title: Antibacterial effect of roselle extracts (Hibiscus sabadariffa), sodium hypochlorite and acetic acid against multidrug-resistant Salmonella strains isolated from tomatoes.
abstract: Antibiotic-resistant Salmonella strains were isolated from saladette and red round type tomatoes, and an analysis done of the antibacterial activity of roselle calyx extracts against any of the identified strains. One hundred saladette tomato samples and 100 red round tomato samples were collected from public markets. Each sample consisted of four whole tomatoes. Salmonella was isolated from the samples by conventional culture procedure. Susceptibility to 16 antibiotics was tested for the isolated Salmonella strains by standard test. The antibacterial effect of four roselle calyx extracts (water, methanol, acetone and ethyl acetate), sodium hypochlorite and acetic acid against antibiotic-resistant Salmonella isolates was evaluated on contaminated tomatoes. Twenty-four Salmonella strains were isolated from 12% of each tomato type. Identified Salmonella serotypes were Typhimurium and Typhi. All isolated strains exhibited resistance to at least three antibiotics and some to as many as 12. Over contaminated tomatoes, the roselle calyx extracts produced a greater reduction (2-2·6 log) in antibiotic-resistant Salmonella strain concentration than sodium hypochlorite and acetic acid.
  
  
  CONCLUSIONS
  The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Multidrug-resistant Salmonella strains were isolated from raw tomatoes purchased in public markets in Mexico and challenged with roselle Hibiscus sabdariffa calyx extracts, sodium hypochlorite and acetic acid. On tomatoes, the extracts caused a greater reduction in the concentration of antibiotic-resistant Salmonella strains than sodium hypochlorite and acetic acid. Roselle calyx extracts are a potentially useful addition to disinfection procedures of raw tomatoes in the field, processing plants, restaurants and homes.
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: E J
authors.initials: EJ
authors.lastname: Gutiérrez-Alcántara
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Rangel-Vargas
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: C A
authors.initials: CA
authors.lastname: Gómez-Aldapa
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.|Catedrática CONACyT, Consejo Nacional de Ciencia y Tecnología, Av. Insurgentes Sur 1582, Col. Crédito Constructor, Del. Benito Juárez C.P. 03940, México, D.F. México.
authors.forename: R N
authors.initials: RN
authors.lastname: Falfan-Cortes
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.|Catedrática CONACyT, Consejo Nacional de Ciencia y Tecnología, Av. Insurgentes Sur 1582, Col. Crédito Constructor, Del. Benito Juárez C.P. 03940, México, D.F. México.
authors.forename: M L
authors.initials: ML
authors.lastname: Rodríguez-Marín
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: A
authors.initials: A
authors.lastname: Godínez-Oviedo
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: H
authors.initials: H
authors.lastname: Cortes-López
authors.affiliation: Área Académica de Químicas, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Castro-Rosas
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods; D024901:Drug Resistance, Multiple, Bacterial; D005517:Foodborne Diseases / Q000382:microbiology / Q000517:prevention & control; D031584:Hibiscus / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000382:microbiology*; D008800:Mexico; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D012485:Salmonella typhi / Q000187:drug effects* / Q000302:isolation & purification; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000302:isolation & purification; D012973:Sodium Hypochlorite / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants; D010936:Plant Extracts; D012973:Sodium Hypochlorite; D019342:Acetic Acid
keywords: Salmonella; antibiotic; antimicrobials; resistance; roselle