Drug sensitivity experiments.

drug sensitivity test is referred to as drug sensitivity test (or drug resistance test). The aim is to understand the
microbiology
sensitivity (or tolerance) to various antibiotics in order to guide the clinical and rational selection of antibiotic drugs
microbiology
trials.
antibiotic is said to be "sensitive" to the antibiotic if it can suppress and kill the pathogenic bacteria in a very small dose. Instead, it is called "insensitive" or "drug resistant". In order to understand which antibiotics are sensitive to the pathogen, in order to use drugs rationally and reduce blindness, drug sensitivity tests should often be carried out.Its general method is: from the patient's infected site to take samples containing pathogenic bacteria, inoculated on the appropriate
culture
base, cultured under certain conditions, and a certain amount of paper contaminated with a variety of antibiotics on the
fleed base
surface (or with stainless steel ring, internal quantitative antibiotic solution), culture after a certain period of time to observe the results.due to the different sensitivity of pathogenic bacteria to various antibiotics, different sizes of inhibited bacteria growth around the drug sheets formed by the "empty circle", called anti-bacterial circle. The size of the anti-bacterial circle is directly related to the sensitivity of pathogenic bacteria to various antibiotics. The antibiotics can then be selected according to the results of the trial.has been automated drug-sensitive test instruments in recent years, making the test more rapid and accurate. At present, the abuse of antibiotics, resulting in an increase in drug-resistant bacteria, even due to long-term large-scale use of broad-spectrum antibiotics, killing normal microorganisms in the body, the loss of mutual control of microorganisms, so that some rare or general non-pathogenic bacteria multiply in large numbers, causing the so-called "secondary infection" situation often occurs, causing artificial difficulties for treatment. Therefore, it is very important to promote the use of drug sensitivity test and insist on rational drug use.. Methods of drug sensitivity testing
Currently commonly used drug sensitivity test methods are: paper tablets
agar
diffusion method (K-B method), dilution method, E test, detection of bacterial resistance methods. Dilution method liquid dilution method and agar dilution method.methods for detecting bacterial resistance include detection of methicillin-resistant Staphylococcus aureus (MRSA), detection of penicillin-resistant enterococci (VER), detection of penicillin-resistant streptococcus pneumoniae (PRP), detection of ultra-broad-spectrum β-endamidease (ESBL) and detection of β-endamidease.. 1. Experimental materials: 1.1 Common nutritional agar culture: can be de-bio-chemical
reagents
shop purchase, do different bacteria drug sensitivity test can choose different cultures, such as E. coli drug sensitivity test can choose ordinary nutritional agar or wheat kei culture. Do salmonella by choosing
serum
culture.1.2 Drug Sensitivity Test Paper: Buy or Make Your Own (See Experimental Preparation) 1.3 Bacteria: Bacteria to Be Tested for Drug Sensitivity 1.4 Inoculation Rings, Alcohol Lights, Punchers, Oxford Cup 1.5 Liquidators, Drop head 2. Experimental preparation: 2.1 preparation of drug-sensitive tablets: purchase or home-made 2.1.1 drug-sensitive tablets preparation: take Xinhua No. 1 qualitative filter paper, with a puncher into a 6 mm diameter round small piece of paper. Take 50 pieces of round paper and place them in
-
empty penicillin bottle, which is wrapped in a single layer of psoria. After 15 pounds 15-20 minutes of high-pressure disinfection, place in a temperature tank or oven at 37 degrees C for several days to make it completely dry.2.2.2 Antibacterial tablets production: in the above-mentioned penicillin bottle containing 50 pieces of penicillin to add 0.25 ml of liquid, and flip the pieces of paper, so that each piece of paper fully soaked in the liquid, flipping the pieces of paper can not be smashed. At the same time record the name of the drug on the mouth of the bottle, put 37 degrees C temperature box overnight, after drying, that is, a tight cap, if conditions can be vacuum drying. Do not moisture, store in a dark and dry place, valid for 3-6 months. The preparation of various commonly used medicines is detailed.2.2 preparation of pharmaceutical fluids (for the trial of commercial drugs): according to the proportion of the use of commercial drugs treatment volume of pharmaceutical liquid, such as commercial drugs in accordance with its indicated amount of treatment 0.01% of drinking water, according to this proportion of pharmaceutical liquid, 10 mg can be added to 10 ml of water mixed. This dilution is the liquid used for drug sensitivity testing.. 3. Experimental operation method 3.1 drug-sensitive tablet method3.1.1 In the "ultra-clean table", the appropriate amount of bacterial culture is selected by the inoculation ring sterilized by (alcohol lamp) flame, and the bacteria are coated on the flat dish medium by dashing. In particular, the appropriate amount of bacteria were sterilized at the edge of the flat dish relative to four points, with each point beginning to draw a line coating to 1/2 of the flat dish. Then, find the second dot dash to 1/2 of the flat dish, in turn, until the bacteria are evenly spread over the flat dish. (Also: the bacteria to be tested can be selected in a small amount of physiological salt water to make bacterial suspension, with sterilized cotton swabs to the bacteria to be tested mixed suspension on the surface of the flat dish petriline.) Requires uniform coating and denseness) 3.1.2 the tweezers after the alcohol lamp flame sterilization slightly stopped, take the drug sensitive tablets attached to the surface of the flat dish petrium. In order to make the drug-sensitive tablets and the culture base closely attached, you can use tweezers to tap a few drug-sensitive tablets. In order to be able to accurately observe the results, it is required that the drug-sensitive tablets can be distributed regularly on the flat dish petrily, generally can be attached in the center of the flat dish, the outer week can be equal distance paste a number of tablets (the outer week can generally be attached to seven tablets), the name of each drug-sensitive tablets to remember.3.1.3, after 24 hours of culture in a temperature tank at 37 degrees C, the effect was observed.3.2 Oxford Cup Method 3.2.1 In the "ultra-net table", the appropriate amount of bacterial culture is selected with an inoculation ring sterilized by (alcohol lamp) flame, and the bacteria are coated on a flat petrium by dashing. In particular, the appropriate amount of bacteria were sterilized at the edge of the flat dish relative to four points, with each point beginning to draw a line coating to 1/2 of the flat dish. Then, find the second dot dash to 1/2 of the flat dish, in turn, until the bacteria are evenly spread over the flat dish. (Also: the bacteria to be tested can be selected in a small amount of physiological salt water to make bacterial suspension, with sterilized cotton swabs to the bacteria to be tested mixed suspension on the surface of the flat dish petriline.) Requires uniform and dense coating 3.2.2 sterile operation of the sterile stainless steel tube (inner diameter 6nm, outer diameter 8nm, high 10nm round tube, the ends of the tube to be smooth, can also be used glass tube, porcelain tube), placed on the culture base, gently pressurized, so that it is in contact with the culture base without gaps, and marked at the tube a variety of drug names. Each plate can have 4-6 tubes. After a few minutes, add a certain amount of various fluids to each tube, do not let it overflow. The results were observed for 8-18 hours at 37 degrees C.3.2.3 to the flat petri dish medium in a temperature tank at 37 degrees C after 24 hours of culture, observe the effect..