reviews Title : First multicenter study on multidrug resistant bacteria carriage in Chinese

1. Conclusion: MDRO prevalence was high in the ICU, but predominantly originating from patients colonized/infected on admission. With a high rate of MDRO on admission, there is a higher prevalence of admitted patients with MDRO making transmission potentially more likely. Concluding that the prevalence of MDRO is high, may minimize the source of MDRO in Chinese healthcare facilities. If efforts to contain MDRO in China only focused on the ICU (eg. infection control, antimicrobial stewardship, environmental cleaning), would that resolve the problem in the ICU if 1/3 of patients already have an MDRO on admission? We agree with the reviewer. Indeed, MDRO is a global problem in and out ICUs. However, ICUs have been shown to be a place for high transmission and where antibiotic use is very high. Therefore, it may be a good place to start a program because teams may be more reactive and motivated regarding the MDRO issue. Decreasing transmission in ICUs may help to decrease MDRO outside ICUs where ICU patients are discharged. We modified the conclusion by underlining the high MDRO admission rate. Materials and Methods: 1. Surveillance Program, paragraph 2: What was the rationale for defining A. baumannii and P. aeruginosa as MDRO based on resistance to a single agent? Was the 3rd generation cephalosporin specifically resistance to ceftazidime? There are no universal definitions for MDR A. baumannii and MDR P. aeruginosa. Therefore, we chose resistance to ceftazidime as a marker for multidrug resistance and changed the text accordingly. 2. Surveillance Program: Were all of the facilities included in the study similar (beds, ICU size and infrastructure, patient population, etc.)? As expected, ICUs were not very similar as it is common in multicentre studies. This is also the interest of multicentre studies to level off differences and make conclusion more generalizable. We have added a brief description of the units and provided data regarding variations by unit in the results section (new Table III). 3. Bacteriology, 2nd sentence: were all colonies that grew on the chromID MRSA considered MRSA? Were there basic tests to confirm the identity of the colony? Did you consider adding a confirmatory test for MRSA? As stated, no additional test was performed regarding methicillin resistance. The specificity of the test is considered very high (>99%) and we have added a reference regarding this issue. 4. Bacteriology, last sentence: Please state what susceptibility testing method was performed for A. baumannii and P. aeruginosa. Vitek2 was used as for other gram-negative bacilli. We change the text accordingly.