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ARS Home » Research » Publications at this Location » Publication #96260
Title: OPTIMIZED BOVINE FECAL CULTURE FOR SALMONELLAE WITH ISOLATE CONFIRMATION AND SEROGROUPING/TYPING BY AN ANTI-SALMONELLA MONOCLONAL ANTIBODY PANEL

Author
item KEEN, JAMES
item HE, THOMAS - FORMER MARC EMPLOYEE
item DANIELS, ED - FORMER MARC EMPLOYEE
item WOOLLEN, NEAL - FORMER MARC EMPLOYEE

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Pre-enrichment, selective enrichment broth, and selective/differential plating agars were compared to determine the most effective combination of conditions to isolate Salmonella spp. from bovine feces. Fresh bovine feces were inoculated with various dosages of nalidixic acid resistant S. typhimurium ATCC 14028. Buffered peptone water (BPW) and tetrathionate broth (TTB) were compared as pre-enrichment variables, and subsequent enrichment in Rappaport's media (R-10 broth) was compared to no selective enrichment. Finally, colony growth on five different agar media was compared: brilliant green-sulfadiazine (BGS), brilliant green-sulpha-mandalate (BGM), brilliant green-novobiocin (BGN), EF-18, and xylose-lysine-tergitol 4 (XLT4). The 20 unique culture protocols at each of six inoculum doses (10^0 to 10^5 cfu/gram) were tested in quadruplicate. Based on multiple logistic regression modeling, the most effective fecal culture protocol was pre-enrichment in either TTB or BPW followed by enrichment in R-10 broth and colony isolation on EF-18 media. Covariate-adjusted odds of successful isolation using R-10 broth were 33 times greater compared to no R-10 enrichment and were 14 times greater for EF-18 compared to BGS. Using TTB, R-10 and EF-18, 79% of isolation attempts were successful, compared to an overall isolation success rate of only 40% for all methods combined. We have employed this optimized protocol to detect naturally occurring Salmonella of numerous serotypes in bovine feces. Post-culture, we use a panel of anti-Salmonella monoclonal antibodies in a rapid ELISA format to both confirm the EF-18 isolates as Salmonella and to assign the isolates to commonly occurring bovine serogroups and serotypes.