First case of Listeria monocytogenes causing peripheral neurological complications

An old woman was admitted to the emergency room with a body temperature of 39 degree celsius, normal pulse, elevated blood pressure and respiratory rate of 24/min. Lumbar puncture was done and it revealed that there were high level of leukocytes and protein. Glucose level was normal. PCR assay was done from cerebrospinal fluid which showed positive to Listeria monocytogenes. After 3 days of admission, the patient started to experience weakness in her right arm. At the same time the patient noticed a mild change in taste. After day 6 of admission, nerve conduction study and some tests were done. After looking at the results, they considered to diagnose with acute polyradiculoneuritis.

Nobody knows how the infection of Listeria monocytogenes led to meningoencephalitis causing polyradiculoneuritis because this is the first case. They suspect that the “molecular mimicry” played a part in the dysimmune process leading to axonal dysfunction.

References

Anon., n.d. Meningitis and Encephalitis. [Online]
Available at: https://psychpedia.blogspot.com/2014/08/meningitis-and-encephalitis.html
[Accessed 7 26 2019].

Tebib, N., Bill, O., Niederhauser, J. & Christina, L., 2018. An uncommon complication of Listeria monocytogenes infection: Polyradiculoneuritis following Listeria meningoencephalitis. [Online]
Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010957/
[Accessed 26 7 2018].

 

 

How do some Listeria survive in food despite the high food hygiene standards

 

A newly defined “stress survival islet” asures survival of some listeria strains despite high hygiene standards in food production.
Credit: Institute of Milk Hygiene/Vetmeduni Vienna

With the high food hygiene standards, Listeria monocytogenes(Lm) is still able to persist in the food. This is due to certain genetic mechanisms which gives protection for Lm from cleaning chemicals. In the genome, there are hypervariable regions which contain genetic inserts such as stress survival islet 1(SSI-1). SSI-1 allows Lm to survive under certain stressful environment. However, this does not demonstrates how it is able to survive the hygiene standards such as the alkaline and oxidative treatment. To unlock the mystery behind it, researchers conducted experiments and identified 2 gene that contributed to Lm survival in alkaline and oxidative environment. The first gene is the transcriptional regulator which regulates the second protein under certain situations and the second gene is the protease which breaks down proteins. In stress situations, unfunctional proteins are created where it is broken down by protease. Hence, both genes make up a functional unit which is identified as stress survival islet 2. Due to this, it is able to survive under alkaline and oxidative environment.

References

Veterinärmedizinische Universität Wien, 2017. An island getaway: Why some Listeria strains survive good food hygiene standards. [Online]
Available at: https://www.sciencedaily.com/releases/2017/08/170830095024.htm
[Accessed 22 7 2018].

 

Understanding how Listeria monocytogenes is vertically transmitted

Placenta plays a important role of providing protection to the developing fetus. Listeria monocytogenes(Lm) is one of the pathogen that can pass through the placental barrier and cause damage to the fetus resulting to its death. Even with antibiotic treatment Lm is still unstoppable. Animal model, organ model and in vitro cell culture was used to aid in our understanding of its virulence. This models used will not give the complete understanding of Lm invading the human placenta as the models used does not replicate an in vivo model of human pregnancy.

An environment of balance between fetal tolerance and pathogen protection is required in pregnancy. It was implicated that Interalin (Inl) A, InlB and InlP which is some of Lm virulence factors have contributed to trophoblast infection. However, in this study it showed otherwise because it was observed that InlA had no role in invading the placenta when pregnant guinea pig was used which had the correct form of the E-cadherin receptor normally bound by InlA. Such different results may due to the fact of limitations in current animal models availability. Hence, future studies to confirm the roles of Interlain is recommended.  LLO and ActA are also some of Lm virulence factors that aid in the infection and vertical transmission as those are necessary for Lm growth in placental cells. Moreover LLO and ActA, also aids Lm to spread to the fetus via cell-to-cell interactions.

References

kalidindi, D., 2015. Disease transmission and cycle. [Online]
Available at: https://www.slideshare.net/DrBharatKalidindi/disease-transmission-and-cycle
[Accessed 22 7 2018].

Lamond, N. M. & Freitag, N. E., 2018. Vertical Transmission of Listeria monocytogenes: Probing the Balance between Protection from Pathogens and Fetal Tolerance. [Online]
Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027155/
[Accessed 22 7 2018].

 

 

Federal Complaint Against Freshy Foods Due to Listeria Contamination

Freshy Foods is a distributor and manufacturer of refrigerated, ready-to-eat (RTE) food, including snack cups, wraps, sandwiches, fruit cups, salads. Ready-to-eat foods fall under the jurisdiction of the Food and Drug Administration.

The business has been accused for violating federal law for distributing Freshy foods products such as wraps and sandwiches which as been contaminated by Listeria monocytogenes. Freshy Foods has a least six cases regarding about this contamination since 2012.

The company declined to recall products when their products were discovered with listeria contamination which was asked by the U.S. Food and Drug Administration.

Workers preparing sandwiches at Freshy Foods facility

The complaint was filed on 22 June in federal civil court in attempt to put Freshy Foods out of business. The complaint criticizes the business for distributing meals that has produced or held in unsanitary conditions.

Melinda K. Plaisier, FDA’s Associate Commissioner for Regulatory Affairs said that the company should stop operations until they are able to demonstrate to the FDA that their products are safe.

 

 

References

Flynn, D., 2018. DOJ: Freshy Foods needs to cease operations until it cleans up. [Online]
Available at: http://www.foodsafetynews.com/2018/06/doj-freshy-foods-needs-to-cease-operations-until-it-cleans-up/#.WzB5PKczbIV
[Accessed 25 6 2018].

McKnight, L., 2018. Elmwood business refused to recall food after listeria found: federal complaint. [Online]
Available at: https://www.nola.com/business/index.ssf/2018/06/elmwood_business_refused_to_re.html
[Accessed 25 6 2018].

Richard, F., 2018. Elmwood enterprise refused to recall meals after listeria discovered: federal grievance. [Online]
Available at: https://daily-world.com/business/elmwood-enterprise-refused-to-recall-meals-after-listeria-discovered-federal-grievance/
[Accessed 25 6 2018].

 

Egypt has banned South Africa’s products due to Listeria contamination

On 10 may, Egyptian Department of Agriculture and Land Reclamation imposed a temporary suspension on the issuance of import permits. This restriction will affect  processed meat products, meat and unspecified agricultural products. This restriction was imposed due to the recent listeriosis outbreak.

Transmission electron micrograph (TEM) of a Listeria sp bacterium in a tissue sample.

When the measures that were endorsed to contain the disease is released by the Department of Agriculture or responsible authority, the suspension imposed by the Egypt will be considered to be removed. Moreover, the South African counterpart was requested by the Egyptian Ministry of Agriculture to prove there is capacity to analyse imported consignments against the disease and issue certificates accordingly.

Similarly, Rwanda ban in South Africa goods such has meat, dairy and vegetables is still in place due the lack of necessary paperwork.

 

References

Jansen, C., 2018. South Africa’s fresh produce industry unaffected by Egypt listeriosis ban. [Online]
Available at: http://www.freshplaza.com/article/194525/South-Africas-fresh-produce-industry-unaffected-by-Egypt-listeriosis-ban
[Accessed 16/5/2018].

Stockclip, n.d. Fresh Raw Pork Chops in Meat Factory. Raw meat cuts on a industrial conveyor belt. Meat processing in food industry. Industrial meat cutting machine processing rib eye meat.. [Online]
Available at: https://stock-clip.com/video/14698591-fresh-raw-pork-chops-in-meat-factory-raw-meat-cuts-on-a-industrial-conveyor-belt
[Accessed 16/5/2018].

Swanepoel, F., 2017. Agriculture training in South Africa badly needs an overhaul. [Online]
Available at: https://mg.co.za/article/2017-11-13-agriculture-training-in-south-africa-badly-needs-an-overhaul
[Accessed 16/5/2018].

Wet, P. d., 2018. Egypt just banned South African imports because of listeriosis. [Online]
Available at: https://www.businessinsider.co.za/egypt-has-banned-south-african-imports-because-of-listeriosis-2018-5
[Accessed 16/5/2018].