<prompt> All of the following statement are true about Staphylococci except :A majority of infection caused by coagulase - ve Staph. are due to staph epidermidisβ -Lactmase production is under plasmid controlExpression of methicillin resistance in Staphylococcus aureus increases when it is incubated at 37 degree C on blood agarMethicillin resistance in Staph. aureus is independent of b-Lactmase production  <response>: Methicillin resistance is expressed more when Staph. is incubated at 30 0 C than at 37 0 C.Penicillin resistance in Staphylococcus is by following ways :1. Production of β lactmase :Plasmid mediated inducible enzyme which is transmitted by transduction more commonly or conjugation.Now only 5 of strains of staph are sensitive to penicillin.Hospital strains mostly form type A penicillinase.Same plasmid carry genes for resistance to tetracycline, Erythromycin, Aminolgycoside too.2. Altered penicillin binding protein :Due to production of novel penicillin binding protein PBP2a. The protein is synthesized by mecAgene.Chromosomally mediated expressed more at 30 0 C than at 37 0 C.Responsible for resistance against penicillinase resistant penicillin such as methicilin, cloxacillin. Strains are called MRSA Methicillin resistant Staph. aureus.3. Tolerance to pencillin :Bacteria only inhibited not killed. 