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Characteristic morphological and phylogenetic analyses demonstrated the presence of Aspergillus fumigatus and Aspergillus lentulus as the aetiological agents in a case of probable invasive aspergillosis (IA). This is believed to be the first report of an A. lentulus strain isolated from a patient with probable IA in Argentina.

Background: Prolonged therapy with ganciclovir (GCV) can result in the development of GCV-resistant strains due to mutations in the viral phosphotransferase (UL97 gene) and/or in the viral DNA polymerase (UL54 gene)., Objectives: The purpose of this study was to detect by molecular methods the most prevalent UL97 mutants which confer ganciclovir-resistance in immunocompromised populations., Study Design: Patients from two populations were selected: (a) renal transplant patients with active cytomegalovirus (CMV) infection and more than one cycle of GCV; (b) HIV-infected patients with retinitis due to CMV, who were under GCV induction, maintenance therapy or withdrawal. Patients were followed up by pp65 antigenemia and by viral isolation from blood or/and urine samples. Two fragments (133 and 255pb) of the UL97 gene were amplified by polymerase chain reaction (PCR) from CMV isolates., Results: Nine from 12 isolates obtained were sequenced, three from two renal transplant patients and six from five HIV-infected patients. A UL97 mutation, known to confer GCV resistance, was found in two isolates from a renal transplant patient. A methionine to valine mutation at codon 460 (M460V) was detected. These isolates exhibited another mutation at codon 605, whose amino acid changed from aspartic acid (D) to glutamic acid (E). These findings were observed after treatment with IV-GCV/ O-GCV/ IV-GCV for 151 days. The 605 mutation was also detected in leukocytes from the same patient previous to the beginning of the treatment with GCV., Conclusions: Although a known resistant mutation appeared in a renal transplant patient, it was not associated with CMV disease. We suggest that the D605E mutation could "partially or totally compensate" for the effect of GCV resistance conferred by the 460 mutation. Further studies should be performed to confirm this hypothesis.

In immunocompromised patients, diagnosis of Cytomegalovirus (CMV) active infection is of utmost importance for the initiation, monitoring and ending of antiviral therapy. Therefore, the presence of viral replication should be demonstrated. Isolation in tissue culture is one of the standard methods. The objective of the present paper was to compare two isolation procedures for CMV: conventional cell culture (CC) and rapid shell vial (SV) assay in human fibroblasts. A total of 584 clinical samples were studied between 1991 and 1998. CMV was isolated in 14.4% of the samples, 11.8% of which were positive by SV and 7.7% by CC. Out of 84 positive samples, concordance between both methods was observed in 36% of the cases. We found that 46% of the samples were positive only by SV, while 18% were positive only by CC. The average time required for obtaining the results by CC was 22.6 +/- 2.3 days. Out of the 69 samples positive by SV, 43% were already positive after 24 hours and the rest after 48 hours. These results indicate that SV was more sensitive and rapid than CC. The main advantage of CC, despite its time-consuming process, is the ability to recover the viral strain for both antiviral susceptibility phenotypical tests and strain characterization. Furthermore, in this study, absence of CC would have resulted in the loss of 18% of the positive diagnoses. In conclusion, simultaneous use of both methods is suggested in order to obtain a rapid result and the highest sensitivity.