Background: About 20 species of aspergillus have been recognized as nosocomial pathogens that cause opportunistic infections. A. fumigatus is the most commonly isolated pathogenic species, followed by A. flavus and A. niger. These fungi cause secondary infections in patients suffering from asthma, cystic fibrosis, sinusitis, meningitis, endocarditis and myocarditis. Microscopical and cultural characteristics can identify aspergillus spp only at the genus/species level and may take several days. Other molecular methods such as PFGE, RFLP and RAPD are tedious and prone to artifacts. A commercial rep-PCR assay that automates rep-PCR has shown promise for rapid fungal identification and strain classification. Methods: Fifty aspergillus isolates from hostpitals located in different geographical regions and 25 isolates from the environment were collected and identified as A. fumigatus, A. flavus, A. terrus, A. niger. Genomic DNA was extracted from each isolate grown on YAG plates and 50 ng of each DNA was amplified using the rep-PCR assay. One microliter of amplified product was processed using the Caliper® 1000 Analyzer and the data were analyzed using the rep-PCR system software. Results: Data showed that strain-level differentiation of aspergillus spp can easily be carried out using the automated rep-PCR and results were concordant with the previous characterization by traditional methods. Significant genetic diversity was appreciated between samples that were isolated from hospital and the environment. Furthermore, heterogeneity was observed among the samples isolated from the environment. The above results were processed and analyzed in 1 working day by a single technician. Conclusions: The automated rep-PCR system showed that it may be an effective genotyping tool for the identification and strain relatedness of fungi. The system has potential to differentiate environmental verses hospital aspergillus strains.
Full conference title:
43rd Interscience Conference on Antimicrobial Agents
- ICAAC 43rd