that has continued to grow now. It approaches 60% across the United States in many of the intensive care units (ICUs)

MRSA has progressed at an average rate of about 2% over the past couple of years.

prevalence of MRSA is highly globa

areas where prevalence is fairly low -- in the Netherlands less than 1% and in Canada 2.3%

2 policies that both countries have

One is a strict search-and-destroy policy: patients from other countries and those with MRSA are isolated upon hospital admission until screening cultures for MRSA are proven negative. The second is a restrictive prescribing policy in which the defined daily dosage used per 1000 people per day in primary healthcare is around 8.9.

aureus was found to be the predominant pathogen in nosocomial skin and skin-structure infections

year 2000.

vancomycin, which is static, as well as some of the beta-lactamases

delay in appropriate treatment

resistant organisms lead to delays in appropriate treatment, and that delays in appropriate treatment lead to resistant organisms

Increased cost of MRSA

increased mortality rate associated with MRSA

vancomycin has the FDA indications, with linezolid second. Daptomycin and tigecycline are approved for skin and skin-structure infections, but quinupristin-dalfopristin is not approved for complicated skin and skin-structure infections with MRSA.

ventilator-associated pneumonia due to MRSA

surgical patients with resistant gram-positive cocci showed a higher mortality rate and increased length of stay

other studies have not found this similar association.

higher association with MRSA than with MSSA

fluoroquinolones, macrolides, previous hospitalizations, enteral feeds, surgery, and the length of stay before culture are independently associated with MRSA infections.

CA-MRSA infections

infections in the community usually manifest as skin infections, such as pimples and boils

occur in otherwise healthy people

HA-MRSA patients are in long-term care facilities, have comorbidities (such as diabetes), are on dialysis, have prolonged hospitalization, and are ICU patients

HA-MRSA is more multidrug resistant

In HA-MRSA, one sees nosocomial pneumonia, catheter-related urinary tract infections, bloodstream infections, and skin and skin-structure infections.

initially resulted from a recombination event, one involving the gene encoding in existing PBP and an inducible beta-lactamase gene.

In terms of microbiologic cure rates at the test-of-cure visit, linezolid was also superior to vancomycin.

Pharmacoeconomic analysis of this comparative trial in complicated skin and skin-structure infections showed that compared with vancomycin, linezolid reduced the length of stay and duration of IV treatment by about 2 days.

we had hardly any incidence of MRSA in the 1960s, 1970s, and 1980s in the United States

Vancomycin is IV only. It is more costly -- even as a generic, based on pharmacoeconomic data -- relative to linezolid.

Quinupristin-dalfopristin is IV only and may cause phlebitis, requiring central line placement.

Linezolid is relatively new; is more expensive (on an acquisition basis) compared with vancomycin; has reversible hematologic and, with long courses, neurologic effects; and has developed some resistance, mainly in enterococcal infections, with prolonged use and with failure to remove retained foreign bodies.

Daptomycin is IV only; quite new; has limited indications; is also expensive, compared with vancomycin; has a muscle effect requiring monitoring of creatine phosphokinase; is inactivated by surfactants, thus obviating its use in pulmonary infections; and to date has no pharmacoeconomic data.

Tigecycline is IV only, very new, and has a broader spectrum than any of the other agents in that it has some gram-negative activity

Dalbavancin is IV only, and we need to have the official data on safety, tolerance, efficacy, indication, and pharmacoeconomics, which will probably be available later this year.

often code some type of antibiotic resistance.

Beta-lactam antibiotics target penicillin-binding proteins.

prevents proper peptidoglycan and cell wall formation so that cells will eventually burst as the bacteria attempt to grow larger (3).

econd, some bacteria can produce a modified penicillin-binding protein that no longer actually binds the antibiotic which again prevents the desired effects of the antibiotic (3).

The spherical bacteria is gram-positive (contains a peptidoglycan layer in its cell wall) and forms colonies that grow in two planes

High replication rates coupled with the great ability of to perform horizontal gene transfer (especially through conjugation) allow bacteria to develop antibiotic resistance and to spread it quickly

Less than 20 years after the first strains of Staphylococcus aureus were found to be resistant to penicillin, 80% of all strains had acquired penicillin resistance.

The decision to fight MRSA in hospitals revolves around three basic questions. First, is MRSA that much worse than MSSA? Second, how effective can we be in reducing the spread of MRSA? Lastly, is fighting MRSA cost effective?

Type I was isolated in 1961 in the UK, Type II in 1982 in Japan, Type III in 1985 in New Zealand and finally Type V at the start of the 21st century in Australia

In a paper by Deurenberg et al. two theories establishing the relationship between the first MRSA strains and present day MRSA strains are proposed. The first is called the single-clone theory which states that all MRSA clones or present day strains have a common ancestor.

The second theory is called the multi-clone theory. This second theory suggests that SCCmec was introduced several times into different Staphylococcus aureus. According to the paper by Deurenberg et al. the multi-clone theory has received greater support recently and it is from this paper that Figure 3 was taken.

he new antibiotic treatment policies did not prove to be an effective way of fighting the spread of MRSA infections in hospitals. The introduction of alcohol hand gel for improved hand hygiene did however prove to be very effective in reducing the spread of MRSA.

here was a 30% decrease in the spread of MRSA in the hospital. In the intervention hospital the introduction of alcohol hand gel reduced the spread of MRSA by 21%

The decrease experienced in the intervention hospital was likely smaller than that compared to the control hospital because the prevention measures of environmental swabbing for MRSA as well as chlorine disinfection of environments contributed to a 32% decrease in the spread of MRSA and these measures were not taken in the control hospita

It is even likely that these synergistic treatments can be used on other bacterial infections that are resistant to a variety of antibiotics.

After concluding that fighting the spread of and treating MRSA properly is crucial, can we be effective in preventing the spread of MRSA in hospitals?

The continued development of resistance to more and more drugs makes the treatment of Staphylococcus aureus infections and especially MRSA infections is becoming increasingly difficult.

have provided great insight as to what direction the fight against MRSA will be heading in

Staphylococcus aureus is a bacterium that naturally inhabits the skin and nose of humans. If the bacterium is able to enter the body (often through wounds or sores) it can cause a number of infections including those of the bloodstream which can become fatal.

quickly developed resistance to this antibiotic

hand hygiene in hospitals has been an effective way of decreasing the spread of MRSA in hospitals

Methicillin was first used to treat Staphylococcus aureus in 1959