Virulence factors of drug resistant strain

The incidence of methicillin resistant Staphylococcus aureus and penicillin resistant Streptococcus pneumoniae have been increasing in Japan. These resistant strains produce toxins and extracellular enzymes working as virulence factors of infection. Some of these toxins and extracellular enzymes are introduced here. The difference of virulence between MRSA and MSSA is not clear but some of MRSA strains are known to produce new type cytotoxins. The difference of virulence factors between penicillin resistant S. pneumoniae and penicillin sensitive S. pneumoniae were not observed.