Utility of a modified silver staining technique for detection of Leptospira
<p><strong>Background:</strong><em> Leptospira</em> are spiral thin and highly motile pathogenic bacteria that are best visualized by dark ground microscopy. Although these bacteria are not stained by the Gram’s stain, the Fontana stain, which is a silver impregnation s...
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| Format: | Article |
| Language: | English |
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Sri Lankan Society for Microbiology
2017-10-01
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| Series: | Sri Lankan Journal of Infectious Diseases |
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| Online Access: | https://sljid.sljol.info/articles/8142 |
| _version_ | 1811231888036069376 |
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| author | C. P. Gunasekara M. H. F. Sumaiha M. K. S. Damayanthi M. M. Weerasekera S. S. N. Fernando |
| author_facet | C. P. Gunasekara M. H. F. Sumaiha M. K. S. Damayanthi M. M. Weerasekera S. S. N. Fernando |
| author_sort | C. P. Gunasekara |
| collection | DOAJ |
| description | <p><strong>Background:</strong><em> Leptospira</em> are spiral thin and highly motile pathogenic bacteria that are best visualized by dark ground microscopy. Although these bacteria are not stained by the Gram’s stain, the Fontana stain, which is a silver impregnation staining method, can be used successfully for light microscopy. It is important to investigate the usefulness of Fontana stain method for direct demonstration of <em>Leptospira</em> in human body fluids.</p><p><strong><br /></strong></p><p><strong>Objectives:</strong> To determine the usefulness and sensitivity of a modified Fontana silver staining method for microscopic detection of <em>Leptospira</em> in clinical specimens.<strong></strong></p><p><strong><br /></strong></p><p><strong>Methodology:</strong> 6×10<sup>8</sup> organisms/ml of <em>Leptospira interrogans</em> serovar Icterohaemorrhagiae and Canicola were spiked into PBS (Phosphate Buffered Saline), alkalinized urine and serum in triplicate and serial dilutions were made (6×10<sup>6</sup> to 6×10<sup>1</sup> organisms/ml). Smears were prepared using 10 µl of each dilution. In addition, centrifuged sediment of urine were also used to prepare smears. Slides were stained by modified Fontana method as reported by Gangadhar et al.(1998) and examined. Numbers of leptospires per field (×100) were recorded.</p><p><strong><br /></strong></p><p><strong>Results:</strong> <em>Leptospira</em> spiked in PBS and urine appeared as thin slender bacteria with characteristic hooked ends after Fontana staining under the light microscope. Serum could not be used for the detection of <em>Leptospira</em> by this method.<em> Leptospires</em> could be detected by staining the spiked PBS and urine at 6x10<sup>3</sup> – 6x10<sup>6</sup> organisms/ml.</p><p><strong><br /></strong></p><p><strong>Conclusion:</strong> <em>Leptospires</em> could be detected by Fontana staining in spiked PBS, urine (uncentrifuged and sediment). Serum was not suitable for detection of leptospires by Fontana staining. The detection limit of leptospires in PBS and urine by Fontana stain was found to be 6000 organisms/ml.</p> |
| first_indexed | 2024-04-12T10:52:30Z |
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| id | doaj.art-c345638d659045f3b68445936fb5586b |
| institution | Directory Open Access Journal |
| issn | 2012-8169 2448-9654 |
| language | English |
| last_indexed | 2024-04-12T10:52:30Z |
| publishDate | 2017-10-01 |
| publisher | Sri Lankan Society for Microbiology |
| record_format | Article |
| series | Sri Lankan Journal of Infectious Diseases |
| spelling | doaj.art-c345638d659045f3b68445936fb5586b2022-12-22T03:36:10ZengSri Lankan Society for MicrobiologySri Lankan Journal of Infectious Diseases2012-81692448-96542017-10-0172859110.4038/sljid.v7i2.81425734Utility of a modified silver staining technique for detection of LeptospiraC. P. Gunasekara0M. H. F. Sumaiha1M. K. S. Damayanthi2M. M. Weerasekera3S. S. N. Fernando4University of Sri JayewardenepuraUniversity of Sri JayewardenepuraUniversity of Sri JayewardenepuraUniversity of Sri JayewardenepuraUniversity of Sri Jayewardenepura<p><strong>Background:</strong><em> Leptospira</em> are spiral thin and highly motile pathogenic bacteria that are best visualized by dark ground microscopy. Although these bacteria are not stained by the Gram’s stain, the Fontana stain, which is a silver impregnation staining method, can be used successfully for light microscopy. It is important to investigate the usefulness of Fontana stain method for direct demonstration of <em>Leptospira</em> in human body fluids.</p><p><strong><br /></strong></p><p><strong>Objectives:</strong> To determine the usefulness and sensitivity of a modified Fontana silver staining method for microscopic detection of <em>Leptospira</em> in clinical specimens.<strong></strong></p><p><strong><br /></strong></p><p><strong>Methodology:</strong> 6×10<sup>8</sup> organisms/ml of <em>Leptospira interrogans</em> serovar Icterohaemorrhagiae and Canicola were spiked into PBS (Phosphate Buffered Saline), alkalinized urine and serum in triplicate and serial dilutions were made (6×10<sup>6</sup> to 6×10<sup>1</sup> organisms/ml). Smears were prepared using 10 µl of each dilution. In addition, centrifuged sediment of urine were also used to prepare smears. Slides were stained by modified Fontana method as reported by Gangadhar et al.(1998) and examined. Numbers of leptospires per field (×100) were recorded.</p><p><strong><br /></strong></p><p><strong>Results:</strong> <em>Leptospira</em> spiked in PBS and urine appeared as thin slender bacteria with characteristic hooked ends after Fontana staining under the light microscope. Serum could not be used for the detection of <em>Leptospira</em> by this method.<em> Leptospires</em> could be detected by staining the spiked PBS and urine at 6x10<sup>3</sup> – 6x10<sup>6</sup> organisms/ml.</p><p><strong><br /></strong></p><p><strong>Conclusion:</strong> <em>Leptospires</em> could be detected by Fontana staining in spiked PBS, urine (uncentrifuged and sediment). Serum was not suitable for detection of leptospires by Fontana staining. The detection limit of leptospires in PBS and urine by Fontana stain was found to be 6000 organisms/ml.</p>https://sljid.sljol.info/articles/8142leptospira, modified fontana silver stain, urine |
| spellingShingle | C. P. Gunasekara M. H. F. Sumaiha M. K. S. Damayanthi M. M. Weerasekera S. S. N. Fernando Utility of a modified silver staining technique for detection of Leptospira Sri Lankan Journal of Infectious Diseases leptospira, modified fontana silver stain, urine |
| title | Utility of a modified silver staining technique for detection of Leptospira |
| title_full | Utility of a modified silver staining technique for detection of Leptospira |
| title_fullStr | Utility of a modified silver staining technique for detection of Leptospira |
| title_full_unstemmed | Utility of a modified silver staining technique for detection of Leptospira |
| title_short | Utility of a modified silver staining technique for detection of Leptospira |
| title_sort | utility of a modified silver staining technique for detection of leptospira |
| topic | leptospira, modified fontana silver stain, urine |
| url | https://sljid.sljol.info/articles/8142 |
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