Author’s response to reviews Title: Fluoroquinolone resistance and mutational profile of gyrA in pulmonary MDR tuberculosis patients Authors: Saba Kabir (sabakabir991@yahoo.com) Zarfishan Tahir (ztahir1@yahoo.com) Nadia Mukhtar (nadiamukhtar84@yahoo.com) Muhammad Sohail (drsohailmmg@gmail.com) Muhammad Saqalein (drsaqalein@gcuf.edu.pk) Abdul Rehman (rehman.mmg@pu.edu.pk) Version: 1 Date: 10 Jan 2020 Author’s response to reviews: Respected Prof. Dirk Krüger Editor-in-Chief BMC Pulmonary Medicine Respected Prof. Dirk Krüger, I am sending the revised manuscript “Fluoroquinolone resistance and mutational profile of gyrA gene in pulmonary MDR tuberculosis patients" for favor of its publication in your esteemed journal, BMC Pulmonary Medicine. While revising I followed the instructions of honorable reviewer and changes are mentioned in "Red color" in the manuscript. Response to Reviewer # 1 1) Line 21-22 how many estimated cases and what is missing estimated number of cases? It is useful information in general if the context of this paper. Case finding is a major issue under current TB control Response: A total of 562 suspected MDR-TB cases were included in this study. History of anti- tuberculosis treatment was obtained from the patients. Out of 562, 313 were the newly diagnosed cases, 97 were treatment failure cases (who completed the treatment but still positive for MTB), 59 were treatment default cases (previously taking anti-tuberculosis therapy, at least for one month, but did not complete the treatment), and for the 93 samples treatment history was unknown (Sample collection and results). 2) Lines 26-28. I suggest that authors mention how they arrived at this sample size?