Beta-lactams, Cyclic amides, are named with Greek letters to indicate the number of ring members: β-lactam antibiotics refer to a large class of antibiotics with β-lactam rings in the internal structure of the chemical, including penicillin and its derivatives, cephalosporin Bacteriocins, monoamide rings, carbapenem and penicillene enzyme inhibitors, etc., as well as newly developed cephalosporins, thiomycins, monocyclic β-lactams and other atypical β-lactams Antibiotics.
Basically all antibiotics that include β-lactam core in their molecular structure belong to β-content amide antibiotics.
The chemical structure of this class of medicines, especially the change of the side chain, has formed many antibiotics with different antibacterial spectrum and antibacterial effects and various clinical pharmacological properties.
2. Mechanism of action
The mechanism of action of β-lactam antibiotics is parallel to each other. They can inhibit cell wall mucopeptide synthase, namely penicillin binding proteins (PBPs), thereby hindering the synthesis of cell wall mucopeptides, causing bacterial cell wall defects and bacteria expansion.
In addition, the lethal effect on bacteria should also include triggering the autolysin activity of the bacteria, and mutant strains lacking autolysin show resistance. Animals have no cell wall and are not affected by β-lactam drugs. Therefore, this drug has a selective bactericidal effect on bacteria and has low toxicity to the host.
What is tetracycline?
Tetracycline is a purely natural antibiotic that can quickly inhibit the growth of bacteria by interfering with the synthesis of bacterial protein, and can kill bacteria when the concentration is very high.
Tetracycline is a broad-spectrum antibiotic that inhibits both Gram-positive bacteria and Gram-negative bacteria. It also has a strong inhibitory effect on Rickettsia, Mycoplasma, and Chlamydia, and certain spirochetes.
Tetracycline is ineffective against typhoid fever, tuberculosis, fungi and viruses. Tetracycline and oxytetracycline used to be the main antibiotic for the patient's anti-infection treatment for a long time.
Later, due to the increasing number of drug-resistant bacteria, the effect of tetracycline antibacterial treatment was getting weaker, and the adverse reactions of tetracycline were numerous.
Now it has been basically eliminated. Tetracycline can now also be used in combination with other drugs to treat peptic ulcers caused by Helicobacter pylori infection, mycoplasma, chlamydia and rickettsia infections.
2. Pharmacological effects
Tetracycline hydrochloride has a broad-spectrum anti-pathogenic microorganism effect, is a fast antibacterial agent, and has a bactericidal effect on certain bacteria at high concentrations.
The mechanism of action is that the drug can specifically bind to the A position of the 30S subunit of the ribosome to prevent the connection of aminoacyl-tRNA at this position, thereby inhibiting the growth of peptide chains and affecting the protein synthesis of bacteria or other pathogenic microorganisms.
Secondly, tetracyclines can cause changes in the permeability of bacterial cell membranes, so the leakage of nucleotides and other important components in the cells, thereby inhibiting DNA replication.
Tetracycline has strong antibacterial activity against Staphylococcus aureus, pneumococcus, Streptococcus pyogenes, Neisseria gonorrhoeae, meningococcus, Escherichia coli, Aerobacter, Shigella, Yersinia, Listeria monocytogenes, Rickettsia, Mycoplasma, Chlamydia, Actinomycetes, etc.
What is Cefalexin?
Cephalexin is a β-lactam antibiotic and a cephalosporin drug. It is a white to slightly yellow crystalline powder; slightly odorous. It is a broad-spectrum semi-synthetic antibiotic and belongs to the first generation of cephalosporins.
It is mainly used to treat mild infections of the respiratory tract, urinary tract, skin and soft tissues caused by penicillinase-producing sensitive bacteria. The incidence of allergic reactions to penicillin allergy to this drug is about 1.1%. Local application is very irritating, and injection administration is limited.
2. Mechanism of action
Cephalexin is a semi-synthetic first-generation oral cephalosporin. Its mechanism of action is to inhibit bacterial cell wall synthesis by combining with one or more penicillin binding proteins (PBPs) of bacteria (cephalexin mainly binds to PBP-3), thereby playing an antibacterial effect.
The antibacterial spectrum of cephalexin is similar to that of cephalothin, but its antibacterial activity is worse than the latter. Except for enterococci and methicillin-resistant staphylococci, gram-positive cocci are sensitive to cephalexin.
Cephalexin has a good antibacterial effect on Neisseria spp. and less sensitive to influenza bacilli. It has certain antibacterial effects on some Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Salmonella, and other Enterobacter spp, Acinetobacter, Pseudomonas aeruginosa and Bacteroides fragilis.
The hazards of Betalactam, Tetracycline and Cefalexin
The problem of resistance caused by antibiotic residues has seriously affected our treatment of bacterial infection-related diseases.
The Antibiotic Resistance: Global Surveillance Report issued by the World Health Organization on April 30, 2014 pointed out that seven different bacteria that cause blood infections (sepsis), diarrhea, pneumonia, urinary tract infections and gonorrhea are resistant to antibiotics.
The medicinal properties are increasing day by day. For example, carbapenem antibiotics are effective drugs to deal with Klebsiella pneumoniae infections, but they have no effect on people infected with resistant Klebsiella pneumoniae strains.
As the last treatment for gonorrhea, the third-generation cephalosporin has no effect in Austria, Australia, Canada, France, Japan, Norway, South Africa, Slovenia, Sweden and the United Kingdom. However, many people around the world get gonorrhea every day.
When animals are administered drugs, the drugs are excreted in feces, urine and other excreta in the form of original or metabolites. Residual drugs are still active in the environment, which will pollute soil microorganisms and insects.
Some drugs with stable properties can still exist stably for a long time after being excreted into the environment, resulting in drug residues in the environment. Streptomycin and oxytetracycline are not easily degraded in the environment; spiramycin is degraded quickly at low concentrations, but it takes 6 months to degrade at high concentrations; bacitracin zinc needs 3 to 4 months for complete degradation under aerobic conditions. It takes longer to degrade in an oxygen-free environment.
According to reports, the concentration of erythromycin and sulfamethoxazole in the sewage pond of animal farms can reach 69g/L. The discharge of these drugs pollutes the environment and destroys the ecological balance.
In recent years, researchers have suspected that the increasing incidence of tumors in the population is related to environmental pollution and animal food drug residues. Estrogen, nitrofurans, arsenic preparations, etc. have all been shown to have carcinogenic, teratogenic, and mutagenic effects.
Features of Betalactam Tetracycline Cefalexin Combo Test
1. 8min reading results
2. Detection limits respond to EU and US FDA norms
3. Single test for every target sample
4. Neither professionals nor equipment required
5. Eyes interpretation or quantitative measurement, suitable for lab and field use
6. Room temperature storage
7. Non-toxic and harmless
Detection Method of Betalactam Tetracycline Cefalexin Combo Test
Betalactam Tetracycline Cefalexin Combo Test is a colloidal gold immunochromatography assay that detects Beta-lactams, Tetracycline and Cefalexin in raw milk, milk powder, pasteurized milk and meets EU MRL. This kit can be applied for on-site rapid testing by various departments.
Samples for Betalactam Tetracycline Cefalexin Combo Test
Samples include: raw milk, milk powder, pasteurized milk.
Detection Limit of Betalactam Tetracycline Cefalexin Combo Test
The LOD may change according to requirement or specimen's difference, please refer to kit instruction for further details.
Importance of Betalactam Tetracycline Cefalexin Combo Test
Betalactam Tetracycline Cefalexin Combo Test can help manufacturers, regulatory agencies, and the public monitor product quality and help humans protect their health.
Components of Betalactam Tetracycline Cefalexin Combo Test
1. Micro-Well Reagent: 8 tests/tube, 12 tubes/box
2. Test Strip: 8pcs/tube, 96pcs/box
3. Manual Instruction: 1pc
Materials for Betalactam Tetracycline Cefalexin Combo Test