Identification of two genetic markers that distinguish pathogenic and nonpathogenic strains of Acanthamoeba spp.

Species-level identification of Acanthamoeba isolates is difficult and gives little or no indication of the isolate's pathogenicity. We identified two amplification-based genetic markers that were highly correlated with pathogenicity in Acanthamoeba spp. One marker, designed to amplify a 485-bp fragment of the small-subunit ribosomal RNA gene (ssrDNA), was preferentially amplified from the nonpathogenic strains; amplifications from the pathogenic strains yielded anomalous fragments of 650 and 900?bp. A second marker was developed on the basis of the anomalous 650-bp fragment. Primers to this sequence preferentially amplified a noncoding locus (called Ac6) only from the pathogenic strains. These two genetic markers may be useful for identification of pathogenic Acanthamoeba spp. strains.     

Cryptococcal Meningitis in Patients with the Acquired Immunodeficiency Syndrome

The optimum therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS) remains unresolved. Traditional therapy consists of amphotericin B with or without flucytosine. Obstacles exist in administering these agents to patients with AIDS. Mortality rates during initial therapy are relatively high. Given the lack of proved benefit, we do not recommend adding flucytosine to amphotericin B routinely. The search for more efficacious and less toxic agents continues. The oral triazoles, especially fluconazole, have increased the options for treatment of this disease. New strategies and novel approaches in managing cryptococcal meningitis in patients with AIDS continue to be developed.     

Contraception and sexually transmitted diseases: Interactions and opportunities

Today "safe sex" means protection from both unintended pregnancy and sexually transmitted disease and human immunodeficiency virus. These parallel complications of sexual activity have serious biologic and clinical sequelae that should be considered at the time of contraceptive selection. In addition, there is ongoing debate regarding potential interactions between antibiotic intervention and contraceptive steroids. This article assesses the impact of hormonal contraception, spermicides, barrier methods, intrauterine devices, and douching on the pathogenesis of sexually transmitted disease and the human immunodeficiency virus infection. It discusses the direct and indirect effects of contraception methods on clinical physiology and host immune responses while also considering the possible consequences on maternal and infant health if pregnancy results from the use of ineffective contraception. Counseling and care for both family planning and infectious disease protection must be provided to all sexually active individuals. (Ann J OBSTET GVNECOL 1993;168:2033-41.)     

The epidemiology of nosocomial Pseudomonas cepacia infections: Endemic infections

Pseudomonas cepacia has recently emerged as an important nosocomial pathogen. We analyzed a national nosocomial infections database, the National Nosocomial Infections Surveillance (NNIS) system, to describe the epidemiology of endemic nosocomial P. cepacia infections. Between 1980 and 1985, the P. cepacia nosocomial infection rate was 2.4 per 100,000 patient discharges. During this period, there was a significant increase in the P. cepacia infection rate. The highest infection rate was reported from large medical school-affiliated hospitals. Over 90% of the infections were reported from medicine and surgery services. The most frequently reported site of infection was the lower respiratory tract (31%), followed by blood (20%) and the urinary tract (20%). Nosocomial P. cepacia infections are often associated with mortality, particularly when they involve the lung. These data confirm the hypothesis that P. cepacia is an emerging nosocomial pathogen and suggest that the epidemiology of endemic infections differs from that reported for epidemic inflections.