LAUSR

We really appreciate the authors and all collaborators who have recently reported their research results in an article entitled “Distribution of Mcr-1 Harboring Hypervirulent Klebsiella Pneumoniae in Clinical Specimens and Lytic Activity of Bacteriophage KpnM Against Isolates”. 1 This study had shown very encouraging research results and important information regarding the use of bacteriophage; KpnM phage in this case, which could be further studied for combating the antibiotic resistance issues. However, first of all, this study lacks clear determination of “hypervirulent” bacteria. 2,3 The phenotypes of hypervirulent K. pneumoniae isolates could be observed via microscopic examinations. 4 Take the observation of thick capsules formation or hyperfimbriae formation on the bacterial cells as examples. 5,6 Since the authors would like to address the hypervirulence in K. pneumoniae isolated in this study, the measurement of CPS staining observed under microscope or EPS/eDNA quantification would give a more comprehensive explanation, instead of showing the mucoid colonies cultured on LB or MacConkey agar show. in Figure 1A and B, for most K. pneumoniae strains show a mucoid colony phenotype especially when cultured on MacConkey agar at 37 °C. In Figure 1C the string test was