Antimicrobial Resistance,Virulence Profile,and Molecular Characterization of Listeria monocytogenes Isolated from Ready-to-eat Food in China,2013-2014

We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus

Clostridium difficile in ready-to-eat foods in Isfahan and Shahrekord,Iran

Objective:To determine the prevalence and antimicrobial resistance of Clostridium difficile(C.difficile) isolated from ready-to-eat foods of Iran.Methods:From January to August 2013,a total of 368 unpacked ieady-to-eat food samples were purchased from randomly selected supermarkets,retail stores and restaurants located in Isfahan and Shahrekord,Iran and were evaluated for the presence of C.difficile.Results:C.difficile spores were detected in 5(1.36%) of the 368 samples.The highest prevalence of C.difficile was found in fasl salad(4.29%).followed by yogurt stew(2%),and olovyeh salad(0.93%).All 140 maccaroni salad and I'alafel sandwich samples were negative for C.difficile.One of the five C.difficile isolates(20%) contained tcdA,tcdB and cdtB toxin genes and four strains(80%) contained tcdA.and tcdB toxin genes.Also,among the five C.difficile isolates,only three strains were found to be toxigenic for toxin A and/or B by ELISA.Isolates were susceptible to vancomycin and metronidazole,but variably resistant to other antimicrobial drugs.Conclusions:This study,combined with studies on other food sources,suggests that widespread contamination of food is common.

An exploratory study of food safety and food handling: Examining ready-to-eat foods in independent delicatessen operations

The US Center for Disease Control and Prevention (CDC, 2009) reports that each year 76 million cases of foodborne illness occur with over 300,000 people hospitalized and 5000 deaths. This study, phase I of a continuing study, identifies key areas for food safety improvement. This study is designed as an exploratory evaluation of independently owned and operated delicatessen operations, using Escherichia coli and Staphylococcus aureus as indicators to assess food handling and the public’s risk for pathogenic contamination from commonly served ready-to-eat/take-away foods. The analysis consisted of a comprehensive strategy of laboratory testing of samples for pathogenic contamination, informal field observation of food handling procedures, and the examination of the most recent health inspection reports for each of the 18 operations visited. The deli turkey, cream cheese and lettuce were tested using bacteria indicator plates. The results showed widespread levels of contamination. Of the 54 samples tested for Escherichia coli, 26 showed positive results which are ~45% for E. coli contamination. Of the 54 samples tested for Staphy-lococcus aureus, 31 showed positive results which are ~57% for S. aureus contamination. One issue discovered while conducting the study was the lack of consistent uniform international standards of contamination tolerance levels. The informal field observations and health report analyses revealed widespread temperature violations and numerous instances of poor food handling. The study offers independent practitioners a strategy designed to improve their health inspections scores, food handling, and mitigation of operator liability. Independent operators traditionally do not enjoy the resources of centralized supervision and expert on-staff training;yet in aggregate they account for significant volume in both dollars and the quantity of product served. This study adds needed scrutiny to this important food niche.

Impact of lactic acid bacteria on the control of Listeria monocytogenes in ready-to-eat foods

Due to the increased demand for ready-to-eat(RTE)minimally processed foods,alternatives to chemical and thermal preservation methods to maintain food safety are highly demanded.A significant safety hazard in RTE food products is the growth of the foodborne pathogen Listeria monocytogenes(L.monocytogenes).After processing,recontamination or cross-contamination of L.monocytogenes in RTE food products may occur and the lack of cooking can lead to an increased risk of listeriosis.Further,some RTE food products(e.g.cheese and cured meat)can have a long processing period and shelf life,thus allowing for the growth and proliferation of L.monocytogenes in the food matrix.Lactic acid bacteria(LAB)are generally recognized as safe probiotics and have been proposed as a biological control approach to eliminate foodborne pathogens including L.monocytogenes.LAB have been reported to extend the shelf life of food products and inhibit pathogen proliferation via growth competition and metabolite production.LAB are native microflora of many RTE foods,but only certain LAB may inhibit pathogen growth.Therefore,the specificity of LAB species should be employed in their use in RTE foods.This review will discuss the antimicrobial mechanisms of LAB against L.monocytogenes,selective use of LAB in food matrices,and their uses in food processing and packaging.

Microbiological assessment of street foods at the point of sale in Maputo(Mozambique)

Objectives:The aim of this study was to assess the microbiological quality and safety of street food sold in the main streets and informal markets of Maputo,the capital of Mozambique.Materials and Methods:From 83 different vendors selling different types of foods,83 samples of ready-to-eat(RTE)street food were analyzed.Mesophiles,Escherichia coli and total coliforms were used as quality and hygiene indicators.Listeria monocytogenes(L.monocytogenes)Salmonella and coagulase-positive staphylococc were used as food safety indicators.Results:High proportions of unsatisfactory food samples were found in both traditional hot(76.7%)and cold(75%)foods.L.monocytogenes and Salmonella were tested negative in this survey.However,when coagulase-positive staphylococci was used as a food safety indicator,approximately 25%(23/83)of the food samples analyzed were classified as unsatisfactory/potentially hazardous.Conclusions:These results,showing that street food sold in Maputo clearly requires adequate sanitary conditions for its preparation and sale,contribute to the development of good manufacturing practices(GMP)for street food in Maputo,Mozambique.This is the first report on the microbiological quality and safety of street food in Mozambique.