Title: Growth of non-0157:H7 shiga-toxin producing Escherichia coli on catfish fillets Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 12, 2013
Publication Date: July 13, 2013
Citation: Khosravi, P., Silva, J., Sommers, C.H., Sheen, S. 2013. Growth of non-0157:H7 shiga-toxin producing Escherichia coli on catfish fillets. Meeting Abstract., IFT Annual Meeting, Chicago, IL., July 13-16, 2013. Volume 1, Page 1. Technical Abstract: Shiga-toxin producing Escherichia coli (STECs) are emerging pathogens which have been involved in numerous foodborne illness outbreaks. In this study the ability of a multi-isolate cocktail of STEC serovars O26:H11, O45:H2, O103:H2, O111:NM, O121:H19, and O145:RM to grow on catfish fillets at refrigeration and abuse temperatures was investigated. Catfish fillet samples (10 g) were inoculated with the STEC cocktails to ca. 3 log CFU/g and incubated under aerobic conditions for up to 120 h. There was no STEC growth at 4 deg C, however, the STECs grew at 10, 15, 20 and 30 deg C in a temperature dependent manner, with higher growth rates being associated with higher temperatures. Lag phase ranged from 15h at 10 deg C to 1.75 h at 30 deg C. Exponential phase growth rates ranged from 0.03 log CFU/g/h at 10 deg C to 0.65 log CFU/g/h at 30 deg C. Growth curves constructed using ComBase DMfit provided a good statistical fit to the observed data, resulting in a high correlation coefficient (R2) of 0.98. The results of this study provide information to risk assessors regarding the growth potential of the STECs on aquaculture-raised fish using catfish as a model system.