| Autor: |
Avila-Novoa MG; Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Ocotlán 47810, Jalisco, Mexico., Navarrete-Sahagún V; Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Ocotlán 47810, Jalisco, Mexico., González-Gómez JP; Laboratorio Nacional para la Investigación en Inocuidad Alimentaria (LANIIA), Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD), Carretera a Eldorado Km. 5.5, Culiacán 80110, Sinaloa, Mexico., Novoa-Valdovinos C; Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Ocotlán 47810, Jalisco, Mexico., Guerrero-Medina PJ; Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Ocotlán 47810, Jalisco, Mexico., García-Frutos R; Departamentos de Farmacobiología y Matemáticas, CUCEI, Universidad de Guadalajara, Marcelino García Barragán 1451, Guadalajara 44430, Jalisco, Mexico., Martínez-Chávez L; Departamentos de Farmacobiología y Matemáticas, CUCEI, Universidad de Guadalajara, Marcelino García Barragán 1451, Guadalajara 44430, Jalisco, Mexico., Martínez-Gonzáles NE; Departamentos de Farmacobiología y Matemáticas, CUCEI, Universidad de Guadalajara, Marcelino García Barragán 1451, Guadalajara 44430, Jalisco, Mexico., Gutiérrez-Lomelí M; Centro de Investigación en Biotecnología Microbiana y Alimentaria, Departamento de Ciencias Básicas, División de Desarrollo Biotecnológico, Centro Universitario de la Ciénega, Universidad de Guadalajara, Av. Universidad 1115, Ocotlán 47810, Jalisco, Mexico. |
| Abstrakt: |
Listeria monocytogenes is an important pathogen that has been implicated in foodborne illnesses and the recall of products such as fruit and vegetables. This study determines the prevalence of virulence-associated genes and serogroups and evaluates the effects of different growth media and environmental conditions on biofilm formation by L. monocytogenes . Eighteen L. monocytogenes isolates from Hass avocados sold at markets in Guadalajara, Mexico, were characterized by virulence-associated genes and serogroup detection with PCR. All isolates harbored 88.8% actA , 88.8% plcA , 83.3% mpl , 77.7% inlB , 77.7% hly , 66.6% prfA , 55.5% plcB , and 33.3% inlA . The results showed that 38.8% of isolates harbored virulence genes belonging to Listeria pathogenicity island 1 (LIPI-1). PCR revealed that the most prevalent serogroup was serogroup III (1/2b, 3b, and 7 ( n = 18, 66.65%)), followed by serogroup IV (4b, 4d-4e ( n = 5, 27.7%)) and serogroup I (1/2a-3a ( n = 1, 5.5%)). The assessment of the ability to develop biofilms using a crystal violet staining method revealed that L. monocytogenes responded to supplement medium TSBA, 1/10 diluted TSBA, and TSB in comparison with 1/10 diluted TSB ( p < 0.05) on polystyrene at 240 h ( p < 0.05). In particular, the biofilm formation by L. monocytogenes (7.78 ± 0.03-8.82 ± 0.03 log 10 CFU/cm 2 ) was significantly different in terms of TSBA on polypropylene type B (PP) ( p < 0.05). In addition, visualization by epifluorescence microscopy, scanning electron microscopy (SEM), and treatment (DNase I and proteinase K) revealed the metabolically active cells and extracellular polymeric substances of biofilms on PP. L. monocytogenes has the ability to develop biofilms that harbor virulence-associated genes, which represent a serious threat to human health and food safety. |
