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USE OF A MOLECULAR PROBE ASSAY FOR MONITORING SALMONELLA SPP. IN BIOSOLIDS SAMPLES
Citation:
Meckes*, M C., J. A. MacDonald, AND C D. Barnes*. USE OF A MOLECULAR PROBE ASSAY FOR MONITORING SALMONELLA SPP. IN BIOSOLIDS SAMPLES. Presented at Biosolid 2002 conference, Austin, TX, 3/3-6/2002.
Description:
Current federal regulations (40 CFR 503) require enumeration of fecal coliform or salmonellae prior to land application of biosolids. This regulation specifies use of enumeration methods included in "Standard methods for the Examination of Water and Wastewater 18th Edition," (SM), or when analyzing for salmonellae, a cultural method developed by Kenner and Clark. For "Class A" biosolids the regulations requires the use of multiple-tube fermentation techniques for fecal coliform or multiple tube enrichment techniques for Salmonella spp. followed by isolation and biochemical and serological confirmation. The difficulties in completing the procedure for enumeration of salmonellae in biosolids and sludges has limited the use of this assay for meeting regulatory requirements. Moreover, the time required to confirm the presence of salmonellae in a given sample is considerably longer than the time required to estimate the density of fecal coliforms. Analytical methods for Salmonella spp. which provide results expeditiously may provide the means for more frequent and routine monitoring of biosolid samples for these organisms. Molecular probes have been used for assaying clinical samples and food samples for several years. These probes ar short strands of genetic material (oligonucleotides) which have a chromogenic or other type of marker attached to the probe. The probe is mated to the genetic material lysed from cells contained within a given sample. The genetic material will only anneal to probes which complement the host's DNA. Consequently, it is important for the probe's oligonucleotide to specific for the organism(s) of interest. This study was conducted to determine if a commercially available molecular probe system cold be used to determine and enumerate Salmonella spp. in biosolids or sludges.