Comparison between rep-PCR-based DNA fingerprint and sequence analyses of clinically relevant Nocardia species

Abstract number: P1688

Embry J., Sussland D., Reece K., Dutch W., Smith C., Atkins E., Ross T., Abedi S., Frye S., Saubolle M., Healy M.

Objectives: Nocardiosis is a localised or disseminated infection caused by ubiquitous, soil borne, aerobic, and saprophytic actinomycetes. Nocardia species most often affect immunocompromised patients. Nocardia asteroides (causes at least 50% of invasive infections). Other pathogenic species include N. farcinica, N. nova, N. transvalensis, N. brasiliensis, and N. pseudobrasiliensis. In the United States, an estimated 500–1,000 new cases of Nocardia infection occur annually and other reports indicate fewer instances in European countries and Japan. Generally, for accurate identification to the species level sequencing is performed. rep-PCR based DNA fingerprinting has shown promise for rapid species and strain-level discrimination for some bacteria and fungi. In this study, we compared rep-PCR-based DNA fingerprint and sequence analyses of clinically relevant Nocardia species.

Methods: A total of 12 Nocardia species were purchased from ATCC including N. abscessus, N. africana, N. asteroides, N. brasiliensis, N. brevicatena, N. carnea, N. farcinica, N. nova, N. otitidis­caviarum, N. paucivorans, N. pseudobrasiliensis, and N. transvalensis. In addition, 30 clinical isolates were collected and analysed. The isolates were cultured, and genomic DNA was extracted from each isolate. DNA was then amplified using the DiversiLab Nocardia Fingerprinting Kit (beta version). The data were processed using the DiversiLab software.

Results: DNA fingerprints were obtained for all Nocardia species using the DiversiLab System. Rep-PCR-based clustering of all Nocardia isolates was in agreement with the sequence-based identification of the clinical isolates and the ATCC isolates. Additionally, the rep-PCR method showed sub-species discrimination.

Conclusions: The DiversiLab System is a rapid molecular genotyping tool that shows promise for differentiation of Nocardia species. The sub-species discrimination indicates potential as a strain typing tool for epidemiological studies.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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