Table 1: Minimum bactericidal concentrations (MBC) of manuka (NPA 20+) and white clover honeys against a variety of bacteria.

BacteriaMBC (% w/v)
Manuka honey NPA20+White clover honey
pH 4.9pH 7.1pH 5.2pH 7.1

Staph. aureus12.512.550>50
E. coli12.5252550
S. mutans UA159>50>50>50>50
S. mutans 1044925252550
S. sobrinus 12.512.52525
S. sanguinis25255050
S. gordonii252525>50
F. nucleatum ATCC 2558612.512.52525
F. nucleatum ATCC 3356825252525
P. gingivalis12.512.512.525
P. intermedia12.512.52512.5

P. gingivalis and P. intermedia were incubated for 48 h while all other bacteria were incubated for 18 h. The highest honey concentration tested was 50% (w/v).
NPA: nonperoxide antibacterial activity.
Natural pH at 50% (w/v) in culture media.