الوصف
Clostridium difficile is a pathogen that can cause severe gastrointestinal disease, particularly in patients undergoing antibiotic therapy, and is a leading cause of hospital-acquired diarrhea. It was first identified as the primary cause of pseudomembranous colitis and frequently isolated from the feces of patients treated with clindamycin. C. difficile produces two main toxins, toxin A (an enterotoxin) and toxin B (a cytotoxin), which act synergistically to cause disease. Some strains produce only toxin B (toxin A-negative, toxin B-positive) but are still virulent. Expression of C. difficile toxins, including toxin A and toxin B, may be enhanced by stressors such as antibiotics and catabolite repression, though multiple regulatory factors contribute to toxin production. Toxin A specifically modifies members of the Ras superfamily of small GTPases via glycosylation, irreversibly inactivating these proteins and disrupting essential cellular signaling pathways. The processes of receptor binding and cell entry are also crucial steps in mediating toxin-induced cellular damage.
دواعي الإستعمال
Diagnosis of Clostridium difficile infection primarily involves detecting toxins A and B in stool samples. False-negative results may occur due to toxin instability and proteolytic degradation. Consequently, diagnostic strategies often incorporate additional antigen detection and molecular tests to improve accuracy.
نوع العينة والكمية والشروط
Stool or proctoscopic specimen Room Temperature, no longer than 2 hours Stability: 24 hours at 2-8 °C
إحتياطات خاصة
Test must be performed within 2 hours of sample collection, due to toxin degradation.
المعدل الطبيعي
سلبي (Negative)