I had a look but found the possible explanation complex; I don't know if it of any help:
Xu, M., Wu, J., & Chen, L. (2019). Virulence, antimicrobial and heavy metal tolerance, and genetic diversity of Vibrio cholerae recovered from commonly consumed freshwater fish. Environmental Science and Pollution Research, 26(26), 27338-27352.
Article Virulence, antimicrobial and heavy metal tolerance, and gene...
At the end of the introduction, there is an interesting paragraph about this.
Perhaps as 2 out of the 3 authors are in ResearchGate, they could add further to this discussion?