AR paper (Berge et al., 2003), Ward’s minimum variance with squared Euclidian distance produced
well-separated homogenous clusters. Milligan (1981) has supported, in his Monte Carlo tests of
cluster analysis review, that Ward’s minimum is the best method to produce well separated clusters.
Table1 AR binary phenotypic clusters using Ward’s method. Table shows 15 clusters and the
number of isolates per cluster. Grey-shaded boxes show the number of resistant isolates to each
antibiotic.