Figure 1.
Houttuynia cordata Thunb and related compounds.
A) Houttuynia cordata Thunb (picture of the plant is from Chinese Pharmacopoeia Commission, 9th edition [8]), B) Houttuynin, C) Sodium houttuyfonate and D) Sodium new houttuyfonate.
Table 1.
Characteristics of 103 hospital-associated MRSA isolates used in this study.
Table 2.
Susceptibility of MRSA strains to SNH and eight antibiotics.
Figure 2.
Activity of SNH at different concentrations in a time-kill analysis against MRSA strains.
A) MRSA 5–20 (MIC = 32 µg/mL); B) MRSA 6–29 (MIC = 32 µg/mL); C) MRSA 8–36 (MIC = 32 µg/mL); D) ATCC33591 (MIC = 32 µg/mL); E) Mu50 (MIC = 64 µg/mL); ▪, GC, growth control; ▴, 1/4×MIC; ×, 1/2×MIC; ⧫, 1×MIC; ○, 2×MIC; □, 4×MIC.
Table 3.
Effects of SNH in combination with antibiotics against 12 MRSA strains in checkerboard assay.
Figure 3.
Sub-MIC levels of SNH and oxacillin alone and in combination against MRSA strains.
A) MRSA 5–20, 1/2×MIC SNH-1/64×MIC OXA (MIC of SNH = 32 µg/mL, MIC of OXA = 128 µg/mL); B) MRSA 6–29, 1/2×MIC SNH-1/64×MIC OXA (MIC of SNH = 32 µg/mL, MIC of OXA = 256 µg/mL); C) MRSA 8–36, 1/2×MIC SNH-1/128×MIC OXA (MIC of SNH = 32 µg/mL, MIC of OXA = 512 µg/mL); D) ATCC 33591 1/2×MIC SNH-1/64×MIC OXA (MIC of SNH = 32 µg/mL, MIC of OXA = 256 µg/mL); E) Mu 50, 1/2×MIC SNH-1/128×MIC OXA (MIC of SNH = 64 µg/mL, MIC of OXA = 512 µg/mL); ▪, GC, growth control; ▴, SNH; ◊, OXA; ○, combination of SNH and OXA.
Figure 4.
Sub-MIC levels of SNH and netilmicin alone and in combination against MRSA strains.
A) MRSA 5–20, 1/2×MIC SNH-1/4×MIC NET (MIC of SNH = 32 µg/mL, MIC of NET = 16 µg/mL); B) MRSA 6–29, 1/2×MIC SNH-1/2×MIC NET (MIC of SNH = 32 µg/mL, MIC of NET = 8 µg/mL); C) MRSA 8–36, 1/2×MIC SNH-1/8×MIC NET (MIC of SNH = 32 µg/mL, MIC of NET = 64 µg/mL); D) ATCC 33591 1/2×MIC SNH-1/4×MIC NET (MIC of SNH = 32 µg/mL, MIC of NET = 4 µg/mL); E) Mu 50, 1/2×MIC SNH-1/4×MIC NET (MIC of SNH = 64 µg/mL, MIC of NET = 16 µg/mL); ▪, GC, growth control; ▴, SNH; ▽, NET; ○, combination of SNH and NET.