Skin and Nasal Sampling Methods-Applicable to Healthy Person Sample Collection

I. Material Preparation

Marked labels; ?

2 mL screw-top tube (outer spiral) containing MoBioBuffer 750 μL; ?

Sterile sampling swab;?

Sterile SCF-1 solution for pre-sampling swab wetting (50 mMTris buffer [pH 7.6], 1 mMEDTA [pH 8.0], 0.5% Tween-20);?

Zippered plastic bag for collection of sampling tubes;? Portable ice box (with ice cubes).

II. Skin condition study

1. Subject exclusion criteria were as follows: ?

① Subjects who have used topical antibiotics or steroids on the face, neck, arms, or hands in the previous seven days. (Screening and sampling may be delayed when the subject meets the exclusion time period for antibiotic or steroid use);?

② Acne must not be present on the face, chest, back, or shoulders;?

③ Scalp, face, arms, forearms or hands with multiple blisters, pustules, burns, abscesses, vesicles or ulcers;?

④ Single blisters, pustules, burns, abscesses, infections, ulcers, scabs, cuts, cracks, or pink spots/hyperpigmented patches or plaques within 4cm from the sampling point;?

⑤ Multiple pink spots/red scaly patches/plaques anywhere on the body (psoriasis or eczema);?

⑥ Uniformly thickened dead skin, cracking and excessive dryness on the palms of the hands bilaterally and/or feet;?

⑦ daily use of over-the-counter anti-dandruff shampoos with unknown ingredients for up to 2 weeks;?

⑧ spreading rash (appearing on multiple body parts or extending over most of the body).

2. Testing conditions:?

Skin examination should be carried out under good lighting conditions, including a general survey of the localized skin (the whole body) and a detailed examination of the sampled area.?

3. Detection of additional criteria:

① through visual inspection to carefully examine the back of the ear wrinkles (behind the right and left ears) and the elbow sockets of the two elbows of both arms (inner elbow);?

② Individuals with any single blister, pustule, burn, abscess, infection, ulcer, scab, incision, fissure, or pinkish/hyperpigmented spot or plaque with visible skin lesions more than 4 centimeters away from the sampling site were still considered eligible for inclusion in the study.

III. Sample Collection Methods

Instructions:

①Aseptic technique should be used to collect all samples (see Appendix for details).

② The pair of sterile latex gloves worn should be used to collect skin samples from one subject only, and care should be taken to avoid contamination of the gloves.?

③ If the gloved hand is used to stretch the skin for sampling and comes into contact with the sampling area, the glove must be changed before sampling the next locus.

Sample collection order:

① behind the ear wrinkles (behind the ear, left and right sides to keep separate collection)?

② elbow socket (inner elbow, left and right sides keep separate collection)?

③Pre-nasal aperture (left and right sides can be combined collection)

Note:? It is more favorable to let the subject lie comfortably flat during the sampling process.

1. Posterior Ear Fold

Posterior Ear Fold: This is the area that begins at the top of the ear where it joins the face and extends to the earlobe where it joins the face.

① Skin samples were collected using a sample collection swab and moistened with SCF-1 solution.?

② To reach the area, fold the ear forward with one hand to expose the crease.?

③ With the other hand, keeping the axis of the swab parallel to the surface of the skin, apply steady pressure approximately 50 times along the reverse crease (complete 50 swipes in approximately 30 seconds).?

④ The head of the swab is inserted into the collection tube, the head of the swab is aseptically cut from the handle, and the cap is screwed back into place.

Note:

For optimal skin surface specimens, the key points of the sampling technique: use of a moist swab, application of steady pressure, and consistency of friction (50 round trips within 30 seconds at the sampling point).?

The left and right sides were sampled, labeled, and stored separately. Tubes were stored in a zippered self-sealing bag on ice and delivered to the laboratory for preservation within 2 hours.

2. Elbow socket (inner elbow)

Elbow socket (inner elbow): the junction of the arm and forearm just above the bend of the inner elbow.

① Skin surface sample collection is performed using a sample collection swab and moistened with sterile SCF-1 solution.

② Stretch the skin of the elbow with one hand, and with the other hand, hold the swab so that the shaft is parallel to the skin surface and rub the swab back and forth along the anterior elbow crease approximately 50 times, applying a steady pressure (approximately 30 seconds to complete 50 rubs).

③ Insert the swab into the tube with the head of the swab inserted into the collection tube, cut the head of the swab aseptically from the handle, and screw the cap back into place.

Note:

For optimal skin surface sampling, the keys to the sampling technique: use of a moist swab, application of steady pressure, and consistency of friction (50 back and forth over 30 seconds at the point of sampling).?

The left and right sides were sampled, labeled and stored separately. Tubes were stored in a zippered self-sealing bag on ice and delivered to the laboratory for preservation within 2 hours.

3. Anterior Nasal Aperture

①Use a sterile swab to gently wipe the mucosal surface of the nostrils with a twisting motion, and use the same swab to wipe the same area twice for each nostril.

② Left and right side for nostril samples as a combination of samples to be sampled and pooled and labeled.

③ Immediately after wiping, the swab was placed in 750 μL of MoBioBuffer and rotated, and the swab sponge was accumulated on the wall of the tube several times for 20 s to ensure the transfer of bacteria into the solution.?

The sample collection tubes were placed in a zippered self-sealing bag and onto ice and transferred to the laboratory for processing within approximately 2 hours.

IV. APPENDIX

Aseptic Technique

Principle:

Aseptic technique was used for the collection and processing of all samples.?

All materials collected in each SOP are guaranteed to be clean and sterile or confirmed sterile before purchase and use.?

The following are recommendations for aseptic technique.?

Aseptic technique practices apply to all sample collection SOPs.

Aseptic Technique-Preparing Sample Collection Tubes

1) Aseptic supplies include (but are not limited to) tubes, tips, MoBiobuffer, and SCF-1 buffer?

2) If tubes are to be filled, MoBioBuffer and SCF-1 will be dispensed in a laminar flow hood.

Aseptic Techniques - Subject Sample Collection

1. Handle biological samples in accordance with all safety guidelines of the local safety committee and/or institutional policy. Gloves, safety glasses or masks and lab coats must be worn throughout the dispensing of serum. Precautions should be observed when collecting any biological samples, including wearing gloves at a minimum.?

2. When hand me sample collection tubes during sampling, care should be taken to keep the gloves clean to avoid cross-contamination inside and outside the collection tubes.?

3. Use clean disposable gloves during the sample collection process.

a) When collecting skin and nasal samples, collect four skin sites before collecting nasal samples. The sampler can complete sample collection from so skin loci with one pair of gloves as long as there is no contact with the sampling area when stretching the skin. Once contact with the sampling area occurs, the gloves should be changed and the next skin sample should be taken.

b) The researcher can use one pair of gloves to collect samples from different oral sites in the same subject's mouth. Similarly, there is no need to change gloves when collecting three vaginal samples from the same subject.

Sterile technique - sample testing

Sterile supplies include (but are not limited to) tubes, tips, all buffers/reagents.