Molecular Characteristics of Community-Acquired Methicillin-Resistant Staphylococcus Aureus in Hokkaido, Northern Main Island of Japan: Identification of Sequence Types 6 and 59 Panton-Valentine Leucocidin-Positive Community-Acquired Methicillin-Resistant Staphylococcus Aureus (Report‪)‬

Introduction Staphylococcus aureus is the most common bacterial pathogen in humans, causing a wide range of infectious diseases. Since the 1960s, methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as a life-threatening multidrug-resistant bacterium worldwide and has been a major cause of nosocomial infections; therefore, this MRSA is alternatively called hospital acquired- (or healthcare associated) (HA-) MRSA. (16) It is believed that MRSA is generated from methicillin-susceptible S. aureus (MSSA) by acquisition in its chromosome of staphylococcal cassette chromosome mec (SCCmec), a genetic element containing mecA, which is critical to methicillin resistance. SCCmec elements are diverse in their structural organization and genetic content and have been classified into several types and subtypes. (25) Three types of SCCmec elements (types I, II, and III) are carried mostly by HA-MRSA strains throughout the world. It has been presumed that a limited number of pandemic HA-MRSA clones with different SCCmec types have been spread worldwide. (43)