title: Prevalence and behavior of multidrug-resistant Salmonella strains on raw whole and cut nopalitos (Opuntia ficus-indica L.) and on nopalitos salads.
abstract: BACKGROUND
  The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Nopalito is a cactaceous that is commonly consumed either raw or cooked in Mexico and other countries. The presence of antibiotic-resistant Salmonella strains on raw whole nopalitos (RWN, without prickles), raw nopalitos cut into squares (RNCS) and in cooked nopalitos salads (CNS) samples was determined. In addition, the behavior of multidrug-resistant Salmonella isolates on RWN, RNCS and CNS at 25° ± 2 °C and 3° ± 2 °C was investigated.
  
  
  RESULTS
  One hundred samples of RWN, 100 of RNCS and 100 more of CNS were collected from public markets. Salmonella strains were isolated and identified in 30, 30 and 10% of the samples, respectively. Seventy multidrug-resistant Salmonella strains were isolated from all the nopalitos samples. Multidrug-resistant Salmonella isolates survived at least 15 days on RWN at 25° ± 2 °C or 3° ± 2 °C. Multidrug-resistant Salmonella isolates grew in the RNCS and CNS samples at 25° ± 2 °C. However, at 3° ± 2 °C the bacterial growth was inhibited.
  
  
  CONCLUSIONS
  This is the first report about multidrug-resistant Salmonella isolation from raw nopalitos and nopalitos salads. Nopalitos from markets are very likely to be an important factor contributing to the endemicity of multidrug-resistant Salmonella-related gastroenteritis in Mexico. © 2017 Society of Chemical Industry.
authors.affiliation: Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, México.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Gómez-Aldapa
authors.affiliation: Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, México.
authors.forename: Eduardo J
authors.initials: EJ
authors.lastname: Gutiérrez-Alcántara
authors.affiliation: Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Guadalajara, Jalisco, México.
authors.forename: M Refugio
authors.initials: MR
authors.lastname: Torres-Vitela
authors.affiliation: Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, México.
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Rangel-Vargas
authors.affiliation: Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Guadalajara, Jalisco, México.
authors.forename: Angelica
authors.initials: A
authors.lastname: Villarruel-López
authors.affiliation: Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Hidalgo, México.
authors.forename: Javier
authors.initials: J
authors.lastname: Castro-Rosas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D008800:Mexico; D029747:Opuntia / Q000382:microbiology*; D012475:Salmonella / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D014675:Vegetables / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Opuntia ficus-indica; Salmonella; antibiotic; multidrug-resistant; nopalitos; vegetable salads