Susceptibility of bacterial strains to desiccation: a simple method to test their stability in microbiological reference materials
✍ Scribed by Birgit Janning; P.H. in't Veld
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 707 KB
- Volume
- 286
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
AbStlWt
The purpose of this work was to predict the behaviour of bacteria within spray-dried powders used for the production of microbiological reference materials. The survival of eighteen bacterial strains desiccated on anhydrous silica gel and stored at 22°C for at least 3 months was determined. According to their percentage survival after desiccation, storage and reconstitution after certain time periods a classification of these bacterial strains was possible. Gram-positive strains such as Enterococcus faecium showed a relatively high resistance to desiccation with more than 30% survival on each day of sampling. Certain Gram-negative strains such as Aeromonas hydrophila were very susceptible to this treatment; culturable cells could not be determined as soon as 1 week after desiccation. Other Gram-negative organisms (e.g., Salmonella serotypes, Exherichia coli and Enterobacter cloacae) were less susceptible to drying than this group but showed a lower resistance than the Gram-positive bacterial strains. The use of anhydrous silica gel is probably a suitable basis for the development of a screening system to characterize the susceptibility of bacterial strains to desiccation. Further, the suitability of methods to improve the stability of the concentration of microorganisms in dry materials could be investigated with the help of this desiccation system.