(See also Overview of Anaerobic Bacteria Overview of Anaerobic Bacteria Bacteria can be classified by their need and tolerance for oxygen: Facultative: Grow aerobically or anaerobically in the presence or absence of oxygen Microaerophilic: Require a low oxygen concentration... read more and Overview of Clostridial Infections Overview of Clostridial Infections Clostridia are spore-forming, gram-positive, anaerobic bacilli present widely in dust, soil, and vegetation and as normal flora in mammalian gastrointestinal tracts. Pathogenic species produce... read more .)
Clostridial necrotizing enteritis is a mild to severe clostridial infection, which can be fatal if not treated promptly.
C. perfringens type C occasionally causes severe necrosis in the small bowel (primarily the jejunum). Disease is mostly caused by clostridial beta-toxin, which is very sensitive to proteolytic enzymes and is inactivated by normal cooking. Necrosis is segmental, involving small or large patches with varying degrees of hemorrhage and intramural gas; necrosis ranges from mucosal injury to full-thickness necrosis and perforation.
Clostridial necrotizing enteritis occurs primarily in populations with multiple risk factors, including the following:
Protein deprivation (causing inadequate synthesis of protease enzymes)
Poor food hygiene
Episodic meat feasting
Staple diets containing trypsin inhibitors (eg, sweet potatoes)
These factors are typically present collectively only in the hinterlands of New Guinea and parts of Africa, Central and South America, and Asia. In New Guinea, the disease is known as pigbel and is usually spread through contaminated pork, other meats, and perhaps peanuts.
Severity varies from mild diarrhea to a fulminant course of severe abdominal pain, vomiting, bloody stool, septic shock, and sometimes death within 24 hours.
Diagnosis of clostridial necrotizing enteritis is based on clinical presentation plus the presence of C. perfringens type C toxin in stool.
Treatment of clostridial necrotizing enteritis is with parenteral antibiotics (penicillin G, metronidazole). Perhaps 50% of seriously ill patients require surgery for perforation, persistent intestinal obstruction, or failure to respond to antibiotics. Experimental toxoid vaccine and antiserum containing beta antitoxin have been used successfully in endemic areas but are not available commercially.
Neutropenic enterocolitis (typhlitis)
This similar life-threatening syndrome develops in the cecum of neutropenic patients (eg, those with leukemia or receiving cancer chemotherapy). It may be associated with sepsis due to C. septicum.
Symptoms of neutropenic enterocolitis are fever, abdominal pain, gastrointestinal bleeding, and diarrhea.
Diagnosis of neutropenic enterocolitis is based on
The presence of severe neutropenia
Results of abdominal CT and blood and stool cultures and toxin tests
Neutropenic enterocolitis must be distinguished from Clostridioides (formerly Clostridium) difficile–induced diarrhea, graft-vs-host disease, and colitis due to cytomegalovirus.
Treatment of neutropenic enterocolitis is with antibiotics, but surgery may be necessary.
Neonatal necrotizing enterocolitis
Neonatal necrotizing enterocolitis Necrotizing Enterocolitis Necrotizing enterocolitis is an acquired disease, primarily of preterm or sick neonates, characterized by mucosal or even deeper intestinal necrosis. It is the most common gastrointestinal emergency... read more , which occurs in neonatal intensive care units, may be caused by C. perfringens, C. butyricum, or C. difficile, but the role of these organisms needs further study. Most cases occur in premature neonates who weigh less than 1500 g.