ARS | Publication request: Molecular Identification of Aspergillus Species: Transplant Associated Infection Surveillance Network (TRANSNET)

Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 3, 2009
Publication Date: April 1, 2009
Citation: Balajee, S., Kano, R., Baddley, J.W., Moser, S.A., Marr, K.A., Alexander, B.D., Andes, D., Kontoyiannis, D.P., Perrone, G., Peterson, S.W., Brandt, M.E., Pappas, P.G., Chiller, T. 2009. Molecular Identification of Aspergillus Species: Transplant Associated Infection Surveillance Network (TRANSNET). Journal of Clinical Microbiology. 47(10):3138-3141.

Interpretive Summary: Human organ transplants often fail due to Invasive Aspergillosis (a fungal infection) that can occur when anti-rejection and other immune system lowering drugs are given to the organ recipient. We have determined DNA sequences from Invasive Aspergillosis (IA) molds to determine the species that cause the disease, and have examined the susceptibility of the different species to a range of anti-fungal antibiotics. While the majority of IA is caused by a single species, Aspergillus fumigatus, significant numbers of IA are cause by three or four other Aspergillus species that have different resistances to anti-fungal antibiotics. Correct and quick identification of the causal species allows use of the most effective antifungal therapies early in the course of disease.

Technical Abstract: A large aggregate collection of clinical isolates of aspergilli (n=218) from transplant patients with proven or probable Invasive Aspergillosis (IA) was available from the Transplant Associated Infection Surveillance Network (TRANSNET), a six-year prospective surveillance study. With the objective to determine the Aspergillus species distribution in this collection, isolates were subjected to comparative sequence analyses using the Internal Transcribed Spacer (ITS) and the beta tubulin regions. Aspergillus fumigatus was the predominant species recovered, followed by A. flavus and A. niger. Several newly described species were identified including A. lentulus and A. calidoustus; both these species had high in vitro minimum inhibitory concentrations (MICs) to multiple antifungal drugs. For the first time, A. tubingensis, a member of the A. niger species complex is described from clinical specimens; all the A. tubingensis isolates had low in vitro MICs to antifungal drugs.