Prevotella Melaninogenica Infection, Gram Stain, Antibiotic Coverage & Susceptibility

In humans, the mouth cavity is a common habitat for a species of Gram-negative, non-spore-forming, obligately anaerobic, coccobacilli bacterium known as Prevotella melaninogenica. Moreover, it can be identified in other parts of the body, where it has the potential to behave as an opportunistic pathogen. P. melaninogenica gets its name from its dark colonies and pigmentation.

If left untreated, a biofilm on teeth caused by P. melaninogenica might result in periodontitis. Moreover, it has been associated with a number of anaerobic infections, frequently in mixtures with other aerobic and anaerobic bacteria.

P. melaninogenica may be useful in the early detection of oral cancer, according to recent research. In agar plates, there were more colonies of P. melaninogenica in patients with oral cancer compared to those without the disease. 

Prevotella Melaninogenica Infection

The mouth cavity is a common habitat for Prevotella melaninogenica, a Gram-negative, non-spore-forming, obligate anaerobic coccobacillus. It frequently coexists with other aerobic and anaerobic bacteria and is a prominent human pathogen in different anaerobic diseases. P. melaninogenica has been linked to a wide variety of diseases, some of which include oral abscesses, infections of the gastrointestinal tract, infections in the female genital tract, infections of the upper and lower respiratory tracts, and infections of the bone marrow. Moreover, it may help promote the growth of plaque and tartar on teeth, both of which can eventually result in periodontitis.

P. melaninogenica can cause infections and has also been found in healthy people's saliva and on the top and sides of the tongue. Prevotella nigrescens and Prevotella pallens are two other oral cavity-colonizing Prevotella species. Prevotella loescheii, Prevotella denticola (strains), Prevotella intermedia, and Prevotella corporis are some of the other species of Prevotella that have pigmentation.

Gram Staining

The bacterium Prevotella melaninogenica belongs to the genus Prevotella and is gram-negative and anaerobic. Gram staining is a scientific method used to categorize bacteria according to the characteristics of their cell walls. Bacterial cells are first stained with crystal violet, then subjected to iodine treatment, alcohol washing, and finally, safranin staining.

During gram staining, P. melaninogenica normally reveals itself as a rod-shaped, gram-negative bacterium. It is important to remember that P. melaninogenica's gram-staining abilities can change based on the growing environment, culture age, and other elements. In order to correctly identify this bacteria, it's crucial to interpret the results of the gram staining in conjunction with those from other laboratory tests.

Antibiotic Coverage & Susceptibility

Antibiotics that can be used to treat this infection include;

• Ticarcillin-clavulanate, 
• Piperacillin-tazobactam, 
• Cefoxitin, 
• Metronidazole, 
• Clindamycin, imipenem, and 
• Meropenem 

These antibiotics are usually effective against Prevotella melaninogenica. Bacteroides spp. has exhibited an increase in antimicrobial resistance, and genes for antibiotic susceptibility and resistance have been discovered in oral clinical isolates of Prevotella intermedia and Prevotella nigrescens. Prevotella intermedia and Prevotella nigrescens have both been found to produce -lactamase, indicating that penicillin may not be the best remedy for infections caused by these organisms.