Description of the Pathogen Mycoplasma pneumoniae is a member of the class Mollicutes, which includes bacterial pathogens and commensals found in many animals and plants. These pathogens comprise the smallest self-replicating prokaryotes known to cause infection in humans. M. pneumoniae…
Anaerobic gram-positive, nonsporulating bacilli of clinical significance include Actinomyces , Bifidobacterium , Eubacterium , Lactobacillus , Mobiluncus , and Cutibacterium (formerly Propionibacterium ) . A taxonomic revision has placed all Propionibacterium species of the skin microbiota within a new genus:…
The anaerobic cocci are major components of the normal microbiota of the mouth, upper respiratory tract, gastrointestinal tract, vagina, and skin. Gram-positive cocci and gram-negative cocci ( Veillonella spp.) are the anaerobic bacteria most commonly isolated from clinical specimens. Traditional…
Fusobacteria are non–spore-forming, nonmotile, pleomorphic, gram-negative ( Fig. 193.1 ), obligate anaerobic bacilli that can cause a wide spectrum of human disease ranging from mild pharyngitis to sepsis, and these organisms are most notorious for causing septic thrombophlebitis of the…
Clinically important anaerobic gram-negative bacilli (AGNB) include B. fragilis group (including Bacteroides and Parabacteroides ), Prevotella , Porphyromonas , and Fusobacterium . Fusobacterium are discussed in Chapter 193 . Infections due to Porphyromonas and Prevotella (previously named Bacteroides species) are…
Clostridia are gram-positive, spore-forming bacilli that cause up to 10% of anaerobic infections and occur at diverse clinical sites. Of the more than 200 recognized species of Clostridium , <20 are associated with invasive and toxigenic human diseases. , Clostridial…
Acknowledgment Substantial material from this chapter in the previous edition has been used. The Pathogen Clostridioides difficile (formerly Clostridium difficile ) is an anaerobic spore-forming, Gram-positive bacillus that was first described as part of a study of the intestinal flora…
Botulism is a neuroparalytic disease of humans and other animals caused by the action of a heat-labile neurotoxin produced almost exclusively by Clostridium botulinum. Botulism is categorized by modes of acquisition: (1) infant botulism, which results from intestinal colonization, outgrowth,…
Tetanus is caused by a neurotoxin produced by Clostridium tetani . It is common in warmer climates. Globally, 15,102 cases of tetanus were reported in 2018 and an estimated 76,600 died. Although a major cause of morbidity and mortality in…
Classification Anaerobic bacteria predominate on normal skin and among the bacterial flora of mucous membranes. , Infections caused by anaerobic bacteria are common, arise from the sites where they are normal flora (endogenous), and can be serious or life-threatening. Anaerobic…