Kanamycin A

Key takeaways

Kanamycin A belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kanamycin A to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kanamycin A from memory before moving on to harder problems.

Reference excerpt

Kanamycin A, often referred to simply as kanamycin, is an antibiotic used to treat severe bacterial infections and tuberculosis. It is not a first line treatment. It is used by mouth, injection into a vein, or injection into a muscle. Kanamycin is recommended for short-term use only, usually from 7 to 10 days. Since antibiotics only show activity against bacteria, it is ineffective in viral infections. Common side effects include hearing and balance problems. Kidney problems may also occur. Kanamycin is not recommended during pregnancy as it may harm the baby. It is likely safe during breastfeeding. Kanamycin is in the aminoglycoside family of medications. It has the weakest antibacterial capabilities of all compounds in this family when used clinically, which is partially due to its increased toxicity in comparison to other aminoglycosides. It works by blocking the production of proteins that are required for bacterial survival. Kanamycin was first isolated in 1957 by Hamao Umezawa from the bacterium Streptomyces kanamyceticus. It was removed from the World Health Organization's List of Essential Medicines in 2019. It is no longer marketed in the United States.

Medical uses

Spectrum of activity Kanamycin is indicated for short-term treatment of bacterial infections caused by one or more of the following pathogens: E. coli, Proteus species (both indole-positive and indole-negative), Enterobacter aerogenes, Klebsiella pneumoniae, Serratia marcescens, and Acinetobacter species. In cases of serious infection when the causative organism is unknown, Kanamycin injection in conjunction with a penicillin- or cephalosporin-type drug may be given initially before obtaining results of susceptibility testing. Kanamycin does not treat viral infections.

Pregnancy and breastfeeding Kanamycin is pregnancy category D in the United States. Kanamycin enters breast milk in small amounts. The manufacturer therefore advises that people should either stop breastfeeding or kanamycin. The American Academy of Pediatrics considers kanamycin okay in breastfeeding.

Children Kanamycin should be used with caution in newborns due to the risk of increased drug concentration resulting from immature kidney function.

Side effects Serious side effects include ringing in the ears or loss of hearing, toxicity to kidneys, and allergic reactions to the drug. Ototoxicity is a common quality among aminoglycosides, and its rate of incidence in kanamycin is around 3-10%. Other side effects include: Gastrointestinal effects

Nausea, vomiting, diarrhea Musculoskeletal effects

Myasthenia gravis Neurologic effects

Headache Paresthesias Blurring of vision Neuromuscular blockade Metabolic effects

Malabsorption syndrome

Mechanism Kanamycin works by interfering with protein synthesis. It binds to the 30S subunit of the bacterial ribosome. This results in incorrect alignment with the mRNA and eventually leads to a misread that causes the wrong amino acid to be placed into the peptide. This leads to nonfunctional peptide chains.

Bacterial resistance Bacterial resistance to kanamycin is a serious and increasing phenomenon, which is very concerning for its use in treating multidrug-resistant tuberculosis and other multidrug-resistant Gram-negative bacterial infections. This is due in part to possible cross-resistance between kanamycin and other aminoglycosides, such as amikacin, capreomycin, and gentamicin. Resistance to these aminoglycosides is due to mutations in the 16S rRNA gene (rrs) within the 30S subunit that stops the antibacterial from binding tightly to the gene. These mutations are most commonly identified through a single-nucleotide variant at the position 1401.

Composition Kanamycin is a mixture of three main components: kanamycin A, B, and C. Kanamycin A is the major component in kanamycin. The effects of these components do not appear to be widely studied as individual compounds when used against prokaryotic and eukaryotic cells. The IUPAC name of Kanamycin A is O-3-amino-3-deoxy-α-D-glucopyranosyl-(1→6)-O-[6-deoxy-6-amino-α-D-glucopyranosyl-(1→4)]-2-deoxy-D-streptamine.

Biosynthesis While the main product produced by Streptomyces kanamyceticus is kanamycin A, additional products are also produced, including kanamycin B, kanamycin C, kanamycin D and kanamycin X. The kanamycin biosynthetic pathway can be divided into two parts. The first part is common to several aminoglycoside antibiotics, such as butirosin and neomycin. In it a unique aminocyclitol, 2-deoxystreptamine, is biosynthesized from D-glucopyranose 6-phosphate in four steps. At this point the kanamycin pathway splits into two branches due to the promiscuity of the next enzyme, which can utilize two different glycosyl donors - UDP-N-acetyl-α-D-glucosamine and UDP-α-D-glucose. One of the branches forms kanamycin C and kanamycin B, while the other branch forms kanamycin D and kanamycin X. However, both kanamycin B and kanamycin D can be converted to kanamycin A, so both branches of the pathway converge at kanamycin A.

Use in research Kanamycin is used in molecular biology as a selective agent most commonly to isolate bacteria (e.g., E. coli) which have taken up genes (e.g., of plasmids) coupled to a gene coding for kanamycin resistance (primarily Neomycin phosphotransferase II [NPT II/Neo]). Bacteria that have been transformed with a plasmid containing the kanamycin resistance gene are plated on kanamycin (50-100 μg/mL) containing agar plates or are grown in media containing kanamycin (50-100 μg/mL). Only the bacteria that have successfully taken up the kanamycin resistance gene become resistant and will grow under these conditions. As a powder, kanamycin is white to off-white and is soluble in water (50 mg/mL).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Kanamycin A

Start with the simplest possible case. Write down what Kanamycin A claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kanamycin A before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kanamycin A ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kanamycin A

In research: Kanamycin A appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Kanamycin A in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Kanamycin A is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aminoglycoside antibiotics, Anti-tuberculosis drugs, Cell culture reagents, so understanding it makes those chapters shorter.
In everyday life: Look for Kanamycin A outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Kanamycin A in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kanamycin A means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Kanamycin A out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kanamycin A in simple terms?

Kanamycin A, often referred to simply as kanamycin, is an antibiotic used to treat severe bacterial infections and tuberculosis. It is not a first line treatment.

Why does Kanamycin A matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kanamycin A?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kanamycin A.