The evaluation of the microbial safety of fresh ready-to-eat vegetables produced by different technologies in Italy (original) (raw)
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Journal of Biological Research-Thessaloniki, 2015
Background: Fresh produce occupies an increasingly important place in the human food supply because of its health-promoting nutritional properties. Most fresh produce is eaten raw or after minimal processing and, consequently, pathogen contamination can represent a serious health risk. There has been an increase in foodborne outbreaks and cases associated with fresh produce, but literature data about the prevalence of pathogen contamination are inconsistent. This study was undertaken to assess the hygienic quality and the prevalence of the most common bacterial pathogens in fresh produce sold in retail markets in Sicily. A total of 125 samples of different types of vegetables were examined by standardized microbiological methods. Results: The aerobic mesophilic count ranged between 2 log and 7 log cfu g −1 and the Enterobacteriaceae counts between < 1 log and 6 log cfu g −1 , with statistically significant differences between unprocessed and minimally processed products (p < 0.05). Escherichia coli was detected only in leaf vegetables at a concentration of 2 log -3 log cfu g −1 . Enterococci were found at a concentration of 2 log -4 log cfu g −1 . Coagulase positive Staphylococci and sulphite-reducing Clostridia were not detected in any sample. Three samples tested positive for Listeria monocytogenes, Yersinia enterocolitica and Salmonella veneziana. Conclusion: Our study provides updated data on the microbiological quality of retail vegetables and confirms the need to implement strategies to increase microbial safety of fresh produce.
Microbiological survey of raw and Ready-To-Eat leafy green vegetables marketed in Italy
International Journal of Food Microbiology, 2015
The presence of foodborne pathogens (Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7, thermotolerant Campylobacter, Yersinia enterocolitica and norovirus) in fresh leafy (FL) and ready-to-eat (RTE) vegetable products, sampled at random on the Italian market, was investigated to evaluate the level of risk to consumers. Nine regional laboratories, representing 18 of the 20 regions of Italy and in which 97.7% of the country's population resides, were involved in this study. All laboratories used the same sampling procedures and analytical methods. The vegetable samples were screened using validated real-time PCR (RT-PCR) methods and standardized reference ISO culturing methods. The results show that 3.7% of 1372 fresh leafy vegetable products and 1.8% of 1160 "fresh-cut" or "ready-to-eat" (RTE) vegetable retailed in supermarkets or farm markets, were contaminated with one or more foodborne pathogens harmful to human health.
Microbiological Contamination of Vegetable Salads
Polish Journal of Natural Science, 2007
Increased consumption, big production units and very efficient delivery service networks of fresh vegetables and salads caused a higher number of foodborne illnesses in the last two decades all over the world. In this study 15 fresh vegetable salads from different marketplaces in Novi Sad were tested by reference microbiological methods (detection of Salmonella spp., enumeration of Listeria monocytogenes, mesophilic aerobic bacteria, yeasts and molds, sporogenic mesophilic aerobic bacteria, sporogenic sulfite-reducing bacteria, Bacillus cereus, Enterobacteriaceae, Escherichia coli and coagulase positive staphylococci). Salmonella spp. was found in one sample which, according to the safety criteria for such a product (if treated as ready-to-eat), was considered to be microbiologically unsafe. The number of Listeria monocytogenes in all tested samples was <100 cfu/g, which is a satisfactory result according to the safety criteria. E. coli was detected in only one sample, and the number of Enterobacteriaceae was in the range from 4.4 to 6.9 log CFU/g. The isolated Enterobacteriaceae strains were identified as Enterobacter cloacae, Klebsiella pneumoniae ssp. pneumoniae and Citrobacter spp.
Recently, epidemics that have occurred as a result of the transmission of pathogenic microorganisms by consuming contaminated fresh vegetables have become more frequent. Among the most massive were poisonings by bacteria originating from spinach in the Unated States of America, from mung beans in Japan, as well as an epidemic caused by Escherichia coli from pumpkin in Germany. Unfortunately, hemolytic uraemic syndrome caused by Escherichia coli in Germany affected 3,950 people in 2011, of whom 53 died. Although vegetables do not represent a natural habitat for bacteria that cause diseases in humans, it is clear that certain groups of human pathogenic microorganisms can find their ecological niches in plant production systems. Ways of contaminating plants with these bacteria are poorly understood. It is assumed that fertilization and irrigation with untreated water are some of the possible ways of transmitting pathogenic bacteria to agricultural crops. The aim of the research was to ...
Evaluation of Salmonella and Listeria monocytogenes contamination on leafy green vegetables
2010
The objective of this study was to monitor Salmonella and Listeria monocytogenes contamination of leafy green vegetables produced in urban and periurban agricultural fields with natural water irrigation. A total of 164 samples comprising of different leafy green vegetables (8 basils, 15 dills, 20 garden cresses, 16 kales, 12 lettuces, 19 mints, 19 parsleys, 18 purslanes, 1 radish, 20 rockets, 14 scallions and 2 spinaches) were randomly collected from nearby agricultural fields in the close vicinity of Ankara Stream over an 8-month period between April 2007 and November 2007. Samples were examined for Salmonella and L. monocytogenes using ISO methods with immunomagnetic separation (IMS) and then polymerase chain reaction (PCR). No Salmonella and L. monocytogenes was detected from the 25-g radish, spinach and scallion samples tested. However, 23 samples (1 basil, 2 dills, 1 garden cress, 1 kale, 2 lettuces, 4 mints, 3 parsleys, 5 purslanes and 4 rockets) were positive for Salmonella a...
Survival of salmonella enteritidis and listeria monocytogenes on salad vegetables
World Journal of Microbiology and Biotechnology, 1998
The in¯uence of initial head-spaces of air ± 4.9% CO 2 /2.1% O 2 /93% N 2 and 5% CO 2 /5.2% O 2 /89.8% N 2 ± on Salmonella enteritidis and Listeria monocytogenes, and on microbial association with shredded carrots and lettuce was studied at 4°C. Both these pathogens survived but did not grow in any vegetable regardless of the packaging system used. Total viable count, lactic acid bacteria and pseudomonads were also monitored. Lactic acid bacteria were the predominant organisms in all samples. The pH dropped signi®cantly during the storage of vegetables.
African Journal of Biological Sciences, 2021
Background: Nowadays, food safety becomes an environmental and public health concern due to the increasing demand of vegetable diets observed from the last decades. This has stipulated research regarding the risks associated with consumption of food stuffs contaminated with pathogenic microorganisms. Objective: The aim of this study was to detect and enumerate pathogenic microorganisms associated with fresh vegetables and their implications for food safety among consumers. Methods: Fresh samples of vegetables including tomato, onion, carrot and spinach were collected immediately after harvest for the bacterial characterization and identification using Bergey's Manual of Systematic Bacteriology while the fungi were identified by their morphology through examination of their microscopic structures. Results: The results show higher number of Vibrio cholerae in the vegetables, a high mean score of 8.7 × 10 8 CFU/ g for AMB, and 5.6 × 10 5 for TCB in tomatoes and 3.9 × 10 6 CFU/g for FCB in carrot sample. There were no statistically significance difference within and between groups in the AMB, FCB and TCB using one-way ANOVA at p = 0.05 and 95% confidence interval (F = 2.065; 0.152 and 4.045 respectively). Spinach contained 495 MPN/g of Aspergillus flavus (ASPf) while onion has 518 MPN/g of Aspergillus niger (ASPn) per each 25 plates of samples. Conclusion: This study concluded that microbial loads on vegetables were above ICMSF limits for vegetables and therefore, consumers should ensure that the raw vegetables are thoroughly washed and adequately processed to prevent chances of food borne diseases.
Food Control, 2014
The current study was carried out to estimate the risks of infection due to consumption of RTE vegetables contaminated with Salmonella and Listeria monocytogenes in Brazil. The risk assessment model was composed of five different modules comprising the retail-consumption steps. Scenarios were simulated using prevalence and concentration levels reported in RTE vegetables in Brazil as well as considering values 10 times lower. In addition, scenarios in which temperature during transportation and storage are maintained below 5 C were also evaluated. Models built in Excel spreadsheets were run (100,000 iterations) using @Risk software. The two outputs were risk of infection per month (probability of infection per month due to consumption of RTE vegetables) and number of infections per month (number of people that consumed RTE vegetables and get infected per month). The QMRA models predicted that the mean risk of Salmonella infection per month is 5.7E-03, while the mean risk of infection for L. monocytogenes was 8.1E-06 per month. The reduction of prevalence of Salmonella from 1.7% to 0.17% resulted in a decrease of risk of infection per month by about 6 times. In the case of L. monocytogenes, the reduction of prevalence from 2.2% to 0.22% resulted in decrease of risk of infection from 8.1E-06 to 1.0E-06. The risks and number of cases predicted in scenarios in which temperature was kept below 5 C were reduced for both pathogens studied when compared to scenarios where this was not the case. The scenario where prevalence and concentration of pathogens was reduced and where temperature was <5 C led to the lowest number of infections due by Salmonella and L. monocytogenes (187 and 3.3E-05 cases, respectively). The results suggest that effective mitigation strategies need to be adopted. The strict control of temperature during transportation, storage and consumption was more effective to reduce risk and number of cases due to L. monocytogenes than to Salmonella. More data is needed to improve the accuracy of risk assessment models developed.
Microbiological Contamination of Vegetable Food as Risk Factor for Human POPULATION,764
Journal of environmental protection and ecology
In this study we have observed the bacterological load in the Tirana market, in some kindergarden and moulds and yeast in fresh vegetables and sprouts. The collection of samples was casual, from different retails in the Tirana city. The results indicate that ready-to-eat vegetables sold in different areas of the Tirana city had poor microbiological quality. The highest microorganism counts were associated with domestic grated carrot, salad and spinach. enterobacteriaceae populations between 10 5 and 10 6 CFU/g were found in 42% of samples. Bacillus cereus was detected only in spinach. Citrobacter freundii and Serratia ficaria were found in some vegetable samples. The microbiologic survey on microbiologic quality of fresh fruit and vegetables, used in nutrition diet in some kindergardens in the Tirana city, was performed using classic methods and ISO 874. For some suspected cases of Escherichia coli O157: H7 were used test kits. The highest microorganism values were observed especially at grated carrot, salad and spinach. A total of 260 fresh vegetables (salad, spinach, different lettuce types) and sprouts (broccoli, garlic, spicy, onion, clover, etc.) were tested for moulds and counts. The most common moulds and yeast found in fresh vegetables and sprouts were Cladosporium and Penicillium. Less often isolated in our analysed samples were Mucor, Fusarium and Aspergillus niger. Over the last several years the detection of outbreaks related to food borne diseases, associated with consumption of domestic and imported fresh fruits and especially vegetables, has increased worldwide.