Title:Ventilator-associated Pneumonia caused by commensal oropharyngeal Flora. A retrospective Analysis of a prospectively collected Database.

Transcription

1 Author's response to reviews Title:Ventilator-associated Pneumonia caused by commensal oropharyngeal Flora. A retrospective Analysis of a prospectively collected Database. Authors: Johannes B.J. Scholte (janscholte@hotmail.com) Johan I.M. van der Velde (johan.vdvelde@gmail.com) Catharina F.M. Linssen (k.linssen@atriummc.nl) Helke A Van Dessel (h.van.dessel@mumc.nl) Dennis C.J.J. Bergmans (d.bergmans@mumc.nl) Paul H.M. Savelkoul (paul.savelkoul@mumc.nl) Paul M.H.J. Roekaerts (p.roekaerts@mumc.nl) Walther N.K.A. van Mook (w.van.mook@mumc.nl) Version:2Date:4 May 2015 Author's response to reviews: see over

2 Cover letter BMC Pulmonary Medicine For the attention of the Editors Research article J.B.J. Scholte, M.D. Luzerner Kantonspital Department of Intensive Care Medicine 6000 Luzern 16, Switzerland Luzern, Mai 6th, 2015 Subject: cover letter Title: Ventilator-associated Pneumonia caused by commensal oropharyngeal Flora. A retrospective Analysis of a prospectively collected Database Reference number: Dear Ms M.J. Delos Santos and Dr. J.D. Chalmers, Thank you for the opportunity to revise our manuscript according to the constructive comments of the reviewers. We gratefully thank the reviewers for their comments. Hereby you receive the revised version of our paper in which we highlighted the changes that we made. We hereby enumerate the specific comments of the reviewers and explain successively how each comment has been addressed in blue Italics. Yours sincerely, on behalf of all the other authors, Jan Scholte

3 Referee 1. This study is very interesting because authors are trying to explore whether commensal oropharyngeal flora (COF) may cause VAP, and I think it has a great significance to be published in this journal. However, there are many serious concerns raised in this literature. Major Compulsory Revisions #1. Because the details of reference population were not provided, it was impossible to be compared, or only referred. Comparison should be made among 159 VAP patients. For example, how about comparing between major pathogens of VAP, such as Pseudomonas aeruginosa, MRSA, and COF with regard to baseline characteristics, and outcome? Indeed, it would have been better to compare the COF-VAP cases with the other non-cof-vap patients. We are aware of this, as we interpreted possible differences in this perspective and we addressed this limitation in the method section as well in the limitation section. The primary aim of our study was to explore whether COF is able to cause VAP. Therefore, the current study might be seen as a pilot study, in which the comparison made with the reference population is only meant to put our results into (a Dutch) perspective. This design was proposed by a professor of statistics, as mentioned in the method section as well as in the Acknowledgement section. #2. Examination of CAP and HAP are not required in the literature, you should concentrate on the VAP. We now principally focus on COF- VAP. However, the results of the COF-HAP and COF-CAP patients support our findings and, therefore, we think that it might be helpful to briefly touched upon the COF- HAP and COF-CAP findings. However, in Table 2, the COF-HAP and CAP data have now been removed. #3. Table 2 is quite complicated; you should reconsider the tables that are more simple and impressive. We now modified Table 2 in order to make it more simple: We deleted the row date of ICU admission, as it indeed added little information. We deleted the number of Epithelial cells and fused the rows ICOs and PMNs. Instead, we added the sentence The percentage of squamous epithelial cells, an indicator of oropharyngeal contamination, was less than 1% in all patients in the results section As positive results of fungi analysis, viruses analysis, and PCRs are infrequent, we merged the row Fungi, viruses and PCRs with the row additional characteristics We deleted the findings of COF-HAP and COF-CAP as requested as we now concentrate on COF- VAP. Consequently, we changed the case numbers in Table 2 and Appendix. We would very much favour providing the COF-HAP and COF-CAP data as supplemental material (See Appendix), as we believe that these cases add supplemental support to our findings. Minor Essential Revisions

4 #1. Since the start of SOD, the rate of incidence of VAP due to COF seems to be decreased. This Could you compare the incidence and details of VAP due to COF between before and after the initiation of SOD? Indeed, as stated in the manuscript, no (possible/probable) COF-VAP was diagnosed after the introduction of SOD/SDD. Recently, we published a manuscript describing the VAP rates before and after SOD/SDD in our clinic in Infectious Disease ( In this manuscript we demonstrated that the VAP rates per 1,000 ventilator days declined from 4.38 ±1.64 before to 1.64±0.43 after the introduction of SOD and SDD. The main figure herein is provided here and the main findings of this article are now referred to in the present manuscript. 7 VAPs per 1,000 ventilator days Year Overall, it is unlikely that the incidence of COF-VAP will decline after SOD/SDD, as discussed in our paper. As the mean incidence of COF-VAP revealed only 15/9 = 1.9 per year, our numbers are too preliminary to suggest that COF-VAP rates are declining as well. Therefore, future studies are warranted.

5 Referee 2. Major Revisions The authors in the current study retrospectively analyze the association and role of Commensal oropharyngeal flora (COF) in causing pneumonia, and specifically VAP. The role of commensal oropharyngeal flora with inherent low pathogenic potential as a source of infection has been a matter of controversy and makes this study unique. The authors ascertain the diagnosis based on clinical, radiographic, CPIS score and most importantly culture data. The different colonies were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. However, the diagnosis of VAP is controversial in the absence of a gold standard test. I would urge the authors to clarify the following 1. Methodology The authors correctly point out that a reference population cannot be equated to controls. Then, why did they use reference population instead of controls with no VAP? It is comparing apples to oranges from different time frame and why did they not adjust for severity of illness or use age-sex matched population? See answer #1 to referee Results The patients with COF diagnosed mostly had a surgical indication for admission and longer duration of ventilation and ICU days. Does this mean they were inherently at higher risk for colonization with COF? The authors could clarify, when the patients developed COP-VAP in relation to days of ventilation. It would also be worth clarifying the length of ICU stay after the diagnosis rather than the overall ICU, ventilator days. Indeed, we believe that COF may act as a pathogen in immunocompromised patients (e.g. with a longer duration of mechanical ventilation and after [major] Surgery). The relation of the onset of COF- VAP to days of ventilation is provided in Table 1. In order to emphasize this likely causal relationship, we now additionally provide this information in the Abstract and the Results section. Median Hospital and ICU LOS after diagnosis are provided in Table Although, there was clinical evidence of pneumonia, more than 50% received antibiotics prior to developing COF-VAP. Does this mean there was suppression of pathogenic bacteria? This could indeed be possible. Therefore, we considered 2 patients (2 and 22) to have possible COF- VAP as previously administered antibiotics could have diminished the growth of P. aeruginosa and S. aureus, respectively making them possible VAP causative microorganisms as well. On the other hand, the identified COF was also susceptible to the antibiotics used, but nonetheless still present in significant amounts in BAL fluid. As both considerations are important for the level of likelihood of COF-VAP, this is now addressed in the end of the results section (level of certainty of the presence of commensal oropharyngeal flora ventilator-associated pneumonia) and Discussion (Antibiotic use). 4. It is well known that prolonged intubation and relative immunosuppression is related with viral reactivation. Of the patients attributed to have COF- VAP many patients had positive viral and fungal PCR Does this mean patients COF was mostly seen in patients who were relatively immunosuppressed?

6 As also stated in the answer to question 2, we indeed believe that (relative) immunosuppression makes it possible for COF-VAP to develop. This thought is addressed in the introduction, discussion, conclusions as well as in the abstract. Due to small numbers of COF-VAP, of which only 3 revealed positive viral and fungal PCR, we can only suggest (but thus not prove or substantiate) this causal relationship. Further research is necessary to prove our suggestions and provide insight into underlying pathophysiological mechanisms. 5. Provided the antibiotics used were also active against COF how were they treated differently?. Patients with suspected VAP were empirically treated according to the ATS protocol and local guidelines: - unless previously culture results are available: Amoxicillin/clavulanic acid [with ciprofloxacin until Legionella test known] when hospitalized less than 5 days. - When Hospitalized longer than 5 days empirical therapy would have been piperacillin/tazobactam. - When previously culture results know, we treat patients accordingly (to target at least these organisms). - When BAL fluid results become available, we try to narrow the spectrum of the antibiotics. - Of course, level of illness is herein an important factor. As COF was considered non-relevant during the studied period, antibiotics were stopped when the clinic allows it. For the antibiotic treatment of the individual cases we would like to refer to Table 2. As stated in the discussion: Four out of the 15 patients with probable COF-VAP received inappropriate antibiotic treatment. The respiratory outcome was unfavourable in 2 out of 3 cases that survived the VAP episode, suggesting that COF-VAP should be treated appropriately. If COF was/is considered to be a true pathogen in the ICU, it should of course be treated as narrow as possible and as broad as needed, providing good antibiotic stewardship. In most cases, Penicillin/Amoxicillin would be appropriate. 6. Why was enterococci excluded from analysis? A. Enterococci were excluded as potentially pathogenic microorganisms in VAP due to a low presumed level of pathogenicity. Enterococcus spp. are generally not seen as true pathogens and in other studies (Medford AR, et al Journal of critical care 24:473 e Raoof S et al Critical care medicine 42: The Canadian Critical Care Trials Group The New England journal of medicine 355: ), these microorganisms were also excluded from VAP causing pathogen analyses. Furthermore, Enterococci had a low level of incidence (only 3 cases [clinical VAP criteria, Enterococcus spp 10^4 cfu/ml or more and ICOs < 2%] identified during the 9,5 year period). B. However, similar to COF, Enterococci may possible cause VAP (in the immunocompromised ICUpatient). Therefore, we considered the exclusion of enterococci as a possible limitation. This is now briefly addressed in the limitations section, in order to clarify this limitation. C. To include enterococci as COF, they are commensal, yet not oropharyngeal.

7 7. Is it possible that COF caused transfer of microbial resistance to antibiotics? This may be possible (due to plasmid-transfer and conjunction e.g.), but this (highly technical) speculation/discussion is beyond the scope of the article. 8. COF was ascertained based on the BAL cultures and clinical features this cannot prove causality but rather show an association in the light of above mentioned concerns. It would be worthwhile stating that, than to conclude COF as causing VAP. A globally accepted gold standard for the diagnosis is lacking. BAL fluid analysis is frequently regarded second best. This was already briefly stated in the introduction section and this statement is now supported with 2 more interesting references. Furthermore we now included this limitation in our limitations section. To the best of our knowledge, we have presented our data in this perspective. Minor revisions Methods para definition (Page 4 63): Grammatical error and sentence need to be fragmented/rephrased. This sentence is now bisected and rephrased. Results (Page 8-133): Incidence of COF is reported wrong it is not 14.5% Suspected COF-VAP cases represent 14.5% of all VAP cases. Probable COF-VAP cases represent 9.4%. The 14.5% might indeed be prone to misleading interpretation. Therefore we deleted this percentage. Level of interest: An article whose findings are important to those with closely related research interests Quality of written English: Needs some language corrections before being published We scanned the manuscript for language errors and the made correction are highlighted in the manuscript.

8 Referee 3. Thank you for the opportunity to review the manuscript : Scholte and collaborators reported a retrospective study of 23 critically ill patients with VAP in which BAL yielded >10 4 cfu/ml commensal oropharyngeal flora(cof) (diagnosed prospectively) during a 9 year period, and 899 patients admissions to ICU. The main findings of this study is that COF was the most likely cause of respiratory deterioration in 9,4% of all VAP cases (n=159) and it was associated with increase of length of both ICU and hospital stay. The manuscript is informative since it presents still very controversial and unknown, issue in the area of pulmonary infections in mechanically ventilated patients. Despite the several articles on VAP that had been recently published, the most original aspect of this manuscript is the discussion on possibility to considering COF as a potential cause of VAP in ICU patients without documented immunosupression (but which could be considered as immunocompromised ). In general, the study is well performed, the question posed by the authors is well defined and the data is sound.. The title and the abstract accurately convey what has been found. However, the results are, in my opinion, incoherently described and presented in only one figure and two tables. As described in the rebuttal to referee 1, we now focus on VAP and modified Table 2. Furthermore, a figure has been added that described the course of clinical and laboratorial characteristics of the suspected cases, as asked below. The limitations of the study are clearly stated, but not all are included in the manuscript. Discussion is generally interesting, but too long. - The focus of the paper is now only on VAP, which slightly shortens the discussion. - The likelihood of COF-VAP evaluation, including parts of the possible role of antibiotics is now moved to the Results section, as it actually better fits in this part of the manuscript. - Two limitations (Gold Standard of VAP and BAL fluid storage related problems) are added to the limitation section, as is stated in point 8 of Referee 2 and in one of the points of referee 3. Conclusions are well balanced and adequately supported by the data. The manuscript is supported by 43 references, and the majority of them had been published within the last years. Overall, the manuscript adheres to relevant standards for reporting and data deposition but needs several corrections. Unfortunately, methodological issues as well as a small number of patients (n=23) included in such a long study period limit the strength of the entire study. As commensal flora is generally sensible to the antibiotics recommended by guidelines which are often used in the treatment of different infections in ICU patients. the importance of this research may be considered as rather limited. Following the concept of good antibiotic stewardship, patients that do not receive antibiotics may increasingly be encountered. Yet, patients with probable COF-VAP probably benefit from immediate and appropriate antibiotic administration, instead of a clinician that refrains from antibiotics because he considers COF-VAP fiction. In this perspective, the clinical importance may even rise in future.

9 Several major and minor issues should be addressed to improve the manuscript. I have also some questions to the Authors. Major comments: Although the Abstract and conclusions show the results, I can t find in the results section (as well as in figures) the most important finding/sentence COF was the most likely causative agent in 9,4% of all VAP episodes. Certainly it needs to be added. The paragraph level of certainty of the presence of commensal oropharyngeal flora ventilatorassociated pneumonia is now provided in the results section instead of in the discussion section. As the outcomes of this paragraph results in our main finding, this main finding is now provided in the results section as well as in the first paragraph of the discussion section. Methods. Definitions: How were CAP and HAP diagnosed in the patients with suspected VAP? Is it possible to diagnose HAP or CAP in the patients with the suspected VAP? Who has clinically diagnosed VAP and evaluated the outcome of this study? Was it a group of experts (physician, microbiologist )? It should be well stated in the manuscript. 1. As stated in the definition section: when a pneumonia was suspected (same clinically criteria) in a patient which was admitted in the hospital less than 3 days and BAL results were indicative for pneumonia or when the potentially pathogenic microorganism was very unlikely to be nosocomial (e.g. Haemophilus influenzae, Mycoplasma spp.), CAP was considered. When a clinically suspected case was admitted for more than 3 days and revealed positive BAL results, but was not mechanically ventilated for 48 in the 72 hours prior to the pneumonia, HAP was diagnosed 2. The definition of COF-CAP and COF-HAP is now slightly changed according to the remark below. We now stressed the fact that CAP is acquired in the community and that HAP is acquired in the nosocomial environment. 3. The outcome of the study (likelihood of COF-VAP) was evaluated by 4 authors (2 consultant Intensivists, 1 consultant in medical microbiology, and 1 junior researcher). This is now stated in the method section as well as in the Author s contribution section Methods. Microbiological data collection: Was the BAL and ETA microbiologically evaluated immediately after it was taken? It should be signed. BALF analysis was performed immediately after collection, and ETA was immediately evaluated when obtained during daytime. This is now clarified in the methods section. How long were the samples with cells and supernatant stored at -80o C? The MALDI-TOF MS analysis was done in 2014 and the majority of the samples were stored up to then. In the previously submitted Table 2, the date of ICU admission was provided. The BAL fluid that was stored the longest, was thus stored for 9 years. To date, BAL fluid samples are stored indefinitely. Is the MALDI-TOF-MS routinely used in the hospital or is it restricted to clinical research (reference) laboratory only?

10 Up to now, MALDI-TOF MS is used for research purposes only. We used a MALDI-TOF MS which was located at a nearby hospital (where the consultant in microbiology, CFML, works), that routinely uses MALDI-TOF MS. When was this diagnosis made? It should be stated in this section. The study was conducted from January 2014 up to July This is now stated as the first sentence in the results section. How many patients were subjected to all diagnostic methods on the day of clinical VAP diagnosis? MALDI-TOF MS analysis as well as PCRs were performed on BAL fluid. ETA was obtained on the day of VAP diagnosis, 1 day before BAL or 1 day after BAL. The days on which the ETA were obtained in relation to the date of the BAL procedure were specifically chosen in order to achieve as much reliable pairs to compare. The chosen 3-day interval could be defended, because changes in ETA outcome is minimal within this timeframe, according to two previous studies (Boots RJ et al Respirology 13: Luna CM et al Chest) In a previous study, we compared the results of ETA with BAL fluid in 288 patients. A sub analysis of 129 patients in which ETA and BALF were obtained the same day, revealed identical results (Cohen s Κ). Scholte et al. 2014, Journal of Clinical Microbiology October;52(10): Since we obtained the cases from the same database as previously used, we do not have the exact data of ETA obtaining, but it will be about 40-50%. For comparison, however, it would have been irrelevant as stated above. Therefore, this information was not included in the text. If considered necessary, we will find the exact numbers. Evident problems with BAL fluid storage, retrieval, and contamination possibility decrease the credibility of this study. Long BAL fluid storage could be enumerated as limitation. This limitation is now addressed. Results: In case it was a study on COF in VAP, there is no need for discussion of CAP or HAP. If it was a study on COF pneumonia at ICU patients (who need mechanical ventilation), the aim of the study, methodology, and title should be slightly changed. These items are now changed, as previously stated ( #2 of Referee 1). Results, Clinical parameters: Selected clinical parameters on a day of VAP diagnosis are presented in table 1. Additional analysis of CRP, WBC, and temperature on days 1,3,7 (with figure and statistics) in 23 patients could be interesting. Moreover, the Authors should consider to include in this section the results of statistical analysis (p )for CRP and WBC reduction/fluctuation. All these parameters are now provided in Figure 2. Results, Table 2 Please mark in the table all patients with diagnosed COF VAP as a single infection. All patients with probable COF-VAP were diagnosed with a single infection: COF-VAP. Therefore, it is not necessary to additionally mark these cases. In the cases were other infections could have been present, probability of COF-VAP has been changed to possible COF-VAP or no COF-VAP (when

11 alternative, infectious, diagnosis was considered more likely). Herein, we assume that moderate growth of a PPMO in ETA semi-quantitative cultures lack positive predictive value as demonstrated in our previous study (PPV 48% [95% CI 39-57] of ETA semiquantitative cultures in 311 VAP suspected cases [Scholte et al 2014 JCM]). In the results section, we now state that probable COF-VAP patients were diagnosed with no other infections. Results, Table 2 Patients with symptoms of clinical sepsis should be classified as sepsis with not known or known origin (peritonitis, pneumonia, CLA-BSI?) All patients were mechanically ventilated. Almost any mechanically ventilated patient in the ICU, with or without infection, fulfils the sepsis criteria. E.g. tachypnoe (>20x) or hypercapnia may be caused by ventilator settings and not by sepsis per se. Therefore, we did not assessed the SIRS and sepsis criteria. Results, Antibiotic treatment: The outcome (clinical improvement, microbiological eradication, surviving - if possible) after adequate and non adequate antibiotic treatment should be presented in this section. According to the Authors, the patients who received non adequate treatments had a positive outcome., Was it really COF VAP? Distinction between the appropriate treated and inappropriate treated patients is now made, also regarding mortality. According to us, inadequately treated COF-VAP patients had a poorer outcome, as stated in the outcome and antibiotic treatment paragraphs of the results, as well as in the treatment paragraph of the discussion and in the conclusions/recommendation. The number of patients, however, was limited and therefore not statistically significant. Minor comments : Abstract, results can be shortened. The sentence In 7 patients, a more likely ausative organism was found and 1 patient was diagnosed with abdominal sepsis is not necessary in the abstract. This sentence is now deleted. Furthermore, CAP and HAP results are now deleted, limiting the length of the result section in the abstract as well. Abstract, conclusion should be framed with caution. The study didn t estimate immunocompromised status of ICU patients. In my opinion it should be rather : Commensal oropharyngeal flora appears to be a potential cause of VAP in limited number of ICU patients. It is probably associated Conclusions are changed according to this suggestion. Keywords: should be more focused on aim/findings of the study, for example : VAP, COF, MALDI-TOF- MS

12 Epidemiology is now deleted as Keyword. VAP, COF, and MALDI-TOF-MS are all included as Keywords. Background, page 3, In my opinion should be : A globally accepted gold standard for the diagnosis of VAP is lacking [6 ] with the exception of the new surveillance VAE definitions.[magill S]Generally more acceptable /recommended for microbiological diagnosis of pneumonia are quantitative specimen collection techniques as bronchoalveolare lavage, protected specimen brushing obtained bronchoscopically and non bronchoscopically (min-bal). These sentences are now changed according to the above made suggestions. Methods: Setting It is not clear if the ICU (in hospital with admissions ) admitted medical and post cardiac surgery patients only. How about the patients with complications after abdominal and other operations? The number of hospitalized in ICU patients during the study period should be reported in this section. Non-elective postoperative patients with complications needing ICU support were of course admitted to our ICU. The PACU is available for a maximum of 48 hours per patient. This is now more clearly stated. Furthermore, the number of ICU hospitalizations (17,254) is now provided in the Results section. Did the Authors use still the same (including /suspected VAP) criteria established /published in 1997?Any changes in 2008 (CDC/NHSN surveillance definition of HAIs, Horan)? During the study period, no policy changes were made concerning diagnosing (suspected) VAP. Information about PSB lacking is not necessary, instead it should be specified what kind of SOD and SDD were used. Information regarding PSB is deleted and it is now specified what kind of SOD and SDD we used. Methods. Definitions: Please add the references for CAP and HAP definitions, and underline that CAP was diagnosed in the patients admitted from home, without earlier contact with health service, but HAP had hospital origin. It should be underlined that H.influenze and Moraxella spp >104 cultured, was considered as early VAP pathogens not commensal flora. It sounds precisely as not predominant. References have now been provided and we clarify the differences of CAP and HAP according to the remarks of the referee Methods. Data collection: The sentence When BAL fluid revealed exclusively significant growth should be deleted from data collection subsection as it is a part of VAP diagnostic criteria. This sentence is now deleted Results. Figure 1 Percentage value of patients with VAP and no VAP should be corrected (total is 101%?). Thank you, correct. Right percentages are now provided.

13 This division /distribution of patients is very surprising. I d rather suggest to compare VAP to others, or pneumonia in ICU ventilated patients (VAP+HAP+CAP) to the patients without pneumonia. See answer #1 to referee 1. Results. Table 1 Despite collected patients characteristics and results together, there is a lack of p for non-surgical and immunocompromised patients. Point well taken. These missing data are now provided in Table 1. Results. Table 1 Reference population, Median hospital LOS/Median ICU LOS.Please delete (=mean ), and add IQR values. Unfortunately, only mean values were available from the NICE (Netherlands Intensive Care Evaluation) database. It was therefore not possible to provide medians, although the latter would indeed have been superior. Results. Table 2: Needs more detailed description in the text. With all previously suggested changes incorporated, the Table is now more illustrative and readable. Furthermore, more information stated in the Table previously, is now provided under the results section. Table2 looks like a data base, so that too much data is presented here, which makes the analysis very time consuming. The table is now adjusted and less interesting information is removed or organised more efficient as stated in the answer of #3 of Referee 1. Date of ICU admission and additional characteristics can be deleted. If it is COF VAP study, the table should present these patients only. Point well taken. The table is now adjusted accordingly. Results, Microbiological results should be shortened since there is no need to repeat information from the table. This paragraph is now significantly shortened and stayed with the main findings. How many patients were subjected to BAL, ETA and MALDI-TOF-MS, PCR analysis? Which the most frequent pathogens were identified in BAL,ETA,..? Please enumerate pathogens and number of strains(n=?) All these findings are now clearly presented in Table 2. Enumerating these findings in the text will be in contrast with the previous suggestion. Discussion should be shortened and can t show/repeat results (correct sections Endotracheal aspirates, Antibiotic used, Entity) The discussion is now shortened, more logically structured and does not show or repeat results.

14 Abbreviations under the tables are repeated. Usually abbreviations are collected under the text not table. All used abbreviations are now collected under the text. Level of interest: An article of importance in its field Quality of written English: Needs some language corrections before being published We scanned the manuscript for language errors and made some minor correction. Additional Editorial Requests: 1. Name of Ethics Committee: Please update your ethics statement to include the name of the ethics committee that approved your study. The name of the ethics committee is now provided in the manuscript 2. Tracked Changes: Please also highlight (with'tracked changes'/coloured/highlighted text) all changes made when revising the manuscript to make it easier for the Editors to give you a prompt final decision on your manuscript. We prefer if you can make text look like it was marked with a highlighter pen the modified part of the original manuscript. In the uploaded manuscript, our changes are highlighted.