Bacterial drug sensitivity test method

currently commonly used drug sensitivity test methods are as follows:
1, qualitative determination of the disk diffusion method (disk diffusion test), K-B method: WHO recommended the global standard method.principle of
: paper sleeping with quantitative antibacterial goods on the
gasid
tablet of the inoculated test bacteria, the drug contained in the sheet absorbs moisture from agar dissolved and then continues to spread to the area around the piece of paper, forming a decreasing gradient concentration. The growth of bacteria within the concentration range of antibacterials around the paper is inhibited, forming a transparent antibacterial circle. The size of the antibacterial circle reflects the sensitivity of the test bacteria to the determination of the drug and is negatively related to the MIC of the test bacteria.
: the diameter of the bactericide ring of the standard strain should fall within the expected range and, if exceeded, should be corrected as out of control.
factors: the quality of
culture
-based, the quality of drug-sensitive paper tablets, the amount of inoculation, the quality of test operation, incubation conditions, the accuracy of the anti-bacterial circle measurement tool and the drug-sensitive properties of the quality control strain itself can all affect the accuracy of the test results.
2, quantitative dilution method (dilution test), mainly to determine the minimum bacterial concentration of a drug, including broth dilution and agar dilution.
Agar Dilution: Principle: Add different doses of antibacterial drugs to a quantitative MH agar that melts and cools to about 50 degrees C to make a plate containing different decreasing concentrations of the drug. Inoculation of untested bacteria (multiple strains can be measured on a tablet), incubation of 16-24h at 35 degrees C, the lowest drug concentration of bacteria-free growth is MIC of the test bacteria.
test is characterized by multiple strains of MIC determination at the same time, the repetition of the results is better than the broth dilution method, and easy to find contamination or drug resistance
cientide
bacteria, is commonly used in the new drug certificate of foreign drug sensitivity test classic reference standards.
3 and E test, combining the advantages of diffusion and dilution.
is a combination of diffusion method and dilution method of their respective advantages, simple operation and diffusion method, but also can be like dilution method direct quantitative measurement of antimicrobial drugs on the test bacteria of the lowest MIC, the results are accurate, good repeatability, but expensive.
4, fully automatic drug sensitivity method, there are Vitek, Microscan, Sensititre ARIS, ATB.
lilac garden netizen ljksbs summed up the commonly used drug antibacterial ring diameter size to judge the results of the standard, as follows:
drug-resistant intermediary sensitive
AMK9 amica star 30ug≤14 15-16 ≥17
CLI Klinmycin 2ug≤14 15-8 20 ≥21
GEN Qingdamycin 10ug≤12 13-14 ≥15
OXA benzoxilin 1ug≤10 11-12 ≥13
PEN penicillin 10U≤28 -≥ a
29 AMS Shubatan 10/10ug≤ 11 12-14 ≥15
AMP ammonia silin 10ug≤13 14-16 ≥17
PI Pirasirin 100ug≤17 - ≥ 18
FZN cephalosporine 30ug≤14 15-17 ≥18
CAZ cephalosporine it is set at 30ug≤14 15-17 ≥18
CIP cyclopic cerium 5 ug≤15 16-20 ≥
21
ATM ammonia 30ug≤ 15 16-21 ≥22
FRX cephalosporine 30ug≤14 15-17 ≥18
IMP aminia With South 10ug ≤13 14-15 ≥16
VAN vancomycin 30ug≥15
SXT compound New Nomin 1.25/23.75 ug ≤10 11-15 ≥16