic and difficult to cure. Changes in the epithelium with the end of puberty completely eliminate this form of gonorrhea.

Currently important primary place infection is the conjunctiva of the eye, and this process (gonorrheal conjunctivitis and keratitis) actively damages the eyes. Ophthalmia neonatorum - gonorrheal conjunctivitis of newborns, occurs when the eyes of the fetus become infected during passage through the birth canal. Copious purulent discharge from a newborn's eye can create significant pressure under the eyelids. If the eyelids are forcibly opened, pus may spray out. Doctors and medical personnel treating these children must carefully protect their eyes. In children or adults, such an infection easily leads to blindness or serious visual impairment due to inflammatory changes in the structures of the eye.

Gonococcal infection from the male urethra can directly spread to other parts of the male reproductive system. In women, it can also invade other parts of the tract, especially the Bartholin's glands and fallopian tubes.

The uterine mucosa is resistant to the effects of gonococci, but the use of contraceptives can facilitate the penetration of gonococci into the endometrium, increasing the risk of complications in the fallopian tubes. Infection of the fallopian tubes usually occurs in the first or second menstrual cycle after infection, but in some cases it occurs later.

Involvement of the fallopian tubes (salpinitis) in the inflammatory process leads to significant twisting and scarring when the disease takes a chronic form.

Scarring of the male urethra can lead to stricture or obliteration of the urethra at one or more focal points.

Sometimes gonococci migrate from the genitourinary tract to the lymphatic system or bloodstream, forming distant foci of infection (for example, endocarditis, perihepatitis and meningitis).

Gonococcemia is associated with various skin lesions from which microorganisms can be isolated. A significant manifestation of extragenital gonococcal infection is purulent destructive arthritis, which is especially common in people aged 15 to 35 years. With an increase in the number of cases of gonorrhea, extragenital lesions become more noticeable.

Gonococci. Sources and routes of infection

Gonococci are never found outside the human body unless they are found on objects most recently contaminated with gonorrheal secretions. Therefore, gonorrheal infections are almost always spread through direct contact, mainly through sexual intercourse. It is extremely rare that gonorrhea is transmitted indirectly through contaminated objects,

Gonorrheal ophthalmia in adults is usually accidental. An infection from the urogenital tract is unintentionally brought into the eyes by the hands of the patient himself or another person.

Vulvovaginitis among children is spread by sharing bedding, baths, toiletries, etc. It usually occurs where children live in overcrowded apartments.

Untreated gonorrheal infections tend to become chronic. In the absence of treatment or improper treatment, women become bacteria carriers for many years after the disappearance of signs of the disease. In 60-80% of infected women, the disease is asymptomatic. In approximately 40% of men, the disease is also asymptomatic.

Gonococci. Laboratory diagnosis of infection

Several microbiological methods are used to establish the diagnosis of gonorrhea. Smears, cultures and oxidase reactions are preliminary tests. To establish an accurate diagnosis of gonorrhea and confirm the results of preliminary tests, the method of fluorescent antibodies and the carbohydrate fermentation reaction are used.

Bacterioscopic diagnostics. Direct smears of genital secretions can be Gram stained. The detection of gram-negative diplococci in purulent cells of genital exudate is a strong argument in favor of the fact that these are gonococci. This is especially true if the discharge is taken from the male urethra, where, in the case of typical acute purulent urethritis, a Gram-stained smear containing clearly visible intracellular diplococci suggests an unequivocal diagnosis.

In women, typical diplococci can be detected in smears of material taken from the Bartholin's glands and Skene's glands at the early stage of the disease. But based on this alone, it is impossible to make even a working diagnosis.

Reasons why:
1. gram-negative diplococci (but not gonococci) are found outside cells;
2. gonococci alone or in pairs are found outside cells;
3. Gram-positive microorganisms with the morphology of gonococci are found in the cells.

All that can be said about Gram-negative diplococci found outside cells is that they may be gonococci. Very rarely, gram-negative dip-lococci that are not gonococci are found inside the purulent cells of genital exudate.

The smear prepared from gonorrheal exudate must be very thin. Gonococci react to Gram staining in such a way that if the smear is thick and uneven in thickness, an erroneous result may be obtained. In the case of chronic gonorrhea, microbes are usually not found in the exudate.

Cultural methods are of particular importance in diagnosing chronic diseases and assessing the effectiveness of treatment. Cultivation of “tender” gonococci is possible only on specially enriched media (blood agar, ascites agar, etc.). The most suitable are special media with the addition of antibiotics that suppress the growth of fungi and bacteria of the genus Proteus, but to which gonococci are insensitive,

Special transport media have been developed that allow suspect cultures to be sent for further identification. In this case, test tubes with screw caps containing the medium and a mixture of air and CO 2 are used. After inoculation of the material, the growth of gonococci is maintained for 48-96 hours.

According to modern recommendations, material suspicious for the isolation of gonococcal culture should be obtained not only from the urogenital tract (endocervical canal, anterior urethra), but also from the anorectal region and pharynx. Rectal gonorrhea can be easily viewed. Careful work using tampons is necessary when examining homosexual men. In women, cervical and rectal smears should be performed because 50% infected women gonococci settle in the rectal area. The infection may remain there even after it disappears from the cervix.

Sterile cotton swabs often contain fatty acids and other substances that inhibit the growth of gonococci. Therefore, it is recommended to use neutral swabs, such as calcium alginate, for collecting samples.

Gonococci can be obtained from the urine of men if the first 10 ml of excreted urine is centrifuged and the sediment is cultured. With more simple method screening, the first few drops of urine that fall on a dry swab are immediately transferred to the medium. Urine cultures in screening programs help identify the source of infection among asymptomatic men.

The next step in the bacteriological study of gonococci is a qualitative analysis of biochemical reactions and identification of microorganisms using antisera. The presence of a specific K-antigen in gonococci makes it possible to use the method of fluorescent antibodies when gonococci are detected in direct smears or exudate, or in smears prepared on cultures.

Gonococci. Social significance of gonorrhea

Gonorrhea has far-reaching medical, social, psychological and even forensic consequences. The disease has acquired a character close to a pandemic - according to the most probable estimates, from 2.5 to 3 million new cases are registered annually in the world, approximately 1 case every 15 seconds. More than half of the cases are teenagers and young people under 25 years of age. Gonorrhea is registered not only among adolescents, but also among children who have not reached puberty. Any discharge from the vagina or urethra in children should be suspicious.

Although the ratio of cases in men and women is approximately 1:1, there are usually three treated men per woman. Manifestations of the disease in men are more acute and unpleasant, which forces them to seek treatment more often. medical care. In women, the disease is often asymptomatic or with mild symptoms. Many of them are diagnosed only as a result of information received from their sexual partners. The “silent” reservoir of asymptomatic women is a primary obstacle to disease control. It is recommended that screening for gonorrhea be considered an essential part of prenatal care, and routine isolation should be performed more frequently during routine gynecological examinations.

The most harmful is the information passed down from generation to generation that gonorrhea is no more dangerous than a runny nose. This false conclusion downplays the danger of gonorrhea and creates the impression that the “cold” is not accompanied by complications.

It has been noted that gonorrhea is the most common cause of infertility in both sexes. In women, sterility is caused by obliteration of the fallopian tubes by scar tissue formed during the resolution of gonorrheal salpingitis. In men, sterility is due to obliteration of the seminal ducts, caused by a similar process of gonorrheal infection and resolution of the inflammatory process with subsequent scarring.

Gonococci. Immunity

Infection with gonorrhea provides little or no immunity to subsequent infections. The antibody response is weak. Apparent immune deficiency may be main reason why the disease remains endemic in the human population. There is a pronounced sensitivity to re-infection. Relative type-specific immunity to gonorrhea is due to opsonins.

Gonococci. Prevention

The population should be educated about the dangers of gonorrhea and the difficulty of its treatment. Unfortunately, the widespread use of chemotherapy drugs and antibiotics in everyday life has created the impression that treating gonorrhea is not a problem. Particular attention should be paid to the danger of self-medication, the use of “ folk remedies”, an appeal to incompetent persons, self-proclaimed “healers”. Patients should not soil toilets with secretions, and they should be warned about the danger of introducing infection into their eyes with their hands. Neonatal ophthalmia can be prevented using the Crede method. Immediately after birth, the baby's eyelids are washed with sterile water. To wash each eye, use a separate swab, which is passed from the nose outwards. Next, the eyelids are opened and 1-2 drops of a 1% solution of silver nitrate are instilled into each eye, strictly ensuring that the entire conjunctival sac is completely covered with the solution. After 2 minutes, the eyes are irrigated with isotonic saline solution.

Vulvovaginitis in children can be prevented by proper cleaning of bedding, nightwear, wash water and bath water. All children should be screened for gonorrhea before they are allowed to have contact with other children in childcare facilities or hospitals. Doctors and medical personnel using rubber or plastic gloves for palpation and examination of the cervix and vagina should replace these gloves before digital examination of the rectum.

Due to the fact that not only gonorrhea is transmitted sexually, every gonorrheal patient must undergo serological testing for syphilis and HIV infection.

The gonococcal vaccine was obtained by isolating and purifying the pili protein. Its effect is that the antibodies produced by the recipient envelop the villi of any gonococcus that has entered the human body, which prevents the bacteria from fixing on the host cells and, thereby, preventing the development of the disease.

There is a gonococcal vaccine (gonovaccine), which is a suspension of an inactivated culture of gonococci in a 0.9% sodium chloride solution. It is used in diagnosis (establishing a cure for gonorrhea), and as an auxiliary method of treatment for sluggish relapses, for fresh torpid and chronic forms of the disease. Prescribed to men with complicated and women with ascending gonorrhea (after acute inflammatory phenomena have subsided).

Conclusion

2. Gonococci (causative agents of gonorrhea) are diplococci that can be located intra- and extracellularly.

3. Neisseria grow only in an atmosphere containing 10% CO2, and only in specially enriched media.

4. Gonococcus pili are a structure that ensures the attachment of the microbe to the columnar epithelium of the mucous membrane.

5. Gonococci from the primary focus of infection (epithelium of the urethra, cervix, rectum) spread to other parts of the body, including the reproductive organs. With repeated infections, deformation of the fallopian tubes occurs due to the formation of scars. Complete obstruction is possible. In men, scarring leads to a narrowing (structure) of the urethra.

6. One of the forms of manifestation of gonococcal infection in adults and, especially, newborns is a specific purulent inflammation of the conjunctiva. The process sometimes involves the tissues of the eye, which can lead to serious visual impairment.

7. Ophthalmia neonatorum is a gonococcal infection that occurs when a fetus passes through an infected birth canal. For the purpose of prevention, all newborns are injected with silver nitrate into the conjunctival sac of both eyes (Crédé method).

Neisseria are gram-negative aerobic cocci belonging to the genus Neisseria, which includes 8 species: Neisseria meningitides, Niesseria gonorrhoeae, N. flava, N. subflava, N. perflava, N. sicca.

Morphology: non-motile non-sporogenous gram-negative diplococci forming a capsule are polymorphic - they occur in the form of small or large forms and also in the form of shelves, are well stained with aniline dyes (methylene blue, brilliant green, etc.), under the influence of penicillin they form L-forms , can change properties and turn into a gram-positive form.

Cultural properties: aerobes, chemoorganotrophs; for growth they require freshly prepared moist media with the addition of native blood proteins, serum or ascitic fluid. Do not cause hemolysis on media containing blood; they do not grow on media containing milk, gelatin and potatoes. On solid nutrient media, after 24 hours, when containing protein II, they form slightly turbid, colorless colonies; without it, they form round transparent colonies in the form of dew drops; on liquid nutrient media, they grow diffusely and form a film, which settles to the bottom after a few hours.

Biochemical activity: extremely low - they decompose only glucose, produce catalase and cytochrome oxidase, there is no proteolytic activity, does not form H2S, ammonia, or indole.

Antigenic structure: Contains A and K antigens, LPS have strong immunogenicity, the main antigenic load is carried by pili and membrane proteins. The outer membrane contains proteins of classes I, II, III, which exhibit strong immunogenic properties

Pathogenicity factors: capsule, pili, endotoxin, membrane proteins

The capsule has an antiphagocytic effect. Pili provide adhesion to the epithelium. The cell wall contains endotoxin. Surface protein class I - provides resistance to bactericidal factors of mucous membranes. Class II - (turbidity proteins, OPA proteins) cause attachment to the epithelium and prevent phagocytosis. N. synthesize IgA protease, which breaks down Ig.

Resistance: very unstable in environment, sensitive to the action of antiseptics, highly sensitive to penicillins, tetracycline, streptomycin. Capable of utilizing penicillins when acquiring beta-lactamases.

Pathogenesis: Entrance gate- columnar epithelium of the genitourinary tract. Gonococci attach to the epithelium through surface proteins, cause cell death and desquamation, are captured by cells, where they multiply, end up on the BM, and then end up on the connection. tissue and cause inflammation or enter the blood with possible dissemination.

Immunity is almost non-existent.

Microbiological diagnostics:

Bacterioscopic examination: The material for examination is purulent discharge from the urethra, vagina, rectum, pharynx, and blood serum. Smears are prepared, Gram staining. With a “+” result, gonococci are detected - Gram+ bean-shaped diplococci are located inside the leukocytes. A positive diagnosis is made in the acute form of gonorrhea before the use of antibiotics.

Bacteriological research. The material is sown on Petri dishes with special nutrient media - KDS, serum agar. The KDS medium contains nutrient agar with the addition of casein, yeast extract and blood serum in a certain concentration. The cultures are incubated at 37°C for 24-72 hours. Gonococci form round transparent colonies resembling dew drops, in contrast to the more cloudy colonies of streptococci or pigmented colonies of staphylococci, which can also grow on these media. Suspicious colonies are subcultured into test tubes on appropriate media to obtain pure cultures, which are identified by their saccharolytic properties on “variegated” media (semi-liquid agar with whey and carbohydrate). Gonococcus ferments only glucose to produce acid.

Serodiagnosis. In some cases, they put RSK Bordet - Zhangu. A suspension of killed gonococci is used as an antigen. The Bordet-Gangou reaction is of auxiliary value in the diagnosis of gonorrhea. It is positive for chronic and complicated gonorrhea.

Treatment: antibiotic therapy (penicillin, tetracycline, kanamycin), immunotherapy - Gonococcal vaccine - a suspension of gonococci killed by heat, is used for vaccine therapy of chronic gonorrhea.

Table of contents of the topic "Aerobic gram-negative cocci. Neisseria. Gonorrhea. Meningitis.":

Gonorrhea. The causative agent of gonorrhea. Gonococcus. Epidemiology of gonorrhea. Source of gonorrhea. Morphology of gonococci. Tinctorial properties of gonococci.

Gonorrhea- an infectious venereal disease, manifested by inflammation of the mucous membranes, mainly of the genitourinary tract. Gonococcus is the causative agent of gonorrhea, an infectious venereal disease manifested by inflammation of the mucous membranes, mainly of the genitourinary tract. The term "gonorrhea" [from the Greek. gone, seed, + (-rirhoia, expiration] was introduced by Claudius Galen in the 2nd century AD, although the disease was known even earlier - Babylonian, Assyrian and Greek myths mention a disease that, judging by the clinical picture, is gonorrhea. Currently gonorrhea is one of the most common infectious diseases. The causative agent of gonorrhea - Neisseria gonorrhoeae (gonococcus) - was first discovered by Neisser in 1879.

Gonococcus. Epidemiology of gonorrhea. Source of gonorrhea.

Source of gonorrhea- a sick man. Basic route of infection with gonorrhea- sexual, infection of the fetus is possible when passing through the mother’s birth canal. There is no congenital immunity. After an illness, immunity to secondary infections is not developed; Super- and re-infections are possible.

Animals are resistant to gonococci, only intraperitoneal administration of microbes causes the death of small laboratory animals.

Morphology and tinctorial properties of gonorrhea

In fresh cultures of gonococci They are non-motile diplococci measuring 1.25-1.0x0.7-0.8 microns, forming a capsule.

Characteristic polymorphism of gonococci- relatively small or large cells, as well as rod-shaped forms, are found in smears. They are well colored with aniline dyes (methylene blue, brilliant green, etc.). They form L-forms, including under the influence of penicillin. Under the influence of chemotherapy drugs, they quickly change their properties and form gram-positive forms. Gonococci have a complexly organized cell wall; the presence of one or another of its components determines their intraspecific differentiation. Based on the presence of pili, gonococci are divided into five types (T1-T5).

Gonococcus types T1 and T2 are equipped with pili (P+ and P++), are surrounded by a capsule and are virulent; other types of bacteria are avirulent. Protein 1 makes up up to 60% of the substance cell membrane and its identification forms the basis for serotyping of gonococci and recognition of bacteria by ELISA. Protein II determines specific clinical manifestations diseases. Bacteria containing proteins 1 and II are usually isolated from lesions urinary tract, and strains containing protein I, but lacking protein I - with disseminated lesions.