Food Safety Magazine
Shiga toxin-producing Escherichia coli (STEC) are pathogens of concern across various products within the food industry, as they have been connected to a wide variety of outbreaks and recalls. Most of the scientific literature concerning the removal of attached STEC cells focuses on E. coli O157:H7, as it was the first STEC to be considered an adulterant in nonintact beef products in the United States after a large outbreak from undercooked ground beef patties in 1982.
Dourou and others determined E. coli O157:H7 biofilm studies performed using laboratory media only were not adequate to mimic what would happen when the bacteria were exposed to food residues in a processing environment. As research about non-O157 STECs, especially serogroups O45 and O121, and their ability to attach and form biofilms is limited, we chose to perform these studies under laboratory conditions. Additional research is needed to determine how these bacteria act when exposed to food residues and other microorganisms present, and how those residues may impact the efficacy of cleaning and sanitation programs to remove STECs from equipment surfaces. In conclusion, our study shows that a complete cleaning and sanitation program administered within food production facilities is more effective at removing STEC bacteria from stainless steel in laboratory media when the chemicals are applied using manufacturers’ recommendations
RASFF-shigatoxin-producing Escherichia coli (stx+; eae+) in sheep meat from Belgium in Belgium
RASFF-Too high count of Escherichia coli (330 MPN/100g) in live mussels (Mytilus galloprovincialis) from Spain in Italy
RASFF-shigatoxin-producing Escherichia coli in chilled lamb meat from the former Yugoslav Republic of Macedonia in Italy
RASFF-shigatoxin-producing Escherichia coli (stx II gen +: <1.0*10*3 CFU/g) in soft cheese from France in France
RASFF-high count of Escherichia coli (1300000 CFU/g) in raw milk cheese from France in France
RASFF-too high count of Escherichia coli (1200000 /g) in raw milk cheese Camembert in France
RASFF-shigatoxin-producing Escherichia coli (stx2+ eae- O145 /25g) in frozen venison from Germany in Italy
RASFF-shigatoxin-producing Escherichia coli (stx +, eae + /25g) in blue cheese from France in Belgium
RASFF-too high count of Escherichia coli (9200 MPN/100g) in live clams from Italy in Italy
Data on the presence of diarrheagenic Escherichia coli pathotypes (DEPs) in alfalfa sprouts and correlations between the presence of coliform bacteria (CB), fecal coliforms (FC), E. coli, DEPs, and Salmonella in alfalfa sprouts are not available. The presence of and correlations between CB, FC, E. coli, DEPs, and Salmonella in alfalfa sprouts were determined. One hundred sprout samples were collected from retail markets in Pachuca, Hidalgo State, Mexico. The presence of indicator bacteria and Salmonella was determined using conventional culture procedures. DEPs were identified using two multiplex PCR procedures. One hundred percent of samples were positive for CB, 90% for FC, 84% for E. coli, 10% for DEPs, and 4% for Salmonella. The populations of CB ranged from 6.2 up to 8.6 log CFU/g. The FC and E. coli concentrations were between , 3 and 1,100 most probable number (MPN)/g. The DEPs identified included enterotoxigenic E. coli (ETEC; 2%), enteropathogenic E. coli (EPEC; 3%), and Shiga toxin–producing E. coli (STEC; 5%). No E. coli O157:H7 strains were detected in any STEC-positive samples. In samples positive for DEPs, the concentrations ranged from 210 to 240 MPN/g for ETEC, 28 to 1,100 MPN/g for EPEC, and 3.6 to 460 MPN/g for STEC. The Salmonella isolates identified included Salmonella enterica serotype Typhimurium in three samples and Salmonella enterica serotype Enteritidis in one. STEC and Salmonella Typhimurium were identified together in one sample. Positive correlations were observed between FC and E. coli, between FC and DEPs, and between E. coli and DEPs. Negative correlations occurred between CB and DEPs and between CB and Salmonella. Neither FC nor E. coli correlated with Salmonella in the sprout samples. To our knowledge, this is the first report of ETEC, EPEC, and STEC isolated from alfalfa sprouts and the first report of correlations between different indicator groups versus DEPs and Salmonella.
The suitability for consumers of a variety of raw milk cheeses purchased over the Internet was investigated in terms of packaging, labelling, physicochemical parameters and microbiological safety. 108 purchases from seven European countries were examined. The prevalences of Salmonella spp., Listeria monocytogenes, Escherichia coli and coagulase positive staphylococci (SA) were determined. All 108 samples were described on websites as raw milk cheeses and thereby qualified for this study. However, after delivery it was noted that 4.6% (5/108) of cheeses were labelled to be manufactured from heat-treated or pasteurized milk. Delivery duration ranged from 24 h to six days. Immediately upon receipt cheese temperatures were observed to range between 5 and 23 °C, whereas in 61.5% of all cases the temperature was higher than 15 °C. Cheese labelling was examined in respect of EC Guideline 2000/13 and Regulation No. 853/2004. Only 17.6% (19/108) of cheeses were properly labelled and fulfilled all European guideline requirements. In 50.9%, 38.8%, 46.3% and 39.8% of all cases (i) specific storage requirements, (ii) name and address of the manufacturer/packer or seller, (iii) net weight and (iv) shelf life (use by date), were missing. Even the labelling information “made from raw milk” was not apparent on 36% of all cheese items delivered. The major foodborne pathogen L. monocytogenes was detected in 1.9% of all samples, one of which had counts of 9.5 × 103 CFU/g. None of the 108 investigated cheeses showed a pH ≤ 5.0 and aw value ≤0.94 which are the limiting values for growth of L. monocytogenes. For two samples (0.9%) and 11 samples (10.2%) the pH and the aw value was ≤4.4 or ≤0.92, respectively at least at one of three stipulated time points (receipt, mid-shelf-life and at expiry). Salmonella spp. could not be detected in any of the samples. E. coli and SA could be detected in a total of 29.6% (≥10 CFU/g; 32/108) and 8.3% (≥100 CFU/g; 9/108) of samples, respectively, indicating poor conditions of hygiene. Results reveal that labelling and hygiene concerns about the safety of Internet purchased cheeses in Europe are justified.
RASFF-Shigatoxin-producing Escherichia coli (3 out of 5 samples, stx2+) in beef from Argentina in Germany
RASFF-shigatoxin-producing Escherichia coli (presence /25g) in soft cheese made from raw cow milk from France in Germany
RASFF-shigatoxin-producing Escherichia coli (O 157:H7 eae+, stx2+ /25g) in frozen raw meat material for minced meat from Spain in France