This is a regressional problem with the dependent variable: the disease dynamics and the independent variables: dichelobacter nodosus. and fusobacterium necrophorum. Multiple regression model is therefore likely to be applicable.

It is important to recognise structure of variables you studied here. Please provide more information in this regard.

To reach the reliable results, distribution of all variables and curve type of explanatories on result should be take into consideration. If you dont have biometrician, i can help you at the analysis phase.

Actually, response to your question depends on the measurement scale of your variables. I can provide the answer to you in four sections.

If your dependent variable (disease dynamics) and independent variables (Dichelobacter nodosus and Fusobacterium necrophorum) are quantitative you should use multiple regression.

If your dependent variable is quantitative but your independent variables are qualitative you should use two way Anova.

If your dependent and independent variables are qualitative you should use log-linear analysis.

If your dependent variable is qualitative but your independent variables are quantitative you should use multinomial logistic regression.