<prompt> All of the following statements are true regarding Staphylococci except -A majority of infections caused by coagulase-negative Staphylococci are due to Staphylococcus epidermidisβ-lactamase production in Staphylococci is under plasmid controlExpression of methicillin resistance in Staphylococcus aureus increases when it is incubated at 37C on blood agar.Methicillin resistance in Staphylococcus aureus is independent of β-lactamase production  <response>: Methicillin resistance is expressed more at 30C than at 37C, so susceptibility studies for methicillin are routinely performed at reduced temperature 30 - 35 C for 24 hrs, with increased concentration of salt in the medium to enhance the expression of resistance.Resistance to antibiotics Penicillin resistance is of three types-1 Production of beta-lactamase penicillinaseIt inactivates penicillin by splitting β-lactam ringIts production is controlled by plasmid.Plasmid is transmitted by transduction mainly or conjugation.Penicillinase is an inducible enzymeAs a result of the widespread dissemination of plasmids containing penicillinase, less than 5 strains of staph. remain susceptible to penicillin.Staphylococci produce four type of penicillinases, A to D. Hospital strains usually forms type A penicillinase.2 Changes in bacterial surface receptors by lack or inaccessibility of certain penicillin binding proteins PBPs in the organism.Methicillin resistant is mainly due to this mechanism and is independent of β - lactamase production.It is due to production of PBP 2a.This change in bacterial surface receptors is normally chromosomal in nature.The resistance gene is mec A gene which is a part of large mobile genetic element - staphylococcal cassette chromosome SCCmec.This genetic material has been transferred to Staph. aureus from S. seiuri.3 Development of tolerance to penicillin, by which the bacterium is only inhibited but not killed.About option aApproximately 75 of the infections caused by coagulase negative staphylococci are due to staphylococcus epidertnidis - 