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Staph infection smells like

What wounds tell us •

Every day, patients are admitted to surgeries, hospitals and outpatient clinics with chronic wounds. Careful inspection gives a wound therapist clues to the appropriate primary care required even before further diagnostic procedures are carried out. So what do the clinical signs and symptoms tell us?

Report: Heidi Heinold

Staphylococcus aureus

Wound surfaceNot all surfaces indicate wound infection. There are greasy white surfaces that are hard to detach from the wound and look like pus. However, this is actually fibrin that has to be removed when treating the wound but which is not a sign of bacterial colonisation or infection.
Bacterial colonisation is differentiated as follows:

Contamination: Bacteria are present in the wound but they are not multiplying. The granulation tissue appears rosy, the healing process is not affected, the typical wound smell does not develop; this appearance is also found in

Colonisation: Here the wound is colonised with germs which can multiply but the patient and wound healing are not yet affected. This is different in

Critical colonisation: In this state between colonisation and local infection there is increased exposure to bacteria. There are no obvious signs of healing and the first signs of infection are present. If granulation tissue is present it appears sensitive. There is an increased production of wound exudate, healing is delayed and pockets may develop as well as discolouration with surfaces that cause intensive, malodorous smells. Local pain can develop or existing pain may intensify as a sign of an active infection, which is characteristic of

Infection: Here we see the classic and systemic signs of infection: Redness, heat, swelling and pain, along with multiplying bacteria. Oedemas develop around the wound, its surroundings are sensitive to pain, there is increased secretion of (as the case may be) purulent fluids. The patient may develop a fever and the blood count may show an increased number of leucocytes.

Wound smell
Smell is one of the first signs of an infection caused by certain types of bacteria. It is necessary to carry out an antibiogram and resistance determination to treat the pathogens systematically. Staphylococci and streptococci – particularly the MRSA strains – initially do not cause specific smells, which makes early identification difficult.

Suspected MRSA/VRE infection: These pathogens cause neither smells nor colourings of the wound cover. As the wounds may have existed for months or even years it is advisable to carry out a germ and resistance determination to prevent further development of resistance. Pseudomonas aeruginosa is phenotypically resistant to silver – one should use only dressings tested and certified by the manufacturer concerning their effectiveness against this species.

Wound rim
Chronic wounds, particularly those found on the lower extremities, point to underlying diseases not apparent or diagnosed for years. Each causes a typical appearance of the rim of a wound so that the therapist can start treatment accordingly.

An irregular, non-horny rim, independent of a warm foot and distended veins, can indicate an ulcus cruris venosum (venous leg ulcer). A regular wound rim with keratosis, independent of a cool, pale to bluish discoloured, and non-oedematous leg, can indicate an ulcus cruris arteriosum (arterial leg ulcer).

A regular, slightly raised and horny wound rim that almost looks cut out with warm, rosy but dry skin can be an indication of undiagnosed or insufficiently treated diabetes mellitus.
We purposely did not show the fourth criterion, wound exudate, because there is not an unambiguous correlation with certain underlying diseases and the resulting wound care procedures, which we have only been able to hint at. The important issue is to increase the clinical awareness of the signs that make wound diagnosis possible even at the first contact with the patient. This is then followed up with further diagnostics, particularly with regard to microbial colonisation.


08. 03.2007

More on the subject:

  • MRSA (118)

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Sniffing The Feet For Infection

Long before rapid analysis of bacterial cultures, the most common way to quickly determine the nature of a bacterial culture was to smell it. Just open up the petri dish or the test tube, inhale and the odors would provide some clues as to which species were growing inside. Pseudomonas aeruginosa has a distinct grape smell. Escherichia coli has a distinct fecal odor. Then there are the staphylococci. Staphylococcus aureus smells like decomposition while S. epidermis smells like old sweat.

The trick to olfactory identification lies in the byproducts of growth. Many chemicals are volatile and can be picked up by a trained nose. It should come as no surprise these chemicals have been targeted for rapid diagnostics. But the human nose isn’t perfect so researchers have gone technical to develop sensors to mimic our nasal receptors.

Electronic noses have come a long way over the years since their introduction in the 1980s. The majority have focused on those volatile organic compounds, also known as VOCs, to best identify what microbial population may be causing disease. With the proper sensor, an infection can quickly be picked up and treatment can begin.

There are already examples of effective e-nose diagnostics. One of the most successful detects tuberculosis. The VOCs from this species are quite unique and can be detected in sputum as well as breath. Gastrointestinal diseases may also be picked up by electronic olfactory sensors. Even blood and urine are being investigated as possible sources of VOCs.

Now a new version of e-nose has arrived with a specific focus on the foot. An Asian team of researchers has shown an e-nose can detect microbial species in diabetic food infection. Though focusing on diabetic feet may seem odd, the authors reveal just how important this infection is to healthcare and quality of life.

Diabetes has several complications including issues with the feet. When infections take over, they can be difficult to resolve and unfortunately, the only resolution is amputation. At one time, this problem wasn’t widespread but with the increasing rate of diabetes, particularly in the United States, it has become a serious issue. The cost to healthcare is at least 1.6 billion dollars annually but that pales compared to the heartbreak to both patient and loved ones. The situation is made even worse as it can be prevented or at least controlled with early diagnosis.

Unfortunately, this is not possible as the most common route for determining microbial species is culture. This can take upwards of a few days prior to analysis. In this short amount of time, the bacteria in the wound can grow to significant numbers and possibly enter the bloodstream. The only way to prevent this is by reducing the time necessary to a matter of hours or even minutes.

The authors of the study aimed to figure out how to rapidly detect an infection so early treatment could begin. To accomplish this, they had to first figure out what bacteria played the greatest role in causing damage. They did this by taking samples from infected feet and culturing them. They found three major contributors, P. aeruginosa, E. coli, and S. aureus.

The next step was to design the nose so it could pick up the VOCs from these three species. They used a machine known as the Cyranose320. It looks like a walkie-talkie when you hold it but it has no speaker or microphone. Instead, it has an air collector attached to an array of 32 sensors. Together, these detectors are capable of identifying the VOCs from six species, including the three found in the diabetic foot infections. This can all happen in less than a minute. The hope of the study was to utilize the Cyranose320 to accurately identify the species found in clinical samples.

The experiments were quite simple. The team grew up the infections on various microbial media and then put the sensor to the test. In single-species infections, the rate of both sensitivity and specificity was near perfect. When polymicrobial cultures were analyzed, the same results were seen. The team could pick up exactly which species were present. It was a total success.

There was, however, a catch. In order to perform the tests, the group had to culture the bacteria prior to analysis. They never tested the Cyranose320 with actual patients. Yet, the results suggest this is the next logical step and should be done in the future.

Although this was in essence a proof-of-concept, they had shown the potential benefit of the e-nose. With continued testing, this machine could help to increase the speed of infection detection as well as lessen the time needed for proper treatment. Should this become reality, those who suffer from the scourge of a diabetic foot ulcer may soon be able to regard this complication as manageable without worrying about the worst case scenario of losing this most valuable part of our anatomy.

Staphylococcal food intoxication | State Institution "Minsk City Center for Hygiene and Epidemiology"

Staphylococcal food intoxication is an acute disease that occurs as a result of eating foods containing staphylococcal enterotoxin, characterized by a predominant lesion of the stomach, a sudden onset, a combination of intoxication and gastroenteritis syndromes.

The causative agents of staphylococcal food intoxication belong to the genus Staphylococcus. More often it is Staphylococcus aureus - Staphylococcus aureus. The causative agents of food intoxication themselves do not take part in the pathogenesis of the disease, i.e. the accumulation of microorganisms in the food product only ensures the production of toxins, which cause the manifestations of the disease.

The pathogen itself is well preserved in the external environment, characterized by a relatively high resistance to drying, freezing, sunlight and chemicals. In the dried state, it can last up to 6 months, in dust - 50-100 days, it may not die for many hours under the influence of direct sunlight. Staphylococcus can tolerate heating at 70-80°C for up to 20-30 minutes, at 150°C - 10 minutes, when boiled - it dies instantly (some strains tolerate heating up to 100°C for half an hour).

Staphylococcus is able to reproduce in the range from 6.6 to 45°C.

Staphylococcal food poisoning is more often associated with the use of milk and dairy products (sour cream, cottage cheese, etc.), meat, fish and vegetable dishes, cakes, pastries, canned fish, semi-finished meat products and ready-made food products, especially "complex dishes", meat, chicken and products prepared from them, as well as salads. Staphylococcus is able to multiply in food without changing the organoleptic properties (smell, taste).

The rate of production of enterotoxin by staphylococci depends not only on the massiveness of the initial contamination and storage conditions of food products (time, temperature), but also on their chemical composition of products (content of carbohydrates, proteins, fats), acidity, etc.

Enterotoxins are resistant to heating (for the destruction of enterotoxin, boiling of food for at least 2 hours is required, which is usually not done, since the organoleptic properties of the products deteriorate).

The source of infection can be a human or animal (patients and carriers). The danger is represented by persons with infectious diseases of the upper respiratory tract, since this can lead to contamination of food by aerogenic means, as well as persons with skin diseases and wounds (pyoderma, panaritium, festering cuts and burns, etc.). Animals (cows, goats, sheep, etc.) can be classified as additional sources of infection (transmission factor - milk in the presence of mastitis and meat). Food products can be contaminated with staphylococcus aerogenically with discharge from the nasopharynx or by contact when the pathogen comes into contact with human skin on inventory, utensils, equipment, or directly on food.

Main clinical manifestations. The incubation period for staphylococcal intoxication is short - from 30 minutes to 6 hours, more often - 2-4 hours. The disease begins acutely, the clinical picture is dominated by symptoms of gastritis in the form of repeated vomiting, there is a cutting pain in the abdomen (epigastric region or around the navel), resembling gastric colic, the nature of the stool may not change or diarrhea is noted, fever.

The main measures to prevent staphylococcal toxicosis are:

  • timely detection of persons with inflammatory diseases of the upper respiratory tract and pustular skin lesions and their removal from food preparation or contact with prepared meals;
  • timely sanitary and veterinary control over the health of dairy and slaughter animals and the safety of animal food raw materials;
  • observance of the rules of personal hygiene;
  • exclusion of contact and separation of flows of raw materials, semi-finished products and finished products
  • observance of cooking technology (including heat treatment modes), as well as ensuring the temperature conditions for storage and the timing of the sale of products.

About staphylococcus and staphylococcal infection — Ministry of Health of the PMR

Staphylococcus is a whole genus of microorganisms, 27 species are known today, with 14 species found on human skin and mucous membranes. Most staphylococci are completely harmless. Of the 14 species mentioned, three are most likely to cause disease: Staphylococcus aureus (the most common and harmful), Staphylococcus epidermidis (also pathogenic, but much less dangerous than aureus) and Staphylococcus saprophyta - practically harmless, however, also capable of causing disease. .

Almost all medical problems associated with staphylococcus imply the presence of Staphylococcus aureus, which has amazing vitality: does not lose activity when dried, lives for 12 hours under direct sunlight, withstands temperatures of 80 0 C for 30 minutes , does not perish in pure ethyl alcohol, is not afraid of hydrogen peroxide.

Staphylococci are ubiquitous, they can be found on almost any part of the human body and surrounding objects. During the first week of life in 90% of newborns in the nasal cavity revealed Staphylococcus aureus. In the first two years of life, staphylococci aureus are found in the nasal cavity in 20% of children, and by the age of 4-6 they are found in 30-50%, in adults the carriage varies between 12-50%.

It is important to always distinguish between such concepts as staphylococcus and staph infection. Staphylococcus aureus is an opportunistic microorganism, a representative of the normal human microflora. The term “opportunistic” means that staphylococcus aureus causes disease only under certain circumstances . It can stay in the body for a long time (even a lifetime) without harming a person, and certain conditions must be created for it to cause a disease. Namely, the weakening of the immune system. If a person's immune defense is working normally, staphylococcus exists in the body without causing any concern to the "owner". If immunity fails, staphylococcus can attack the human body, which leads to the appearance of a wide variety of diseases (more than a hundred names): from relatively mild skin pustular infections to such severe processes as pneumonia (pneumonia), meningitis (inflammation of the meninges), osteomyelitis ( bone damage), sepsis (an inflammatory process in all human organs or "blood poisoning"), toxic shock, and others. The most common toxic staphylococcal disease is food poisoning.

Of course, staphylococcal infections are treatable. This is done by doctors of various specialties. Treatment of staphylococcal diseases is a surprisingly difficult task, because there is no microbe that can compare with staphylococcus in its ability to develop resistance to antibiotics and other antibacterial agents. Therefore, treatment should be prescribed only after determining the sensitivity to antibacterial agents. All experts agree with this.

Things are more complicated in healthy carriage, when the microbe is present in the human body (for example, on the nasopharyngeal mucosa), but the disease does not develop due to the balance of microbial aggression factors and the protective forces of the human immune system. However, the carrier can pose a serious danger to others. Such a person is especially dangerous if he works in the food industry (cook, distributor of ready meals), in medicine (children's department nurse, surgeon or obstetrician-gynecologist, etc.).

The issues of treatment of carriage of Staphylococcus aureus have been exciting the medical community for decades. When should this opportunistic bacterium be fought and when not? What to do with resistant strain? How to treat him?

Carrier without symptoms does not need to be treated! Nothing and never. Live quietly and forget about this analysis. If Staphylococcus aureus is sown in a perfectly healthy child or adult in a stool (breast milk, swab from the nasopharynx, pharynx, vagina, and so on), it makes no sense to treat it.

If you are a carrier with symptoms, you must be completely sure that they are related to Staphylococcus aureus. Only in this case, after consulting a doctor, you can take a prescription and go to the pharmacy.

Mandatory treatment is subject to people who, being carriers of staphylococcus, in the performance of their professional duties, can cause the occurrence of staphylococcal infection in other people. The list of professions whose representatives are subject to treatment in connection with the carriage of staphylococcus aureus is specified in a special policy document. In addition to medical workers, it includes, for example, catering workers. The danger of staphylococcal carriage in this category also lies in the fact that staphylococci can get into cooked food and cause a massive food poisoning disease. It also makes sense to be treated for healthy staph carriers who live with people who suffer from repeated staph infections (for example, furunculosis) or severe chronic diseases.

Treatment of carriage of Staphylococcus aureus with antibiotics is impractical. There are enough other means in the arsenal of specialists. Antibiotic treatment of dysbacteriosis with a high content of staphylococcus is completely contraindicated, as this will lead to the opposite result - more intensive reproduction of staphylococcus.

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