EPA-OW: 1682: Salmonella in Sewage Sludge (Biosolids) by MSRV Medium
Official Method Name
|
Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rapport-Vassiliadis (MSRV) Medium |
---|---|
Current Revision
| July 2006 Rev. 0 |
Media
|
SOILS/SEDIMENT |
Instrumentation
|
Not Applicable |
Method Subcategory
|
Microbiological |
Method Source
|
|
Citation
|
|
Brief Method Summary
|
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. |
Scope and Application
|
Detection and enumeration of Samonella in treated biosolids. Although selective for Salmonella bacteria it does not differentiate among Samonella species. |
Applicable Concentration Range
|
|
Interferences
|
High numbers of competing or inhibitory organisms or toxic substances such as metals and organic compounds can result in low estimates of Salmonella. |
Quality Control Requirements
|
Minimum QC requires a positive control, a negative control, and a blank. |
Sample Handling
|
Collect samples in sterile, non-toxic glass or plastic containers with leakproof lids. |
Maximum Holding Time
|
N/A |
Relative Cost
|
Unknown |
Sample Preparation Methods
|