Correlation of rRNA gene amplicon pyrosequencing and bacterial culture for microbial compositional analysis of faecal samples from elderly Irish subjects

Aims: The aim of this investigation was to establish the degree of correlation between measurements from culture-dependent microbiological techniques and from next generation sequencing technologies. Methods and Results: Data generated by both techniques were collected from faecal samples from 185 elderly Irish people involved in the ongoing ELDER-MET study (http://eldermet.ucc.ie). The results for three groups of intestinal bacteria were compared. Bifidobacterium sp., Lactobacillus sp. and Enterobacteriaceae were enumerated on selective media through culture-dependent techniques, whereas proportions of these bacteria were determined through sequencing technology against the background of other bacteria. The Spearman's rank correlation coefficient determined a good correlation between results from culture-dependent microbiology and culture-independent techniques for all three bacterial groups assessed (correlation coefficients for Bifidobacterium sp., Lactobacillus sp. and Enterobacteriaceae were 0.380, 0.366 and 0.437, respectively). Conclusion: Correlation between the two methods implies that a single method is capable of profiling intestinal Bifidobacterium, Lactobacillus and Enterobacteriaceae populations. However, both methods have advantages that justify their use in tandem. Significance and Impact of the Study: This is the first extensive study to compare bacterial counts from culture-dependent microbiological techniques and from next generation sequencing technologies.