The Journal of protozoology最新文献

A large retrospective study was conducted to evaluate the impact of culturing cytomegalovirus from the respiratory secretions of AIDS patients with Pneumocystis carinii pneumonia. Pneumocystis carinii was found in 220 (67%) of 327 episodes and cytomegalovirus was found in 106 (48%) of the P. carinii-positive patients. Cytomegalovirus-positive and -negative patients were similar at baseline and had a similar number of hospital days, but had a lower incidence of early deterioration in oxygenation, fewer intensive-care days, were less frequently intubated, and had a higher 30-day survival. The better short-term outcome of cytomegalovirus positive patients observed in this study may relate to the immunosuppressive effects of cytomegalovirus.

Cryptosporidium muris-like oocysts in 5 g of camel feces were concentrated by the Sheather sugar flotation method, saline-washed, pelleted and reconstituted to an approximate concentration of 2.5 million per ml. One- to 2-microliters inocula were given per os to 25 2- to 20-day-old mice, with 15 contact control litter-mates. The 15- and 20- day inoculates had acid-fast-positive fecal smears by day-12 after inoculation. Necropsies of mice inoculated at 2 and 5 days of age showed colonization only of gastric glands by day-12, and day-27, respectively. Control mice were negative. Identical methods using similar oocysts from cattle produced no evidence of transmission.

The synergistic activities of anti-Pneumocystis drugs were investigated. Macrolide antibiotics alone and in combination with sulfonamides were tested for their effects on P. carinii pneumonia in rats.

Understanding the pathophysiology of Pneumocystis carinii infection has been limited by the availability of methods for precisely measuring the interaction of P. carinii with host cells. Here we describe a new method which allows for the rapid assessment of P. carinii binding to, and internalization by, adherent alveolar macrophages. The method is based on the detection of fluorescein-labelled P. carinii by an automated fluorescence measurement system.

Three culture systems employing mammalian lung cell monolayers were evaluated in terms of their ability to support the replication of primary isolates of rat-derived Pneumocystis carinii. For each system, analysis of variance was used to identify changes in the numbers of P. carinii over time. Significant replication was consistently demonstrated over lung fibroblasts (MRC-5), however, increases perceived in the culture supernatant were clearly influenced by the density of the underlying monolayer.

The influence of viruses and bacteria on Pneumocystis carinii pneumonia (PCP) is suspected but not known for certain. A number of adventitious viruses and bacteria are common among commercially available and institutionally raised rodents, which may impact upon, or interfere with, the induction of PCP in rodents in several ways. Based upon the biological behavior and prevalence of certain rodent agents, the potential for such impact is great. Infectious agents can directly interfere with research by inducing severe disease in the immunocompromised host. They may also influence the course of P. carinii infection or disease via direct effects upon the respiratory tract or via indirect effects on lymphoreticular cells or other organ systems. Examples of likely agents and their potential effects are discussed.