Sexually Transmitted Diseases - I. I. Mavrov 2005

Other bacterial infections of the urogenital tract
Urogenital infections caused by Neisseria

Laboratory examination of patients with inflammatory lesions of the urogenital Organs reveals Gram-negative diplococci belonging to the family Neisseriaceae, the genus Neisseria (N. sicca, N. flavescens, N. subflava, N. lactamicus, N. mucosa), and the genus Branhamella (B. catarrhalis). Although they are part of the normal microflora of the respiratory tract and nasopharynx, they occasionally cause inflammatory processes in the Urethra and Vagina, as well as tonsillar and pharyngeal infections. In such cases, the source of pathogenic neisseriae may be a sexual partner (via penioral and orovaginal transmission routes).

Morphology and Identification. Neisseriae are non-motile, non-spore-forming Gram-negative diplococci. Individual cocci are Kidney-shaped and apposed to each other by their flat or concave sides. They are strict aerobes. On solid nutrient media, they form transparent, smooth-edged colonies that are non-pigmented or yellowish. They lack hemolytic activity and produce oxidase. Unlike gonococci (Neisseria gonorrhoeae), which ferment only glucose, other Neisseria species exhibit variable biochemical activity. For example, N. sicca forms matte, brittle, wrinkled colonies on enriched media and decomposes glucose, sucrose, and maltose; N. flavescens does not ferment CARBOHYDRATES and produces a yellow pigment; N. subflava decomposes glucose and maltose and produces a yellow pigment; N. lactamius ferments glucose, maltose, and lactose and produces a yellow pigment; N. mucosa exhibits pronounced biochemical activity, decomposing glucose, maltose, fructose, sucrose, and starch. They grow well on serum and plain Agar media, forming mucoid colonies that are mobile and easily removed. Microscopic examination of smears from these colonies reveals Gram-negative diplococci characterized by polychromasia, polymorphism, and the presence of a capsule. Branhamella catarrhalis does not ferment carbohydrates and does not produce hydrogen sulfide or indole. In nutrient media, it causes sac-like liquefaction of gelatin.

The MORPHOLOGY OF MICROORGANISMS observed in the specimen is not sufficient on its own to identify the pathogen. The known similarity between these microorganisms and gonococci can sometimes lead to diagnostic errors. Therefore, it is first necessary to rule out gonococcal infection with utmost reliability. To confirm the presence of gonococci, specimens must be collected simultaneously from the urethra, vagina, cervix, and rectum, and prostatic secretions and urine should also be analyzed. When penioral and orovaginal sexual contact is suspected, the Pharynx and Tonsils must be examined. Definitive Diagnosis relies on the results of culture studies and the determination of enzymatic activity (Fermentation of various carbohydrates). A comprehensive set of microbiological and biochemical tests performed to identify and differentiate Gram-negative diplococci from gonococci is of paramount importance.

Neisseriae occur either alone or in combination with other microorganisms (anaerobes, Gram-negative rods, Mycoplasmas, etc.) in sexually active women. The sexual partners of these women frequently suffer from nongonococcal urethritis. Ordinarily nonpathogenic neisseriae are more commonly detected in men with a history of Gonorrhea. For instance, in patients with post-gonococcal urethritis, N. mucosa was detected in 10.3%, B. catarrhalis in 4.2%, N. subflava in 1.8%, and N. sicca in 1.8% of those examined (I. I. Mavrov, 1978). In the urethra of male patients with urethritis, neisseriae are found both in pure culture and in association with other microorganisms (staphylococci, Pseudomonas aeruginosa, mycoplasmas, C. albicans, etc.).

Treatment and Prevention. Neisseriae are resistant to various Antibiotics (penicillin, tetracycline, erythromycin, etc.). They are frequently resistant to three, four, five, or even six antibiotics. At the same regard, most of these microorganisms demonstrate susceptibility to Aminoglycosides (gentamicin, sisomicin, amikacin, etc.) and third-generation Cephalosporins (ceftizoxime, cefoperazone, cefotaxime, or claforan). "Older" aminoglycosides (streptomycin, neomycin, kanamycin) lack sufficient activity against neisseriae. Gentamicin, tobramycin, sisomicin, and amikacin exhibit pronounced activity against most clinically significant Gram-negative microorganisms, including neisseriae.

Prevention of diseases caused by Gram-negative microorganisms resembling gonococci involves detecting the pathogen, ensuring its timely identification; performing a comprehensive set of microbiological and biochemical tests to differentiate Gram-negative diplococci from gonococci; treating pronounced clinical manifestations in affected individuals and their sexual partners; and applying non-specific therapy Methods aimed at boosting the body's resistance.