ARS | Publication request: EVALUATION OF CULTURE METHODS USED FOR INVESTIGATION OF SALMONELLA ENTERICASEROVAR ECOLOGY IN FECES

Submitted to: Microbial Ecology International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: May 3, 2001
Publication Date: N/A

Technical Abstract: The present study evaluated culture methods to optimize detection and isolation of a wide range of Salmonella serovars from feces. Fecal samples were obtained from cows, horses and pigs. Select samples were seeded with antibiotic resistance carring Typhmurium and Choleraesuis strains acting as positive controls. Two pre-enrichment (buffered peptone water [BP], GN broth, Hajna), 3 selective enrichment (Rappaport-Vassiliadis [RV] broth, selenite cystine [SC] broth, tetrathionate [T] broth) and 5 selective plating (brilliant green sulfa [BGS], xylose lysine tergitol 4 [XLT4], Hektoen enteric [HE], Rambach [RA], Chromagar Salmonella [CAS]) media were evaluated. Colonies were counted on selective agars as presumptive Salmonella (PSC) or non-Salmonella (NSC). Differentiation of PSC and NSC was more difficult on BGS and HE and best on CAS, while XLT4 and HE favored H2S producing serovars. Both pre-enrichment media increased PSC detection. RV and SC inhibited NSC more than T. RA detected colony morphological differences among serovars. No single method appeared to be adequate to investigate Salmonella serovar ecology. Future work will use two selective enrichments, RV and SC, after BP pre-enrichment with isolation on XLT4 and CAS followed by RA for differentiation indices.