Research – A Novel Selective Medium for Simultaneous Enrichment of Shiga Toxin–Producing Escherichia coli and Salmonella in Ground Beef

Journal of Food Protection 


Microbiological analysis of ground beef for contamination by both Salmonella and Shiga toxin–producing Escherichia coli (STEC) is performed by the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS), as part of its Performance Standards Verification Testing program. FSIS has established a zero tolerance for STEC serotype O157:H7 and serogroups O26, O45, O103, O111, O121, and O145 because they are regarded as adulterants. The detection and isolation of these specific serogroups presents a technical challenge necessitating time-consuming and costly laboratory procedures that often exceed the technical capabilities of many small internal and reference laboratories. We describe here a method using a novel STEC and Salmonella selective (SSS) broth that allows for simultaneous selective enrichment of STEC and Salmonella sp., providing isolation and detection from the same broth. The method only involves direct plating from beef enrichments to detect suspect isolates that can be easily confirmed by using immunoassays or PCR, rendering the isolation simpler and less costly than the current described methods. In a side-by-side comparison with modified tryptic soy broth (mTSB), the use of SSS broth resulted in primarily isolating STEC and Salmonella sp., while substantially suppressing the growth of other gram-negative Enterobacteriacae by 90%. Significantly more (χ2 < 3.84) samples containing E. coli O157:H7 and STEC O26, O111, O121, and O145 and a nondifferent (χ2 > 3.84) number of samples containing STEC O103 and O45 were identified when enriching in SSS broth. Coenrichment using six different Salmonella serovars showed numerically greater but not significant (χ2 < 3.84) positive samples by using SSS broth compared with mTSB for a majority of serotypes.

Research – Kitchen Towel As Risk Factor for Home Based Food Poisoning

Abstracts Online

Background: Cross contamination in the kitchen could contribute to home-based food poisoning. This study aimed at investigating the potential role of kitchen towels in cross contamination in the kitchen. Methods: A total of 100 kitchen towels were collected after one month of use. The bacteria were cultured and identified by standard biochemical tests. A questionnaire was also designed to investigate the potential risk factors which could affect the result. Results:  Bacterial growth was found in 49% of the kitchen towels and significantly increased by size of family, extended family and presence on children. Multipurpose towels had higher CFU than single use towels (1.31 x 107 vs 6.60 x 104; p<0.05) and humid towels had higher CFU than dry ones (4.8 x 105 vs 0.5x 105; p<0.05). The mean CFU from the towels was found to be 2.76 x 105 and was significantly higher from the cotton towels (4.98 x 105) compared to the nylon (1.64 x 105) and mixture of both towels (1.89 x 105). Out of the 49 samples which were positive for bacterial growth, 36.7% grew coliforms, 36.7% Enterococcus spp., 30.6% Pseudomonas spp., 28.6% grew Bacillus spp., 14.3% S. aureus, 4.1% Proteus spp., 2.0% coagulase negative Staphylococcus. Furthermore, S. aureus was isolated at higher rate from families of lower socio-economic status (p<0.05) and those with children (p<0.05). The risk of having coliforms was twice on humid towels than the dried ones. It was also noted that as the CFU increased, the detection rate of coliform, Enterococcus spp., Proteus spp. and Bacillus spp. also increased significantly. Furthermore, Enterococcus spp. and S. aureus were isolated at higher prevalence in bigger families (p<0.05). Diet was also found to be an important factor. Coliform and S. aureus were detected at significantly higher prevalence from families on non-vegetarian diets while a higher prevalence of Enterococcus species from the kitchen towels of vegetarian families. Conclusions: This study conclude that kitchen towels could be very important source bacterial contamination which could contribute to food poisoning. The multipurpose usage of kitchen towels should be discouraged.

Kenya – Aflatoxin Risk

The Star

Kenya has been mapped as an aflatoxin hotspot, a leading cause of liver cancer, hiding in grains like maize and animal food products.

Findings of a study released last month by the International Livestock Research Institute (ILRI) showed a large amount of milk and grains consumed by Kenyans have aflatoxin levels exceeding internationally accepted limit.

Aflatoxin is a tasteless poison produced by Aspergillus flavus fungus caused by a mould in soil that commonly affect cereals. It is mostly passed to humans through animal food products or direct ingestion of affected crops.

The study dubbed “Measuring and mitigating risk of mycotoxins in maize and dairy products for poor consumers in Kenya” was done from samples of of livestock feeds collected from farmers in five counties.

Kenya Agricultural and Livestock Research Organisation director general Eliud Kireger however dismissed the report as alarmist, saying that most Kenyans could have died if that was the case.

He however acknowledged that aflatoxin is a major threat to food security in the country, asking the government to subsidise bio-control products to tackle aflatoxin.

“The government must provide farmers with Aflasafe KE01, just the same way it subsidize fertilizer. The product effectively clear aflatoxin from soils,” said Kireger.

Public health director, Kepha Ombacho told the Star on phone that the state is conducting several activities to curb food poisoning through aflatoxin. He however, declined to comment further on the report, promising a comprehensive statement later.

The ILRI study established that Kenya had aflatoxin levels of between 0.02 parts per billion (ppb) to 9661 ppb with positive samples ranging from 75-100 per cent.

USA – Father may lose all four limbs after contracting flesh-eating bacteria in NJ – Vibrio vulnificans

News and Tribune

CAMDEN, NJ (RNN) – A 60-year-old father is hospitalized in intensive care after his family says he contracted flesh-eating bacteria while crabbing in a New Jersey river.

Doctors say Angel Perez, 60, developed necrotizing fasciitis, caused by a variety of Vibrio bacteria. The father is now in the ICU at Cooper University Hospital in Camden, NJ, according to NJ Advance Media.

Perez’s daughter, Dilena Perez-Dilan, says her father is an avid crabber. She says hours after he went crabbing near the Maurice River on July 2, his right leg began to swell then quickly got worse.

“It turned brown, blackish color. It was swelling, it was blistered,” Perez-Dilan told WPVI.

According to Perez’s family, it only took a few hours for the infection to spread to all four of his limbs, turning his skin raw and red with blisters and scarring.

“He is in critical condition,” Perez-Dilan told NJ Advance Media. “The infection has spread to his blood…his skin; you can see it spreading from his feet all the way above his kneecap. His forearms are black in color; they have blisters, cuts and sores.”

RASFF Alert- Aflatoxin -Pistachio- Almonds – Ground Ogbono – Hazlenuts – Groundnuts – Peanuts

kswfoodworld food safety poisoning

RASFF-aflatoxins (B1 = 35.4; Tot. = 38.4 µg/kg – ppb) in pistachio kernels from the United States, via Turkey in Greece

RASFF -aflatoxins (B1 = 6.2; Tot. = 6.9 µg/kg – ppb) in almonds from the United States in Spain

RASFF-aflatoxins (Tot. = >24 µg/kg – ppb) in almonds without shell from the United States in Spain

RASFF-aflatoxins (B1 = >24.0; Tot. = >24.0 µg/kg – ppb) in almonds from the United States in Spain

RASFF-aflatoxins (B1 = 19.3; Tot. = 25 µg/kg – ppb) in ground ogbono from Nigeria in the UK

RASFF-aflatoxins (Tot. = 56.2 µg/kg – ppb) in hazelnut kernels from Turkey in Germany

RASFF-aflatoxins (B1 = 50; Tot. = 55 µg/kg – ppb) in groundnuts from India in the Netherlands

RASFF-aflatoxins (B1 = 9.0; Tot. = 9.0 µg/kg – ppb) in groundnuts from Argentina in the Netherlands

RASFF-aflatoxins (B1 = 18; Tot. = 22 µg/kg – ppb) in peanuts from Egypt in the Netherlands

RASFF-aflatoxins (B1 = 67.6 µg/kg – ppb) in groundnut kernels from India in Greece

RASFF-aflatoxins (B1 = 200 µg/kg – ppb) in groundnuts from Sudan in the Netherlands

RASFF-aflatoxins (B1 = 39; Tot. = 42 µg/kg – ppb) in pistachios from the United States in France

RASFF-aflatoxins (B1 = 134.8; Tot. = 139.4 µg/kg – ppb) in pistachios from the United States in the UK

RASFF-aflatoxins (B1 = 24 µg/kg – ppb) in almonds from the United States in Spain

RASFF-aflatoxins (B1 = 24 µg/kg – ppb) in almonds from the United States in Spain

RASFF-aflatoxins (B1 = 24.1 µg/kg – ppb) in almonds from the United States in Spain

RASFF Alerts – Listeria monocytogenes – Chorizo – Chilled Smoked Bacon – Frozen Cooked Bacon Pieces

kswfoodworld food safety poisoning

RASFF-Listeria monocytogenes (presence /25g) in chorizo from Portugal in Portugal

RASFF-Listeria monocytogenes (present /25g) in chilled smoked bacon from Poland in Poland

RASFF-Listeria monocytogenes (presence /25g) in frozen cooked smoked bacon pieces from the Netherlands in the UK

RASFF Alert – Yeasts – Organic Teriyaki Sauce

kswfoodworld food safety poisoning

RASFF-high count of yeasts in organic teriyaki sauce from the Netherlands in the Netherlands