In the recent decades, pathogenic microorganisms with resistance
to common drugs have become increasingly widespread;
some examples include methicillin-resistant [1–4]
strains of Staphylococcus aureus (MRSA), vancomycin-resistant
strains of S. aureus (MRCNS or “methicillin-resistant
coagulase-negative staphylococci”), drug-resistant strains of
Streptococcus pneumoniae (DRSP), and vancomycin-intermediate
strains of S. aureus (VISA) [1–4]. MRSA have been
viewed as one of the leading nosocomial pathogens [5–7]. In
the last decade of the 20th century, there has been an unprecedented
spread of MRSA on a global scale. According to
the data of the National Nosocomial Infections Surveillance
in the USA, in 1998, the proportion of MRSA in intensive