The methicillin-resistant Staphylococcus aureus or MRSA (also known by its English acronym MRSA – Methicillin-resistant Staphylococcus aureus) is a bacterium that has become resistant to multiple antibiotics, first to penicillin in 1947, and soon after methicillin. It was originally discovered in the UK in 1961 and is currently much hype, particularly in hospital buildings, where, because of increasing resistance, Staphylococcus aureus (golden staph) is even called a superbug (or super-germ). MRSA may also be known as oxacillin-resistant Staphylococcus aureus (ORSA) and multiple-resistant Staphylococcus aureus, while in strains of S. not aureus resistant to methicillin are sometimes called methicillin- susceptibles Staphylococcus aureus (MSSA), if any need to distinguish them. Although, MRSA has traditionally been seen as a means of a hospital associated infection, there is now an epidemic in the U.S. of MRSA that is acquired by the community. Theabbreviations CA-MRSA (community associated MRSA) and HA-MRSA (hospitalassociated MRSA) are used to distinguish the two situations.
Methicillin-resistant aureus – is the bacterium that causes difficulty to cure disease in humans, such as blood diseases, pneumonia. Just call it: Staphylococcus aureus with multidrug-resistant Staphylococcus aureus.
Methicillin-resistant aureus – represents any strain of Staphylococcus aureus bacteria that is resistant to a large group of antibiotics – beta-lactams (including penicillins and cephalosporins). Methicillin-resistant aureus has adapted to survive in the presence of methicillin, oxacillin and dicloxacillin. Most often linked with it, hospital (nosocomial) infections. In hospitals, patients with open wounds and with the weakened immune systems are at greater risk of infection than other patients. Hospital staff who does not comply with proper sanitary regulations, may transfer bacteria from patient to patient, according to Infectious Diseases. Methicillin-esistantStaphylococcus Aureus (MRSA) (2010). Visitors with a staph infection of Methicillin-resistant are encouraged to follow the rotocol of infectious hospital: use of gloves, gowns and masks if indicated. Visitors, including health care workers, who do not follow such protocols, facilitate the spread of bacteria in kitchens, bathrooms,elevators, and in various other areas.
Methicillin-resistant aureus isoften referred to as the agents of community-acquired staph infections methicillin-resistant or health sanitary connected methicillin-resistant staphylococcal infections, although this distinction is complex. The first cases of community-acquired staph infections methicillin-resistant were described in the mid 1990’s in Australia, New Zealand, the United States, United Kingdom, France, Finland, Canada, the feature was that sick people who have not stayed in hospitals. New strains of community-acquired staph of methicillin-resistant, quickly became the most common cause of skin infections among individuals seeking treatment in urban areas of the United States. These strains also commonly cause skin infections in athletes, prisoners and soldiers. However, in many cases, the sick and children require hospitalization. As a fact, methicillin-resistant staph infection kills about 18,000 Americans annually.
methicillin-resistant aureus was first discovered in 1961 in the United Kingdom. For the first time its appearance in the U.S. pointed out in 1981 among injecting drug users. In 1997, four deaths were reported involving children from the Minnesota and North Dakota. Statistics indicate a growing epidemic to spiral out of control. It is difficult to determine the extent of morbidity and mortality from this disease. Population studies of the incidence of infection in San Francisco during 2004-2005, showed that about 1300 people suffer from the infection within a year. In 2004, the study showed that in the United States with S. aureus infection was on average three times the increased duration of hospital stay (14.3 vs. 4.5 days), and five times greater risk of death (11,2% vs. 2.3%) than patients without this infection.
Mortality. Although reports claim that Noskin and other patients got infected with MRSA are five times more likely to die than other patients is not yet clear that patients who are infected with MRSA have a higher mortality rate. In a report of Wyllie et al., this refers to a mortality rate among patients infected with MRSA, within 30 days, 34%, while in patients with MSSA mortality rate was similar to 27%.
Presentation and clinical interests. The most common colonies of S. aureus are in the respiratory system and open wounds, intravenous catheters and urinary system.
MRSA infections are usually asymptomatic in healthy individuals and that can last from several weeks to several years. Patients with compromised immune systems have a higher risk of symptomatic secondary infection (manifestation of disease symptoms).
Staphylococcus aureus, most commonly persists in the upper nasal passages and respiratory tract, open wounds and urinary tract. In healthy people, the disease can be asymptomatic for a period of several weeks to many years. In patients with compromised immune systems, to a large extent a higher risk of symptomatic infection.
There have been taken additional sanitary measures for those who are in contact with infected people: family members, medical staff. They are found to be effective in minimizing the spread of infection in hospitals in the United States, Denmark, Finland and the Netherlands.
There is a significant progression of infection in 24-48 hours after the initial pressing of symptoms. At the end of 72 hours, the bacteria can penetrate into human tissue and acquire resistance to drugs. Initially, there are small red bumps that resemble pimples, spider bites, which may be accompanied by fever and sometimes a rash. A few days later bumps become larger, more painful, and can be filled with pus. About 75% metitsillin rezistentnyh staphylococci localized in the skin, soft tissue and can be effectively treated. However, strains have increased virulence and survive the disease more serious than the traditional staph infection. They can affect vital organs and lead to widespread infection (sepsis), toxic shock syndrome and necrotizing pneumonia. It is believed that this is due to the toxins of strains. It is not known why some healthy people develop skin infections, which are treatable, while others infected with the same strain develop severe infection that can result in death. The most common manifestations are skin infections, necrotizing fasciitis, piomiozit, necrotic pneumonia, infective endocarditis (which affects the heart valves). Often, the infection leads to the formation of abscesses that require surgical intervention.
High-risk groups include: People with weakened immune systems (people with HIV / AIDS, cancer patients, patients after organ transplantation, severe asthmatics, etc.); Diabetics, People who use injection drugs, Patients receiving antibiotics, Kids Older people, Students living in dormitories, Persons within or working in medical institutions for a long period of time, People who spend time in coastal waters, beaches, People who spend time in a confined space with other people, including prisoners, soldiers, athletes.
Staphylococcal infections occur mainly in hospitals and medical facilities, nursing homes. However, it should be noted that the infection may be outside hospitals – in closed systems, such as prisons, with constant admission of new inmates, usually with poor health and non-compliant rules of personal hygiene. Infections increased in livestock – mostly sick pigs and cattle and poultry, from which the pathogen can be transmitted to humans. In the United States was to increase the number of reported outbreaks of infection transmitted through the skin into the locker rooms and gymnasiums, even among the healthy population. Also methicillin-resistant staphylococcal infection becomes a problem in pediatrics, according to Methicillin-Resistant Staphylococcus Aureus (MRSA) (2011).
Prevention and control of infection: Screening System, Disinfection of surfaces – alcohol was effective disinfectant – can be used quaternary ammonium in combination with alcohol to extend the disinfection. In health care, methicillin-resistant staph can survive on surfaces and clothing of health workers. Complete decontamination of the surface is needed in the wards, procedural; Personal hygiene- Isolation of patients with suspected (or confirmed) by infection with S. aureus, Limited and rational use of antibiotics.
Laboratory diagnosis. Detection of outbreaks of staphylococcal infection methicillin-resistant conducted microbiological diagnostic and reference laboratories. There are rapid methods for determining the form and characterize the strain of the pathogen. Methods such as real-time PCR or quantitative PCR is increasingly used in clinical laboratories for rapid detection and identification of strains of Staphylococcus methicillin-resistant. Another widely used laboratory test – a test of latex agglutination, allowing to determine β-lactam-resistant penitsillin connecting protein (English) PBP2a, which confers resistance of Staphylococcus aureus to methicillin and oxacillin.
According to Methicillin-Resistant Staphylococcus Aureus (MRSA) (2011), vancomycin and teicoplanin are glycopeptide antibiotic (s) used to treat MRSAinfections. Teicoplanin is a congener estructural vancomycin that has a similar spectrum of activity, but with a higher average length (t ½). Both drugs have a slow oral absorption, so they are administered intravenously for infections in the body(system), with the exception of pseudomembranous colitis where vancomycin can be administered orally. Many new strains of MRSA were found that showed resistance to antibiotics even to vancomycin and teicoplanin. Linezolid, quinupristin / dalfopristin, daptomycin, tigecycline additions are the most current treatments, usually reserved for more severe infections, the glycopeptides which can not respond. The less severe infections may be treated by oral agents (administered orally), including: linezolid, rifampicin + fusidic acid, pristinamycin, cotrimoxazole (trimedoprimasulfamedoxazole +), doxycycline, and lindamycin. On May 8, 2006 a team of researchers from Merck Pharmaceuticals, the magazine Nature, which published, and was discovered by them, a new type of antibiotic, called platensimicina, and demonstrated that this could be used to effectively combat the MRSA .
Although colonization of MRSA in an otherwise healthy individual is usually not serious, infection with this germ can be life threatening in patients with deep wounds, intravenous catheters or other instruments that introduce foreign bodies, or as a secondary infection in patients with a weakened immune system.
MRSA infection occurs mainly nosocomial, for example an infection contracted in a hospital. Its most serious nosocomial pneumonia is a disease that can be fatal and is spread by the insertion of a tube fan in the patient’s body. In the United States report are increasing outbreaks of MRSA colonization by skin contact in locker rooms and gymnasiums, even among healthy populations, and MRSA causes at least 20% of infections of S. aureus in people who use drugs intravenously. While MRSA, as noted above, does not respond to common antibiotics, other drugs such as vancomycin and linezolid, which help fight infection.
In Europe, EFSA estimates that in 2010 the main animal reservoirs of MRSA (antibiotic resistant staph) in affected by countries where there are pigs, calves and broilers, especially in factory farms. Infections can be subtle or completely asymptomatic. Among MRSA strains, strain “CC398” is most often associated with asymptomatic carriage in intensive farming of animals for food production. The CC398 has been associated in some cases of deep infections of the skin and soft tissue infections, pneumonia or sepsis in humans. Where the CC398 is common in animal food producers, farmers, veterinarians, and their families are more likely colonization and infection than the general population. MRSA often carries genes for enterotoxin but before 2010 there was only one report of food poisoning identified as due to MRSA.
CC398 strain was also isolated from animals (dogs and cats) and horses on farms with infected livestock, with sporadic cases in “many other pets.” But no study, by EFSA has specifically assessed the risk of transmission to humans from small animals, or following contact with horses or horse meat, according to Antimicrobial (Drug) Resistance (2010).
MRSA infections in pets are becoming more frequent, and almost always, the strains responsible for infection of these animals are the same as those frequently encountered in hospitals in the same geographic region. Humans are therefore likely to spread MRSA to pets, and these can then be a reservoir for humans. Horses can be colonized and / or infected with MRSA from humans or animals from other sources in their environment (dogs, cats …). There are sporadic reports of cases of disease in humans (typically minor skin infections), attributable to a source equine. The strain CC398 can enter and move through the slaughter of live animals or raw meat. Based on data available in 2008/2009, although this strain can be part of the microflora of some endemic slaughterhouses, the risk of infection for slaughterhouse workers and the persons handling meat seems to stay low, according to Methicillin-resistant Staphylococcus aureus (MRSA) (2011).
MRSA can cause potentially lethal infections and usually only can be treated with expensive, intravenous antibiotics. A drug-resistant strain of potentially deadly bacteria crossed the borders of U.S. hospitals and is spreading, researchers say. They said that the Staphylococcus aureus is resistant to methicillin, or MRSA, and it is beginning to appear outside hospitals in San Francisco, Boston, New York and Los Angeles.
“Once this reaches the general population, it is really unstoppable,” said Binh Diep, a researcher at the University of California at San Francisco, who led the study. “This is why we are trying to spread the message of prevention,” said Diep. According to chemical analysis, bacteria are spreading among the communities of San Francisco and Boston, the scientists said. “We believe it is spreading through sexual activity,” Diep said. This superbug can cause life-threatening infections and usually only can be treated with expensive, intravenous antibiotics. MRSA killed 19,000 Americans in 2005, most of them in hospitals, according to a report published in October in the Journal of the American Medical Association. About 30 percent of people carries staph chronically, which may be transmitted by contact with other people or because the bacteria are deposited on surfaces or objects that people touch then. The bacteria can cause deep tissue infections if they enter the body through a wound in the skin. Of the people who carry staph, most carry it in your nose, but MRSA can also live in and around the anus and therefore frequently transmitted via anal sex. Staph infections look like a rash on the skin, which if left untreated can become inflamed and fill with pus. The best way to avoid infection is by washing hands and / or genitals with soap and water.
Antimicrobial (Drug) Resistance (2010). Methicillin-Resistant Staphylococcus aureus (MRSA). Retrieved February 19, 2011 from http://www.niaid.nih.gov/topics/antimicrobialresistance/examples/mrsa/pages/default.aspx
Infectious Diseases. Methicillin-Resistant Staphylococcus Aureus (MRSA) (2010). Retrieved February 19, 2011 from
Methicillin-Resistant Staphylococcus Aureus (MRSA) (2011). Retrieved February 19, 2011 from http://www.medicinenet.com/mrsa_infection/article.htm
Methicillin-Resistant Staphylococcus Aureus (MRSA) (2011). Retrieved February 19, 2011 from http://www.health.state.ny.us/diseases/communicable/staphylococcus_aureus/methicillin_resistant/fact_sheet.htm
Methicillin-resistant Staphylococcus aureus (MRSA) (2011). Minnesota Department of Health. Retrieved February 19, 2011 from http://www.health.state.mn.us/divs/idepc/diseases/mrsa/index.html
Often referred to as a superbug, MRSA infection may begin as a skin sore, pimple, or boil, before becoming serious, potentially harmful, and sometimes fatal.
Here are some key facts about MRSA. More detail and supporting information is in the main article.
- MRSA is a form of bacterial infection that is resistant to numerous antibiotics.
- "Staphylococcus aureus" refers to a bacterium that commonly resides inside the nose and on human skin.
- Around one in three people carry staph in their nose, usually without any illness. Two in 100 people carry MRSA.
- The majority of invasive MRSA infections are contracted with healthcare settings.
- Germ-killing soaps and ointments used in intensive care units have been found to significantly reduce MRSA cases.
MRSA: Meaning and definition
"Methicillin" is an antibiotic related to penicillin; it was once effective against staphylococci (staph), a type of bacteria. Staph bacteria have since developed a resistance to penicillin-related antibiotics, including methicillin - these resistant bacteria are called methicillin-resistant staphylococcus aureus, or MRSA.
MRSA is a form of bacterial infection that is resistant to numerous antibiotics.
In the United States, staph bacteria are one of the most common causes of skin infections, including:
Staph bacteria can cause infections, and the resulting conditions range from mild to life threatening. These conditions include:
Around 94,360 invasive MRSA infections are diagnosed annually in the U.S., with 18,650 associated deaths. MRSA infections are typically classified as healthcare-associated or community-associated; approximately 86 percent of all invasive MRSA infections are healthcare-associated.
Treatment of MRSA
If MRSA is diagnosed, treatment will vary depending on the following factors:
- type of infection
- location of infection
- severity of symptoms
- antibiotics to which the strain of MRSA responds
Management of MRSA infections may include:
- pus drainage from lesion
- culture and susceptibility testing of drained material
- wound care and hygiene
- antimicrobial therapy (in cases of possible cellulitis without abscess)
Medication options for MRSA skin and soft tissue infections may include:
- tetracycline drugs - doxycycline and minocycline
- trimethoprim and sulfamethoxazole
Ultimately, MRSA is caused by bacterium strains that have acquired a resistance to particular antibiotics.
MRSA is contagious
MRSA can spread from person-to-person (skin-to-skin contact) and from person-to-object-to-person when an individual has active MRSA or is colonized by the bacteria.
Skin-to-skin contact with someone carrying MRSA is not necessary for infection to spread. MRSA bacteria are also able to survive for extensive periods on surfaces and objects including door handles, floors, sinks, taps, cleaning equipment, and fabric.
MRSA surface longevity
MRSA bacteria have the aptitude to survive for extensive periods on surfaces and objects in hospitals including door handles, floors, sinks, taps, cleaning equipment and fabric.
One study to determine the survival of resistant staph on common hospital surfaces looked at staph survival on five materials commonly found in a hospital:
- 100 percent smooth cotton (clothing)
- 100 percent cotton terry (towels and wash cloths)
- 60 percent cotton, 40 percent polyester blend (scrub suits, lab coats and clothing)
- 100 percent polyester (privacy drapes, curtains, and clothing)
- 100 percent polypropylene plastic (splash aprons)
Swatches of fabric were injected with 10,000-100,000 colony-forming units (CFU) of the microorganism and observed daily. They found that S. aureus survived on the materials for the following number of days:
- cotton - 4-21 days
- terry - 2-14 days
- polyester blend - 1-3 days
- polyester - 1-40 days
- polypropylene - 40-greater than 51
These results demonstrate the need for thorough contact control and meticulous disinfection procedures to limit spread of bacteria.
MRSA frequently causes illness in people with a compromised immune system who interact with or reside in hospitals and healthcare facilities.
This is referred to as healthcare-associated MRSA (or hospital-acquired MRSA) and often occurs for one of the following reasons:
- A break in the skin barrier - such as a surgical wound, burn, catheter, or intravenous line that allows bacteria to enter the body.
- Older age - comorbidities or multiple complex health issues, and weakened immune systems due to a specific health condition, or the use of medications that lower immune function.
- Large numbers of people - the simple fact that hospitals and healthcare facilities are visited by many different people provides an environment for bacteria to easily spread.
Those with a weakened immune system can include:
- patients in hospital for a long period of time
- patients on kidney dialysis
- patients receiving cancer treatment or specific medications that affect immune function
- those who inject illegal drugs
- individuals who have had surgery within a year of being back in hospital
According to the Centers for Disease Control and Prevention (CDC) study, invasive healthcare-associated MRSA infections declined 54 percent between 2005 and 2011, with 30,800 fewer severe MRSA infections and 9,000 fewer deaths.
A similar study conducted by the National Healthcare Safety Network (NHSN) found that rates of health care-associated MRSA bloodstream infections fell nearly 50 percent from 1997-2007.
The average age of a person with healthcare-associated MRSA was 68.
Who is at risk of MRSA
People most at risk of developing healthcare-associated MRSA in the hospital include those that have:
- weakened immune systems
- open wounds
- a catheter or intravenous drip inserted
- burns or cuts to the skin surface
- severe skin conditions
- had surgery
- frequent antibiotics as part of their treatment
Regular skin-to-skin interaction in sports such as rugby, ice hockey, soccer, or basketball increase the risk of developing community-associated MRSA.
Community-associated MRSA is contracted outside of a hospital setting; it is less common than healthcare-associated MRSA. Factors that cause increased risk of developing community-associated MRSA include:
- living in an environment with a lot of people; military bases, jail, on-campus housing
- regular skin-to-skin interaction for example in contact or collision sports such as rugby, ice hockey, soccer, and basketball
- cuts or grazes to the skin or regular injection of drugs
- contaminated surfaces
- unhygienic facilities or lack of personal hygiene
- previous antibiotics use
The CDC reports that 14 percent of people with MRSA infections contracted them outside of healthcare setting.
The average age of a person with community-associated MRSA was 23.
The 5 Cs can be used to remember what factors make it easier for MRSA to be transmitted:
- contact (skin-to-skin)
- compromised skin (open wounds)
- contaminated (items and surfaces)
- cleanliness (lack of)
MRSA infection symptoms
MRSA symptoms depend on what area of the body is infected. Although many people carry MRSA bacteria in their mucosa (for instance, the membrane on the inside of the nose), they may never display any symptoms of active infection.
Staph skin infections, including MRSA, appear as a bump or sore area of the skin that could be mistaken for an insect bite. The infected area might be:
- hot to the touch
- full of pus or other liquid
- accompanied by a fever
Symptoms of a serious MRSA infection in the blood or deep tissues include:
- fever of 100.4 °F or higher
- aches and pains of the muscles
- swelling and tenderness in the affected body part
- chest pains
- breathlessness (dyspnea)
- wounds that do not heal
MRSA: Prevention tips
Tips to prevent MRSA depend on whether it is healthcare-associated or community-associated:
Preventing healthcare-associated MRSA infection
Actions such as regular hand washing can reduce risk of community-associated MRSA outside of hospitals.
Doctors, nurses, and other healthcare providers have the following measures in place to prevent MRSA infections:
- Hand cleanliness - using soap and water or alcohol-based hand rub between caring for patients.
- Hospital rooms and equipment - ensuring thorough cleaning.
- Keeping patients with MRSA separate from other patients - either in a single room or shared with another person who has MRSA.
- Healthcare providers clothing - wearing gloves and gown over clothing while caring for MRSA patients.
- Visitor clothing - wearing of gloves and gowns.
- Disposal and cleanliness - visitors and hospital providers removing and disposing of gowns and gloves after exiting the patient's room and washing hands thoroughly.
- Access to common areas - patients with MRSA will be asked to limit movement around the hospital, avoid gift shops or cafeterias and stay in their rooms.
- MRSA swabbing - to identify if some non-MRSA patients have MRSA on their skin.
Preventing community-associated MRSA infection
The following actions can reduce risk of community-associated MRSA outside of hospitals:
- regular hand-washing
- keeping fingernails short
- avoiding sharing products such as soaps, lotions, creams, and cosmetics with others
- avoiding sharing unwashed towels
- avoiding sharing personal items such as razors, nail files, toothbrushes, combs, or hairbrushes
MRSA tests and diagnosis
Healthy people are sometimes tested to identify if they have MRSA on their skin before being admitted to the hospital. The test involves swabbing the inside the patient's nostrils or skin.
If the person is found to be colonized with MRSA, removal (decolonization) of the bacteria is possible by using:
- antibacterial body wash or powder for the skin (chlorhexidine baths)
- cream for inside the nose (intranasal mupirocin)
- antibacterial shampoo for the scalp (chlorhexidine soap shower/bath procedure)
Germ-killing soaps and ointments used in intensive care units (ICU) have been found to reduce cases of MRSA by 40 percent.