Skin infections & Quinolones

Bacterial skin infections are very common, and they can range from merely annoying to deadly. Most bacterial infections of the skin are caused by two bacteria, Staphylococcus aureus and a form of Streptococcus.

MRSA (methicillin resistant Staphylococcus aureus)
What is methicillin resistant Staphylococcus aureus (MRSA)?
  • methicillin resistant Staphylococcus aureus (MRSA)
  • MRSA stands for methicillin resistant Staphylococcus aureus (S. aureus) bacteria. This organism is known for causing skin infections, in addition to many other types of infections. There are other designations in the scientific literature for these bacteria according to where the bacteria are acquired by patients, such as community-acquired MRSA (CA-MRSA), and hospital-acquired MRSA or epidemic MRSA (EMRSA).

    Although S. aureus has been causing infections (staph infections) probably as long as the human race has existed, MRSA has a relatively short history. MRSA was first noted in 1961, about two years after the antibiotic methicillin was initially used to treat S. aureus and other infectious bacteria.
    The resistance to methicillin was due to a penicillin-binding protein coded for by a mobile genetic element termed the methicillin resistant gene (mecA).

In recent years, the gene has continued to evolve so that many MRSA strains are currently resistant to several different antibiotics. S. aureus is sometimes termed a "superbug" because of its ability to become resistant to several antibiotics.
Unfortunately, MRSA can be found worldwide.Staphylococcus aureus bacteria is carried by 1 in 3 people.
Many people carry or are colonised by staph bacteria, have no symptoms and only suffer an infection when they have another illness, wound or graze. Antibiotics were effective against staph for many years but now multi-drug resistant staph has emerged (MRSA).
Many catch MRSA via hospital treatment. 1% of the population now carry it as a result. Community Acquired MRSA (CA MRSA) is a different type of MRSA. It mainly causes skin infections and can be treated by more drugs. It does however spread faster and can do more damage than the hospital strain to those it infects. (MRSA, sometimes called mrsa staff,mersa,mursa,merced or msra, is not a virus. Viruses need to infect something to keep on living. Bacteria can exist on their own for months)

What are the symptoms of MRSA?
Most MRSA infections are skin infections that produce the following signs and symptoms:
  • Cellulitis' infection of the skin or the fat and tissues that lie immediately beneath the skin, usually starting as small red bumps in the skin'
  • Sty' infection of eyelid gland'
  • Boils' pus-filled infections of hair follicles'
  • Carbuncles'infections larger than an abscess, usually with several openings to the skin'
  • Abscesses' pus-filled infections of hair follicles
  • Impetigo'a skin infection with pus-filled blisters'

One major problem with MRSA is that occasionally the skin infection can spread to almost any other organ in the body. When this happens, more severe symptoms develop. MRSA that spreads to internal organs can become life-threatening. Fever, chills, low blood pressure, joint pains, severe headaches, shortness of breath, and "rash over most of the body" are symptoms that need immediate medical attention, especially when associated with skin infections.

How is MRSA infection transmitted?
There are two major ways people become infected with MRSA:
Is physical contact with someone who is either infected or is a carrier (people who are not infected but are colonized with the bacteria on their body) of MRSA.
2nd. Is for people to physically contact MRSA on any objects such as door handles, floors, sinks, or towels that have been touched by an MRSA-infected person or carrier.

Normal skin tissue in people usually does not allow MRSA infection to develop; however, if there are cuts, abrasions, or other skin flaws such as psoriasis , MRSA may proliferate.
Many otherwise healthy individuals, especially children and young adults, do not notice small skin imperfections or scrapes and may be lax in taking precautions about skin contacts. This is the likely reason MRSA outbreaks occur in diverse types of people such as school team players (like football players or wrestlers), dormitory residents, and armed-services personnel in constant close contact.
People with higher risk of MRSA infection are those with obvious skin breaks (surgical patients, hospital patients with intravenous lines, burns, or skin ulcers) and patients with depressed immune systems (infants, elderly, or HIV-infected individuals) or chronic diseases (diabetes or cancer). Patients with pneumonia (lung infection) due to MRSA can transmit MRSA by airborne droplets. Health-care workers as a group are repeatedly exposed to MRSA-positive patients and can have a high rate of infection if precautions are not taken.
Health-care workers and patient visitors should use disposable masks, gowns, and gloves when they enter the MRSA-infected patient's room.

How is MRSA treated?
There are 3 key treatment regimes that are commonly used:
1-For those who are colonized:
A nasal treatment and a skin wash. This is often the strategy when MRSA is rare or prior to an operation as a means of preventing infection. Where MRSA is common some doctors will not suggest decolonization as many will be decolonized within months within the local community. Some deep seated - throat and intestine - colonization may require drug treatment.
2-For those who have a potential or active bloodstream infection:
Drugs such as Vancomycin, Linezolid or Daptomycin.
3-For those with infected wounds:
Special honey, silver bandages, garlic preparations and tea tree oil are all believed to be effective in killing MRSA in a wound. Many who have the skin infections common with CA MRSA simply need incision and drainage of the infected area and good hygiene while it heals. Antibiotics are not always needed.

How is MRSA diagnosed?
A skin sample, pus on the skin, or blood, urine, or biopsy material (tissue sample) is sent to a microbiology lab and cultured for S. aureus.
If S. aureus is isolated (grown on a Petri plate), the bacteria are then exposed to different antibiotics including methicillin.
S. aureus that grows well when methicillin is in the culture are termed MRSA, and the patient is diagnosed as MRSA-infected.
The same procedure is done to determine if someone is an MRSA carrier (screening for a carrier), but sample skin or mucous membrane sites are only swabbed, not biopsied.
In 2008, the U.S. Food and Drug Administration (FDA) approved a rapid blood test that can detect the presence of MRSA genetic material in a blood sample in as little as two hours. The test is also able to determine whether the genetic material is from MRSA or from less dangerous Staph bacteria. The test is not recommended for use in monitoring treatment of MRSA infections and should not be used as the only basis for the diagnosis of a MRSA infection.