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Citron DM. Appelbaum PC.: How far should a clinical laboratory go in identifying anaerobic isolates, and who should pay? Clinical Infectious Diseases. 16 Suppl 4:S435-8, 1993 Identification of anaerobic bacteria in specimens from sites of infection due to mixed organisms can be time-consuming and expensive. Laboratories should limit anaerobic workups by testing only those specimens that have been properly collected and transported to the laboratory. Use of selective and differential media for initial processing can provide rapid and relevant information to the clinician. Anaerobes isolated from normally sterile sites and sites of serious infection should always be completely identified. Group-or genus-level identifications may suffice in other instances. The Bacteroides fragilis group of organisms should always be identified because of their virulence and resistance to many antimicrobial agents. Some of the other organisms that warrant identification include Clostridium septicum (associated with gastrointestinal malignancy); Clostridium ramosum, Clostridium innocuum, and Clostridium clostridioforme (which are resistant to antibiotics); Clostridium perfringens (a cause of myonecrosis and gas gangrene,potentially serious infection); anaerobic cocci (which may be resistant to metronidazole and clindamycin); and fusobacteria (which may be virulent and resistant to clindamycin and penicillin).

Newfield RS. Vargas I. Huma Z.: Eikenella corrodens infections. Case report in two adolescent females with IDDM. Diabetes Care. 19:1011-3, 1996 OBJECTIVE: To alert physicians caring for patients with diabetes to the microorganism Eikenella corrodens and to discuss the appropriate preventive and therapeutic measures to take against this potentially morbid opportunistic gram-negative bacilli. CASES: We present two cases of extra-oral E. corrodens infections in adolescent females with IDDM. The first patient had diabetes of four years' duration, which was moderately well controlled. Chronic finger biting resulted in a complex felon that evolved gradually and worsened while the patient received cephalexin orally. Delay in seeking further intervention resulted in necrosis of her distal fingertip and nail bed. The second patient had poorly controlled diabetes for five years. She developed an acute thigh abscess at an insulin injection site that resolved after drainage and intravenous antibiotics. CONCLUSIONS: E. corrodens commonly inhabits the human oral cavity and becomes a pathogen mostly when host defenses are impaired, causing abscesses and infections that are at times fatal. Patients with IDDM are compromised hosts and with daily microtrauma to their skin via glucose monitoring and insulin injections, are prone to develop E. corrodens infections that can be introduced through oral secretions by licking or biting their skin. Educational efforts aimed at preventing exposure of traumatized skin to oral secretions can minimize the risk of E. corrodens infections in compromised hosts. Early intravenous administration of antibiotics, bearing in mind E. corrodens resistance to clindamycin, metronidazole, and other antibiotics, coupled with prompt surgical intervention, is essential in successfully managing E. corrodens infections.

The first step in treating patients with CDAD is to discontinue the causative agent wherever possible. The choice for initial antibiotic therapy depends on the severity of disease. Oral vancomycin or metronidazole remain the mainstays of therapy for C. difficile infection, with vancomycin reserved for patients with more severe disease and/or those who have not responded to metronidazole. Metronidazole is currently favored in guidelines from the CDC on the basis of cost and concern that oral vancomycin promotes colonization with vancomycin-resistant Enterococcus. Oral fluids (water and electrolytes) may be necessary to counteract fluid loss as a result of excessive diarrhea, which can quickly lead to dehydration. Patients with fulminant disease and toxic megacolon may require colectomy. Recurrence of C. difficile infection (CDI) is becoming an increasing problem. Most recurrences happen 7 - 14 days after completion of therapy, suggesting relapse rather than re-infection. If a patient develops a second episode of CDI following initial successful treatment, it is recommended that if possible, the same drug be used to treat the second episode. Contributing factors to recurrent CDI include: Continuing exposure to organisms either through re-infection (via contaminated environment or poor hand hygiene) or an endogenous source, such as C. difficile spores in GI tract. An inability to mount an adequate anti-Toxin A IgM and/or IgG antibody response (i.e., poor host immune response); a likely reason why CDI affects an increasingly elderly population. Unfortunately a vicious cycle can arise whereby the initial treatment prescribed, vancomycin or metronidazole, significally disrupts normal colonic flora reducing colonization resistance and leaving the patient vulnerable to the next recurrent episode.Other treatments including the use of probiotics or anion-exchange resins to absorb toxins, may work in some cases but none work in every case.The goal of all treatment is to reestablish normal colonic flora so as to control C. difficile (over)growth.