Overuse, inappropriate prescribing, and extensive use in agriculture are the main reasons for antibiotic resistance. Please go through the following PDF attachments for more details.
I think you are talking about aquired resistance not primary resistance. In most cases exposing microbes to antimicrobials will kill sensitive strains and resistent strains survive and continue to multiply. That is the most common scenario.
Antibiotic resistance is primarily caused by selective pressures favoring growth/increase of resistant genes of bacterial species when the infections they cause are not sufficiently eradicated. Resistant ones can then multiply and through plasmids/transduction or even conjugation... Spread the resistant genes. Hope this helps.
Overuse, inappropriate prescribing, and extensive use in agriculture are the main reasons for antibiotic resistance. Please go through the following PDF attachments for more details.
Antibiotic resistance is a state whereby the bacteria use specific defense strategies, called “resistance mechanisms to reduce or eliminate the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. These mechanism may be using a protective membrane to prohibit the entry of antibiotic, secrete certain enzymes to break down the antibiotic drug and make it ineffective, produce cell pumps to get rid of important antibiotic drugs, and change features so that the antibiotic does not recognize and destroy them.
Antibiotic resistance is shown by natural selection. The antibiotic effect is an environmental pressure on the bacteria, but mutations that appear in some bacterial cells make them survive the antibiotic effect. This feature then moves on to the next offspring, which is characterized as a generation with complete antibiotic resistance. Several studies have shown that the use of antibiotics significantly affects the evolution of the number of resistant microorganisms. Overuse of broad-spectrum antibiotics, such as second and third generation cephalosporins, accelerates the development of methicillin resistance. Other factors include inaccurate medical diagnosis, prescription of unnecessary medications, improper use of antibiotics by the patient, and use of antibiotics as feed additives to encourage their growth.
Scientists have recently confirmed that the bacterial protein LexA plays an important role in bacterial genetic change.
Great discussion. For practical purposes, selection of primary resistant strains is more common. Mostly these strains are less pathogenic. Any study testing the selected primary resistant strains with regard to their pathogenic potential? This is just a suggestion. Dietmar