title: Presence and correlation of some enteric indicator bacteria, diarrheagenic Escherichia coli pathotypes, and Salmonella serotypes in alfalfa sprouts from local retail markets in Pachuca, Mexico.
abstract: Data on the presence of diarrheagenic Escherichia coli pathotypes (DEPs) in alfalfa sprouts and correlations between the presence of coliform bacteria (CB), fecal coliforms (FC), E. coli, DEPs, and Salmonella in alfalfa sprouts are not available. The presence of and correlations between CB, FC, E. coli, DEPs, and Salmonella in alfalfa sprouts were determined. One hundred sprout samples were collected from retail markets in Pachuca, Hidalgo State, Mexico. The presence of indicator bacteria and Salmonella was determined using conventional culture procedures. DEPs were identified using two multiplex PCR procedures. One hundred percent of samples were positive for CB, 90% for FC, 84% for E. coli, 10% for DEPs, and 4% for Salmonella. The populations of CB ranged from 6.2 up to 8.6 log CFU/g. The FC and E. coli concentrations were between , 3 and 1,100 most probable number (MPN)/g. The DEPs identified included enterotoxigenic E. coli (ETEC; 2%), enteropathogenic E. coli (EPEC; 3%), and Shiga toxin-producing E. coli (STEC; 5%). No E. coli O157:H7 strains were detected in any STEC-positive samples. In samples positive for DEPs, the concentrations ranged from 210 to 240 MPN/g for ETEC, 28 to 1,100 MPN/g for EPEC, and 3.6 to 460 MPN/g for STEC. The Salmonella isolates identified included Salmonella enterica serotype Typhimurium in three samples and Salmonella enterica serotype Enteritidis in one. STEC and Salmonella Typhimurium were identified together in one sample. Positive correlations were observed between FC and E. coli, between FC and DEPs, and between E. coli and DEPs. Negative correlations occurred between CB and DEPs and between CB and Salmonella. Neither FC nor E. coli correlated with Salmonella in the sprout samples. To our knowledge, this is the first report of ETEC, EPEC, and STEC isolated from alfalfa sprouts and the first report of correlations between different indicator groups versus DEPs and Salmonella.
authors.affiliation: Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo Kilometer 4.5, 42183 Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Rangel-Vargas
authors.affiliation: Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo Kilometer 4.5, 42183 Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Gómez-Aldapa
authors.affiliation: Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingeniería, Universidad de Guadalajara, Marcelino García Barragán 1451, 44430 Guadalajara, Jalisco, Mexico.
authors.forename: M Del Refugio
authors.initials: Mdel R
authors.lastname: Torres-Vitela
authors.affiliation: Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingeniería, Universidad de Guadalajara, Marcelino García Barragán 1451, 44430 Guadalajara, Jalisco, Mexico.
authors.forename: Angélica
authors.initials: A
authors.lastname: Villarruel-López
authors.affiliation: Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo Kilometer 4.5, 42183 Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Gordillo-Martínez
authors.affiliation: Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, Carretera Pachuca-Tulancingo Kilometer 4.5, 42183 Mineral de la Reforma, Hidalgo, Mexico. jcastro@uaeh.edu.mx.
authors.forename: Javier
authors.initials: J
authors.lastname: Castro-Rosas
mesh_terms: D015169:Colony Count, Microbial; D054308:Enteropathogenic Escherichia coli / Q000302:isolation & purification*; D054307:Enterotoxigenic Escherichia coli / Q000302:isolation & purification*; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D000455:Medicago sativa / Q000382:microbiology*; D008800:Mexico; D016133:Polymerase Chain Reaction; D012477:Salmonella enteritidis / Q000302:isolation & purification*; D012486:Salmonella typhimurium / Q000302:isolation & purification*