1. Background information
The first tetracyclines were natural products derived from the fermentations of actinomycetes. In 1948, Benjamin Duggar found Chlortetracycline (also called Aureomycin) from Streptomyces aureofaciens. In 1950, Pfizer found oxytetracycline, and other tetracyclines would be found in the next decades. The tetracyclines can be divided into two groups, the one is the natural tetracyclines, the other is the semisynthetic derivatives. All tetracyclines are about equally active and typically have about the same broad spectrum, which comprises both aerobic and anaerobic gram-positive and gram-negative bacteria, mycoplasmas, rickettsiae, chlamydiae, and even some protozoa.
2. Antimicrobial activity and mechanisms of bacterial resistance
2.1 Tetracyclines mode of action
Tetracyclines preferentially bind to bacterial ribosomes and interact with a highly conserved 16S ribosomal RNA (rRNA) target in the 30S ribosomal subunit, arresting translation by sterically interfering with the docking of aminoacyl-transfer RNA (tRNA) during elongation.
2.2 Mechanisms of Bacterial Resistance to Tetracyclines
The most common mechanism by which microbes become resistant to tetracyclines is decreased accumulation of drug into previously susceptible organisms. Two mechanisms include 1) impaired uptake into bacteria, which occurs in mutant strains that do not have the necessary transport system, and 2) the much more common plasmid- or transposon-mediated acquisition of active efflux pimps. The genomes for these capabilities may be transferred either by transduction (as in Staphylococcus aureus) or by conjugation (as in many enterobacteria). A second mechanism of resistance is the production of a “protective” protein that acts by either preventing binding, dislodging the bound drug, or altering the negative impact of binding on ribosomal function.
3. The harm of veterinary drug residues
Tetracycline drugs are primarily excreted by glomerular filtration, the residual drug will be deposited on the bone or tooth, then combined with calcium within it, and resulted in yellow tooth. Long-term consumption of food containing antibiotics will cause great harm to people's health and cause bone deformities and growth inhibition, interfere with the normal physiological function of human body, affect the growth and development of children and adolescents, and to reduce the body's resistance to bacterial pathogens, and can cause liver and kidney damage, cause vestibular reaction, allergic reactions, allergy and drug resistance.
4. Comparison of detection methods
The primary detection methods are as followed :
[Microbiological inhibition]
Principle :
Antibiotics inhibit the growth of microorganisms, and the size of antimicrobial circle is positively correlated with the concentration of antibiotics.
Advantages and disadvantages :
Relatively simple operation, low cost, suitable for rapid screening of bulk samples, but often lack of specificity and accuracy, and interference by other antibiotics.
[Chromatography]
Principle :
Chromatography includes high performance liquid chromatography, thin layer chromatography, etc. Tetracycline antibiotics in food are mainly determined by liquid chromatography. HPLC has more advantages in the analysis of multiple residual antibiotics.
Advantages and disadvantages :
Precision, accuracy, high sensitivity, good repeatability, but the equipment and operators have certain requirements.
[Immunization]
Principle :
This is an analysis technique based on the specificity and reversible binding ability of antigen and antibody.
Advantages and disadvantages :
Simple operation, high sensitivity, high specificity, suitable for batch sample analysis, but only suitable for rapid screening.
[Electrophoresis]
Principle :
The capillary column is filled with a buffer solution, inserted into two buffer tanks at the same level, and the sample is introduced from one end of the capillary. When a certain voltage is applied to both ends of the capillary, the charged solute moves toward the opposite polarity of the charge. . Due to the different concentrations between the components, their migration speed is different. Therefore, after a certain period of time, the components will be sorted according to their speed or concentration, and then arrive at the detector and be detected to obtain a current spectrum according to time distribution.
Advantages and disadvantages :
Simple operation, the column is not contaminated by the sample, the analysis speed is fast, the separation efficiency is high, the sample usage is small, and the operation cost is low.
[Combination of analysis technics]
Principle :
By pre-treatment of the sample, the unnecessary interferences are separated and removed, the purification of the sample is achieved, and the disadvantage of poor specificity of the analysis technique can be compensated for.
Advantages and disadvantages :
The analysis range is wide, the sensitivity is high, the result is accurate and reliable, but the required instrument requirements are high, it is not suitable for promotion at the grassroots level, and it is mostly used for residue confirmation.
5. Introduction of our products
100002 - BT Combo Rapid Test Kit
100006 - Tetracyclines Rapid Test Kit (High sensitivity)
100007 - Tetracyclines Rapid Test Kit (Low sensitivity)
100015 - TriTest BTS Rapid Test Kit
100016 - TriTest BTM1 Rapid Test Kit
100017 - TriTest BTM Rapid Test Kit
100018 - QuaTest BTSC Rapid Test Kit
100019 - TriTest BTCex Rapid Test Kit
