Antibiotic-loving bacteria don't just resist drugs, they get a kick out of them
Developing antibiotic resistance has been found to give the disease-causing bacterium E. coli an additional boost, making it grow faster and become fitter after repeated exposure the antibiotic doxycycline.
The mutations that give E. Coli resistance to doxycycline also made them reproduce faster and grow colonies three times larger than ordinary, non-resistant E. Coli. The research is published in the journal Nature Ecology and Evolution.
The researchers exposed E. Coli to eight rounds of antibiotics over four days. In that period, the bacteria gained a number of mutations. One of the mutations was linked to antibiotic resistance, giving the bacteria more pumps to remove the drug from the cell.
The second mutation was to delete a large section of its genome that is normally involved in helping the bacteria coat a surface by forming a 'biofilm'. This section of DNA is actually the remnants of a virus, which causes the cell to split and spill its contents, helping other cells to grow nearby to form a film.
The E. Coli in the study were grown in a liquid culture, in a similar environment to the human bloodstream. Here, without the need to form a biofilm, the E. Coli cut out this section of DNA – which makes up 4% of its genome – when exposed to doxycycline, allowing it to devote its energy to growing faster and forming larger colonies instead. Even when the exposure to doxycycline was stopped, the bacteria did not lose this newly-gained trait.
"We didn't anticipate the viral change at all," study author Robert Beardmore of the University of Exeter told IBTimes UK. "That was much stronger than the pump mutation in evolutionary terms. We saw more strength with selection and a faster change on quite a large chunk of the genome."
This property was not unique to doxycycline, and similar features were found in two different classes of antibiotics, Beardmore said. However, only certain strains of E. Coli gained these mutations when exposed to the antibiotic.
"It's not every antibiotic and it's not every E. Coli, and certainly not every bacterium. But it is pretty strange that that feature is there," Beardmore said. "There's something special about the way doxycycline is inhibiting the cell that causes these features."
Doxycycline is a broad-spectrum antibiotic used for a number of infections, such as chlamydia, Lyme disease, pneumonia and acne. It's also used as a preventative treatment for malaria, and can be taken for months for a trip to a country where the disease is prevalent. This widespread use means the antibiotic can be found in the environment, such as in rivers and soil.
If E. Coli is exposed to doxycycline in the environment, it could quickly develop the mutations to grow larger colonies as well as becoming resistant to the antibiotic, Beardmore said. However, he said that doxycycline should not be dropped as a treatment for various kinds of infection.
"Doxycycline may be a perfectly good drug to treat a range of bacteria with. But when E. Coli comes into contact with it in a river or field, if it's got the right kind of genome then you'll see these effects and doxycycline will boost the growth."
Source: http://www.ibtimes.co.uk/antibiotic-loving-bacteria-dont-just-resist-drugs-they-get-kick-out-them-1603881
what is the cost of viagra tablets in india
generic cialis
power v8 viagra forum
viagra usa
where to get the cheapest cialis
buy generic viagra
how do you know if someone has taken viagra
cheap generic viagra
quando prendere cialis 5 mg
cheap viagra
how long i can use viagra
viagra for men.viagra without prescription
andropausa viagra
viagra pills for sale
cialis and retinal detachment
generic cialis online
viagra preis apotheke deutschland
cheap viagra
red eyes after cialis
generic cialis online
Monday, June 1, 2026
Bupropion Treatment Decisions: Formulations, Dosing, and Managing Seizure Risk
Bupropion is available in multiple formulations with different release characteristics, and the decision between these products affects both dosing schedules and safety considerations. Understanding the formulation landscape helps patients and providers choose the product that best fits clinical needs. Immediate-release bupropion requires dosing three times daily because of the drug's relatively short half-life and the need to avoid high single doses that increase seizure risk. Doses of 100 mg three times daily represent the standard, with a maximum of 450 mg total daily not to be exceeded. The multiple daily doses make this formulation less convenient than the sustained and extended-release versions. Sustained-release bupropion allows twice-daily dosing, with individual doses not exceeding 200 mg to manage seizure risk. Total daily doses up to 400 mg are used for depression. This formulation is commonly prescribed and widely available in generic form. Extended-release bupropion formulas allow once-daily dosing, which simplifies adherence. The extended-release design distributes the drug's absorption over many hours, reducing peak plasma concentration for any single dose and associated seizure risk. Total daily doses of up to 450 mg are used once daily in the extended-release products. Seizure risk is the overarching safety consideration that shapes bupropion dosing rules. At recommended doses, seizure risk is low and comparable to other antidepressants. Risk increases meaningfully with doses above approved thresholds and in patients with predisposing conditions including personal history of seizures, eating disorders with purging behavior, heavy alcohol use or abrupt alcohol discontinuation, and head trauma. Prescribers screen for these risk factors before prescribing. The activating nature of bupropion means prescribers typically advise against taking any formulation late in the day because insomnia is a common consequence of evening dosing. Morning dosing or morning-plus-noon dosing patterns for twice-daily regimens are standard recommendations. For attention deficit hyperactivity disorder, bupropion has off-label prescribing history as a third or fourth-line option when first-line stimulant medications are not appropriate or not tolerated. When discontinuing bupropion, abrupt stopping does not produce the severe discontinuation syndrome characteristic of some SSRIs. The dopaminergic and noradrenergic mechanisms of bupropion produce a milder withdrawal profile. Gradual tapering is still advisable given its activating properties. For patients who want to understand how prescribers choose between bupropion formulations and manage clinical risk, reviewing wellbutrin-bupropion treatment decisions provides clinically grounded context. For patients comparing bupropion with SSRIs and other antidepressant classes for specific clinical concerns, the resources at antidepressant medication category guides offer comprehensive information.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.