Abstract:
Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant pathogen causing
life-threatening infections. It can be classified as community-associated (CA) or healthcareassociated
(HA), based on antibiotic susceptibility and molecular analysis. The objective of this
study is to describe MRSA prevalence and predominant MRSA types identified in clinical cultures
collected from patients admitted to Teaching Hospital-Karapitiya and General Hospital-Matara in
Southern Sri Lanka. S. aureus isolates from consecutive clinical cultures and associated
demographic data were collected from September 2019 for fourteen months from microbiology
laboratories of the two hospitals. All S. aureus and MRSA isolates were confirmed using standard
microbiological methods. Based on antibiotic susceptibility profile, isolates were classified as
HA-MRSA (generally resistant to β-lactam antibiotics, erythromycin, clindamycin and
fluoroquinolones) and CA-MRSA (generally resistant only to ß-lactam agents and erythromycin),
as described by the Centers for Disease Control and Prevention, USA. These two types were
further confirmed as HA-MRSA (generally habour SCCmecI, II and III) and CA-MRSA
(generally harbour SCCmecIV and V) using Staphylococcal Cassette
Chromosome mec (SCCmec) typing using standard methodology.
