Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics
OBJECTIVE: The preservation of Streptococcus pneumoniae by standard freezing methods for subsequent tests - such as serotyping and antibiotic susceptibility - is not possible or is difficult in many developing countries because of the high cost of equipment, inadequate equipment maintenance, and irr...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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The World Health Organization
2001-01-01
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| Series: | Bulletin of the World Health Organization |
| Subjects: | |
| Online Access: | http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S0042-96862001000100009 |
| _version_ | 1797285145872433152 |
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| author | Siberry George Brahmadathan K.N. Pandian Rajeswar Lalitha M.K. Steinhoff Mark C. John T. Jacob |
| author_facet | Siberry George Brahmadathan K.N. Pandian Rajeswar Lalitha M.K. Steinhoff Mark C. John T. Jacob |
| author_sort | Siberry George |
| collection | DOAJ |
| description | OBJECTIVE: The preservation of Streptococcus pneumoniae by standard freezing methods for subsequent tests - such as serotyping and antibiotic susceptibility - is not possible or is difficult in many developing countries because of the high cost of equipment, inadequate equipment maintenance, and irregular power supply. We evaluated alternative low-cost methods, by comparing different culture media and storage temperatures. METHODS: Clinical isolates of five capsular types (1, 5, 7, 19, and 23) of S. pneumoniae were preserved in rabbit blood, sheep blood, skimmed milk, or glycerol-chocolate broth, and stored at -20 masculineC or -70 masculineC. The cultures were also preserved by lyophilization or sand desiccation, followed by storage at room temperature and 4 masculineC. The viability of the preserved cultures was determined by making serial colony counts on day 0 and after 1 week, 4 weeks, 4 months and 16 months. The viability of cultures preserved by sand desiccation and storage at 4 masculineC was also determined every 6 months for up to 68 months. FINDINGS: Irrespective of the media used, cultures maintained at -20 masculineC became nonviable by the fourth month, while those maintained at -70 masculineC were still viable at 16 months. Cultures preserved by lyophilization or sand desiccation lost their viability by the fourth month when maintained at local room temperature (30-42 masculineC), but remained viable when stored at 4 masculineC for up to 68 months. CONCLUSION: Our results confirm that freezing at -70 masculineC, or lyophilization and storage at 4 masculineC are the ideal methods for the preservation of S. pneumoniae. In laboratories where lyophilization is not feasible, sand desiccation and storage at 4 masculineC offers an alternative low-cost method for the long-term preservation of S. pneumoniae. |
| first_indexed | 2024-03-07T17:58:56Z |
| format | Article |
| id | doaj.art-b5befd9ddcc44bd3a32c38755209a819 |
| institution | Directory Open Access Journal |
| issn | 0042-9686 |
| language | English |
| last_indexed | 2024-03-07T17:58:56Z |
| publishDate | 2001-01-01 |
| publisher | The World Health Organization |
| record_format | Article |
| series | Bulletin of the World Health Organization |
| spelling | doaj.art-b5befd9ddcc44bd3a32c38755209a8192024-03-02T11:20:37ZengThe World Health OrganizationBulletin of the World Health Organization0042-96862001-01-017914347Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropicsSiberry GeorgeBrahmadathan K.N.Pandian RajeswarLalitha M.K.Steinhoff Mark C.John T. JacobOBJECTIVE: The preservation of Streptococcus pneumoniae by standard freezing methods for subsequent tests - such as serotyping and antibiotic susceptibility - is not possible or is difficult in many developing countries because of the high cost of equipment, inadequate equipment maintenance, and irregular power supply. We evaluated alternative low-cost methods, by comparing different culture media and storage temperatures. METHODS: Clinical isolates of five capsular types (1, 5, 7, 19, and 23) of S. pneumoniae were preserved in rabbit blood, sheep blood, skimmed milk, or glycerol-chocolate broth, and stored at -20 masculineC or -70 masculineC. The cultures were also preserved by lyophilization or sand desiccation, followed by storage at room temperature and 4 masculineC. The viability of the preserved cultures was determined by making serial colony counts on day 0 and after 1 week, 4 weeks, 4 months and 16 months. The viability of cultures preserved by sand desiccation and storage at 4 masculineC was also determined every 6 months for up to 68 months. FINDINGS: Irrespective of the media used, cultures maintained at -20 masculineC became nonviable by the fourth month, while those maintained at -70 masculineC were still viable at 16 months. Cultures preserved by lyophilization or sand desiccation lost their viability by the fourth month when maintained at local room temperature (30-42 masculineC), but remained viable when stored at 4 masculineC for up to 68 months. CONCLUSION: Our results confirm that freezing at -70 masculineC, or lyophilization and storage at 4 masculineC are the ideal methods for the preservation of S. pneumoniae. In laboratories where lyophilization is not feasible, sand desiccation and storage at 4 masculineC offers an alternative low-cost method for the long-term preservation of S. pneumoniae.http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S0042-96862001000100009Streptococcus pneumoniae/preservationculture mediacryopreservation/methodslyophilization/methodsdesiccation/methodstropical climate |
| spellingShingle | Siberry George Brahmadathan K.N. Pandian Rajeswar Lalitha M.K. Steinhoff Mark C. John T. Jacob Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics Bulletin of the World Health Organization Streptococcus pneumoniae/preservation culture media cryopreservation/methods lyophilization/methods desiccation/methods tropical climate |
| title | Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics |
| title_full | Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics |
| title_fullStr | Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics |
| title_full_unstemmed | Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics |
| title_short | Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniaein the tropics |
| title_sort | comparison of different culture media and storage temperatures for the long term preservation of streptococcus pneumoniaein the tropics |
| topic | Streptococcus pneumoniae/preservation culture media cryopreservation/methods lyophilization/methods desiccation/methods tropical climate |
| url | http://www.scielosp.org/scielo.php?script=sci_arttext&pid=S0042-96862001000100009 |
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