Chapter 135. Gas Gangrene and Other Clostridial Infections (Part 2)

Clinical ManifestationsIntestinal DisordersFood Poisoning C. perfringens, primarily type A, is the second or third most common cause of food poisoning in the United States (Chap. 122). The responsible toxin is thought to be a cytotoxin produced by 75% of strains isolated from cases of foodborne disease. The cytotoxin binds to a receptor on the small-bowel brush border and induces a calcium ion–dependent alteration in permeability. The associated loss of ions alters intracellular metabolism, resulting in cell death. Outbreaks generally have resulted from problems in the cooling and storage of food cooked in bulk. The food sources primarily involved are...
Nội dung trích xuất từ tài liệu:
Chapter 135. Gas Gangrene and Other Clostridial Infections (Part 2) Chapter 135. Gas Gangrene and Other Clostridial Infections (Part 2) Clinical Manifestations Intestinal Disorders Food Poisoning C. perfringens, primarily type A, is the second or third most common causeof food poisoning in the United States (Chap. 122). The responsible toxin isthought to be a cytotoxin produced by >75% of strains isolated from cases of food-borne disease. The cytotoxin binds to a receptor on the small-bowel brush borderand induces a calcium ion–dependent alteration in permeability. The associatedloss of ions alters intracellular metabolism, resulting in cell death. Outbreaksgenerally have resulted from problems in the cooling and storage of food cookedin bulk. The food sources primarily involved are meat, meat products, and poultry.Generally, the implicated meats have been cooked, allowed to cool, and thenrecooked the following day, often in a stew or hash. Strains of C. perfringens thatcontaminate meat manage to survive initial cooking. During reheating, theorganisms sporulate and germinate. The disease is associated with an attack ratethat is often as high as 70%. Symptoms of food poisoning from type A strainsdevelop 8–24 h after ingestion of foods heavily contaminated with the organism.The primary symptoms include epigastric pain, nausea, and watery diarrheausually lasting 12–24 h. Fever and vomiting are uncommon. Molecular methodsincluding ribotyping and pulsed-field gel electrophoresis have been used to detectfecal cytotoxin in outbreaks of food poisoning caused by C. perfringens. C. perfringens has also been implicated in a more severe form of diarrheathan that of classic food poisoning. This more severe disease tends to occur in theelderly and has been associated with antibiotic use in hospitalized populations. Inthis form of disease, diarrhea is generally more profuse, of longer duration, andaccompanied by abdominal pain. Blood and mucus have been detected in the fecesof the affected patients. In one hospital-based study of a cluster of cases,widespread environmental contamination with C. perfringens spores wasdocumented. Enteritis Necroticans Necrotizing enteritis (enteritis necroticans, or pigbel) is caused by β toxinproduced by type C strains of C. perfringens following ingestion of a high-proteinmeal in conjunction with trypsin inhibitors (e.g., in sweet potatoes) by asusceptible host who has limited intestinal proteolytic activity. This disease hasbeen reported among children and adults in New Guinea. A similar disease,darmbrand, was epidemic in Germany after World War II. Clinical features ofpigbel include acute abdominal pain, bloody diarrhea, vomiting, shock, andperitonitis; 40% of patients die. Pathologic studies reveal an acute ulcerativeprocess of the bowel restricted to the small intestine. The mucosa is lifted off thesubmucosa, with the formation of large denuded areas. Pseudomembranescomposed of sloughed epithelium are common, and gas may dissect into thesubmucosa. The source of the organisms may be the patients own intestinal flora;cultures of ingested pork have failed to yield the organism. Antibodies to the βtoxin of C. perfringens have been of considerable benefit in changing the course ofestablished disease. In a large-scale trial, children immunized with C. perfringensβ toxoid were protected. Neutropenic Enterocolitis (Typhlitis) See Chaps. 82 and 157. Suppurative Deep-Tissue Infections Clostridia are frequently recovered from various suppurative conditions inconjunction with other anaerobic and aerobic bacteria but can also be the onlyorganisms isolated. These suppurative conditions, which exist with severe localinflammation but usually without the characteristic systemic signs induced byclostridial toxins, include intraabdominal sepsis, empyema, pelvic abscess,subcutaneous abscess, frostbite with gas gangrene, infection of a stump in anamputee, brain abscess, prostatic abscess, perianal abscess, conjunctivitis,infection of a renal cell carcinoma, and infection of an aortic graft. Clostridia are isolated from approximately two-thirds of patients withintraabdominal infections resulting from intestinal perforation. C. ramosum, C.perfringens, and C. bifermentans are the most commonly isolated species. Thepresence of clostridial species does not affect the clinical presentation or outcomeof these infections (Chap. 157). An association has been made between malignancy and the isolation of C.septicum in the absence of a grossly contaminated deep traumatic wound; in thissituation, C. septicum may cause spontaneous nontraumatic myonecrosis (Fig.135-1). A major site for such a malig ...