Numbers of PBPs (penicillin-binding proteins) in MSSA (methicillin-sensitive S. aureus) and MRSA (methicillin-resistant S. aureus) strains

Range 148-824 PBPS/cell Table - link
Organism Bacteria Staphylococcus aureus
Reference Pucci MJ, Dougherty TJ. Direct quantitation of the numbers of individual penicillin-binding proteins per cell in Staphylococcus aureus. J Bacteriol. 2002 Jan184(2):588-91. p.589 table 1PubMed ID11751840
Method Abstract: "The absolute numbers of each PBP were determined by direct measurement and have been reported for two Staphylococcus aureus strains, RN4220 (methicillin-sensitive S. aureus) and RN450M (methicillin-resistant S. aureus). From the specific activity of the labeled penicillin and the absolute number of disintegrations per minute, and from the number of CFU per milliliter calculated from proteins and optical density, a determination of the number of PBPs per cell was made. These numbers ranged from approximately 150 to 825 PBPs/cell and represent the first direct determination of absolute numbers of PBPs in S. aureus."
Comments P.589 right column: "By analysis of multiple fields under phase-contrast microscopy, [investigators] found that clusters were predominantly tetrads under the selected growth conditions, and a factor of 4 was used to convert numbers of CFU to numbers of cells (Table 1)." P.590 left column top paragraph: "The number of molecules of radiolabeled penicillin per CFU divided by 4 yielded the numbers of individual PBPs per cell. Results from a total of four independent experiments are included in the values in Table 1, and the averages and standard deviations for all 12 data points are presented." P.590 right column: "Whereas E. coli was found to have about 2,700 PBPs per cell (ref 9), S. aureus RN4220 had 1,078 PBPs and S. aureus RN450M had 1,935 PBPs (1,111 minus values for PBP 2a) (Table 1)."
Entered by Uri M
ID 113013