EPA-OW: 1682: Salmonella in Sewage Sludge (Biosolids) by MSRV Medium
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Official Method Name
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Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rapport-Vassiliadis (MSRV) Medium |
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Current Revision
| July 2006 Rev. 0 |
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Media
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SOILS/SEDIMENT |
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Instrumentation
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Not Applicable |
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Method Subcategory
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Microbiological |
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Method Source
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Citation
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Brief Method Summary
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Tryptic soil broth (TSB) enrichment medium in tubes is inoculated with a measured amount of sample and incubated for 24 hours. After incubation, positive (cloudy) tubes are spotted onto plates of MSRV medium and incubated at 42 deg. C for 16 - 18 hours. The MSRV medium uses novobiocin and malachite green to inhibit non-Salmonella species, while allowing most Salmonella species to grow. MSRV and the elevated temperature (42 deg. C) are inhibitory for S. typhi. Presumptive colonies are isolated on xylose-lysine desoxycholate (XLD) agar and confirmed using lysine-iron (LIA), triple sugar iron (TSI) agar, and urea broth followed by serological typing using polyvalent O antisera. |
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Scope and Application
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Detection and enumeration of Samonella in treated biosolids. Although selective for Salmonella bacteria it does not differentiate among Samonella species. |
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Applicable Concentration Range
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Interferences
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High numbers of competing or inhibitory organisms or toxic substances such as metals and organic compounds can result in low estimates of Salmonella. |
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Quality Control Requirements
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Minimum QC requires a positive control, a negative control, and a blank. |
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Sample Handling
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Collect samples in sterile, non-toxic glass or plastic containers with leakproof lids. |
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Maximum Holding Time
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N/A |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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