921. Metagenomic Analysis of Anterior Nares Colonization in Nursing Home Residents
Session: Poster Abstract Session: Bacterial Pathogenesis
Saturday, October 22, 2011
Room: Poster Hall B1

Background: Metagenomics allows us to study microbial communities at different body sites. The bacteria that cause healthcare associated infections (HAIs) are a part of these communities. Community composition may influence colonization with individual pathogens including Staphylococcus aureus. Methods: We swabbed the anterior nares of eleven nursing home-dwelling, adults who did not have diabetes, skin breakdown or recent antibiotic use. After the genomic DNA was extracted from each swab, the variable region V2 of the 16S rRNA gene was amplified using the “universal” bacterial 16S primers 27F and 338R, and the resulting PCR products sequenced using the 454 FLX Titanium platform. The number of 16S sequences obtained for each samples ranged from 6,167 to 10,572. Species-level taxonomic assignments of the 16S rRNA gene sequences were performed using the RDP Classifier and SpeciateIT. Samples were also cultured for S. aureus and pathogenic Gram-negative bacilli. Results: The eleven subjects were all men. Our data showed that using 16S rRNA gene profiling, S. aureus was present and the dominant species in only 2 of the 11 subjects (subjects 1299 and 1300). This was confirmed qualitatively via microbiological culture. Our data also demonstrated by both culture and 16S sequencing that Gram-negative bacilli from the genera Proteus, Stenotrophomonas, Escherichia, Acinetobacter, and Citrobacter are present in the bacterial flora of the anterior nares. Conclusion: The relative abundance of 16S sequences from S. aureus was very high in subjects who were S. aureus colonized by culture. The relative abundance of 16S sequence from Gram-negative bacilli in our nursing home dwelling population is larger than that seen in healthy adults.


Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Mary-Claire Roghmann, MD, MS1,2, J. Kristie Johnson, PhD1,3 and Emmanuel Mongodin, PhD1, (1)University of Maryland School of Medicine, Baltimore, MD, (2)VA Maryland Healthcare System, Baltimore, MD, (3)Univ. of Maryland Med. Ctr., Baltimore, MD


M. C. Roghmann, None

J. K. Johnson, None

E. Mongodin, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.