Top 7 Causes of Food Poisoning

The top seven causes of food poisoning are Salmonella, Listeria, Staphylococcus, Trichinosis, E. coli, Campylobacter, Clostridium.

The Health Department estimates that food poisoning affects around 5.4 million Australians each year – that’s close to one-quarter of the entire population.

There are many different types of contaminations that can cause cases of food poisoning and it is usually difficult to detect the source. Often food smells and tastes fine but can actually contain bacteria, chemicals or viruses. These are just a few causes of food poisoning and they could make you very sick if you consume food contaminated with them.

Salmonella

Salmonella enterica is a bacterium that causes salmonellosis – a particularly nasty type of gastroenteritis. Young children, older adults and people with a weakened immune system are most susceptible to salmonella bacteria.

Food can become contaminated with salmonella in many different ways, some of which are:

• From coming into contact with an infected food handler
• From faecal matter, both human and animal, transferred from unwashed hands, utensils or surfaces
• From handling food after touching small rodents, reptiles and some birds

Beef, dairy, eggs and poultry are foods most likely to be contaminated with salmonella; however other foods, like fruits or vegetable, can also carry the bacteria.

Symptoms

People infected with salmonella usually experience symptoms between 12 to 72 hours after infection. The symptoms include usually last for between 4 and 7 days and can include:

• Fever
• Stomach cramps
• Diarrhoea

In a small number of extreme cases, salmonellosis can result in a person contracting Reiter’s Syndrome, a condition that can eventually result in a person suffering from chronic arthritis.

Treatment

A specific treatment for salmonellosis is not always required. Often rest and continual hydration are all that is needed; however, antibiotic therapy might be necessary in some cases. People who have suffered from salmonella related food poisoning are advised not to return to work or school until they have been symptom-free for a minimum of 48 hours.

Listeria

Listeria monocytogenes is bacteria that can cause acute food poisoning. Pregnant women, people with a lowered immune system, young children and older adults are the groups most at risk of infection.

Some examples of foods with a high risk of contamination are:

• Raw and cooked seafood
• Precooked deli meats
• Premixed raw vegetables
• Unpasteurised milk
• Soft cheeses and soft-serve ice cream

Symptoms

People suffering from a listeria infection can experience:

• Tiredness
• Fever
• Headaches
• General aches and pains

In severe cases, listeria infections can lead to septicaemia (blood poisoning) or meningitis (an infection in the brain). Pregnant women are extremely susceptible to listeria and even a mild infection can cause miscarriage, premature birth or stillbirth.

Treatment

Early use of antibiotics can often treat listeria infections but prevention is definitely better. Practising a high level of food safety will help avoid the spread of listeria and therefore contamination.

People who handle and prepare food should ensure that:

• They wash their hands before and after touching food
• All utensils are washed between use
• Raw fruits and vegetables are well washed before use
• They use either a fridge or microwave to defrost food
• Cook all meat and animal products thoroughly
• Food in the fridge is kept below 5 degrees Celsius and hot food is kept above 60 degrees Celsius

Staphylococcus

Staphylococcus aureus, also known as S. aureus or golden staph, is a common bacterium that lives on the skin, in the mouth and in the nose. Golden staph infections often begin with a minor cut that then becomes infected and can vary from a small sore to a flesh-eating infection.

Symptoms

A Golden staph infection usually appears as a dry, yellow skin infection and symptoms can include:

• Soreness
• Redness
• Heat
• Swelling

In severe cases, people can experience

• High fever
• Skin rashes
• Blisters
• Impetigo – a highly contagious skin infection

Humans and animals are the primary sources of staphylococci and food handlers have a high risk of spreading the bacteria and causing food poisoning. Foods most likely to be contaminated with golden staph are meats, poultry, eggs and dairy.

Treatment

Antibiotics, namely penicillin, are used to treat Golden staph infections though if unsuccessful, surgical cleaning is sometimes required. To promote good food safety, people touching food should continually wash their hands thoroughly or use sterile disposable gloves.

Trichinosis

Trichinosis is a roundworm infection that lives and reproduces inside a host body. The worms are usually found in meat-eating animals and can spread to humans through the consumption of trichinosis eggs found on raw or undercooked meats.

If the trichinosis eggs are ingested, they can live in the intestines and hatch into adult worms. The adult worms then produce more eggs that can travel to various different types of tissue in the body.

Symptoms

People infected with trichinosis don’t always have symptoms however if they do, they could experience:

• Nausea and vomiting
• Abdominal Pain
• Diarrhoea
• Tiredness

If the infection has progressed to the point that muscle or other tissue has been affected by the worms, then they could also experience:

• Fever
• Swelling
• Headaches
• Weakness
• Muscle pain
• Sensitivity to light
• Conjunctivitis

Treatment

Mild cases of trichinosis can often be left untreated however some cases will require medical treatment. Anti-parasitic medication, pain relief and anti-inflammatory medications are all possible treatments for trichinosis infection. However, like other illnesses prevention is always the best defence.

To help prevent a trichinosis infection, you are advised to:

• Avoid eating undercooked or raw meat and game
• Never eat undercooked or raw poultry
• Freezing some meats for around three weeks can kill trichinosis
• Practice good food safety and wash hands and utensils thoroughly

E. coli

1. coli, or Escherichia coli, is a bacteria that lives in the digestive systems of humans and animals. Although of the many different types of E. coli, not all are harmful to humans, some can cause severe illness and even lead to death.

Humans can develop an E. coli infection when they come into contact with animal or human faeces. This usually occurs when contaminated water or food is consumed. E. coli can contaminate food throughout all stages of the food processing supply-chain and is often caused by poor food safety.

Particular high-risk foods are meat, poultry, dairy, fruits and vegetables. In some cases, entire towns have become ill after their water supply became infected with E. coli.

Symptoms

1. coli can cause different symptoms, depending on the infection. Some of which are:

• Severe abdominal cramps
• Nausea and vomiting
• Fever
• Bloody diarrhoea

In severe cases, E. coli can cause:

• Anaemia
• Kidney failure
• Urinary tract infections

Treatment

Treatment for an E. coli infection varies depending on the severity. Rehydration and rest is often all that is needed to treat the infection and over time it will clear up.

In severe cases, where anaemia or kidney failure has resulted, dialysis or a blood transfusion may be necessary. Antibiotics and anti-diarrhoea medications are not usually recommended to treat E. coli infections.

To help prevent an E. coli infection practicing good food safety is essential. Thoroughly cooking foods and ensuring hands and utensils are properly washed and sanitised will also help to avoid the spread of E. coli bacteria.

Campylobacter

Campylobacter bacteria can cause a food poisoning called campylobacteriosis. It is a very common cause of diarrhoea and most often affects infants, young adults and men.

Handling and then consuming bacteria, often found on raw or undercooked poultry, is the main cause of campylobacteriosis. The campylobacter bacterium is found inside live poultry is easily transferred during the initial processing stage. Studies indicate that a very high percentage of supermarket chicken is contaminated with traces of the bacteria.

Milk and water contaminated with campylobacter bacteria can also cause infection and unwashed hands can cause the infection to spread between humans and animals.

Symptoms

A campylobacteriosis infection can cause:

• Stomach cramps
• Diarrhoea (often bloody)
• Fever
• Nausea and vomiting

Treatment

Antibiotics are not normally recommended unless specifically prescribed by your doctor and in most cases, rest and rehydration is the preferred treatment. Diarrhoea can cause severe dehydration and ensure that you are drinking plenty of water and electrolyte-rich drinks will help your body recover.

Being extra careful when handling raw poultry can help stop the spread of campylobacter bacteria. It is necessary to wash and sanitise your hands well and also any chopping boards and utensils that have come into contact with food, particularly poultry.

Clostridium

Clostridium, often-called C. diff, is a bacterium that lives in the digestive tract. In small quantities it is often harmless however, if the bacteria overgrow, they can cause the release of a toxin that attacks the host’s intestines. This condition is called Clostridium difficilecolitis or C. difficile.

Symptoms

Some possible symptoms of C. difficile are:

• Abdominal pain and tenderness
• Watery diarrhoea

In more severe cases, the infection can cause:

• Weight loss
• Loss of appetite
• High fever
• Severe stomach cramps
• Blood or pus in the stool

Patients in hospitals and hospices are most at risk of contracting the infection particularly those who have had surgery, chemotherapy, colon disease, kidney disease or have a weakened immune system.

Treatment

Antibiotics are the usual treatment for C. difficile infections and in some cases can require a double dose. Probiotics are both good for the prevention and treatment of C. difficile infections as ‘good bacteria’ works to reduce the number of clostridium bacteria. As most recommended food poisoning treatments, fluids and rehydration are also advised.

Preventing the spread of clostridium bacteria is crucial for avoiding incidents of food poisoning. The spores of the bacteria are present in an infected stool and can live on surfaces for a long time. This means that practising good food safety is vital and keeping hands, surfaces and utensils sanitary is a must

Written

BY SALLY SANTACRUZ

Importance of contact lens hygiene

Importance of contact lens hygiene

Caught short without your contact lens case or care solutions? Lens unexpectedly falls out? What would you do? NBA star Ron Baker, faced with just this dilemma earlier this year chose to pop his lens in his mouth to wet it and then place it back on his eye. This was seen by countless people around the world as the video clip spread online, eliciting cringes from the eye health community and shrugs from wearers who have done the same.

During the holidays, when routines are disrupted and time is at a premium, contact lens wearers may also be tempted to skip regular hygiene practices. But is it wise? Scientists from the Centre for Ocular Research & Education (CORE) at the University of Waterloo conducted an eye-popping experiment to help consumers picture the risks.

To demonstrate the rapid growth of bacteria associated with mishandling contact lenses, CORE researchers exposed new, clean contact lenses to human saliva and then placed them into petri plates for monitoring. The action of putting a contact lens in the mouth resulted in significant growth of microorganisms after only two days of incubation (Figure 1).

They then examined the effect of handling contact lenses with both clean and unwashed hands. Unwashed hands were pressed into agar (Figure 2a), and also used to handle a new contact lens (Figure 2b). Scientists then repeated the procedure after following recommended handwashing practices, touching both the agar directly, along with applying and removing a contact lens (Figures 2c and 2d). The results clearly demonstrate the impact handling has on contact lenses. Samples that had been placed in the mouth or touched with unwashed hands showed significantly higher numbers of visible bacteria. By comparison, the contact lens touched with clean hands had only a minimal bacterial load.

“Contact lenses are a safe, highly effective form of vision correction used by millions of people, but ignoring good contact lens care can have a devastating effect on eye health and vision,” says CORE senior research associate Miriam Heynen, MSc, who conducted the experiment with laboratory research assistant Vivian Chan, Bsc., after hearing a news report on poor contact lens care habits.

She continued, “Bacteria are present on surfaces all around us and this simple experiment is a graphic demonstration of how they reproduce over just a short amount of time. Taking care of your contact lenses is a must, no matter how pressed for time you are. Handle with clean, dry hands, use a case and care solution as recommended by an eye care practitioner, and always keep spare contact lenses and spectacles with you. Proper care is simple, essential for good health, and after seeing these photos, a no-brainer for anyone who appreciates their eyes.”

Contact lens wearers can more easily resolve to practice better hygiene during the holiday season and the New Year, thanks to a printable, easy-to-read tip sheet available from CORE which covers good hand hygiene along with other reminders on safe contact lens wear

The Golden rules for sterility testing of antibiotic samples in a study using Tetracycline

https://biopharma-asia.com/magazine-articles/the-golden-rules-for-sterility-testing-of-antibiotic-samples-in-a-study-using-tetracycline/

Flows that help bacteria feed and organize biofilms

Under threat of being scrubbed away with disinfectant, individual bacteria can improve their odds of survival by joining together to form colonies, called biofilms. What Arnold Mathijssen, postdoctoral fellow in bioengineering at Stanford University, wanted to understand was how stationary biofilms find food once they've devoured nearby nutrients.

Leading an international team of researchers in creating simulations of how fluids move, Mathijssen found that individual bacteria and biofilms can generate currents strong enough to draw distant nutrients.

When bacteria move, they disturb the liquids that surround them in the microscopic world. The researchers explored the strength of that disturbance in a single bacterium that moves in a way that is similar to many pathogenic species, including those that cause gastritis and cholera. They found that as this bacterium swims forward, it creates a tiny but stable current in the surrounding liquid with fluid moving toward its center and away from the head and tail.

Then, they calculated the flows produced by a colony of randomly arranged bacteria and were surprised to see that it created a strong, consistent tide capable of pulling in nutrients. This occurred regardless of the orientation of each bacterium so long as the colony was thicker in some areas than others, which causes fluid to move from high points to low points. Simulations of more orderly bacteria resulted in even stronger circulation.

Within organized biofilms, the researchers found two common patterns of movement: vortexes and asters. In a vortex pattern, the bacteria move in concentric circles and produce a flow that brings nutrients down to the biofilm's center and then pushes the fluid out the sides. In an aster pattern, the bacteria move toward a central point, creating a flow that moves from the edge of the biofilm until it rises back up, over the center.

"The powerful thing about this is you can add these patterns up," Mathijssen said. "Rather than having to know the position and orientation of every single bacterium, you only need to know the basic patterns that make up the colony and then it's very easy to derive the overall transport flow."

The researchers were able to combine vortex and aster patterns within a single biofilm to determine how the bacteria would push, pull and whirl the fluids around them. As a final test, the researchers took calculations representing the complex, realistic motion of bacteria swarming -- as they might on the surface of a table -- and predicted the strength of that swarm's transport flow. The result were large vortices that spanned distances beyond the boundaries of the biofilm, suitable for keeping the colony fed.

See:

Arnold J. T. M. Mathijssen, Francisca Guzmán-Lastra, Andreas Kaiser, Hartmut Löwen. Nutrient Transport Driven by Microbial Active Carpets. Physical Review Letters, 2018; 121 (24) DOI: 10.1103/PhysRevLett.121.248101

What is viable and nonviable Particle Count?

What is viable and nonviable Particle Count?

What is the fumigation and fogging?

What is the fumigation and fogging?

Link:  Using Antibiotic Disc 

Microbiology Society

Vicki Symington (Microbiology Society) and John Schollar (National Centre for Biotechnology Education, Reading) demonstrate how to use antibiotic discs. This technique is used to test if antibiotics have an inhibitory effect on the growth of micro-organisms. The Microbiology Society is a membership charity for scientists interested in microbes, their effects and their practical uses. It is one of the largest microbiology societies in Europe with a worldwide membership based in universities, industry, hospitals, research institutes and schools. Our principal goal is to develop, expand and strengthen the networks available to our members so that they can generate new knowledge about microbes and ensure that it is shared with other communities. The impacts from this will drive us towards a world in which the science of microbiology provides maximum benefit to society. Visit website to find out more: http://www.microbiologysociety.org