Crabs, marinade and pathogens

Knowing the survival characteristics of foodborne pathogens in raw ready-to-eat (RTE) seafood is the key to predicting whether they pose a microbiological hazard. The present study examined the survival of Escherichia coli O157:H7, Salmonella Typhimurium, Vibrio parahaemoliticus, Listeria monocytogenes, and Staphylococcus aure- us in raw RTE crab marinated in soy sauce.

cartooncrab_1_jpg103a1464-d351-465e-90ed-f6ab47e3c8bboriginalInoculated crabs (initial bacterial population = 4.1–4.4 log CFU/g) were immersed in soy sauce and then stored at refrigeration (5 °C) or room temperature (22 °C) for up to 28 days. At 5 °C, all bacteria (except V. parahaemolyticus) survived in crab samples until Day 28 (counts of 1.4, 1.6, 3.1, 3.2 log CFU/g for E. coli O157:H7, S. Typhimurium, L. monocytogenes, and S. aureus, respectively). Howev- er, at 22 °C, all tested bacteria were more susceptible to the antimicrobial effects of marination. Regardless of tem- perature, foodborne pathogens attached to crab samples were more resistant to marination than those suspended in soy sauce samples; however, the survival pattern for each species was different. Gram-positive bac- teria were most resistant to marination conditions (high salinity, low pH), whereas V. parahaemolyticus was ex- tremely susceptible.

Marination is the only antibacterial step in the manufacturing processes; however, the results presented herein reveal that this is not sufficient to inactivate foodborne pathogens. In particular, the survival of pathogens on crabs at refrigeration temperature may pose a major hazard for the consumption of raw RTE seafood. Thus, appropriate decontamination methods and implementation of safety management practices are needed.

This study provides predictive microbiological information of foodborne pathogens in raw RTE seafood with margination.

Survival of foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Vibrio parahaemolyticus) in raw ready-to-eat crab marinated in soy sauce

International Journal of Food Microbiology 238 (2016) 50–55, DOI:

TJ Cho, NH Kim, SA Kim, JH Song

9 sickened; UK E. coli outbreak linked to crab meat last year

In Aug. 2011, crab meat was linked to an E. coli O157 outbreak in Plymouth, England. Researchers have now published a journal article about that investigation in Epidemiology and Infection.

“Nine cases, eight laboratory-confirmed with E. coli O157 phage type 21/28 verocytotoxin 2 and one epidemiologically linked, had onsets from 30 July 2011 to 15 August 2011. We compared cases (n = 8) with controls (n = 28) of similar age and sex (median age 61 vs. 55 years, females 75% vs. 61%). Cases were 58 times more likely to have eaten crab (88% vs. 11%; odds ratio 58, 95% confidence interval 4-2700). Eight cases consumed crab sourced from the same supplier who was not registered with the local authority. This outbreak pointed to crab as a possible vehicle of E. coli O157 infection. We ensured the withdrawal of crab meat sourced from unregistered suppliers from food venues by 25 August 2011. We also emphasized the importance of only using registered suppliers to the food venues. Since then no further associated cases have been reported.”

The authors explain that, “supplier X fished for crabs in the sea locally using his own boat. We identified a number of domestic addresses as sites where the crabs were processed. Crab processing usually includes boiling or pasteurization, followed by hand-picking of the boiled meat and packing it for distribution. The process should be a subject of standard food safety control measures, regulated by hazard analysis and critical control point (HACCP) principles. These domestic addresses were not registered or approved for food production and processing, and were not regulated. We were not allowed to access them for inspection.

“The distribution of the processed crab meat to food outlets was based on local acquaintances, agreed by word of mouth. The area of distribution of the supplied crab was limited to Plymouth and the last distribution occurred on 15 August 2011.

“Crabs could have been infected at the outset in their sea habitat as the coastal water can be polluted by feces from domesticated animals, by influx of water from field streams or sewage overflow. Use of a personal boat with no toilet and hand-hygiene facilities could have contributed to contamination during transportation. Processing of the crabs, including boiling, hand-picking and handling of the boiled meat, at domestic addresses was not regulated according to HACCP principles, with no records on storage temperatures, boiling lengths and temperatures, personnel hygiene, etc. Supplier X could have been a healthy carrier of E. coli O157. Contamination of fish and shellfish with E. coli due to poor hygiene and sanitary conditions has been documented in the past. However, due to lack of information on handling crabs prior to distribution, and microbiological evidence, we cannot conclude where or how the crab meat became infected with E. coli O157.”

Woman, 64, almost killed by Plymouth E. coli outbreak

Joan Hunt, 64, of Brixton, spent three weeks in hospital and needed treatment in intensive care after being infected with E. coli O157 in a UK outbreak linked to crab meat – or its preparation.

She has been left with only 35 per cent kidney function after developing the potentially deadly complication HUS.

Hunt recently told her story to the Plymouth Herald to raise awareness of symptoms and thank the hospital team who saved her life.

She is recovering after becoming dangerously ill in August – the month of a reported Plymouth E. coli outbreak believed to be linked to crab meat.

Joan does not know the source of her poisoning as she had not eaten crab. None of her family became sick.

"I felt I was going to die. I wasn’t in control of my body, my body was controlling me. It was frightening.”

As reported in The Herald earlier this month, there is an ongoing investigation into an E. coli outbreak in Plymouth with a possible link to an unapproved crab supplier.

Investigators took action after nine cases emerged in August. There have been no further reports of illness linked to crab since.

Cookie dough and crabs: 9 sick with E. coli O157 in Plymouth ‘linked to crab meat’

In yet another example of prompt public alerts by UK health types, nine people were sickened with E. coli O157 in Plymouth in August and it’s now being made public (see E. coli O157 linked to leeks sickens 250 and kills 1 in UK; 8-month outbreak only now being made public).

A 3-month delay is, sortof, an improvement on an 8-month delay in public notification.

The Plymouth Herald reports this morning that environmental health officers and the Health Protection Agency (HPA) launched an inquiry after nine cases were confirmed in the city – in August.

It is believed to be the first reported outbreak of the E.coli O157 strain associated with the consumption of crab meat.

The investigation is continuing but there is a suspected link with an unapproved crab supplier.

Investigators revealed they took action after nine cases emerged in August. There have been no further reports of illness linked to crab since.

The South West HPA and Plymouth City Council said in a joint statement: "A wider investigation is still ongoing following on from the outbreak, so we are not in a position to give full details but we suspect a link to an unapproved crab supplier.

"Environmental health officers from the council acted swiftly to identify crab meat as a possible source and removed all potentially affected crab meat from food establishments as a precautionary measure.

"The team worked closely with the SW (North) Health Protection Unit to investigate the cases and ensure that GPs in Plymouth and beyond were aware of the issue, if anyone presented with symptoms."

The team also alerted food outlets in the city about the importance of only buying food or ingredients from approved or registered suppliers.

A study into the outbreak showed a ‘statistically significant’ association between cases and the consumption of crab meat away from home.