Prevotella bacteria, computer illustration. Prevotella are Gram-negative, anaerobic, rod to coccobacillus shaped bacteria. One of the common species is Prevotella melaninogenica. It can cause infections of the oral cavity, respiratory tract, and gastrointestinal tract, such as periodontal disease, lung abscesses, and abdominal infections. Another species, Prevotella bivia, can cause infections of the female reproductive system, such as pelvic inflammatory disease, endometritis, and postpartum infections. Prevotella disiens can cause infections of the head and neck, such as brain abscesses, sinusitis, and dental infections. Prevotella intermedia causes infections of the oral cavity, respiratory tract, and gastrointestinal tract, such as periodontal disease, pneumonia, and abdominal infections.