Center Of Excellence For Antibody Research (CEAR) Department Of Social And Environmental Medicine Faculty Of Tropical Medicine Mahidol University

Dear Manager of See-Sky Company Limited

As you sent the See-Sky lamp device, model LS-1888A, to CEAR to test its antibacterial efficacy, CEAR has tested it against the following bacteria: 1. Staphylococcus aureus 2. Pseudomonas aeruginosa 3. Klebsiella pneumoniae

By testing the efectiveness of inhibiting bacteria, all 3 pathogens were performed in an acrylic simulated cabinet used to test air purifiers for inhibiting bacteria. It is a closed rectangular cabinet, size 0.8 meters wide, 1.5 meters long and 1.5 meters high, with a volume of 1.8 cubic meters, with a bacterial sprayer placed in the middle of the cabinet. And place the bacterial culture dish in 20 diferent locations around the cabinet and install the See-Sky lamp, model LS-1888A in front, 1 foot from the bacterial sprayer, 1 foot from the floor and 2 feet away from the sprayer. from the cabinet wall, 1 ft. each side, and then switch on the bacterial aerosol sprayer (each) at a concentration of 1 x 106 CFU/ ml and switch on the See-Sky lamp, model LS-1888A (respectively) All 20 bacterial culture dishes were taken to culture the bacteria and count the number of bacteria. The same experiment was performed but the See-Sky lamp, model LS-1888A was not switched on. Both types of experiments were performed 3 times each, and colony content from both experiments was compared. Then calculate the diference as a percentage (%), it will be the ability to reduce the amount of bacteria of the See-Sky lamp, model LS-1888A as a percentage (%). See-Sky brand lights, model LS-1888A, can reduce the amount of bacteria in the air as follows.

• The maximum reduction in Staphylococcus aureus was 99.9% (1 plate), 99.8% (1 plate), 99.7% (1 plate), 99.3% (1 plate) and 99.1% (1 plate), and the mean infection was 94% (mean of all 20 plates). ) after turning on the See-Sky lamp, model LS-1888A for 60 minutes.
• The highest reduction of Pseudomonas aeruginosa was 99.9% (1 plate) 99.5% (4 plates) 99.2% (1 plate) 99.1% (2 plates) and the average was 94.9 % (average of all 20 plates) after turning on the See lamp. -Sky Model LS-1888A for 60 minutes
• The maximum reduction in Klebsiella pneumoniae was 100% (1 plate), 99.8% (2 plates), 99.7% (1 plate), 99.5% (1 plate) and 99.1% (1 plate), and the mean reduction was 96.8% (mean of all 20 plates). ) after turning on the See-Sky lamp, model LS-1888A for 60 minutes.

Therefore, please be informed accordingly.

Assoc. Prof. Dr. Pongram Ramsut, MD.

Head of the Center of Excellence for Antibody Research

Head of Department of Social and Environmental Medicine

Research Report

Research to test the efficiency of killing bacteria in the air of the See-Sky lamp device, model LS-1888A, according to the standards of the Department of Medical Sciences, Ministry of Public Health.

Bacteria used for Testing:

1. Staphylococcus aureus

2. Pseudomonas aeruginosa

3. Klebsiella pneumoniae

Bacterial Inhibition Test Chamber

The efficacy of all 3 types of bacteria was tested in an acrylic simulation cabinet. It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. And place the bacteria culture dish at 20 different locations throughout the cabinet (Figure 1) and install the See-Sky lamp, model LS-1888A in the center of the ceiling above the test cabinet. which are 1.5 meters high from the floor, then turn on the switch for each bacterial aerosol sprayer (respectively) at a concentration of 1 x 106 CFU/ml mixed with 200 ml of distilled water and turn on the lamp, See-Sky brand, model LS-1888A as At 60 minutes, 20 bacterial culture dishes were taken to culture the bacteria, and the number of bacteria from all 20 dishes was counted. The same experiment was performed but the See-Sky lamp, model LS-1888A was not switched on. Both types of experiments were performed, each 3 repeats, following the standard method previously performed (Sirikul et al, 2006), and comparing colony counts from the two trials. Then calculate the difference as a percentage (%), it is the ability to reduce the bacteria content of the See-Sky lamp model LS-1888A as a percentage (%).

- Figure 1. An acrylic simulation cabinet used to test See-Sky lamps, model LS-1888A in antibacterial activity. which is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, by placing the bacterial sprayer in the middle of the cabinet (red circle) and placing the bacterial culture dish at various locations throughout 20 cabinets (number 1 - 20) as follows:

1) The back side of the bacterial inhaler, from top to bottom, left side plate number 1-3, right side plate number 4-6
2) The front side of the bacterial inhaler from top to bottom, left side plate number 7-9, right side plate number 10-12.
3) On the floor around the bacterial nebulizer The rear side of the plate sprayer No. 13-15, the side of the plate sprayer No. 16-17, the front side of the plate sprayer No. 18-20.

Method of testing Spray only bacteria without turning on the lamp, See-Sky brand, model LS-1888A (Control)

- Prepare bacteria Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae (respectively) were cultured on agar medium. Then incubated at 37 °C for 18-24 hours, after that, 1 colony was inoculated into liquid medium and then incubated at 37 °C, 200 rpm., 12-14 hours.

- Clean the sterile in the simulation cabinet with Virkon solution and 70% alcohol and turn on the sterile UVC lamp after 1 hour of cleaning.

- Bacteria that were incubated overnight in liquid medium were used to measure turbidity. The turbidity of the culture was 2.37 x 10 7 CFU/ml.

- Dilution from 2.37 x 10 7 CFU/ml. to 1 x 10 6 CFU/ml.

- Aspirate the sterile dilution to 1 x 10 6 CFU/ml. Then come 200 μl. Put in sterile distilled water 200 ml. Then pour it into the nebulizer. Then place the bacterial nebulizer in the middle of the cabinet (Figure 1).

- Place all 20 culture medium plates at different points as shown in Figure 2.

- Plug in the plug, turn on the switch to allow the bacterial nebulizer to work. Then wait for the inhaler for 1 hour. Turn off the switch to stop the bacterial inhaler.

- All 20 plates were placed in bags and incubated at 37 °C for 12-14 h, and the plates were taken to count the number of colonies of each bacterial species (respectively).

Bacterial Mist Spray Test along with the See-Sky lamp, model LS-1888A, in the test cabinet

- Prepare bacteria Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae (respectively) were cultured on agar medium. Then incubated at 37 °C for 18-24 hours, after that, 1 colony was inoculated into liquid medium and then incubated at 37 °C, 200 rpm., 12-14 hours.

- Clean and sterile the simulation cabinet with Virkon solution and 70% alcohol and turn on the UVC disinfection lamp after cleaning for 1 hour, keep the cabinet sterile.

- The cultured culture was incubated overnight in liquid medium to measure the turbidity (Optical density; OD) and the turbidity was 2.37 x 10 7 CFU/ml.

- Dilution from 2.37 x 10 7 CFU/ml. to 1 x 10 6 CFU/ml.

- Aspirate the sterile dilution to 1 x 10 6 CFU/ml. Then come 200 μl. Put in sterile distilled water 200 ml. Then place the bacterial nebulizer in the middle of the cabinet.

- Place all 20 culture medium plates at the different points as shown in Figure 1 and Figure 2.

- Install See-Sky lamp, model LS-1888A, placed in front of 1 foot from the bacterial sprayer, 1 foot from the floor and 1 foot from the cabinet wall in front and on each side (Figure 1 and Fig. 2)

- Plug in and turn on the switch for the See-Sky bacterial nebulizer and See-Sky lamp, model LS-1888A to work, then wait for the sprayer for 1 hour, turn off the switch to stop the bacterial nebulizer and See-Sky lamp, model LS-1888A

- Place all 20 plates in bags and incubate at 37°C for 12-14 hours, and then take the plates to count the number of colonies of each bacterial species (respectively).

Figure 2 shows a simulated acrylic cabinet used to test the air purifier in antibacterial action. By placing the bacterial nebulizer in the middle of the cabinet, place all 20 agar plates at various points as shown in Figure 1 and install the See-Sky lamp, model LS-1888A, placed in front of 1 foot from the bacterial nebulizer. 1 ft. from the floor and 1 ft. from the wall of the front and side cabinets, then plug in the power switch to allow See- Sky bacterial aerosol sprayer and lamp, model LS-1888A, model LS-1888A, then wait for the sprayer to complete 1 hour. Turn off the switch to stop the bacterial aerosol sprayer and See-Sky lamp, model LS-1888A, and take a plate to count the number of colonies of each type of bacteria (respectively).

Test Results

1. Bacteria Staphylococcus Aureus

1.1. Bacteria specific spray test Staphylococcus aureus without turning on the lamp, brand See-Sky Model LS-1888A (Control

Antibacterial efficacy test Staphylococcus aureus in an acrylic cabinet. It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. and place the bacterial culture dish at 20 different locations throughout the cabinet (Figure 1) and switch on the bacterial aerosol sprayer. Staphylococcus aureus at a concentration of 1 x 106 CFU/ml mixed with 200 ml of distilled water for 60 min. All 20 culture plates were cultured with bacteria and counted the number of bacteria from all 20 dishes by repeating the experiment 3 times.

The results of bacterial counting from all 20 plates and 3 trials are shown in Table 1.

The location where the highest number of bacteria was found was plate19, located in the center on the floor in front of the nebulizer, counting 4,112 and 2736. 2,112 colonies from Experiments 1, 2 and 3, respectively, with a mean of 2,950 colonies, and the site where the least number of bacteria was found was plate 4, located behind the right rear and at the top of the inhaler. Bacterial droplets counted 0, 0 and 1 colony from experiments 1, 2 and 3, respectively, with a mean of 0.33 colonies.

Table 1 compares bacterial colonies. Staphylococcus aureus from 20 counted plates after 60 minutes of bacterial spraying in a closed cabinet without the See-Sky lamp, model LS-1888A, under the same test 3 times.

1.2. Bacteria specific spray test Staphylococcus aureus by turning on the lamp, See-Sky brand, model LS-1888A.

Antibacterial efficacy test Staphylococcus aureus in an acrylic replica It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. and place the bacterial culture dish at 20 different locations throughout the cabinet (Figure 1) and switch on the bacterial aerosol sprayer. Staphylococcus aureus at a concentration of 1 x 106 CFU/ml with the See-Sky lamp switch on, model LS-1888A for 60 minutes, and the 20 bacterial culture dishes were taken to culture the bacteria. The number of bacteria from all 20 dishes was counted by repeating the experiment 3 times.

The results of bacterial counting from all 20 plates and 3 times are shown in Table 2. The location where the highest number of bacteria was found was plate 8, located in the upper left front of the nebulizer, counting 86 92. and 103 colonies from Trials 1, 2, and 3, respectively, with a mean of 93.7 colonies, and the location where the least number of bacteria was found was plate 17, located on the floor to the right of the bacterial aerosol counted nebulizer. 0, 0 and 0 colonies were obtained from experiments 1, 2 and 3, respectively, with a mean of 0 colonies.

Table 2. Comparison of bacterial colonies. Staphylococcus aureus from 20 counted plates after 60 minutes of bacterial spraying in a closed cabinet with the See-Sky lamp model LS-1888A on. The same test was performed 3 times.

1.3. Comparison of bacterial counts Staphylococcus aureus in open cabinets and unopened lamps, See-Sky brand, model LS-1888A

Table 3 is a comparison of the average values of bacteria in the See-Sky lamp, model LS-1888A, from Table 1, and the mean values of the bacteria in the See-Sky lamp, model LS-1888A. The values were taken from Table 2 and calculated the percentage reduction of mean bacteria in each of the 20 culture plates. The results are shown in Table 4 when comparing the percentage reduction of the mean bacterial Staphylococcus aureus from the petri dish at each point in the incubator of 20 plates showed that the petri dish with the highest bacterial reduction at 99.9% was plates 13, followed by 99.8%, plates 19, followed by 99.7%, plates 20, followed. with 99.3 % was plates 17 and 99.1 % was plates 14 (Table 4).

When counting the total number of bacteria from all 20 plates across the three tests before and after using the air purifier, there was a reduction in bacteria from 23,529 to 1403 colonies, representing a reduction of 22,126 colonies, representing a 94 reduction. % (Table 4)

Table 3 compares the mean colony counts of bacteria. Staphylococcus aureus from 20 counted plates after 60 minutes of bacterial spraying in an open cabinet with a See-Sky lamp, model LS-1888A.

Table 4 compares the percentage reduction of mean bacteria. Staphylococcus aureus at each point in the in vitro and a decrease in the total number of bacteria. Before and after using See-Sky lamp, model LS-1888A.

2. Pseudomonas Aeruginosa Bacteria

2.1. Spray test only for Pseudomonas aeruginosa bacteria without turning on the See-Sky lamp, model LS-1888A (Control).

Test of antibacterial efficacy against Pseudomonas aeruginosa in an acrylic simulated cabinet. It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. and place the bacterial culture dish at 20 different locations throughout the cabinet (Figure 1) and switch on the Pseudomonas aeruginosa aerosol sprayer at a concentration of 1 x 106 CFU/ml mixed with 200 ml of distilled water to At 60 minutes, all 20 bacterial culture dishes were cultured and counted the number of bacteria from all 20 dishes by repeating the experiment 3 times.

The results of bacterial counting from all 20 plates and 3 trials are shown in Table 5.

The location where the highest number of bacteria was found was plate19, located in the middle in front of the bacterial inhaler, counted 3988, 3100 and 3001. Colonies from Experiments 1, 3 and 2, respectively, with a mean of 3363 colonies, and the location where the least number of bacteria was found was plate4, located behind the right rear and at the top of the bacterial aerosol apparatus. 1, 3 and 4 colonies were counted from trials 2, 1 and 3, respectively, with a mean of 3 colonies (Table 5).

Table 5. Comparison of colonies of Pseudomonas aeruginosa bacteria from 20 counted plates after 60 min bacterial spraying in a closed cabinet without the See-Sky lamp, model LS-1888A, was performed 3 times the same test.

2.2. Spray test only for Pseudomonas aeruginosa bacteria with See-Sky lamp, model LS-1888A.

Test of antibacterial efficacy against Pseudomonas aeruginosa in an acrylic simulated cabinet. It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. Place the bacterial culture dish in 20 different locations throughout the cabinet (Figure 1) and switch on the Pseudomonas aeruginosa aerosol sprayer at a concentration of 1 x 106 CFU/ml with the See lamp switch on. -Sky, model LS-1888A for 60 minutes, then bring all 20 bacteria culture plates to culture bacteria. The bacterial counts from all 20 dishes were counted by repeating the experiment 3 times.

The results of the bacterial counts from all 20 plates and 3 trials are shown in Table 6. The location where the highest number of bacteria was found was plate7, located in the upper left front of the nebulizer, counting 101, 84 and 94. Colonies from Trials 1, 2 and 3, respectively, with mean counts of 93 colonies, and the location where the least number of bacteria was found was plate 17, located on the floor right behind the bacterial aerosol counted nebulizer. 1, 3 and 2 colonies from Trials 1, 2 and 3, respectively, with a mean of 2 colonies (Table 6).

Table 6. Comparison of colonies of Pseudomonas aeruginosa bacteria from 20 counted plates after 60 min bacterial spraying in a closed cabinet with the See-Sky lamp, model LS-1888A on, 3 times the same test.

2.3. Comparison of Pseudomonas aeruginosa bacteria content in open and unopened cabinets, See-Sky lamp, model LS-1888A.

Table 7 is a comparison of the average bacteria in the air purifier unopened cabinet. The values were taken from Table 5 and the average bacteria in the cabinet with the air purifier open. The values were taken from Table 6 and calculated the percentage reduction of the mean bacteria in each of the 20 petri dishes. The results are shown in Table 8.

By comparing the mean percentage reduction of Pseudomonas aeruginosa bacteria from 20 petri dishes at each point in the incubator, it was found that the 99.9% petri dish had the highest reduction in bacteria, plates 19, followed by 99.5%. are plates 15, 16, 17 and 20, followed by 99.2 %, plates 13, followed by 99.1 %, plates 3 and 18 (Table 8).

When counting the total number of bacteria from all 20 plates in the three tests before and after using the air purifier, there was a reduction in bacteria from 26,200 to 1,346 colonies, equivalent to a reduction of 24,854 colonies. 94.9 % (Table 8)

Table 7 compares the mean colonies of Pseudomonas aeruginosa bacteria from 20 counted plates after 60 min bacterial spraying in an unopened cabinet with the See-Sky lamp on, model LS-1888A.

Table 8 compares the percentage reduction of the mean bacterial Pseudomonas aeruginosa at each in vitro point and the reduction in the total number of bacteria. Before and after using the lamp LS-1888A.

3. Klebsiella pneumoniae bacteria

3.1. Spray test only for Klebsiella pneumoniae without turning on the See-Sky lamp, model LS-1888A (Control).

Antibacterial efficacy test for Klebsiella pneumoniae in an acrylic model. It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. Place the bacterial culture dish in 20 different locations throughout the cabinet (Figure 1) and switch on the Klebsiella pneumoniae nebulizer at a concentration of 1 x 106 CFU/ml mixed with 200 ml of distilled water for a period of time. After 60 minutes, all 20 bacterial culture dishes were cultured and counted the number of bacteria from all 20 dishes. The experiment was repeated 3 times.

The results of bacterial counting from all 20 plates and 3 trials are shown in Table 9.

The location where the highest number of bacteria was found was plate19 in the middle in front of the bacterial inhaler, counting 4112, 3554 and 2736. Colonies from Experiments 1, 2 and 3, respectively, with a mean of 3467 colonies, and the location where the least number of bacteria was found was plate 1, located behind the left and at the top of the apparatus. Bacterial aerosols were counted at 8, 9 and 11 colonies from experiments 2, 3 and 1, respectively, with a mean of 3 colonies (Table 9).

Table 9. Comparison of colonies of Klebsiella pneumoniae from 20 counted plates after 60 minutes of bacterial spraying in a closed cabinet without lamp, See-Sky, model LS-1888A.

By doing the same test 3 times.

3.2. Spray test only for Klebsiella pneumoniae bacteria by turning on the See-Sky lamp, model LS-1888A.

Antibacterial efficacy test for Klebsiella pneumoniae in an acrylic simulated cabinet.

It is a closed rectangular cabinet, width 0.8 meters, length 1.5 meters and height 1.5 meters, volume 1.8 cubic meters, with a sprayer placed in the middle of the cabinet. Place the bacterial culture dish in 20 different locations throughout the cabinet (Figure 1) and switch on the Klebsiella pneumonia nebulizer at a concentration of 1 x 106 CFU/ml with the lamp switch on. See-Sky model LS-1888A for 60 minutes and then take all 20 bacteria culture plates to culture bacteria. The bacterial counts from all 20 dishes were counted by repeating the experiment 3 times.

The results of bacterial counting from all 20 plates and 3 times are shown in Table 10. The location where the highest number of bacteria was found was plate 8, located in the upper left front of the nebulizer, counting 34 98 and 15 colonies from Trials 1, 2 and 3, respectively, with a mean of 49 colonies, and the location where the least number of bacteria was found was plate 19, located behind the left side and on the bacterial aerosol counted nebulizer. 0 colonies were obtained from experiments 1, 2 and 3 with a mean of 0 colonies (Table 10).

Table 10. Comparison of colonies of Klebsiella pneumoniae from 20 counted plates after 60 minutes of bacterial spraying in a closed cabinet with the See-Sky lamp, model LS-1888A on, 3 times the same test.

3.3. Comparison of Klebsiella pneumoniae bacterial counts in the open and unopened cabinets, the average number of bacteria in the See-Sky lampshade, model LS-1888A.

Table 11 is a comparison of the mean bacterial values in the unopened cabinet, the mean bacterial values in the Far-UVC 222 lamp open cabinet, taken from Table 9, and the mean bacteria in the Far-UVC 222 open cabinet taken from Table 9. From Table 10, the mean percentage reduction of bacteria in each of the 20 petri dishes was calculated. At each point in the incubator of 20 plates, the petri dish with the highest bacterial reduction at 100% was plates 19, followed by 99.8% for plates 17 and 18. 99.7% was plates 16, 99.5% was plates 14 and 99.1%. is plates 13 (Table 12)

When counting the total number of bacteria from all 20 plates from the three tests before and after using the See-Sky lamp model LS-1888A, there was a reduction in bacteria from 23,529 to 754 colonies, representing a reduction of 22,775 cattle. Loni, representing a 96.8% reduction (Table 12).

Table 11 compares the mean colonies of Klebsiella pneumoniae from 20 counted plates after 60 min bacterial spraying in an unopened cabinet with a See-Sky lamp, model LS-1888A.

Table 12 compares the percentage reduction of the mean Klebsiella pneumoniae bacterium at each in vitro point and the reduction in the total bacterial count. Before and after using See-Sky lamp, model LS-1888A.

Summary of the Test Results

See-Sky lamp, model LS-1888A, can reduce the amount of bacteria in the air as follows:

• The maximum reduction in Staphylococcus aureus was 99.9% (1 plate), 99.8% (1 plate), 99.7% (1 plate), 99.3% (1 plate) and 99.1% (1 plate), and the mean infection was 94% (mean of all 20 plates). ) after turning on the See-Sky lamp, model LS-1888A for 60 minutes.
• The highest reduction in Pseudomonas aeruginosa was 99.9% (1 plate) 99.5% (4 plates) 99.2% (1 plate) 99.1% (2 plates) and the mean reduction was 94.9% (average of all 20 plates) after the lamp was turned on. See-Sky model LS-1888A for 60 minutes
• The maximum reduction in Klebsiella pneumoniae was 100% (1 plate), 99.8% (2 plates), 99.7% (1 plate), 99.5% (1 plate) and 99.1% (1 plate), and the mean reduction was 96.8% (mean of all 20 plates). ) after turning on the See-Sky lamp, model LS-1888A for 60 minutes.

References

Sirigul C, Wongwit W, Phaprasit W, Paveenkittiporn W, Blacksell SD, Ramasoota P.

Development of a combined air sampling and quantitative real-time PCR method for detection of Legionella SPP. Southeast Asia J Trop Med Public Health. 2006; 37(3):508-512.