Question

1. why might some antibiotics show greater evidence of bacterial resistance than others?

2. do any of the results obtained suggest that bacterial genes that confer resistance to certain antibiotics also work against chemically similar antibiotics?

3. Staphylococcus epidermidis is gernally not considered a harmful species of bacteria; in fact, it may be beneficial to humans to have this organism living on our skin. even so, why should we be concerned that this species shows resistance to a variety of antibiotics? try to address serveral different reasons.

4. it is becoming more and more common to find antibiotic resistann t bacteria outside of medical facilities. however, it is still often the case that hospital patients become infected with resistant bacteria that are rarely found outside of the hostpial environment. what factors make it more likely to that a hospital patient (rather than a person outside of a hospital) will end up with an infection caused by antibiotic-resistant bacteria?

5. if all antibiotic use suddenly balted, would populations of human-infecting bacteria eveolve in terms of their antibiotic resistance alleles? (hint: to answer this completely, you need to consider possible metabollic costs of resistance)

Answer 1

1).Ans: Most bacteria contains an extra DNA, apart from its chromosomal DNA i.e Plasmids. These plasmids are short, circular and contain several things like a bacterial origin of replication, multiple cloning sites and most importantly antibiotic-resistant marker gene, which confers resistance to that antibiotic. So if you want to separate your bacteria of interest from a group of bacterial colony, you just have to add that specific antibiotic (your bacteria has resistance ) into the media. Only your bacteria of interest will grow, not others. That is why antibiotics show greater evidence of bacterial resistance than others

4) Ans: There are several reasons why bacteria are getting antibiotic resistant. Say for instance :

Antibiotics are the most commonly prescribed drugs used in human medicine and can be lifesaving drugs.But it has been seen, up to 50% of the time antibiotics are not optimally prescribed, which means incorrect dosing or duration.

The bacteria that contaminate food can become resistant because of the use of antibiotics in people and in food animals, like the bacteria Salmonella and Campylobacter, it is primarily the use of antibiotics in food animals that increases resistance. Because of the link the between antibiotic use in food-producing animals and the occurrence of antibiotic-resistant infections in humans, antibiotics that are medically important to treat infections in humans should be used in food-producing animals only under veterinary oversight and only to manage and treat infectious disease, not to promote growth.

The other major factor in the growth of antibiotic resistance is spread of the resistant strains of bacteria from person to person, or from the non-human sources in the environment.

2) Ans: Yes there is a good probability that bacterial antibiotic resistant gene will show resistance to chemical analogues of antibiotic. In near future, this can be very useful in preparing a new generation of antibiotics.