Burn patients are particularly exposed to deep-seated nosocomial infections caused by Candida species. Superficial carriage of C. albicans is a potential source of infection and dissemination, and typing methods could be useful to trace the different isolates. We report the use of random amplified polymorphic DNA to type isolates of C. albicans in the Hôpital Cochin burn unit. This molecular typing method, which is based on PCR with arbitrary short primers, was evaluated on a panel of 32 C. albicans strains isolated from various anatomical sites of unrelated patients, and the strains showed 22 different patterns. Random amplified polymorphic DNA was then used in the epidemiological surveillance of the patients in the burn unit over a 9-month period. Seven patterns were identified among 84 isolates from 18 patients. One pattern (pattern A) corresponding to isolates from 7 of the 18 patients (68% of isolates) predominated throughout the 9-month study, while some strains with other profiles were isolated only once. Some profiles appeared to show a particular geographic pattern within the unit, suggesting transmission from room to room. These results underline the importance of fungal surveillance in such patients and the need to inform nursing staff of measures to prevent the spread of Candida spp. from patient to patient.

Infection by Toxoplasma gondii is asymptomatic, leading to an immune response that controls the disease. In immune-compromised patients, however, quiescent cysts can reactivate, leading to toxoplasmic encephalitis. We studied the infection of cells of the central nervous system in an attempt to understand the process leading to this complication. Primary cultures of rat hippocampal glial cells and neurons were infected with the virulent strain RH and examined by immunofluorescent microscopy after fixation of cells and staining with antibodies specific to the different cell types. After 24 h of infection, glial cells were highly infected and showed active division of the parasite. Neurons, on the other hand, were much less efficiently infected than glial cells, but actual penetration of the parasites was demonstrated by confocal microscopy. Whereas glial cells contained vacuoles with several parasites, the vacuoles observed in neurons usually contained one parasite or, rarely, two, indicating that the parasites inside neurons did not undergo active division. This was corroborated by determination of the incorporation of [3H]-uracil. Little is known about the mechanism of neuronal infection by Toxoplasma. The experimental setup used in this study should help to improve our understanding of neuronal infection and bring insight into the physiopathology of toxoplasmic encephalitis.

A case of congenital toxoplasmic chorioretinitis was diagnosed (specific-immunoglobulin G [IgG] and -IgM comparative Western blot analysis) in a baby whose mother was immune during pregnancy. Maternal sera showed an increase in specific IgG and emergence of both IgM and IgA during pregnancy. The mother was probably reinfected through contact with kittens.

No abstract

Immunofluorescence cross-reactions in Trichinella spiralis serodiagnosis are sometimes difficult to identify. We compared the results of an indirect immunofluorescence assay and the profiles obtained by Western blot (immunoblot) analysis for three groups of patients: 10 T. spiralis-infected patients, 10 patients with autoimmune diseases, and 7 patients with parasitic diseases other than trichinellosis. The degree of immunofluorescence cross-reaction was variable. Western blotting allowed us to differentiate Trichinella infection from other parasitic diseases. In 3 of 10 serum samples from patients with autoimmune diseases, bands which had the same sizes as Trichinella bands were observed, and they could correspond to shared epitopes such as heat shock proteins.