Article Text

P1.21 Comparison of shipped versus freshly frozen self-collected vaginal samples for microbiota assessment
  1. Brotman R1,
  2. P Gajer1,
  3. Holm Jb1,
  4. Robinson Cr1,
  5. D Jones2,
  6. A Chatterjee1,
  7. M Humphrys1,
  8. Forney Lj2,
  9. J Ravel1,
  10. Ghanem Kg2
  1. 1Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, USA
  2. 2Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, USA; 3Department of Biological Sciences, University of Idaho, Moscow, USA


Introduction Studies have confirmed that self-collected and clinician-collected mid-vaginal swabs sample the same microbial diversity. Self-collected samples shipped through the mail for PCR-based STI testing has also been validated. We sought to determine if the microbiota of shipped vaginal samples are concordant with freshly frozen samples.

Methods In January-February 2016, 20 women self-collected six mid-vaginal swabs which were then stored in two different nucleic acid preservatives (3 E-swabs in 2 ml of modified C2 (MO BIO) and 3 in 2 ml of Amies/RNALater). Modified C2 was selected for ease of use in laboratory processing and DNA extraction. For each set of 3 swabs, 2 were immediately frozen (−80°C) and one was sent at room temperature to the University of Idaho in a FedEx “Clinical Pak” which was then return shipped to Baltimore. Meta-taxonomic analysis was performed by sequencing the V3-V4 regions of the 16S rRNA gene. Hierarchical clustering of vaginal microbiota was used to assign community state types (CST) to each sample. Bayesian hierarchical models were applied to perform within-women comparisons of shipped and freshly frozen samples.

Results Average duration of transit for the shipped samples was 8 days (SD: 1.60, range: 6–11). Paired comparison of CSTs between a woman’s shipped and freshly frozen samples as well as between C2 and Amies/RNALater revealed no differences (100% concordance, kappa: 1.0 for both). After correction for multiple testing, no significant differences between phylotype relative and absolute abundances were detected in C2 or Amies/RNALater groups. Similarly, there were no statistically significant differences between total bacterial loads of shipped versus freshly frozen samples in C2 (p-value: 0.47) or Amies/RNALater (p-value: 0.21) samples.

Conclusion There were no differences in vaginal microbiota composition and structure between a woman’s shipped and freshly frozen vaginal samples stored in Amies/RNAlater or C2. These data enable future studies to allow participants to self-collect and mail vaginal microbiota specimens.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.