An accidental discovery which changed medicine
The antibiotic industry appeared 65 years ago. The date of its birth is December 17, 1941. It was on this day that Vannevar Bush, the head of the Office of Scientific Research and Atomic Project, addressed the leaders of 9 major pharmaceutical companies on behalf of the US government. It was about penicillin, which was discovered by microbiologist Alexander Fleming in Penicillium notatum mold, and then (for grants from the Rockefeller Foundation) was allocated in its pure form by biochemist Ernst Boris Cheyne and tested in the clinic by pathologist Howard Walter Flory.
During World War II, hundreds of thousands of soldiers survived precisely because of the invention of penicillin. The point is that a lot of diseases had ceased to be fatal – while before, people often died from pneumonia, syphilis, and even sore throat.
A little bit of history
But why did it take to invent new antibiotics drugs when there is well-proven penicillin? The thing is that microbes appeared that are not sensitive to the action of the “father” of antibiotics. Such a confrontation is an entirely natural thing for any living organism, and it is explainable from evolutionary theory. First, in any population of bacteria, there are more resistant specimens, which during natural selection begin to dominate in the colony. And, secondly, it turned out that microorganisms can pass on to each other acquired survival abilities.
In general, in the short time of the intense struggle of humanity with the microworld, representatives of the latter experienced an evolution that can be generally compared to three Mesozoic eras. Bacteria began to resist by using a particular enzyme to break the so-called beta-lactam ring – part of the penicillin molecule, which gives it antibacterial activity.
Chemists have attached radicals to the penicillin molecule, shielding this ring from a hostile enzyme. So ampicillin, methicillin and other penicillins of new generations appeared.
Ampicillin. What are the peculiarities?
Today, most medical practitioners prefer antibiotics of the penicillin group, namely aminopenicillins. And for a good reason.
Aminopenicillins are semisynthetic broad-spectrum penicillins. The leading representatives of this group are ampicillin and amoxicillin. Even though they are not resistant to bacterial penicillinases and are not effective against Pseudomonas aeruginosa, the spectrum of their actions turned out to be so vast that it became possible to treat most infections caused by clinically significant gram-negative microbes effectively.
Ampicillin (Ampicillin) is an effective bactericidal antibiotic of the penicillin group with a broad spectrum of antibacterial action. The active substance of the drug dissolves the cell walls of pathogens. Also, there is a suppression of metabolic processes between microbial cells at the membrane level, which is detrimental to them.
Under the action of ampicillin, both gram-positive and gram-negative bacteria and some pathogens of intestinal infections die, so this semi-synthetic antibiotic is used to treat various infectious diseases of the respiratory tract (pneumonia, bronchopneumonia, tonsillitis), urinary tract, liver, and gastrointestinal tract. It was first introduced into use in 1961 by the British company Beecham.
Ampicillin represents a white bitter crystalline powder. It is stable in an acidic environment, soluble in water, but almost insoluble in alcohol.
Ampicillin is prepared by acylation of 6-amino penicillanic acid with amino phenyl acetic acid residue.
Since ampicillin is a kind of penicillin, the mechanism of action is similar to it – an irreversible inhibitor of transpeptidase involved in the synthesis of the peptidoglycan cell wall.
This medicine is not destroyed in the acidic environment of the stomach, but it is well absorbed being taken orally. Active against gram-positive microorganisms that are affected by benzylpenicillin. Besides, it acts on several Gram-negative organisms (Salmonella, Shigella, Proteus, E. coli, Klebsiella pneumonia (Friedlander wand), Pfeiffer wand (Influenza wand)).
Therefore Ampicillin is presented as a broad-spectrum antibiotic and can be used for diseases caused by mixed infection. Ampicillin does not work on penicillin-forming staphylococci resistant to benzylpenicillin since it is destroyed by penicillinase.
Ampicillin is forbidden if there is a hypersensitivity to penicillin. Other contraindications are infectious mononucleosis, lymphocytic leukemia, liver failure, gastrointestinal tract history (especially colitis associated with the use of antibiotics), age up to 1 month.
Pharmacological action – bactericidal, broad spectrum antibacterial.
Inhibits transpeptidase prevents the formation of peptide bonds and disrupts the late stages of peptidoglycan synthesis of the cell wall of the fissile microorganism, causing lysis of bacteria.
Ampicillin is active against a wide range of gram-positive (alpha and beta-hemolytic streptococci, Streptococcus pneumonia, Staphylococcus spp., Bacillus anthracis, Clostridium spp., moderately active against most enterococci, including Enterococcus faecalis), Listeria spp., and also gram-negative microorganisms (Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrhoeae, Proteus mirabilis, Yersinia multocida (Pasteurella), Salmonella spp., Shigella spp., Bordetella spp., Escherichia coli), and aerobic bacteria asporogenous.
Ampicillin is not effective against penicillin-forming strains of Staphylococcus spp., all strains of Pseudomonas aeruginosa, most strains of Klebsiella spp., and Enterobacter spp., Proteus vulgaris (interpositive).
When ingested, 30–40% of the dose is absorbed from the gastrointestinal tract, and maximum concentration is reached in 1.5–2 hours. A relatively small part (10–30%) connects to plasma proteins. The drug is spread in most organs and tissues, can be found in therapeutic concentrations in pleural, peritoneal and synovial fluids. It penetrates poorly through the blood-brain barrier, with inflammation of the meninges, the permeability of the blood-brain barrier increases — virtually no biotransformation.
Ampicillin is excreted mainly by the kidneys in unchanged form, high concentrations of antibiotic are created in the urine and partially excreted in the bile, in nursing mothers – with milk. It does not accumulate.
Use of Ampicillin
Infectious and inflammatory diseases which are caused by susceptible microorganisms: infections of the respiratory tract and ENT organs(pneumonia, lung abscess, bronchitis, sinusitis, tonsillitis, pharyngitis, otitis media), infections of the kidneys and urinary tract (cystitis, pyelonephritis, pyelitis, urethritis), infections biliary system (cholangitis, cholecystitis), chlamydial infections in pregnant women (with erythromycin intolerance), cervicitis, pasteurellosis, listeriosis, diseases of the skin and soft tissues (erysipelas, impetigo, secondary infected dermatoses), infections of musculoskeletal system, gastrointestinal tract infection (typhoid and paratyphoid fevers, dysentery, shigellosis, salmonellosis, salmonella carrier), abdominal infections (peritonitis), bacterial endocarditis (prevention and treatment), Gonorrhea, meningitis, sepsis, pertussis.