1 Scope of application
Suitable for microbiological testing of settling bacteria, planktonic bacteria workbenches, and workers' hands in dust-free workshops.
2 Definitions
2.1 Floating bacteria: live microbial particles suspended in the air, using specialized methods The instrument is used to reproduce visible bacterial activity through specialized culture medium under suitable growth conditions.
2.2 Settling bacteria: live microbial particles in the air that reproduce to visible bacterial activity under suitable growth conditions through specialized culture media.
2.3 CFU: Colony forming unit.
3 Testing Methods
3.1 Preparation of reagents/culture media
3.1.1 According to the sampling quantity, prepare 0.9% physiological saline and soy casein agar medium according to the prescribed requirements. Divide the prepared medium into triangular bottles, seal them with rubber stoppers, and wrap them with white paper; Use a pipette to transfer 10ml of 0.9% physiological saline solution into a test tube, seal it with a stopper, and wrap it with white paper. Wrap the corresponding number of pipettes and cotton swabs; Place the petri dish into the stainless steel container In the poison cylinder, all items are extinguished by high-pressure steam at 121 ℃ Bacteria for 15 minutes;
3.1.2 Extinguish After the completion of the culture, part of the culture medium will be poured into a petri dish and used to detect planktonic and settling bacteria. If not used on the same day, it should be stored at a low temperature of 2-8 ℃. Place some of the culture medium in a constant temperature water bath at 45 ± 5 ℃. After the physiological saline tube has cooled down, it can be sampled in a dust-free workshop;
3.2 The sampling steps for settling bacteria are as follows:
3.2.1 Mark the solidified culture dish according to the sampling position;
3.2.2 When arranging sampling points, try to avoid return air vents with concentrated dust particles as much as possible;
3.2.3 Place the culture dish on a workbench about 0.8-1.5m above the ground, remove the lid of the dish, and expose the culture medium to the air for 30 minutes for sampling;
After all sampling is completed, cover the culture dish and invert it.
3.2.5 When the culture dish is used for testing, in order to avoid the impact caused by the transportation or handling of the culture dish, a negative control test should be conducted simultaneously. One control dish should be taken from each time or area, operated in the same way as the sampling dish but without exposing the sample. Then, it should be placed in the culture box together with the sampled culture dish for cultivation, and the results should be sterile.
3.3 The sampling steps for planktonic bacteria are as follows:
3.3.1 Before sampling, use a suppressor Poison elimination The top cover, turntable, and inner and outer surfaces of the toxic sampler;
3.3.2 Turn on the planktonic bacteria sampler to eliminate residual bacteria in the instrument Evacuate the toxic agent for no less than 5 minutes, check the flow rate, and adjust the sampling parameters according to the sampling volume. Each sampling point should sample no less than 500L;
When arranging sampling points, the sampling point position should be about 0.8-1.5m above the ground, and the measurement point position of the air supply outlet should be about 30cm away from the air supply surface;
3.3.4 Consumption Eliminate the toxic agent against the opponent After poisoning, place the culture dish into the turntable, cover it with a porous sampling head cover, remove the protective cover, and open the planktonic bacteria sampler for sampling;
After the sampling is completed, mark the culture dishes that have been sampled;
After all sampling is completed, use the filter Gently spray the toxic agent onto the inner wall of the instrument cover and the turntable;
3.3.7 When using culture dishes for testing, in order to avoid the impact caused by the transportation or handling of the culture dishes, negative control tests should be conducted simultaneously. One control dish should be taken from each time or area, and operated in the same way as the sampling dish but without exposing the sample. Then, it should be placed in the culture box together with the sampled culture dish for cultivation, and the results should be sterile.
3.4 Microbial sampling of workers' hands should be carried out according to the following steps:
3.4.1 will be extinguished Mark the bacterial physiological saline tube properly;
3.4.2 Consumption Eliminate the toxic agent against the opponent Poison, remove and extinguish Bacterial swab, open and extinguish Plug the bacterial physiological saline tube and immerse a cotton swab to extinguish it In bacterial physiological salt, after the cotton swab is soaked, lightly press it on the test tube wall several times and remove it Excessive moisture;
3.4.3 Require the examinee to close their fingers together and immerse themselves in the solution Apply a cotton swab of bacterial physiological saline back and forth on the hand 10 times, covering the entire palm area;
3.4.4 Remove the part of the cotton swab that comes into contact with the hand, and drop the cotton swab head in to extinguish it In the bacterial physiological saline tube, send for testing;
3.4.5 After each pair of sampling points is sampled, apply cancellation The poison is eliminated by the opponent's scissors and hands Poison.
After the sampling is completed, take another cotton swab and remove the part in contact with the hand. The cotton swab tip should be dropped into the swab to extinguish it Use a physiological saline tube as a negative control.
3.5 Microbial sampling on the workbench should be carried out according to the following steps:
3.5.1 Extinguish first Mark the bacterial physiological saline tube with the tag number corresponding to the worker's hand taken;
3.5.2 The experimenter should wear sterile gloves and use disinfectant Poison should be disinfected by hand and positioning frame Poison, if necessary, burn the positioning frame with an alcohol lamp to accelerate the evaporation of alcohol;
3.5.3 Select the sampling location and fix the positioning frame;
3.5.4 Remove and extinguish Bacterial swab, open and extinguish Plug the bacterial physiological saline tube and immerse a cotton swab to extinguish it In bacterial physiological salt, after the cotton swab is soaked, lightly press it on the test tube wall and remove it Remove excessive moisture;
3.5.5 Apply a cotton swab back and forth in the positioning frame 10 times;
3.5.6 Remove the part of the cotton swab that comes into contact with the hand Remove the cotton swab head and wipe it out In the bacterial physiological saline tube, send for testing;
3.5.7 After each sampling point is sampled, apply cancellation Eliminate the toxic opponent with a positioning frame and scissors Poison.
After sampling, take another cotton swab and remove the part in contact with the hand Remove the cotton swab head and wipe it out Use a physiological saline tube as a negative control.
3.6 Microbial testing after sampling
3.6.1 For samples taken in a culture dish, invert the dish and incubate at 34 ± 1 ℃ for 24-48 hours, then count;
For sampling with a sampling tube, sonicate the sampling tube in an ultrasonic cleaning machine for 5 minutes, mix well, and dilute the diluted solution to a 10 fold concentration on a clean workbench; Used to be extinguished Transfer 1ml of diluent into a sterile petri dish using a pipette, immediately pour the culture medium, mix well, and solidify. Pour 2 plates into each dilution, invert at 34 ± 1 ℃ for 24-48 hours, and count;
3.7 Result determination
3.7.1 The bacterial count on the workbench should be ≤ 10cfu/cm2 (i.e. ≤ 250cfu/25cm2);
3.7.2 The amount of bacteria on workers' hands should be ≤ 300cfu/hand;
3.7.3 The number of settling bacteria at level 100000 should be ≤ 10 per dish;
The concentration of planktonic bacteria at level 100000 should be ≤ 500 cells/m3 (≤ 125 cells/250L);
