A Multi-level Antimicrobial Surface Coating for a Healthier Environment
Phase: PHASE2
Conditions: Hospital Acquired Infections
Sponsor: Hong Kong University of Science and Technology

 
Protocol for the use of multilevel antimicrobial coating on patient 
privacy curtains in Kowloon Hospital  
 
Approved by Clinical Research Ethics Review Committee, (Operation) (Kowloon Central/ 
Kowloon East) 
Hospital Authority, Hong Kong 
 
Project Approval Number: Approval Number: KC/KE-16-0189/ER-2 
Document No: HA RE001F3 
Protocol ID: ITT/008/15GP 
 
 Reviewed Date: 02-01-2019 
 
Study Title: A Multi-level Antimicrobial 
Surface Coating for a Healthier Environment 
 
Investigation Team: 
 
1. Prof King Lun Yeung (kekyeung@ust.hk) 
2. Dr. Awais Farid (afarid@ust.hk) 
3. Dr. Christopher Lai (laikcc@ha.org.hk) 
4. Dr. Dominic Tsang (nctsang@ha.org.hk) 
5. Prof Joseph Kwan (joekwan@ust.hk) 
 
 
 

1 
 
Site information: Kowloon Hospital (147A Argyle Street, Kowloon, Hong Kong) 
Collaborators: 1. Hong Kong University of Science and technology, Hong Kong 
2. Innovation and Technology Fund (ITF), Hong Kong 
 
Preparation site: Core lab (Pathology Unit), 3rd floor, main building, Kowloon Hospital 
Sampling Site: Rehabilitation ward 3B,  
 Male cubicle (3rd cubicle)  
o No of beds: 8 
o No curtains: 12 
o Available Nursing counter: yes (13 staff members including nurses and supporting 
staff) 
o Visitors allowed: Yes, (12:00-13:00 and 17:00-19:00 every day)  
o Additional cubicle for 3rd phase of study: 2nd cubicle, 4 beds, 4 curtains  
 Female cubicle (3rd cubicle)  
o No of beds: 8 
o No curtains: 12 
o Available Nursing counter and Head nurse office: yes (15 staff members including 
nurses and supporting staff) 
o Visitors allowed: Yes, (12:00-13:00 and 17:00-19:00 every day)  
o Additional cubicle for 3rd phase of study: 2nd cubicle, 4 beds, 4 curtains 
 
Material Requirement: 
1. Antimicrobial coating (C16): 100 Liters/ every 3rd week (for each phase) 
2. Prepare duplicate Agar plates of 
a. Chromagar MRSA: Selective media for MRSA (ca. 4000 plates) 
b. TSA (Tryptic soya agar): for total bacteria count (ca. 4000 plates) 
3. Prepare of neutralizing solution: 20 liters 
4. Preparation of Polywipe sponge: 2000 (40 boxes) 
5. Preparation of buffer solution for dilution (5 liters) 
6. Labelling of Agar plates (ca. 8000 plates) 
7. Drying of Agar plates at room temperature  
8. Autoclave for Sterilization after enumeration  
 
Study Status: (Completed) 
Summary 
 Submission of study protocol to ethical review committee: June 2017 
 Approval of clinical trials by Research Ethics Committee (Kowloon Central/Kowloon East): 
Aug 2017 

2 
 
 Completion of background/pilot study: Oct 2017 
 Completion of data collection in three phases: June 2018 
 
Sampling Duration, Time Frame, and work plan: 
 
 
Team Members: 
 
 
 
 
 
 
 
 
 
 
Background 
/Pilot Study 
Survey 
Observation 
Period 
(1st 
Data 
Set/Phase 1 ) 
Washo
ut 
Survey 
Observation 
Period 
(2nd Data Set/ 
Phase 2) 
Wash
out 
Survey 
Observation Period 
(3rd Data Set/ Phase 3) 
8 weeks 
4 weeks 
4 weeks 
3 week 
2 Week  
4 weeks 
3 week 
 2 week 
4 weeks 
04 Sep -30 Oct 
(2017) 
31 Oct –  
28 Nov 
(2017) 
01 Dec - 30 Dec 
(2017) 
1st Jan - 05 Feb  
(2018) 
06 Feb – 08 Mar 
(2018) 
26 Mar – 30 Apr 
(2018) 
22 May – 20 Jun 
(2018) 
  
8 curtains from 
Male  
12 curtains from 
Female Cubicle 
  
50% coated curtain,  
50% standard 
curtain  
  
  
12 Curtains from 
Male Cubicles  
12 Curtains from 
Female Cubicle 
  
50% coated curtain,  
50% standard 
curtain  
  
  
16 Curtains from Male 
Cubicles  
16 Curtains from Female 
Cubicle 
  
50% coated curtain,  
50% standard curtain  
  
  
No of samples: 480 
  
  
  
No of samples: 576 
  
  
  
No of samples: 768 
HKUST 
1. Prof King Lun Yeung (Principal Investigator) 
2. Prof Joseph Kwan (Co-Investigator) 
3. Dr. Farid Awais (PhD Student) 
4. Dr. Chang Qing (Post Doc) 
5. Mr. Bryant (MSc Student) 
6. Ms. Sylvia (MSc Student) 
7. Ms. Vacentia (PhD student) 
8. Mr. Robben (Research Assistant) 
9. Ms. Song xizi (Research Assistant) 
 
Kowloon Hospital 
1. Dr. Dominic Tsang (Co-Investigator) 
2. Dr. Christopher Lai (Co-Investigator) 
3. Ms. Yeung Kin Yuk (ICT Nurse) 
4. Mr. Kennedy Tse (ICT Nurse) 
5. Ms Mary Tse (Core-lab In-charge) 
6. Ms Kari Hung (Core-lab In-charge) 
7. Ms Mo Mei Mei (Ward Manager) 
8. Mr. H K Tsui (Media Preparation)  

3 
 
Brief Summary of Project: 
This project aimed to study the use of the multi-level antimicrobial coating in a working hospital 
environment. Patient privacy curtains from a public sector hospital were coated and installed in 
rehabilitation ward in comparison of normally washed curtains in the same setting and compared 
the mean reduction on both control and treatment end to assess the effectiveness of coating 
against hospital acquired infections including MDROs. 
Detailed Description: 
[1] A multi-level antimicrobial coating was produced in the HKUST laboratory using the newly 
developed staged flow micromixing to prepare contact-killing and anti-adhesion coating made of 
US-FDA approved polymeric materials. The process was optimized to scale-up the production to 5 
liters per hour. 300 liters of the multi-level antimicrobial coating was prepared for the study for a 
total of 24 weeks as three liters of the coating was needed for one patient privacy curtain. 
[2] The study was conducted in the rehabilitation ward of the Kowloon Hospital including both 
male and female cubicles. It was carried out in three stages with each stage consisting of survey 
and a four weeks’ observation period, separated by three weeks’ washout period. In the 
rehabilitation ward of Kowloon Hospital, a set of male and female cubicle was recruited for the 
study after getting maximum number of bacterial contamination on patient privacy curtains in 
pilot study of 8 weeks. Each cubicle had 12 curtains besides admitted patients where all the 
samples are collected. 
[3] Environmental sampling was carried out using sponge swab on the surfaces of the patient 
privacy curtains.  The total bacteria count and quantitative isolation of MRSA was done using 
established protocols. The total bacteria count provides a quantitative measure of surface 
cleanliness, while the MRSA count was indicative of the risk of contact transmission from 
contaminated surfaces. 2-4 weeks survey provided control data on the cleanliness of patients 
privacy curtains in terms of total bacteria and MRSA counts. 
During the study period, the Kowloon Hospital/Queen Elizabeth Hospital infection control team 
monitored MDROs regularly as part of their routine operation. The procedure and schedule was 
followed strictly the infection control protocol. All infection control measures implemented after 
isolation of MDROs were followed according to the hospital’s usual practice as advised by the 
infection control team. In the study, the identification of the organisms in patients more than 48 
hours after admission without prior isolation of the organisms in clinical or screening specimens 
was defined as nosocomial.  
[4] The investigators demonstrated a cross-over intervention study. In the first stage of study, half 
of the patient privacy curtains were considered as treatment (antimicrobial coated) and the other 

4 
 
half of the curtains as control in the same setting in a cubicle. As the study was double blind, so 
coding was done to identify the treatment as control curtains. 
[5] Sample were taken from eight highly touched areas of 50x50 cm² on weekly bases for three 
consecutive weeks on 7th day of first installation. On each period/phase 480, 576 and 786 samples 
were collected accordingly using the developed sample protocol. In total, the investigators 
collected 1824 samples from 76 patient privacy curtains in which 912 (50%) were control curtain 
and 912 (50%) are antimicrobial coated curtains.  
[6] Healthcare workers from the participating wards were assessed for their acceptance of the 
multilevel antimicrobial disinfectant coating by way of a questionnaire. Additional reformulation 
may be necessary to increase the acceptability of the coating technology to the healthcare 
workers. 
[7] For the bacteria count, duplicate plates of TSA (total bacteria count) and Chromagar MRSA 
(selective agar for MRSA detection) were used for enumeration. CFU/m² is calculated after 48 
hours’ incubation at 37C. Data was analyzed using SPSS V.21 to assess the effectiveness of the 
coating in reducing the contamination level of the surface. The total bacteria count on the patient 
privacy curtains was compared between the control and treatment group using Mann-Whitney 
test and T-test. ANOVA analysis allowed the comparison of different periods of study of phase 
wise as well as week wise. The significance of the statistical test is defined to have a P value <0.05. 
Study Design: 
Interventional cross-over study 
Study Objectives 
1) To compare the antibacterial effect of in use antimicrobial coated patient privacy curtains with 
standard curtains: 
i) Total bacterial count over time 
ii) Time of first MDRO contamination  
iii) Percentage of MDRO contamination  
2) To assess healthcare worker’s acceptance of the multi-level antimicrobial coating.  
Inclusion Criteria 
For the clinical setting of the allocated ward with a prior history of high MDRO (preferably MRSA) 
prevalence is included. 
Exclusion Criteria 
For the clinical setting of the allocated ward with a prior history of low MDRO prevalence is 
excluded. 

5 
 
Primary Outcome Measure: 
 
1. Change in total bacteria count and MRSA in control vs treatment patient privacy curtains 
To quantify the effectiveness of antimicrobial coating, percentage change (both in log and linear 
scale) in mean bacterial count (CFU/m2 units) in control versus treatment curtains is used. The 
data was collected in 3 phases of 4 weeks each, so the time frame used is representative of the 
complete observation period.  
[Time Frame: 12 weeks] 
 
2. Durability of antimicrobial coating in affecting bacterial load amongst treated patient 
privacy curtains 
Change in bacterial load amongst treatment curtains is observed as a function of time during each 
phase of the data collection period (for 4 weeks). In total, data was collected in 3 phases of 4 weeks 
each, so the total observation period is 12 weeks and timeframe of each frame is 4 weeks. 
3) [Time Frame: 12 weeks] 
 
Secondary Outcome Measures: 
 
1. Agreement/disagreement of hospital staff regarding technology acceptance and 
adaptation  
A survey was conducted using a self-structured questionnaire to get feedback from the hospital 
staff regarding their acceptance of the technology. The questionnaire contained questions 
regarding the physical (smell, appearance and feel) aspects of the coating as well as general 
approval/disapproval based on their experience with the technology. A scale of -5(worst) to 
+5(best), with 0 representing neutral was used, representing a dimensionless quantity based on 
staff's personal preferences. Mean of the user's response to each question was used for 
quantification. The users observed the technology during the entire 12 weeks of the study period 
(during all 3 phases of data collection). Users were give a 4-week time period to submit their survey 
responses. 
[Time Frame: 4weeks] 
 
 
 
 
 
 

6 
 
 
Protocol: 
1. Curtain receiving, coating, coding, and transportation: 
1. Every 2nd week, HKUST team received 26 washed (routinely cleaned) curtains from 
rehabilitation ward linin room on ground floor. 
2. 13 curtains were kept in a designated cabinet in the linin room at 3rd floor Rehabilitation 
ward 3B. These 13 curtains were coded according to assigned numbers as control curtains.  
3. 13 remaining washed curtains out of 26 were transported to HKUST by using three large 
luggage bags 
4. As each curtain absorbs approx. 3 Liters of the coating solution, so our team had ensured 
availability of 30 liters of C16 coating material on completion of each phase.  
5. Our team preferably prepared fresh C6 coating and diluted C6 in tab water at the time of 
coating to prepare C16.  
6. We had three 95 Liters capacity big containers, that were used to coat the curtains in HKUST 
premises during Pilot study.  
7. The best practice to coat the curtain was dipping method (dip a dry curtain in a filled 
container of C16 coating). 
8. Curtains were soaked/dipped for 30 minutes in coating material to absorb properly and 
uniformly.  
9. After soaking, curtains were squeezed gently to remove extra solution/liquid and 
transferred to clean and dry container.    
10. 13 wet coated curtains were transferred to laundry to dry as following: 
a. Hot air of 65oC for 30 minutes.  
Arms 
Assigned Interventions 
Active Comparator:  Regular Patient privacy curtain  
 
Control arm is a regular patient privacy curtain, washed 
and dried in hospital laundry using commercially 
available sodium hypochlorite and hydrogen peroxide. 
Combination 
Product: 
Regular 
Patient privacy curtain  
 
Laundered curtains, used in the 
hospital, coming from the hospital 
inventory. 
Experimental Comparator: Antimicrobial Coated 
Curtains 
 
Treatment arm is antimicrobial coated curtains that are 
coated by dipping method, dried and provided to 
nursing/supporting staff to change after every 3-4 
weeks. 
Combination Product:  
Regular patient privacy curtains  
 
Antimicrobial Coated curtains  
 
 

7 
 
 
b. Cold air of 20oC for 3-5 minutes to reduce the temperature of curtains.  
11. 13 dry, coated curtains were brought back to the linen room of rehabilitation ward, coding 
was done according to the assigned number to keep the study blind. Only principal 
investigator has the knowledge of the factitious codes to keep study double blind.  
12. All the curtains (13 coated and 13 uncoated) were prepared for installation in 1 week 
including receiving, transportation, coating, drying, and coding during pilot study.  
13. Drying protocol amendment 
a. Drying protocol was amended due to shedding of coating in heavy circular 
mechanical motion in laundry dryer. For this purpose, curtains were kept on room 
temperature for overnight, and next morning when there was no apparent dipping, 
they were shifted to walk in incubator of Pathology lab at 50oC for 24-36 hours for 
best drying results. 
b. Drying in HKUST premises was difficult with minimum resources, heavy weight and 
humidity issue along with transportation.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
           Flow chart from curtain receiving to storage and installation 
 
*1 extra pair of curtains for control and treatment end was kept as a back up 
 
26 washed curtains received from 
Rehab Ward before starting new 
Phase   
13 curtains were kept in linen 
room cabinet after coding 
13 curtains were transferred to HKUST 
for coating/coated in KH Core lab 
After coding, 13 dry coated 
curtains were transferred to 
linin room for further action 
Installation of 6 coded, coated and 
6 coded uncoated curtains in male 
and female cubicle respectively, 
total 24 in male and female cubicle 

8 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2. Curtain installation: 
1. Every 3rd week, our team changed the curtains from 2 cubicles (1 male and one female) 
according to curtain changing policy of hospital.  
2. At the start of every phase of study, following the standard protocol; after taking official 
consent from ward manager we changed the curtains at once from both cubicles.  
3. There were two types of curtains clippings, with metal ring and cloth strips so that curtains 
were changed according to the type of clips/ring.  
4. As there was the capacity of 12 curtains in one cubicle, so six curtains were coated and six 
uncoated. The sequence was alternative as one coated next uncoated and so on. After 
installation, we informed ward manager about completion of curtain hanging in the 
designated ward and took first sample at day 7 because we gave sufficient time to curtains 
to be contaminate in hospital environment. 
5. There was a backup pair of the curtain in case of need to change curtain due to spoilage, 
vomitus, blood or MDRO diagnosed the patient. Staff was informed to notify our team 
about the date and reason of curtain changing.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fig 1. Illustration of coating in container, method of coating by dipping method, 
squeezing, transportation and drying of patient privacy curtains 

9 
 
 
 
 
 
 
 
 
 
 
 
 
Fig 3. Illustration of 8 sampling location on a curtain received from Rehabilitation ward of KH, 
Designated 50x50cm² area were sampled following the protocol 
 
 
 
 
 
 
 
 
 
 
Fig 2. Illustration of curtains installation in cubicles as one control other treatment showing 
matched paired randomization 
 
 
 
 
Environmental Sampling: 
1. Sampling Frequency: Curtains were sampled on a weekly basis for the total duration of 3 
weeks. So, every curtain was sampled three times during complete sampling duration. First 
7 days was the time of exposure to contaminate leading with next 3 weeks of sampling.  
2. Sampling Area: Each curtain was sampled for eight areas for the size of 50x50cm² each. 
Four areas from top side starting from patient’s head side to toe side on the bed, and four 
areas from bottom side moving from toe to head side. As the size of curtain varies from 
430cm to 480cm in length, for the best results after pilot study, we calibrated 8 areas 
keeping 50 cm from above, 37cm from lateral margins and 57-70cm in between.   
 
 
 
 
 
 
 
Area 1: Upper Head side  
 
Area 2: Upper 2nd area 
 
Area 3: Upper 3rd area 
 
Area 4: Upper Toe Area 
 
Area 5: Lower Toe Side  
 
Area 6: Lower 2nd area 
 
Area 7: Lower 3rd area 
 
Area 8: Lower Head Area 
Coated 
uncoated 
uncoated 
Coated 
Coated 

10 
 
3. Sampling Side of the curtain: Sampling was done from the inner side of the  
curtain, (inner side was more exposed to the risk of contamination as a frequent touch of the 
patient on the bed, nursing staff, cleaning staff, monitoring staff, attendants, and doctor).   
4. Sampling material: Polywipe sponge were used to sample 50x50cm² area on the curtain.  
5. Sampling technique: Both sides of a sponge were used by swabbing on the curtain. Holding 
the sponge from the middle of one side with the right hand, keeping vertically, swab area 
starting from upper left margin towards the upper right margin of 50x50cm² area from one 
side of the sponge. The same method was used swabbing from right to left side with other 
side of the sponge. Sampling was done gently, slowly and softly by not repeating the swab 
to   sampled area.   
6. Sampling frame: 50x50cm² frame of plastic covered with a disposable plastic sheet was 
used as back support for smooth sampling and accurate measurement. Every time, 
sterilized plastic was removed and new sheet was used to reduce the chance of microbial 
spread or false positive result on control and treatment arm of the study 
Sample size calculation using G-power 3.1.9.2 
In our previous study carried out in orthopedics wards, a total of 2249 samples were taken from 
hospital surfaces over a study period of 1 year. The following was the mean and standard 
deviation of log total-bacteria-count in the previous study.  
 
 
Group Statistics 
Type (1/2) 
N 
Mean 
Std. Deviation 
Std. Error Mean 
log (CFU/m²) 
treatment 
1130 
4.13126 
.544325 
.016193 
control 
1119 
4.32627 
.531846 
.015899 
         Basic information of previous field study in orthopedic ward 
 
Assumptions: 
1. 
The sample taken may have a higher standard deviation than the previous study. SD assumed 
to be 1log. 
2. 
0.21 log reduction on the total bacteria count on the bed partition curtains was assumed. This 
was based on the difference of the control and the treatment group in the previous study. 
 
t tests - Means: Difference between two independent means (two groups) 
Analysis: 
A priori: Compute required sample size  
Input: 
Tail(s) 
= One 
 
Effect size d 
= 0.2000000 
 
α err prob 
= 0.05 

11 
 
 
Power (1-β err prob) 
= 0.95 
 
Allocation ratio N2/N1 
= 1 
Output: 
Noncentrality parameter δ 
= 3.2924155 
 
Critical t 
= 1.6462631 
 
Df 
= 1082 
 
Sample size group 1 
= 542 
 
Sample size group 2 
= 542 
 
Total sample size 
= 1084 
 
Actual power 
= 0.9500669 
 
Hence a minimum of 1084 specimens were adequate for our study. To best fit the wards size and 
sampling schedule, we reckon a sample size of 1800 was best suited for our study. 
 
 
Safety Training for investigators: 
Infection control team of Kowloon Hospital provided safety training to all participants of research 
team. Infection control nurse described the safety measures according to hospital safety guidelines. 
After full day training, participants were assessed by written question about using of person 
protective equipment including mask, gloves, gowns, and caps. All successful participants were 
allowed to become a part of investigating team. Ward managers in pathology and rehabilitation 
wards also explained about emergency exits and dealing with emergency in case of any accident 
during working hours. Finally, all participants were provided with staff access cards with validity 
till completion of study (June 30, 2018).   
Pre-sampling arrangement: 
1. 
Preparation of neutralizing solution: 
a. 
Neutralizing solution: 1-liter preparation, (Polysorbate/Tween 80, 30 g/L; Saponin, 30 
g/L; and lecithin, 3 g/L; pH 7.0). 
b. 
As normal preparation, pH was 5-6, so we used NaOH as a base to bring pH at 7.  
c. 
According to sampling plan the required 20 liters neutralizing solution was prepared on 
weekly basis by keeping it sterilized to prevent contamination that might gave false positive 
results.   
2. 
Preparation of spreading beads: 
a. 
For 100µl solution spread on agar medial on agar plates, we poured 5-10 beads on each 
plate and shake gently until all liquid media spread and absorbed.  
b. 
All the beads were pre autoclaved and sterilized to prevent contamination.  
3. 
Pouring of neutralizer into sponge containing zip bags: 
a. 
10ml of neutralizing solution was poured into sterilized empty zip plastic bags.  
b. 
We used a new 10ml pipette glass tube and electric pipette to pour neutralizer on 

12 
 
operation bench in KH core lab, before sampling.  
c. 
The team dealing with neutralizer pouring was operating carefully 
to measure the appropriate amount, prevent spoilage and maintain 
hygiene and safety.   
d. 
Zipped bags were opened minimally, to reduce the chances of 
contamination.  
4. 
Labelling: 
a. 
All the bags were labelled before sampling 
b. 
Labelled the bags with bed number, coding, sampling area 
5. 
Transportation Containers: 
a. 
Sampling material containers were have following items to bring in rehabilitation ward 
(1 set for male and similar another set for female cubicle) for 1-time sampling: 
 
Polywipe sponges 110, (required 96, extra 14 in case of contamination/ fall in floor 
during sampling) 
 
 Plastic gloves (blue colored), already given in polywipe sponge box 
 
Plastic holing clips, to identify measured area 
 
Measuring tapes, to measure 50x50cm² area as a sampling area 
 
Neutralizing solution in zipped labelled bags 110, (required 96, extra 14 in case of 
contamination/ fall in floor/ leakage) 
 
Autoclave medium size bag to put used gloves used sponge and wrappers of sponge  
 
 
Sampling Arrangements and methods: 
 
1. Sampling Cubicles (Location): one male cubicle (3rd cubicle) and one female cubicle were 
allocated for this study after pilot study results. These were located on 3rd floor or 
rehabilitation building (ward 3B).  
2. Sampling time: Every visit, sampling was started at 8:30 am and finished till 12:00 pm.  
3. Following the Rules: Sampling team had to follow the rules of Kowloon Hospital in rehab 
wards. The team had to sample curtains smoothly and quietly to minimize disturbance to 
working staff as well as patients in beds. The team was not allowed to encroach patient 
treatment or investigations/ file to keep the confidentiality.  
4. Gowning for safety: All the members were gowned properly by wearing personal protective 
equipment (disposable gown, gloves, mask and head cover). For gowning, individual 
followed the step mentioned in safety training, as all sampling taking persons had gone 
through safety training by infection control team of Kowloon Hospital.   
5. Sample taking notification and Consent: Team was notifying ward manager/ ward in-charge 
about sampling plan and take verbal permission to proceed.  
6. Sampling Teams: In the female cubicle, two female team members took samples. One 

13 
 
member was take a sample of swabbing the area; other was helping to provide gloves, 
sponge, identification of appropriate area, calibrate the size and provide support by 
holding the frame of 50x50cm². The same sampling protocol was adopted in a male cubicle 
where male team members were taking the samples.  
7. Safety precaution:  
Following safety measures were accomplished before and during sampling:  
a. Before sampling, clean the hands having gloves with available disinfectant. 
b.  Put plastic disposable gloves and take out sponge from its plastic packing.  
c. Again disinfect plastic gloves and let it dry for few second.  
d. Hold the sponge firmly from one side and keep sampling designed 50x50cm² area. 
e. Don’t touch any other, other area holding the sponge, and prevent felling down on 
contaminated floor 
f. In case, sponge was touch with other surface or fell on floor, please discard that 
sponge and resample the same area with a new sponge 
8. Sample preservation: 
a.  After proper sampling, we put the sponge in zipped plastic bag containing 10 ml 
neutralizing solution quickly to reduce chance of contamination 
b. 2nd team member opened the zipped bag for sampling member for convenient 
proceeding 
c. The 2nd team member zipped up the sampling bag aseptically, confirmed the 
correct labeling, and kept in an aseptic container.  
d. 2nd team member also mixed the neutralizer gently with a sampled sponge  
e. Sponge sample in neutralizing solution bag were kept in a safe container until all 
the sampling was not completed.  
9. Degowning and Transportation:  
a. After completion of all samples from patient privacy curtains, the team were 
degowning according to the protocol by removing PPE. 
b. Transportation boxes were brought back to pathology core lab of KH from 
rehabilitation ward immediately after completion of sampling. 
c. Transportation containers were brought back by holding with one hand gloved 
another hand without gloves according to infection prevention policy 

14 
 
 
 
Fig 4. Illustration of sampling method on curtains in Kowloon Hospital, preservation and inoculation 
on TSA and Chromagar plates 
 
 
 
 

15 
 
Post Sampling Procedures: 
 
1. Arrangements of Agar Media Plates: Queen Elizabeth Hospital’s (QEH) Media preparation 
unit prepared TSA and Chromagar MRSA agar plates according to needs of this research.  
a. Principal investigator was notifying Mr. Tsui (coordinator for media preparation on 
QEH) two weeks ago about the preparation of required media plates.  
b. All the prepared media was preserved at 3-4oC in QEH. Media plates boxes were 
labelled as HKUST-TSA and HKUST-MRSA plates in different batches.  
c. Prepared boxed were transferred to Kowloon Hospital’s cold room for long term 
use as well as prevention from contamination.   
d. For the media preparation, sampling team coordinated by emails or meet them in 
person if there was any change in requirement.  
2. Agar plates Standardization: As the agar plates were kept at lower temperature (3-4oC), 
agar plates should normalize to normal room temperature as recommended. We kept out 
the agar plates on the desk before going for sampling, and in the meanwhile, plates were 
ready to use after 3-4 hrs.  
3. Unboxing and labelling of agar plates: All the prepared plates were packed in boxes, so 
before using the plates, team was unboxing, calculating and separating two type of media 
plates. Each plate was labelled as 
a. Code, i.e., 1040 
b. Sampling area number (1-8) 
c. Plate number (first or duplicate) 
d. Location (Male/ Female) 
             i.e. (M-1040-4-2) 
 
   Male-code 1040- Area 4- sample 2 
4. Sample inoculation area: Samples were inoculated on the desks in Kowloon hospital 
pathology core lab. All the team members were participating in this procedure following 
safety measure, wearing PPE. 
5. Mixing of Sponges containing neutralizer bag: Before taking 100µl of a neutralizing solution, 
it was compulsory to mix sponge very well so that all suspected microbes would come out 
from the sponge into the solution. Mixing was gentle, continuous and for the period of a 
minimum 1 minute.  
6. Dilution in PBS: 100µl of neutralizing solution was diluted in 900µl of PBS, mixed well and 
then100µl was put on agar plated to inoculate. This was performed for TSA plates because 
bacterial load was high and plates were unable to read.  
7. Inoculation Procedure:  
a. 100µl of well mixed neutralizing solution was dropped by using 100 -200 µl pipette 
with sterilized pipette tube on Chromagar MRSA plates and spread homogenously 
(M-1040-4-2) 

16 
 
 
 
 
 
 
 
 
Fig 5. Illustration of incubation, enumeration and decontamination with 
autoclave in pathology ward of Kowloon Hospital 
by sterilized beads by gentle shaking 
b. 100µl of solution from PBS mixed solution was dropped by using 100 -200 µl pipette 
with sterilized pipette tube on TSA plates and spread homogenously by sterilized 
beads by gentle shaking 
c.  All the plated were shaked well in clock wise circular motion for 1-2 minutes for 
homogenous spread 
d. When there was not a visible solution on agar plates, opened the agar plates and 
took out beads in autoclave bag respectively.  
e. All inoculated agar plates were finally transferred to an incubator and kept for 
48hours at 37oC.  
f. Inoculated plates were transferred in a specified labelled container to prevent any 
infection spread or spoilage 
 
 
 
 
 
 
 
 
 
 
 
8. Cleaning inoculation area: All the desks were cleaned with bleach (NaClO) or other 
available disinfectant, recommended by hospital infection control authority using cotton 
wipes. All touched surface, including inoculated transfer container, was cleaned with 
recommended disinfectant.  
9. Results: 
a. At 48hrs, all the plates were counted to calculate CFU/m². 
b. TSA (Tryptic Soya Agar) was used to count total bacteria. The colonies were pale to 
yellow in the circular pattern. The average number of colonies was 50-250 on TSA 
plates as PBS diluted factor. 
c. Chromagar MRSA was used a selective media to check MRSA. MRSA appeared as 
Purple to Pink rounded colonies. In case of yellow or blue colonies growth on media, 
we did not count those unknown gram positive bacteria. 
d. Counted plated were wrapped with plastic tape and put in autoclave bags to 
autoclave clinical waste. KH staff helped to autoclave used plates for safety 
measures.   

17 
 
e. After discarding counted plates safely, the counting area, material touched or 
exposed was cleaned using standard disinfection. 
f. Results were saved in an official register for keeping the data in privacy  
g. All the data was uploaded to excel sheet and analyzed for a bacterial reduction on 
comparative ends of control and treatment curtains.  
h. Weekly, data was assessed and shared with Prof King Lung Yeung along with a 
central continuous excel sheet with raw data.   
i. HKUST team also shared the results with KH and QEH research team on a monthly 
basis as a summarized report and brief power point briefing session in the 
conference room of KH after coordination.  
 
Data Analysis: 
The duplicate system in total bacteria count helped to monitor the validity of the data point. 
Logical elimination of plate count was determined while comparing the bacteria morphology 
of the first plate with the second plate. If the bacteria morphology was not consistent, the 
plate with more bacteria was eliminated, and the plate with a lower value was taken due to 
the chance of contamination on a non-selective agar plate.  
The Colony Forming Unit (CFU) obtained on the duplicated plates was averaged, and the CFU 
per unit area was calculated. CFU per unit area was allowing the comparison of microbiological 
contamination of the sampled surface. With the dilution factor of the samples, the Total 
bacteria count (TBC) was determined. The microbiological contamination level of an item was 
represented by the CFU/unit area of the item.  
CFU on Müller-Hinton Agar represents the total aerobic bacteria count. By dividing the CFU 
with the area sampled, CFU/m2 was obtained. Data points that did not contain any CFU count 
were assumed to have 0.5 CFU. The assumption was made based on the minimum detection 
value that can be obtained. 
 
All analysis was carried out using Statistical Package for the Social Sciences for Windows, 
version 25.0 (SPSS, Inc., Chicago, IL, USA) to analyze the effectiveness of the coating in reducing 
the contamination level of the surface. The total bacteria count on the patient partition 
curtains was compared to the control and treatment group using Mann-Whitley test and T-test. 
Chi-square test and Fisher’s exact test were also used to compare categorical variables such as 
the percentage of MRSA. Parametric test was carried out to evaluate the cleanliness baseline 
in each of the wards before and after treatment. ANOVA analysis allowed the comparison of 
different periods of study and the differences among wards. Median time to first 
contamination (days) of MDRO for each curtain type was compared using the Wilcoxon rank-
sum test. The significance of the statistical test was defined to have a P value <0.05.  
 

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Healthcare workers from the participating wards were assessed for their acceptance of the 
multilevel antimicrobial disinfectant coating by way of a questionnaire. Additional 
reformulation may be necessary to increase the acceptability of the coating technology to the 
healthcare workers. 
 
Ethical Concerns: 
The study involved an evidence-based and data guided intervention that was designed to bring 
about prompt improvement in the quality and effectiveness of healthcare deliveries in 
hospitals. The patient data collected by ICT did not involve identifiable personal data; and was 
regarded as part of standard care hence no further consent seeking was deemed necessary. 
The publish of study results is on the basis of the principle of justice since the study findings 
could direct limited resources pertaining to infection control and help to further reduce cross-
transmission of infections in hospital setting. 
Sampling and intervention were solely performed on the curtains and the care of the patient 
is not affected. All the laboratory forms and data files did not contain personal information, 
and only aggregated data was used in the final report or publications.