On the basis of the numbers of Nocardia strains referred to the National Reference Center for Mycoses and Antifungal Agents (NRC), Institut Pasteur, Paris, in the period from 1987 to 1990, it was estimated that between 150 and 250 cases of nocardiosis are diagnosed in France each year. A total of 63 clinical isolates were referred to the NRC and identified as Nocardia asteroides (66.7%), Nocardia farcinica (23.8%), Nocardia brasiliensis (3.2%), Nocardia otitidiscaviarum (4.8%) and Nocardia carnea (1.5%). Nocardia asteroides accounted for 71.4% of pulmonary infections, 80.0% of central nervous system infections and 80.0% of systemic infections. Patients infected with Nocardia farcinica died in 57.1% of cases, compared with 17.6% of patients infected with Nocardia asteroides. Corticosteroid therapy represented a significant factor in mortality. Isolates of Nocardia asteroides revealed variable resistance, whereas isolates of Nocardia farcinica were resistant to most antimicrobial agents. Only amoxicillin/clavulanic acid, imipenem, cefoxitin, kanamycin, amikacin, minocycline and vancomycin showed activity against both species. Nocardiosis caused by Nocardia farcinica may be a growing problem because of the relatively high incidence in AIDS patients and the resistance of this species to most antimicrobial agents.

Mutations in one or more genes encoding complement-regulatory proteins predispose to atypical hemolytic uremic syndrome (aHUS) and its recurrence following kidney transplantation. We evaluated plasma complement level and performed a screening for mutations in genes encoding complement Factors H and I (CFH, CFI) and membrane cofactor protein (MCP) in 24 kidney transplant recipients experiencing de novo thrombotic microangiopathy (TMA). Six patients presented with low C3 and/or low Factor B levels suggestive complement alternative pathway. A mutation in the CFH or CFI gene was found in 7/24 patients (29%), two of whom had a mutation in both genes. On the contrary, no mutation was identified in a control kidney transplant patients group (n = 25) without TMA. Patients with or without mutations were similar with regard to clinical features. Eight out of 24 patients lost their graft within 1 year of posttransplantation including six patients with a CFH mutation or a decrease of C3 or CFB in plasma. To conclude, kidney transplant patients with de novo TMA exhibit an unexpectedly high frequency of CFH and CFI mutations. These results suggest that genetic abnormalities may represent risk factors for de novo TMA after kidney transplantation and raise the question of the best therapeutic strategy.

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Aims: The present study describes a system based on PCR and restriction endonuclease analysis (REA) to distinguish the seven currently recognized Malassezia species. Methods and Results: Fifty‐five representative yeast isolates were examined. A single primer pair was designed to amplify the large subunit ribosomal RNA (LSU rRNA) gene of the seven Malassezia species, and identification was achieved by digestion of the PCR products with three restriction endonucleases: BanI, HaeII and MspI. A specific restriction endonuclease analysis pattern was determined for each species investigated. Moreover, PCR‐REA allowed the detection and characterization of mixtures of several Malassezia species. Conclusion: PCR‐REA of only the LSU rRNA gene is a reliable and rapid method to distinguish all Malassezia species. Significance and impact of the study: PCR‐REA represents a considerable saving in time over currently available identification procedures. This method should be evaluated on clinical material directly.

We studied fungemia over time in outbred mice infected with Cryptococcus neoformans and looked at its relationship with the intravenous (i.v.) inoculum size, tissue burden and survival. Fungemia was evaluated by culture of 10 ml of peripheral blood from living mice or by culture of buffy coats from sacrificed animals. For all inoculum sizes studied, fungemia could last several weeks after the i.v. inoculation. Individual susceptibility of outbred mice to cryptococcal infection was evidenced by variations in the course, duration and magnitude of fungemia and tissue localizations. These results suggest that the fungus can recirculate after the initial i.v. inoculation. Fungemia, assessed by culture of buffy coats, correlated with the extent of infection in the spleen, lung or brain (PB 0·001) on day 1 after inoculation but only with yeast burden in lung or spleen on day 8, thus demonstrating that brain reacts differently to C. neoformans infection than other organs. Comparison of blood culture techniques and examination of smears suggest that cryptococci might circulate within leucocytes. Finally, quantitative blood cultures may accurately assess the fungal load during experimental cryptococcosis.

Two regions of the gene coding for 16S rRNA in Nocardiaspecies were selected as genus-specific primer sequences for a PCR assay. The PCR protocol was tested with 60 strains of clinically relevant Nocardia isolates and type strains. It gave positive results for all strains tested. Conversely, the PCR assay was negative for all tested species belonging to the most closely related genera, including Dietzia, Gordona,Mycobacterium, Rhodococcus,Streptomyces, and Tsukamurella. Besides, unlike the latter group of isolates, all Nocardia strains exhibited one MlnI recognition site but no SacI restriction site. This assay offers a specific and rapid alternative to chemotaxonomic methods for the identification of Nocardiaspp. isolated from pathogenic samples.

We conducted a retrospective survey of nocardiosis in 9 city hospitals in northern Italy from 1982 to 1992. The medical records of 30 patients with documented nocardiosis were reviewed. Microbiological data included morphology, biochemical characteristics, serology and in vitro susceptibility testing. The 29 isolates (1 case was diagnosed on the basis of serological results) were Nocardia asteroides (n = 25) and Nocardia farcinica (n = 4). Predisposing factors including immunosuppression for organ transplant rejection prophylaxis, lung disease (silicotuberculosis and pulmonary fibrosis), solid tumours and hematological malignancies, and AIDS. Three patients had no identified risk factors. 20 cases of pulmonary nocardiosis were observed. Sites of infection in patients without previous pulmonary involvement were: brain abscesses, soft tissues, pericardium, blood, and cerebrospinal fluid. Most strains tested were susceptible to amikacin and imipenem. Resistance to several antimicrobial agents was found, particularly erythromycin, fosfomycin, pefloxacin, sulphonamides and trimethoprim. Antimicrobial chemotherapy included sulphonamides, amikacin, ceftriaxone, imipenem and minocycline. 21 patients survived, although 2 relapsed transiently. Nocardiosis appears to be more common than generally realised by physicians in northern Italy. The local species distribution and disease spectrum are similar to those described elsewhere. Nocardiosis should be part of the differential diagnosis in patients with pulmonary infiltrates or brain abscess, particularly those with predisposing factors.

By disc diffusion, 28 clinical isolates of four species of Nocardia were tested against 16 antimicrobial agents. Among the drugs included in the study, only a few exhibited in-vitro activities. A species difference in susceptibility was noted for amoxicillin + clavulanic acid, kanamycin, gentamicin, chloramphenicol, minocycline and erythromycin, which was of clinical and taxonomic interest. All six N. brasiliensis and six N. otitidis-caviarum were susceptible to gentamicin and minocycline, while all 15 N. asteroides were not. In addition, N. otitidis-caviarum was susceptible to kanamycin and chloramphenicol, while the sensitivity of N. farcinica was less predictable. The only antibiotic to which members of all of the Nocardia species tested were susceptible was amikacin, which therefore appears to be a good candidate for the treatment of all forms of nocardial infections.