The polymerase chain reaction was used for the detection of Clostridium difficile, the etiologic agent of antibiotic-associated colitis. An upstream primer identical to a coding region (segment I) of the C. difficile 16S rRNA gene and a downstream primer complementary to a highly conserved region of eubacterial 16S rRNA served to amplify a targeted 270-base-pair fragment of genomic DNA. This technique allowed the detection of as few as 10 C. difficile organisms among 10(6) Escherichia coli bacteria. This level of sensitivity represents a 100-fold increase over that of conventional anaerobic culture. C. difficile was detected in DNA extracted directly from the stools of 23 patients with antibiotic-associated colitis and from those of four patients with diarrhea whose stools had been negative for C. difficile when assessed in a cytotoxicity assay. No amplification products were found in the stools of asymptomatic patients. When detected in stools of symptomatic patients, amplification products of C. difficile were confirmed by Southern blotting with a nonradioactive, horseradish peroxidase-catalyzed, chemiluminescent probing system in which biotin-labeled oligonucleotides were used. This system discriminates between C. difficile and similar organisms, such as Clostridium sordellii and Clostridium bifermentans. The combination of the polymerase chain reaction with enzyme-linked probing results in a faster and more sensitive assay for C. difficile than standard culture.

Actinomycosis is caused by the anaerobic bacterium Actinomyces israelii. Asymptomatic colonization of the cervix with this organism has been noted in users of an intrauterine device (IUD), and its prevalence ranges between 1.6% and 36%. Rarely, symptomatic infection may occur, with the potential for extensive morbidity and even death. Herein we report a patient who survived severe disseminated actinomycosis yet presented with the clinical picture of a metastasized malignancy. This is the first report of disseminated pelvic actinomycosis presenting as an external lesion of the abdominal wall and in which a Progestasert IUD (Alza, Palo Alto, CA) was present. The common difficulty, and thus delay, in diagnosing this disease led to considerable morbidity due to an infection considered curable with penicillin. We recommend that all patients with an IUD or a history of IUD use have such information made known to those responsible for interpreting the Papanicolaou smear. Such knowledge may heighten suspicion and focus attention on the identification of these organisms before onset of clinical disease. It is important to consider this disease when caring for patients with an IUD or when counseling those contemplating its use as a contraceptive.

Two recombinant herpes simplex viruses, of type 1 background, were constructed with two large deletions and duplicate sets (type 1 and type 2) of the genes coding for glycoproteins D, G, and E. One recombinant (R7020) is thymidine kinase-positive, and the other (R7017) is thymidine kinase-negative. Evaluation in rodents indicated that these viruses are genetically stable, capable of establishing latency, protective against severe herpetic diseases, and protective against the establishment of latency. In Aotus monkeys, R7020 replicates at the site of inoculation but does not disseminate in the body. It can reactivate from the latent state but without causing recurrent lesions, even in immunosuppressed monkeys.