Prevotella is a genus of Gram-negative anaerobic bacteria. Prevotella species are found in the oral cavity, vaginal mucosa, and gastrointestinal tract of humans and animals. Some Prevotella species are opportunistic pathogens, causing infections in immunocompromised individuals.
The genus Prevotella consists of rod-shaped or coccoid bacteria that are non-spore forming and non-motile. The cells are typically 0.5-1.0 µm in diameter and 2-10 µm long. The cell walls of Prevotella species contain lipopolysaccharides (LPS) which provide them with resistance to many antibiotics and detergents.
The primary function of Prevotella species is the breakdown of complex carbohydrates, including plant polysaccharides such as cellulose and xylan, into simpler molecules that can be used by the host for energy production. In the oral cavity,Prevotellaspecies contribute to the degradation of dietary starches and fibers through their production of enzymes such as amylase and cellulase. In the gastrointestinal tract, these same enzymes allowPrevotellaspecies to break down indigestible plant matter present in the diet.
In addition to their role in carbohydrate metabolism, Prevotellaspecies have also been shown to synthesize vitamins B12 and K2 . Vitamin B12 is an essential nutrient required for DNA synthesis, while vitamin K2 is important for blood clotting . Both vitamins are produced by certain strains of Prevotellain vitroand likely play a similar role in vivo .
While most Prevotellaspecies are commensals , some opportunistic members of this genus can cause infections in immunocompromised individuals . These infections typically occur in hospital settings where patients with weakened immune systems are more susceptible to infection . One common infection caused byPrevotellasis bacteremia , which is defined as the presence of live bacteria in the bloodstream . Bacteremia can lead to sepsis , a potentially life-threatening condition characterized by inflammation throughout the body . Other infections associated withPrevotellainclude pneumonia , endocarditis , osteomyelitis , brain abscesses , and wound infections . Treatment for these infections typically involves antibiotics active against Gram-negative bacteria , although some strains may be resistant to multiple classes of drugs .