Silica desiccant packets for storage and transport of Streptococcus pneumoniae and other clinically relevant species

PLoS One. 2013 Aug 7;8(8):e72353. doi: 10.1371/journal.pone.0072353. Print 2013.

Abstract

Bacterial isolates are often transported between laboratories for research and diagnostic purposes. Silica desiccant packets (SDPs), which are inexpensive and do not require freezing, were evaluated for storage and recovery of bacterial isolates. Conditions such as inoculum size, swab type and temperature of storage were investigated using ten Streptococcus pneumoniae isolates. The optimized protocol was then tested using 49 additional S. pneumoniae isolates representing 40 serogroups. Overall, S. pneumoniae growth was considered satisfactory (>100 colony forming units) for 98/109 (89.9%) and 20/20 (100%) swabs after 14 days at room temperature or 28 days at 4° C, respectively. Storage in SDPs did not impact on the ability of S. pneumoniae isolates to be subsequently serotyped. When the survival of nine other clinically relevant bacterial species was tested, seven were viable after 28 days at room temperature, the exceptions being Neisseria gonorrhoeae and Haemophilus influenzae. SDPs are suitable for transport and short-term storage of bacterial species including S. pneumoniae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriological Techniques
  • Culture Techniques
  • Hygroscopic Agents / chemistry*
  • Microbial Viability
  • Refrigeration
  • Silicon Dioxide / chemistry*
  • Specimen Handling / methods*
  • Streptococcus pneumoniae / physiology*

Substances

  • Hygroscopic Agents
  • Silicon Dioxide

Grants and funding

This work was supported by The Bill and Melinda Gates Foundation as part of the PneuCarriage project (Grant 52099), and the Victorian Government's Operational Infrastructure Support Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.