Scientists at UT Southwestern have discovered a key protein that helps the bacteria that causes Legionnaires’ disease to set up house in the cells of humans and other hosts. The findings, published in Science, could offer insights into how other bacteria are able to survive inside cells, knowledge that could lead to new treatments for a wide variety of infections.
“Many infectious bacteria, from listeria to chlamydia to salmonella, use systems that allow them to dwell within their host’s cells,” says study leader Vincent Tagliabracci, Ph.D., assistant professor of molecular biology at UTSW and member of the Harold C. Simmons Comprehensive Cancer Center. “Better understanding the tools they use to make this happen is teaching us some interesting biochemistry and could eventually lead to new targets for therapy.”
Tagliabracci’s lab studies atypical kinases, unusual forms of enzymes that transfer chemical groups called phosphates onto proteins or lipids, changing their function. Research here and elsewhere has shown that Legionella, the genus of bacteria that cause Legionnaires’ disease, is a particularly rich source of these noncanonical kinases. According to the Centers for Disease Control and Prevention, nearly 10,000 cases of Legionnaires’ disease were reported in the U.S. in 2018, though the true incidence is believed to be higher.
After identifying a new Legionella atypical kinase named MavQ, Tagliabracci and his colleagues used a live-cell imaging technique combined with a relatively new molecular tagging method to see where MavQ is found in infected human cells, a clue to its function. Rather than residing in a specific location, the researchers were surprised to see that the protein oscillated back and forth between the endoplasmic reticulum — a network of membranes important for protein and lipid synthesis — and bubble- or tube-shaped structures within the cell.
Further research suggests that MavQ, along with a partner molecule called SidP, remodels the endoplasmic reticulum so that Legionella can steal parts of the membrane to help create and sustain the vacuole, a structure that houses the parasite inside cells and protects it from immune attack.
Tagliabracci, a Michael L. Rosenberg Scholar in Medical Research and a Cancer Prevention & Research Institute of Texas (CPRIT) Scholar, says that he suspects other bacterial pathogens may use similar mechanisms to co-opt existing host cell structures to create their own protective dwellings.
This work was funded by NIH grants DP2GM137419, R01GM113079, T32GM008203-29, F30HL143859-01, Welch Foundation grants I-1911, I-1789, CPRIT grant RP170674, and Polish National Agency for Scientific Exchange scholarship PPN/BEK/2018/1/00431.
The Armenian Ministry of Health reports an outbreak of intestinal infections in the country’s Sisian community.
To date, the ministry has recorded 370 cases with diagnoses that are characteristic of intestinal infections and 7 of the 370 patients are currently undergoing treatment at a hospital.
The Ministry of Health said that the patients are in serious condition, while other residents are receiving outpatient treatment.
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Sample from water and from patients have been taken for microbial testing to include enteropathogenic intestinal bacteria, Yersinia enterocolitis and Campylobacter, as well as Norovirus and Adenovirus.
278 cases of legionnaires’ disease were detected in Denmark in 2020. Of these, 94.6% had been infected in Denmark. That is the highest number ever.
The Statens Serum Institut (SSI) has issued the annual report on how many cases of Legionnaires’ disease (LS) were found in Denmark in 2020.
A total of 278 cases of LS, also known as legionella pneumonia, were detected. Of these, 165 were men (59.4%) and 113 women (40.6%).
Out of these, 39 patients died within 30 days after the disease had broken out or they had been hospitalized. It gives a mortality rate of 14%.
Out of the 278, 263 people were infected in Denmark. This corresponds to 94.6%. This is an increase of 25% compared to the average for the last three years, and thus the highest number ever.
“The increase in the number of infected in Denmark may be related to a higher test activity in 2020. It may be due to the fact that many hospitalized patients with suspected covid-19 have also been examined for legionella infection,” says head of department Søren Anker Uldum from SSI.
There are only 15 cases (5.4%) where people in 2020 were infected with LS when traveling abroad. In 9 cases, it was while traveling in Europe. 5 were infected while traveling in Asia and 1 traveling to the American continent.
The proportion of travel-related LS cases is usually 20-25%
“Due to the extensive travel restrictions in 2020 due to the Covid-19 pandemic, there has been very limited travel activity. This is probably the reason for the few travel-associated legionella cases in 2020 ”, says Søren Anker Uldum.
You can read more about Legionnaires’ disease here.
You can also see the annual statement for legionnaires’ disease in Denmark in 2020 here .
The HSE-Health Protection Surveillance Centre (HPSC) is providing advice to parents about preventing cryptosporidiosis following a large increase in a potentially serious tummy bug in children over the last few weeks.
Since the beginning of March, the number of cases of cryptosporidiosis has more than doubled in comparison to the average rates, especially in small children aged 1 to 4 years of age. When children spend time outdoors and in particular on farms, they are more likely to pick up this bug and it is important they wash their hands regularly with soap under warm running water.
Factsheet to assist parents
Hands should always be washed:
It is important to know that:
Symptoms:
Symptoms of cryptosporidiosis generally begin about a week after swallowing the bug, but can start after only a couple of days. The symptoms last about one week (but can last longer). People who are immunocompromised (whose body’s defence system is weak due to a medical condition or because of medication) can have severe symptoms if they catch cryptosporidiosis.
The most common symptom of cryptosporidiosis is watery diarrhoea. Other symptoms include:
Some people with cryptosporidiosis will not get sick at all.
Cryptosporidiosis is spread when the bug passes from the person or animal in the stools or manure, and anything contaminated by the stools or manure (hands, touch surfaces, handles, food, water and outdoor surfaces) can lead to a person becoming infected.
Monitoring developments in the field of food safety is an essential task of early detection. This is why the FSVO summarises and evaluates the main information in Seismo Info. The publication is sent out by newsletter.
The aim of early detection for food safety is to identify and assess potential risks of food to the health of consumers.
The FSVO distinguishes between different types of risk:
The detection of newly emerging risks requires vigilant monitoring of societal and ecological changes, technological developments, economic trends and political conditions.
The information gathered is compiled in the ADURA database, which can be accessed by federal and cantonal experts and to some extent also by the public.
The FSVO summarises and evaluates the main information every month in Seismo Info. The publication is communicated via the «Food safety and nutrition» newsletter (Subscription in French, German or Italian).
«Briefing letters» are short summaries of issues. They are characterised by in-depth research on a specific topic. Their purpose is to draw attention to hazards or risks that could endanger food safety in the medium to long term.
Anyone can contribute to early detection by submitting information to seismo@blv.admin.ch. Specialists check the information and incorporate it into the ADURA database or Seismo Info as appropriate.
Employers, the self-employed and people in control of premises, such as landlords, have a duty to protect people by identifying and controlling risks associated with legionella.
If your building was closed or has reduced occupancy during the coronavirus (COVID-19) pandemic, water system stagnation can occur due to lack of use, increasing the risks of Legionnaires’ disease.
You should review your risk assessment and and manage the legionella risks when you:
If the water system is still used regularly, maintain the appropriate measures to prevent legionella growth.
You can find out what Legionnaires’ disease is, where it comes from, how people get it and symptoms and treatment by reading our guidance What is Legionnaires’ disease?.
New Jersey officials have found a potentially deadly bacteria in the water at one of New Jersey’s largest prisons, according to a staff memo obtained by NJ Advance Media.
Legionella was detected in a medical building at Northern State Prison in Newark, according to the document, and staff have since moved inmates out of the affected area. The bacteria causes Legionnaire’s disease, a form of pneumonia especially dangerous for people with compromised immune systems,
Once more offices open up, following the easing of coronavirus measures, a new danger presents itself – Legionnaires’ disease. This arises because of poorly maintained water and air conditioning systems.
The number of cases of Legionella is increasing globally, with a marked change recorded in the U.S. The number of cases now stands, typically, at 10,000 cases per year. The disease is a form of pneumonia caused by Legionella bacteria (L. pneumophila). These organisms can be inhaled into the lungs through water aerosols and droplet, suspended in the air when water is used. Signs and symptoms typically include fever, cough, and chest pain, and it can result in death in up to 10 percent of cases.
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