The authors presented an antimicrobial activity assay to test the potency of curcumin with and without the presence of antibiotics against Enterotoxigenic E. coli. It was found that curcumin is not active against Enterotoxigenic E. coli. up to 330 mg/mL. However, when combining with 12 antibiotics, there were synergistic effect to enhance the potency against Enterotoxigenic E. coli. Therefore, the authors concluded that curcumin is not active against Enterotoxigenic E. coli. However, when combining with other antibiotics, there were synergistic effect. Although this work may assist the development of drugs against diarrheagenic E. coli, there are some misinterpretations on the fold of increases, and the results might not apply to other Enterotoxigenic E. coli with limited strains tested.

Major points:

1. In page 3 line 97-98, the authors concluded that the highest fold increases in area were observed for AMC (85.9%), followed by CTX (74.6%) and CAZ (74.2%). However, according to the data from table 3, figure 2b and the equation on the caption (B2-A2)/A2 × 100, the fold of increase for AMC from 12mm to 15 mm is only 56.2%, and for CTX from 28mm to 35mm is only 56.2%, too. This data does not support the claim by the authors.

2. In addition, the fold of increases for CZ from 19mm to 22mm is 34.1%, which is not consistent with the data on figure 2B.

3. In section 4.1, the enterotoxigenic E. coli strain ETEC 078:H11 is used for current study. However, in section 4.2 E. coli strain O7:H104 was grown on agar plates. Which one is the strain used for this study?

4. The authors only used one enterotoxigenic E. coli strain for all the activity assay. This data is very limited to make conclusion about the effect of curcumin against Enterotoxigenic E. coli.

Minor points:

1. Table 2 is a duplicate of the first column of Table 3, and they should be combined.
2. In table 3, 900 mg/mL should be 330 mg/mL.
3. The meaning of the blue box on Table 3 should be defined.

Overall, this manuscript has several wrong interpretations of their results, which happens to be crucial conclusion of the current study. Moreover, this work needs more experiment against other Enterotoxigenic E. coli strains to evaluate the activity and extent of synergistic effect of curcumin.

The authors presented an antimicrobial activity assay to test the potency of curcumin with and without the presence of antibiotics against Enterotoxigenic E. coli. It was found that curcumin is not active against Enterotoxigenic E. coli. up to 900 mM. However, when combining with 12 antibiotics, there were synergistic effect to enhance the potency against Enterotoxigenic E. coli. Therefore, the authors concluded that curcumin is not active against Enterotoxigenic E. coli, but can be combined with other antibiotics for better performance. Although this work may assist the development of drugs against diarrheagenic E. coli, there are some concerns about the conclusion with limited strain tested.

The authors only used one enterotoxigenic E. coli strain O7:H104 for all the activity assay. This data is very limited to make conclusion about the effect of curcumin against Enterotoxigenic E. coli.

In addition, the control of the activity of curcumin against Enterotoxigenic E. coli was performed using microdilution assay. However, the activity assay of other antibiotics in combination with curcumin were conducted with disc diffusion. It is uncertain if curcumin itself is potent against Enterotoxigenic E. coli when using disc diffusion techniques. It is possible that the activity may vary using different techniques.

Moreover, Table 2B and Table 3 have many duplicate data and should be combined.

Overall, this manuscript put the results too hastily and needs more experiment to evaluate the effect of curcumin against Enterotoxigenic E. coli.