EPA-OW: 1682:  Salmonella in Sewage Sludge (Biosolids) by MSRV Medium

  • Summary
  • Analytes
  • Revision
  • Data and Sites
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
  EPA-OW
Citation
  SW-846 Online: Test Methods for Evaluating Solid Waste, Physical/Chemical Methods
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