Category Archives: Research

New Zealand – Managing Salmonella Enteritidis in commercial chicken flocks

Posted on October 12, 2021 by | Leave a comment

MPI

Salmonella Enteritidis is a serious disease affecting people. Infection can occur from eating eggs and poultry meat. To help eliminate Salmonella Enteritidis, commercial chicken operators need to meet extra requirements from October 2021.

Commercial chicken operators must meet extra rules

From 6 October 2021, commercial chicken operators must comply with an emergency control scheme (ECS). The rules are to:

  • identify, monitor, and evaluate the risks around producing and selling chicken products
  • better manage the risks to public health from Salmonella Enteritidis (SE).

The Ministry for Primary Industries (MPI) consulted with the poultry industry about the ECS.

How to comply with the SE Emergency Control Scheme Order [PDF, 1001 KB]

Animal Products Order: Emergency Control Scheme – Managing SE in Commercial Chicken Flocks [PDF, 609 KB]

The rules apply to all those in the chicken supply chain

Specific chicken products must be produced and sold under the ECS. The rules apply to all operators within the chicken supply chain, including:

  • breeders, hatcheries, and rearers
  • egg laying and broiler farms
  • processing sites of chicken meat and eggs.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Salmonella in Chicken, Salmonella in Eggs

ECDC – Cholera – Annual Epidemiological Report for 2019

Posted on October 11, 2021 by | Leave a comment

ECDC

Food Illness

Key facts

•In the European Union/European Economic Area (EU/EEA), cholera is a rare disease that is primarily associated with travel to endemic countries outside of the EU/EEA.

•In 2019, seven EU countries reported 26 confirmed cases of cholera, which was similar to previous years.

•Most cases (16/26) were reported by the United Kingdom.

Click to access CHOL_AER_2019_Report.pdf

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Posted in ECDC, Food Micro Blog, Food Microbiology Blog, Food Microbiology Research, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Vibrio cholera, vibrio cholerae

EU – Latest Cryptosporidium parasite statistics show rise in Europe

Posted on October 11, 2021 by | Leave a comment

Food Safety News

Infections from the Cryptosporidium parasite are continuing to rise in Europe, according to a report published this month by the European Centre for Disease Prevention and Control (ECDC).

Outbreaks associated with food and drink, such as juice, have been reported. The parasites are microscopic and do not make food smell, look or taste unusual.

For 2018, 20 countries reported 14,299 cryptosporidiosis cases, of which 14,252 were confirmed. The number of confirmed patients was more than the 11,435 in 2017. The notification rate for 2018 was higher than in the previous four years from 2014 to 2017.

Germany, Netherlands, Spain and the United Kingdom accounted for 76 percent of all confirmed cases in 2018, with the UK alone making up 41 percent with 5,820 infections.

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Posted in Cryptosporidiosis, Cryptosporidium, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research

Research – Microbiome population dynamics of cold smoked sockeye salmon during refrigerated storage and after culture enrichment 

Posted on October 10, 2021 by | Leave a comment

Journal of Food Protection

Cold smoked salmon is a ready-to-eat seafood product of high commercial importance. The processing and storage steps facilitate the introduction, growth and persistence of foodborne pathogens and spoilage bacteria. The growth of commensal bacteria during storage and once the product is opened also influence the quality and safety of cold smoked salmon. Here we investigated the microbial community through targeted 16s rRNA gene and shotgun metagenomic sequencing, as means to better understand the interactions among bacteria in cold smoked salmon. Cold smoked salmon samples were tested over 30 days of aerobic storage at 4℃ and cultured at each timepoint in buffered Listeria enrichment broth (BLEB) commonly used to detect Listeria in foods. The microbiomes were comprised of Firmicutes and Proteobacteria namely, Carnobacterium , Brochothrix , Pseudomonas , Serratia , and Psychrobacter . Pseudomonas species were the most diverse species with 181 taxa identified. Additionally, we identified potential homologs to 10 classes of bacteriocins in microbiomes of cold smoked salmon stored at 4°C and corresponding BLEB culture enrichments. The findings presented here contribute to our understanding of microbiome population dynamics in cold smoked salmon, including changes in bacterial taxa during aerobic cold storage and after culture enrichment.  This may facilitate improvements to pathogen detection and quality preservation of this food.

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Posted in Brochothrix thermosphacta, Carnobacterium, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiome, Pseudomonas, Research, Serratia

Research – An Analysis of Tuna Recalls in the United States, 2002 through 2020

Posted on October 10, 2021 by | Leave a comment

Journal of Food Protection

This manuscript reviews 18 years of voluntary recalls for commercially sold tuna in the United States. This recall information is a valuable indicator of the failure to implement procedures for food safety. The voluntary recalls involve fresh, frozen, processed, hermetically sealed and retorted in a shelf stable pack (i.e., canned tuna), and formulated into other tuna products. The FDA regulations that regulate the capture, processing, transportation, and sale of raw and processed seafood are discussed. These regulations include the current Good Manufacturing Practices, the Food Modernization Act, the Emergency Permit Control, Low Acid Canned Foods, the Seafood Hazard Analysis and Critical Control Points, Food Labeling, and Sanitary Food Transportation. The importance of traceability and Food Safety Culture to successfully prevent or implement recalls is also discussed. The recalls themselves were separated into product treatment groups: uncooked, canned shelf-stable items, and using tuna as an ingredient. The recalls were further categorized and summarized by reason or cause, such as biological and chemical contamination, undeclared ingredients, under-processing, and foreign materials. The primary causes of recalls of the reviewed tuna products were, in order, Listeria monocytogenes , undeclared allergens, elevated histamine levels, and under-processing of retorted tuna items. The recalls for elevated levels of histamine primarily occurred in uncooked (raw) tuna. Recalls for Listeria sp. and undeclared allergens were considered to be primarily Class I recalls, while recalls for elevated levels of histamine and under-processing were almost always assigned to the less serious Class II designation.

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Posted in food contamination, food handler, Food Hazard, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Poisoning, Food Safety, Food Testing, Histamine, Listeria, Listeria monocytogenes, Research

Research – A pilot-scale evaluation of using gaseous chlorine dioxide for decontamination of foodborne pathogens on produce and low-moisture foods

Posted on October 9, 2021 by | Leave a comment

Wiley Online

Small-scale studies have shown that chlorine dioxide gas, ClO2(g), was effective for decontamination of produce, nuts, and spices. This study conducted a pilot-scale evaluation to identify effective ClO2(g) treatment parameters for commercial-scale applications. The gas was produced by a generator utilizing sodium chlorite and chlorine gas for decontamination of Shiga toxin-producing Escherichia coli (STEC), Listeria monocytogenes, and Salmonella inoculated on tomatoes, blueberries, baby-cut carrots, almonds, and peppercorns. Inoculated samples and 45 kg tomatoes in a 1,246-L treatment chamber were exposed to various ClO2(g) concentrations (mg/L) and times 9 (hr) at 70–95% RH to determine the treatment effects on the pathogen reductions. Results showed that the treatment caused higher reductions on produce. A ClO2(g) treatment of 1 mg/L-3 hr at 70% RH reduced 4.9–6.8, 5.1–5.6, and 4.2–6.3 log CFU/g of STEC, L. monocytogenes, and Salmonella, respectively, on produce, with the highest reductions on baby-cut carrots. For almonds and peppercorns, ClO2(g) treatments under higher RH caused higher reductions. The treatment of 2 mg/L-9 hr or 3 mg/L-4 hr at 95% RH reduced >4.0 log of STEC and Salmonella on almonds, and 1 mg/L-5 hr at 85% RH achieved >5.0 log reductions on peppercorns. Applying moisture to the surfaces of almonds caused >4.0 log reductions using 1 mg/L-5 hr at 95% RH. This study identified effective ClO2(g) treatment parameters for achieving >4.0 log reductions of common pathogens on tomatoes, blueberries, baby-cut carrots, almonds, and peppercorns and showed that ClO2(g) generator is suitable for large-scale decontamination. These findings can be used for pilot-scale ClO2(g) decontamination of these products and for testing using ClO2(g) for commercial-scale decontamination trials.

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Posted in Decontamination Microbial, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Technology

Research – Detection of Escherichia albertii in retail oysters

Posted on October 9, 2021 by | Leave a comment

Journal of Food Protection

Escherichia albertii  is an emerging foodborne pathogen. Owing to its distribution in river water,  it is important to determine the presence of  E. albertii  in aquaculture-related foods. In this study, we investigated the distribution of  E. albertii  in retail oyster samples.  A total of  427 raw oyster samples (385 Pacific oysters, and 42 Japanese rock oysters) were enriched in  modified Escherichia coli  broth (mEC) or mEC supplemented with novobiocin (NmEC) at 42 °C. The cultures were used for  E. albertii -specific nested PCR assay, as well as for  E. albertii  isolation using  deoxycholate hydrogen sulfide lactose agar  (DHL), DHL supplemented with rhamnose and xylose (RX-DHL), and MacConkey agar supplemented with rhamnose and xylose (RX-MAC). The population of  E. albertii  in nested PCR-positive samples was  determined using the  most probable number  (MPN) method.  E. albertii  isolates were subjected to biochemical and genetic characterization.  E. albertii   was detected in 5 of 315 (1.6%) Pacific oyster samples  (one piece each), 2 of 70 (2.9 %)  Pacific oyster samples  (25 g each), and 2 of 42 (4.8 %) Japanese rock oyster samples  procured from four geographically distant regions. A total of 64  E. albertii  strains were isolated from eight of the nine nested PCR assay-positive oyster samples, and  the MPN value was under the detection limit (< 3 MPN/10 g).  A specific season or month for detecting  E. albertii  was not observed in this study, suggesting that the pathogen is present in seawater.   All the  E. albertii  isolates, except one, were positive for the virulence factor  eae,  indicating that these isolates have  the potential to infect humans.

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Posted in E.albertii, E.coli, eae, food contamination, Food Hazard, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Pathogen, Food Safety, Food Testing, Research

Research – Inactivation of Salmonella enterica serovar Typhimurium and Staphylococcus aureus in rice by radio-frequency heating 

Posted on October 8, 2021 by | Leave a comment

Journal of Food Protection

The objectives of this study were to determine the effect of the milling degree (MD) of Oryza sativa L. (Korean rice) on the heating rate, pathogen inactivation (Salmonella Typhimurium and Staphylococcus aureus), and color change resulting from radio-frequency (RF) heating. Rice samples inoculated with pathogens were placed in a polypropylene jar and subjected to RF heating for 0-75 s. The heating rate of rice with a 2% MD was the highest during RF heating, followed by those with a 0, 8, and 10% MD, and the reduction of pathogens showed the same trend. The reduction of the levels of pathogens in rice with a MD 0 and 2% was significantly higher than that observed for rice with a MD of 8 and 10% under the same treatment conditions. For example, log reductions of S. Typhimurium in rice by 55 s RF heating were 3.64, 5.19, 2.18, and 1.80 for milling degree of 0, 2, 8, and 10%, respectively. At the same treatment conditions, log reduction of S. aureus were 2.77, 5.08, 1.15, and 0.90 for milling degree of 0, 2, 8, and 10%, respectively. The color of rice measured according to L*, a*, and b* was not significantly altered after RF heating, regardless of the MD. Therefore, the MD of rice should be considered before RF heating is applied to inactivate foodborne pathogens.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Staphylococcus aureus, Technology

Research – Emergence of Vibrio cholerae O1 Sequence Type 75, South Africa, 2018–2020

Posted on October 8, 2021 by | Leave a comment

CDC

Abstract

We describe the molecular epidemiology of cholera in South Africa during 2018–2020. Vibrio cholerae O1 sequence type (ST) 75 recently emerged and became more prevalent than the V. cholerae O1 biotype El Tor pandemic clone. ST75 isolates were found across large spatial and temporal distances, suggesting local ST75 spread.

The seventh cholera pandemic, caused by Vibrio cholerae O1 biotype El Tor (7PET), arrived in Africa during 1970 and became endemic in many countries on the continent (1). Cholera was first reported in South Africa in 1974 (2). However, South Africa is not considered a cholera-endemic area; outbreaks typically are associated with importation, particularly from neighboring countries. The last cholera outbreak in South Africa was triggered by imported cases from an outbreak in Zimbabwe during 2008; South Africa reported 12,706 cases during November 2008–April 2009 (3).

Globally, 7PET isolates are genetically homogeneous and linked to the Bay of Bengal in South Asia (4,5). Most 7PET isolates are multidrug-resistant sequence type (ST) 69 (6). Rarely, 7PET has a single-locus variant, ST515, in isolates from Africa belonging to lineage T10 (7). As of September 2021, all cholera isolates from South Africa have been characterized as 7PET ST69 by multilocus sequence typing (MLST).

South Africa actively surveils for cholera. Since the 2008–2009 outbreak, few cases have been identified: 5 during 2010–2014, most of which were imported, and none during 2015–2017. During 2008–2009, large outbreaks occurred in 3 provinces, Mpumalanga, Limpopo, and KwaZulu-Natal (3), but all were caused by imported cases from neighboring Zimbabwe and Mozambique. Therefore, given their experience, healthcare workers and laboratorians in these provinces typically will test for cholera in all cases of acute watery diarrhea.

In South Africa, the National Institute for Communicable Diseases (NICD) is notified of suspected cholera cases. NICD’s Centre for Enteric Diseases supports case investigations and receives all human and environmental V. cholerae isolates for further investigation. The case definition for confirmed cholera is isolation of V. cholerae O1 or O139 from a person with diarrhea. We investigated the molecular epidemiology of V. cholerae in South Africa during 2018–2020.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Vibrio, Vibrio cholera

Research – Transfer of Salmonella from inert food contact surfaces to wheat flour, cornmeal and NaCl.

Posted on October 8, 2021 by | Leave a comment

Journal of Food Protection

Salmonella contamination in a dry processing facility frequently requires removal methods that are non-aqueous. Removal of pathogens from food processing systems with a purge of uncontaminated dry food materials has been proposed, however, little is known with the respect to efficacy. In this study, survival of Salmonella on inert contact surfaces and transfer of Salmonella from inert contact surfaces to low-moisture foods was evaluated. Six stainless steel and polymeric food contact material types, in bead form, were contaminated at 11 log CFU/mL and then stored at two temperatures, 25°C and 4°C for six months. Simultaneously, three dry food materials/ingredients were used to remove Salmonella from contaminated beads. Wheat flour, cornmeal, and NaCl (1 g each) were mechanically mixed with 3 beads of each material type. The rate of microbial transfer from contaminated beads to food materials was measured. Further experimentation using multiple transfers were applied on two representative beads types, 316 stainless steel and polypropylene, representing common surface contact materials used in processing equipment. Survival of Salmonella on beads depended on storage temperature, surviving longer at 4°C compared to 25°C (p<0.05), but was not influenced by type of bead material. Transfer of Salmonella from stainless steel beads to flour was significantly greater than from plastic (p<0.05). Transfer rates from stainless steel to wheat flour, cornmeal, and NaCl were measured as -0.5713, -0.2592, and -1.4221 Log CFU Salmonella removed/cm 2 /g clean material used. Transfer rates for polypropylene to whole wheat flour, cornmeal, and NaCl were more than 10-fold lower at -0.0156, -0.0148, and -0.0129 Log CFU Salmonella removed/cm 2 /g clean material used. These results indicate that while material type may not influence Salmonella survival during storage, Salmonella is more easily removed from stainless steel than polyethylene.

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Posted in Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, Food Technology, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Research, Salmonella, Technology