ABSTRACT
El objetivo de este estudio descriptivo y transversal fue describir la presencia de microorganismos indicadores y las BPM en los locales que producen sándwiches de verdura en el Mercado Central de Abasto de Asunción (MCAA) en el 2014. Se eligieron sándwiches de verduras debido a la materia prima cruda y mayonesa, a que no sufren tratamiento térmico y son de consumo masivo. Se elaboró una lista de verificación para las BPM según la FAO/OMS. Se estudiaron 20 muestras en 10 locales(2/local) para Recuento de Aerobios Mesófilos (RAM), coliformes totales, E. coli y S. aureus. El límite microbiológico fue dado por la Norma Sanitaria del Ministerio de Salud de Perú y la técnica utilizada fue el Recuento en Placa, utilizando placas de 3M PETRIFILM.El 90% de los 10 localestenía limpieza adecuada,todos refirieron lavadode las verduras previa utilización, para lo cual usaban agua de canilla (90%)o agua reutilizada (10%). El 70% de los manipuladores refirió lavadode manos previa manipulación y 90% después.El 80% de los locales refirió utilizar mayonesa comercial y el 30% la mantenía a temperatura ambiente durante todo el día.El 20% de los locales ofrecíaal día siguiente los sándwiches no vendidos. El 95% (19 de 20)de las muestras se considera microbiológicamente como No Aptas para el consumo, el 70% presentó recuentos mayores para RAM, 85% para coliformes, 30% para E. coli y 75% para S. aureus. Estos productos pueden ser considerados de riesgo para el consumo humano.
The objective of this cross-sectional descriptive study was to evaluate the presence of indicator microorganismsand to describe the Good Manufacturing Practices (GMP) in places producing vegetable sandwiches of the Central Supply Market of Asunción (MCAAfor its name in SpanishMercado Central de Abasto de Asunción)in 2014. Vegetable sandwiches were chosen for being of high risk, as they use raw materials and mayonnaise, they do not undergo heat treatment and are of massive consumption.For GMP, a checklist was prepared according to FAO / WHO. Twenty samples in 10 shops (2 samples per shop) were studied for Mesophilic Aerobic Count, total coliform counts, E. coli and S. aureus. Ninety percent of the 10 stores had adequate cleaning. Hundred percent claimed to wash the raw material (vegetables) before being used, 90% used tap water and 10% washed them with reused water. Seventy percent of the cooks washed their hands before preparing the sandwiches and 90% afterwards. Eighty percent of the stores used commercial mayonnaise and 30% keepthem at room temperature throughout the day. Twenty percent of the stores offered unsold sandwiches the next day.Of the 20 samples, 19 (95%) were considered microbiologically as "Not Apt" for consumption, 70% due to high Counting of Mesophilic Aerobes, 85% coliforms, 30% E. coli and 75% S. aureus. These products can be considered as a risk for human consumption.
Subject(s)
Good Manipulation Practices , Pollution Indicators , Street FoodABSTRACT
Aims: To evaluate the Egyptian street-vended sandwiches of meat and meat products for the presence of Listeria monocytogenes and Enterobacteriaceae group. To evaluate the microbiological quality of street-vended sandwiches of meat and meat products sold in Cairo-Egypt. Place and Duration of Study: Department of Food Microbiology, National Research Center, Cairo, at during the period of January 2011 to September 2012. Methology: Seventy sandwiches of meat and meat products including ten samples each of burger, hawawshi, kofta, liver, luncheon, sausages and shawerma sandwiches were randomly collected from the street-vendors and food shops in Great-Cairo governorate. Samples were investigated for their loads of Enterobacteriaceae counts as well as the presence of L. monocytogenes. Enterobacteriaceae counts was done using the conventional International method (FDA), however isolation and identification of L. monocytogenes was carried out using three different microbiological examination methods including classic selective conventional media, chromogenic media, as well as rapid identification method “food-system kits”. 168 isolates of Listeria spp were identified following the biochemical identification tests (Bergey’s Manual) and confirmed using Hi Listeria identification kits and latex test kits. Results: Enterobacteriaceae group were detected in 51% of the examined samples with an average counts of 37x102 cfu/g. Listeria spp. were detected in range between 24% and 36%, depended on the method used, with numbers ranged from 16x102 to 23x102 cfu/g. All samples that were contaminated with Listeria spp. harboured L. monocytogenes. Listeria spp. was not detected in all the examined Hawawshi sandwiches with an exception of one positive sample detected using the chromogenic media. The obtained results indicated that 37 out 68 (54%) isolates, picked up from classic selective conventional media, and 62 out of 100 (62%) isolates from chromogenic medium were confirmed as L. monocytogenes indicating that chromogenic medium may be the superior for isolation of the pathogen from ready-to-eat sandwiches of meat and products. Conclusion: The obtained results indicated that these foods presented a source of infection to the consumer. Measures to control the quality of the raw material, environmental and hygienic conditions during preparation and serving should be taken. The chromogenic media was the most efficient for the isolation of the pathogen during this course of study.