Table 1

Antimicrobial activity of aurothiomalate, methotrexate and sulfasalazine against RA associated pathogens

Cmax1.4–4 µg/mL17 230.2–0.6 µg/mL246.0 µg/mL(*)
Anaerobic bacteria
Actinomyces spp (n=6)>280 µg/mL (70; >280)n.a.>600 µg/mL (300; >600)
Capnocytophaga spp (n=6)35 µg/mL (18; >280)n.a.>600 µg/mL (600; >600)
Eikenella spp (n=6)>280 µg/mL (18; >280)n.a.>600 µg/mL (300; >600)
Fusobacterium spp (n=6)53 µg/mL (18; 280)30 µg/mL (3.75; >30)300 µg/mL (150; 300)
Parvimonas spp (n=6)210 µg/mL (70; >280)n.a.n.a.
Prevotella spp (n=6)>280 µg/mL (>280; >280)n.a.n.a.
Porphyromonas spp (n=6)53 µg/mL (17.5; 140)n.a.450 µg/mL (150; >600)
Viridans Streptococci
Streptococcus spp (n=8)>280 µg/mL (>280; >280)2.3 µg/mL (0.5; 15)n.a.
Aerobic bacteria
Escherichia coli (n=6)>280 µg/mL (140; >280)n.a.n.a.
Proteus mirabilis (n=6)>280 µg/mL (>280; >280)n.a.n.a.
Staphylococcus aureus (n=6)>280 µg/mL (>280; >280)n.a.n.a.
  • Minimum inhibitory concentrations, presented as median (min; max) µg/mL for disease-modifying anti rheumatic drugs which demonstrated antimicrobial activity in the diffusion disk screening assay.

  • Cmax, maximum serum concentrations from diverse pharmacokinetic studies, as shown in online supplemental table 1; n.a., not applicable because no antimicrobial activity was observed in the agar diffusion screening assay; For the calculation of median minimum inhibitory concentrations, the highest concentrations tested were used if no inhibition was observed.

  • *Pharmacokinetic data were taken from the summary of product characteristics (Sulfasalazin-Heyl, Germany).

  • ATM, Aurothiomalate; MTX, Methotrexate; RA, rheumatoid arthritis; SSZ, Sulfasalazine.