Category Archives: Microbiology Investigations

Research – Deep ultraviolet fluorescence sensing with multispectral imaging to detect and monitor food-borne pathogens on the leafy green phyllosphere

Wiley Online

Demand for sustainable and safe raw agricultural commodities is growing rapidly worldwide. Reducing the risk of foodborne illnesses associated with fresh produce is a task which the industry and academic researchers have been struggling with for many years. There is an immediate need to devise a non-invasive optical detection system to monitor the food-borne pathogens on the leaf surface. The detection of foodborne pathogens on leafy produce is performed often too late because of the invasive techniques used to evaluate the pathogen colonization. Use of deep ultraviolet fluorescence (DUVF) sensing and visible–near infrared multispectral imaging (MSI) has previously been used to monitor plant interactions against both biotic and abiotic stress regimes. Using the patho-system that we developed to monitor Salmonella sp. and Listeria sp. ingression in leafy greens such as lettuce/spinach, we show that plant response in terms of fluctuation of chlorophyll pigments post-Salmonella/Listeria treatment is rapid. We also show that the mode of application of Salmonella/Listeria via foliar or root supplementation changes the ChlA response. Our data also reveals that the plant sentinel response in terms of early photosynthetic response may be critical to detect food-borne pathogens on leafy greens. MSI demonstrated that plant stress was detectable and proportional to the bacterial inoculation rate on plants. Our research may lead to implementation of better strategies and technology to increase yield and reduce risks associated with contamination of foodborne bacterial pathogens.

Research – Severe Streptococcus equi Subspecies zooepidemicus Outbreak from Unpasteurized Dairy Product Consumption, Italy

CDC

Abstract

During November 2021–May 2022, we identified 37 clinical cases of Streptococcus equi subspecies zooepidemicus infections in central Italy. Epidemiologic investigations and whole-genome sequencing showed unpasteurized fresh dairy products were the outbreak source. Early diagnosis by using sequencing technology prevented the spread of life-threatening S. equi subsp. zooepidemicus infections.

Streptococcus equi subspecies zooepidemicus is a β-hemolytic streptococcus expressing Lancefield group C antigen and is 1 of 3 S. equi subspecies. S. equi subsp. zooepidemicus is an opportunistic pathogen that can infect domestic animals, pets, and wildlife (16). Sporadic human cases have been reported (7), characterized by clinical manifestations that vary from meningitis to sepsis. Human infection generally occurs through direct contact with infected animals or by consumption of contaminated unpasteurized milk or other dairy products (810). We report a large S. equi subsp. zooepidemicus outbreak in Italy.

Research – Forgotten but not gone: Yersinia infections in England, 1975 to 2020

Eurosurveillance

Yersiniosis, most often caused by  is one of the most common bacterial food-borne zoonoses in Europe with reported overall incidence of 1.8 cases per 100,000 population in 2020 [1]. There is, however, marked variation among countries, with the highest numbers of cases per 100,000 population reported in Denmark and Finland (7.1 and 7.0, respectively) and the lowest in Romania and Bulgaria (0.03 and 0.06, respectively) [1]. Transmission is primarily faecal–oral via food or water contaminated with animal faeces [2]. Yersiniosis has been associated with the consumption of pork meat (raw or undercooked), occupational exposure to pigs, untreated drinking water, milk, vegetables, juices, ready-to-eat and other foods [36]. The incidence of yersiniosis in Europe is higher in males and in children under 5 years, and no clear seasonal pattern has been reported over the last decade [1,3]. Yersiniosis commonly presents as diarrhoea, abdominal pain and fever, and can manifest as acute mesenteric lymphadenitis and terminal ileitis. Although it is usually self-limiting with a low case fatality rate (0.05%), symptoms often persist for several weeks [3,6].

The reported incidence of  infections in the United Kingdom (UK) is well below the European average (0.2 cases per 100,000 in 2019) [3]. Routine testing for  is not currently recommended in the UK, unless there is a clinical suspicion (e.g. appendicitis, mesenteric lymphadenitis, terminal ileitis or reactive arthritis) [7]. The aim of this study was to describe the changing incidence and epidemiology of diagnosed  infections in England between 1975 and 2020 and to estimate the potential under-ascertainment of  due to the lack of routine testing.

Research – Researchers explore probiotics to control Campylobacter

Feedstuffs

On-farm control measures are required to mitigate the risk of the bacteria being transmitted to humans working with poultry and people who visit poultry farms. Abdelaziz’s lab is studying the impact of inoculating eggs (in-ovo) with probiotics on gut health and immune system development of broilers before they hatch.

Probiotics are live bacteria, fungi, or yeasts that help poultry maintain healthy digestive systems. They are increasingly being included in poultry diets as alternatives to antibiotics. Abdelaziz and his team believe in-ovo technology can be used to deliver probiotics to chicken embryos and help boost chicks’ immune systems before they hatch.

During their investigation, Abdelaziz and his team have found certain probiotics (lactobacilli) applied in-ovo to chick embryos increased immune-related genes in the chicks’ guts which could promote healthy immune systems of chick embryos. Future studies will investigate whether Lactobacillus-induced immune responses protect against harmful microorganisms after chicks hatch.

Researchers urge Campylobacter focus in the Czech Republic

Food Safety News

Scientists in the Czech Republic have called for a national reference laboratory for human Campylobacter infections to be created in the country.

From 2018 to 2021, 81,115 cases were reported in the electronic Infectious Disease Information System (ISIN). Slightly more men than women were sick. Campylobacter jejuni makes up the majority of cases followed by Campylobacter coli. The highest incidence was in people aged 1 to 4 years old.

Almost 10,000 people were hospitalized and 34 deaths were reported including five children younger than 5, three teenagers, seven people aged 21 to 35, and 19 people older than 57.

Preventative measures should be aimed at children younger than 5 because of the high incidence and people older than 80 who are at higher risk of severe illness and hospitalization, said scientists.

RASFF Alerts – Animal Feed – Ergot Alkaloids – Triticale

RASFF

Ergot (Claviceps purpurea) in triticale from France in Belgium and Poland

RASFF Alerts – Mold/Mould – Corn – Hulled Sunflower Seeds – Feed Material

RASFF

Corn – mould from Ukraine in Poland

RASFF

Sunflower meal from hulled sunflower seeds – mold from Ukraine in Poland and Lithuania

RASFF

Mould in feed material from Ukraine in Poland

RASFF Alert – Animal Feed – Salmonella

RASFF

Salmonella spp. in rapeseed cakes from Germany in the Netherlands

Kenya – Salmonella and E. coli suspected in large, deadly outbreak in Kenya

Food Safety News

Four people have died and more than 600 were sickened at two schools in Kenya recently.

The Ministry of Health (MOH) is investigating a suspected gastroenteritis outbreak at Mukumu Girls and Butere Boys high schools in Kakamega County.

The illness appears to have started on March 1 and as of April 14, 627 patients are sick with 19 students admitted to seven health facilities across the country. Symptoms include fever, abdominal pain, cramps, vomiting, and diarrhea. One teacher and three students have died.

Both schools have been closed by the Ministry of Education and Kakamega County government while investigations are ongoing.

Research – CFA’s dataset central to preparing response to awaited changes in EU Listeria regulations – but more involvement needed from other sections of industry

CFA

Work continues on building a consortium of European and international industry and the industry Response to the EU’s awaited but undefined proposed changes to Listeria monocytogenes (Lm) legislation (EU Microbiological Criteria for Foodstuffs Regulation 2073/2005) (CFA News #56 and #57).

Potential changes to the regulation include:

  • loss of 100 cfu/g as an upper limit and introduction of zero tolerance/not detected in 25g
  • requirements to set shelf life by challenge testing and not durability testing.

This is the most important policy matter for the UK industry, which can demonstrate through hard data (epidemiology, food and environmental sampling) that its approach is much more effective from a public health perspective than that in other major European countries and across Europe, the UK listeriosis rate consistently being half that of Europe as a whole.

Read more at the link above.