Abstract

Fecal coliforms (FC), Escherichia coli, diarrheagenic E. coli pathotypes (enterotoxigenic, enteropathogenic, enteroinvasive, enteroaggregative and non-O157 Shiga toxin-producing) and Salmonella frequencies were determined for fresh-cut jicama [Pachyrhizus erosus (L.) Urban] root. One hundred fresh-cut jicama samples were collected from public markets in Pachuca, Mexico. Frequencies on 100 samples were 80% for FC, 50% for E. coli, 12% for diarrheagenic E. coli pathotypes (DEP) and 8% forSalmonella. Identified DEP included atypical enteropathogenic E. coli (atypical EPEC) on four samples, enterotoxigenic E. coli (ETEC) on four, and non-O157 Shiga toxin-producing E. coli (non-O157 STEC) on eight. Simultaneous presence of non-O157 STEC and atypical EPEC was found in one sample, and of non-O157 STEC and ETEC in three samples. No E. coli O157:H7 was detected in any STEC-positive samples. IdentifiedSalmonella serotypes included Typhimurium on three samples, Enteritidis on two, and Typhi, Agona and Newport on one. Both atypical EPEC and S. Typhi were identified in one sample, and non-O157 STEC and S. Typhimurium in one sample. No correlations (p>0.05) were observed between FC and Salmonella, E. coli and Salmonella, and DEP and Salmonella. The Kruskal-Wallis ANOVA test indicated no significant difference (p>0.05) in sample microbiological quality between source markets.

Key words: Diarrheagenic Escherichia coli pathotypes (DEP), enteropathogenic E. coli(EPEC), enterotoxigenic Escherichia coli (ETEC), Shiga toxin-producing E. coli (STEC),Salmonella, Jicama, Pachyrhizus erosus.