Performance of 2 commercial real-time polymerase chain reaction assays for the detection of Aspergillus and Pneumocystis DNA in bronchoalveolar lavage fluid samples from critical care patients.

This article investigates the performance of 2 commercial real-time polymerase chain reaction (PCR) assays, MycAssay™ Aspergillus (Myc(Asp)Assay) and MycAssay™ Pneumocystis (Myc(PCP)Assay), on the ABI 7300 platform for the detection of Aspergillus (Asp) or Pneumocystis jirovecii (Pj) DNA in bronchoalveolar lavage (BAL) samples from 20 patients. Operationally, patients enrolled were clustered into 3 groups: invasive aspergillosis group (IA, 7 patients), Pj pneumonia group (PCP, 8 patients), and negative control group (5 patients). All the IA patients were Myc(Asp)Assay positive, whereas 12 non-IA patients returned negative PCR results. Furthermore, 7 of 8 PCP patients were Myc(PCP)Assay positive, while 9 non-PCP patients were PCR negative. In conclusion, these data provide an early indication of the effectiveness of both the Myc(Asp)Assay and Myc(PCP)Assay on the ABI 7300 platform for the detection of either Asp or Pj DNA in BAL from patients with deep fungal infections.

A new species, Aspergillus persii, as an agent of onychomycosis.

Onychomycosis due to non-dermatophytic fungi is a well-known and increasingly common infection. For the first time ever, we report two cases of onychomycosis caused by Aspergillus persii, a recently described new Aspergillus species. After ten and three years respectively, both patients showed relapsing nail infections, and mycological tests were still positive for A. persii. In vitro antifungal susceptibility tests demonstrated that both strains were only susceptible to itraconazole, voriconazole, posaconazole and terbinafine of the agents tested.

[Interactions and false positive results of galactomannan antigen detection for diagnosis of invasive aspergillosis]. / Interazioni e falsi positivi della ricerca dell'antigene galattomannano, per la diagnosi di aspergillosi invasiva.

Invasive aspergillosis (IA) is a leading cause of morbidity and mortality in immunocompromised hosts, with a survival rate lower than 50%. Although proven diagnosis of IA requires histopathological evidence of deep-tissue invasion, eventually supported by microbiological cultures, critical conditions of patients often hamper invasive diagnostic procedures, and many IA cases are not diagnosed during life. Detection of circulating galactomannan antigens is a non-invasive method widely used to support the diagnosis of IA. However, results of test performance have been variable and, in particular, the method shows specificity problems due to cross reactions and false positive results caused by other microorganisms, foods, antibiotics, graft versus host disease and particular physiological conditions of premature infants. It appears therefore mandatory to know exactly all these possible interactions, in order to properly evaluate GM test results and correctly apply them to the diagnosis of IA and to clinical practice.

Infections in patients with febrile neutropenia: epidemiology, microbiology, and risk stratification.

Determinations of the type and setting of empirical therapy for immunocompromised patients with fever are complicated by the characteristics of the underlying illness and the effects of treatments already received, as well as by changing microbiological patterns and trends in drug resistance at national and institutional levels. Several systems have been proposed to distinguish patients who could benefit from outpatient antibiotic therapy from patients who require hospitalization. Practical considerations may decide whether the necessary monitoring during the period of neutropenia can be achieved.

False-positive galactomannan platelia Aspergillus test results for patients receiving piperacillin-tazobactam.

At the bone marrow transplantation center of the San Martino Hospital (Genoa), we observed an increase in the rate of patients with positive Platelia Aspergillus (PA; Bio-Rad) test results, from 10% (38 of 386 patients) in the period from January 1999 through January 2003 to 36% (21 of 59 patients) in the period from February 2003 through May 2003. Positivity was significantly (P<.001) associated with the administration of piperacillin-tazobactam (PT) (17 [74%] of 23 patients who received PT had positive results vs. 4 [11%] of 36 who did not receive PT). Multivariate analysis found administration of PT ( chi 2=34.7; P<.001) and underlying disease ( chi 2=21.14; P<.001) to be associated with PA positivity. Of 15 PT batches tested, 12 had positive PA test results.

Aspergillus galactomannan antigen in the cerebrospinal fluid of bone marrow transplant recipients with probable cerebral aspergillosis.

The Aspergillus galactomannan test was performed on cerebrospinal fluid and serum samples from 5 patients with probable cerebral aspergillosis and from 16 control patients. Cerebrospinal fluid galactomannan levels were significantly higher in aspergillosis patients, and most galactomannan was produced intrathecally. Comparison of serum galactomannan values in pulmonary and cerebral aspergillosis patients showed significant overlapping. Detection of Aspergillus galactomannan in cerebrospinal fluid may be diagnostic of cerebral aspergillosis.