Bacteroides

Abstract

The genus Bacteroides belongs taxonomically to the family Bacteroidaceae, order Bacteroidales, class Bacteroidia, phylum Bacteroidetes. Of the six genera (i.e., Acetofilamentum, Acetomicrobium, Acetothermus, Anaerorhabdus, Bacteroides, and Capsularis) within the family Bacteroidaceae, the genus Bacteroides (bacter, rod; -oides, from eidos, shape or figure; Bacteroides, rodlike) is not only very complex (with a large number of individual species) but also includes several important pathogens of humans and animals. Bacteroides are strict anaerobes, and many species are obligate parasite of humans and animals. The genus Bacteroides is the most important constituents of normal human flora of gastrointestinal tract. In 1863, Pasteur reported a variety of anaerobic bacteria that could only be grown in gaseous environment having substantially reduced oxygen tension. With the improvement in anaerobic technology over the past 20–30 years, a high incidence of anaerobic organisms has been demonstrated in clinical specimens and better understanding of these organisms has evolved. In humans anaerobic bacteria are normally prevalent in the oral cavity, gastrointestinal The genus Bacteroides belongs taxonomically to the family Bacteroidaceae, order Bacteroidales, class Bacteroidia, phylum Bacteroidetes. Of the six genera (i.e., Acetofilamentum, Acetomicrobium, Acetothermus, Anaerorhabdus, Bacteroides, and Capsularis) within the family Bacteroidaceae, the genus Bacteroides (bacter, rod; -oides, from eidos, shape or figure; Bacteroides, rodlike) is not only very complex (with a large number of individual species) but also includes several important pathogens of humans and animals. Bacteroides are strict anaerobes, and many species are obligate parasite of humans and animals. The genus Bacteroides is the most important constituents of normal human flora of gastrointestinal tract. In 1863, Pasteur reported a variety of anaerobic bacteria that could only be grown in gaseous environment having substantially reduced oxygen tension. With the improvement in anaerobic technology over the past 20–30 years, a high incidence of anaerobic organisms has been demonstrated in clinical specimens and better understanding of these organisms has evolved. In humans anaerobic bacteria are normally prevalent in the oral cavity, gastrointestinal tract and genital organ. The Bacteroides are gram-negative, nonspore-forming bacilli. Bacteroides are commonly found in the human intestine, where they have a symbiotic hostbacterial relationship with humans. They assist in breaking down food and in producing valuable nutrients and energy that the body needs. However, when Bacteriodes are introduced to parts of the body other than the gastrointestinal area, they can cause or exacerbate abscess. From these endogenous sources, a wide variety of human infection may occur, the common infections caused by these bacteria are periodontal disease; postaspiration, pleuro-pulmonary infection; genital tract infection in women, and intraabdominal abscesses. Bacteroides fragilis is the most common species and its putative presence has implications for antimicrobial selection.1