Transcript Hospital-acquired and community

Hospital-acquired and
community-acquired MRSA in
hospitals
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Hospital-acquired methicillin
resistant s.aureus
High percentage of hospital S.aureus isolates •
has been found to be also resistant to methicillin
or oxacillin.
Antibiotic resistant is caused by chromosomal •
acquisition of the gene for a modified penicillinbinding protein.This protein codes for a new
peptidoglycan transpeptidase with a low affinity
for all currently available beta-lactam
antibiotics,and thus renders infections with
methicillin-resistant S.aureus unresponsive to
beta-lactam therapy.
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Community –acquired methicillin –ristant •
S.aureus:
MRSA emerged in the community setting •
occurring among young healthy individuals with
no exposure to the healthcare setting.since then
this CA-MRSA has rapidly spread throughout the
world.Outbreaks of CA-MRSA have been
reported among children,athletes,nurseries and
obstertical wards.
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The patients in the hospital are divided into five
compartments:
•
-number of susceptible patients.
-number of patients colonized with the CA- MRSA •
strain.
-number of patients colonized with the HA- MRSA •
strain.
-number of patients infected with the CA-MRSA strain •
-number of patients infected with the HA-MRSA strain. •
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Estimated methicillin-resistant S.aureus
MRSA-related hospitalization rates during
7 years
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Pediatric pneumonia caused by
CA-MRSA
CA-MRSA, which carries genes for Panton- •
Valentine leukocidin (PVL), has become a
major concern worldwide. CA-MRSA is mainly
associated with skin and soft tissue infections in
young, otherwise healthy, persons in the
community and also with life-threatening sepsis
and community-acquired pneumonia (preceded
(
by)6influenza).
PVL, in combination with
staphylococcal protein A, destroys respiratory
tissue and bacteria-engulfing immune cells.
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Necrotizing Fasciitis is a life- •
threatening infection of the superficial
muscle fascia and adjacent subcutaneous
tissue. staphylococcus aurous has been
occasionally reported as a monomicrobial
causative agent of necrotizing fasciitis and
methicillin-resistant staphylococcus aureus
was described as the cause of hospitalassociated necrotizing.
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Necrotizing fasciitis of the
back caused by MRSA.
The lower back showed
erythematous lesions with
skin necrosis.
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Some studies suggest that CA-MRSA will •
become the dominant MRSA strain in the
hospital setting and other studies shown
that when no colonized or infected patients
enter the hospital, competitive exclusion of
HA-MRSA by CA-MRSA will occur with
increased severity of CA-MRSA infections
resulting in longer hospitalizations and a
larger in-hospital reservoir of CA-MRSA.
Improving compliance with hand hygiene
and decolonization of CA-MRSA carriers
.are effective control strategies.
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