on hemodialysis, iii. Receive cancer treatment or medicines that weaken their immune system, iv. Inject illegal drugs, v. Had surgery in the past year.
The prevention of horizontal transmission of MRSA has become increasingly important as the prevalence of this pathogen increases. Oral carriage of MRSA may serve as a
reservoir for re-colonization of other body sites or for cross-infection to other patients or health care workers. Therefore, it is important that consideration be given to the oral cavity
if eradication of colonization by MRSA is clinically appropriate. Eradication of throat carriage of MRSA has been achieve with use of topical chlorhexidine 0.2 in addition to
normal control measures of patient isolation, nasal mupirocin and chlorhexidine body washes.
1.2. MRSA infection in the Community
MRSA infections can also occur in healthy people who have not recently been in the hospital. The strains were labeled community-associated MRSA CA-MRSA if they had
been isolated within 48 hours of hospitalization from patients who had not been in any hospital for 1 year. CA-
MRSA resistance is usually limited to β-lactams and the strains remain
susceptible to
clindamycin, gentamycin,
sulfamethoxazole-trimethoprim, vancimycin, rifampin, tetracycline and linezolide. Most CA-MRSA strains characterized by
carry the Panton-Valentine leukocidin genes, leading to leukocyte destruction, skin abcesses and necrotizing pneumonitis, and also presence of staphylococcal chromosome
cassette mec SCCmec IVa, a novel smaller variant of the methicillin-resistant locus. Other S aureus strains that are not resistant to methicillin will be referred to as methicillin-
sensitive Staphylococcus aureus MSSA. Most of CA-MRSA infections are on the skin or less commonly lung infections. These infections can occur among people who are likely to
have cuts or wounds and who have close contact with one another, such as members of sports teams. People who may be at risk are: i. Atlletes and other people who may share
items such as towels or razors, ii. Children in day-care. iii. Members of military, iv. People who have gotten tattoos. In some cases these organisms can cause invasive infection
such as septic arthritis, bacteriemia, or community-acquired necrotising pneumonia. An early skin infection often has the initial appearance of an insect bite. These infections often
develop into cellulitis, furuncles, large boils or clusters of boils up to 10 cm in diameter and deep-seated abscesses often in the thighs or buttocks. If the bacteria gain access to
the lungs, fortunately a rare event, a devastating pneumonia that kills more than 40 of patients can result.
The fundamental differences between HA-MRSA and CA-MRSA have been discussed and summarized in table1.
Table 1. Comparison between healthcare-associated and community-acquired Methicillin resistant Staphylococcus aureus. Sievert et al. 2013
CA-MRSA HA-MRSA
Clinical spectrum
Skin and soft tissue infections Wound
infections, urinary
tarct infections and bacteraemia
Epidemiology Affected healthy people in the
community Mostly affects hospital patients
Underlying condition
Dernmatological Healthcare associated risk factors
Age group Younger
older
Resistant pattern
Sensitive to multiple antibiotics Resistant to multiple antibiotic
Toxin production
May produce PVL toxin Not yet reported produce PVL toxin
1.3. MRSA testing
