Staph infections caused by the bacterium staphylococcus aureus are increasing in frequency and are more difficult to treat with antibiotics many staph infections are now caused by mrsa and methicllian resistant strain of s aureus. What explains the more widespread phenomenon of mrsa prevalence in staph infections

This question lacks options, options are: A) Vaccines for MRSA have become not effective because of changes to human immune systems. B) The presence of antibiotics induced the bacterial genomes to mutate and develop resistance to the drug. C) Decreased hospital sanitation practices to save money have resulted in increased presence of resistant staph infections. D) Selective pressures by excessive antibiotic use have increased the frequency of resistant strains of S. aureus over the last few decades.The correct answer is D.

Explanation:

The susceptibility of the various germs has varied greatly in recent years. Strains that had been consistently susceptible to all antimicrobial agents for decades have now developed resistance to these classic therapies, they have the ability to rapidly develop resistance to the newer antimicrobials. Methicillin Resistant Staphylococci (MRSA) is a clear example of this situation. The mechanism that confers resistance to methicillin is complex, since the bacterium has generated a genetic variation, which is encoded in the mecA gene, by which it modifies the structure of its penicillin-binding or binding protein (PBP2a), This prevents methicillin from adhering to the place where it is going to exert the action of blocking the transpeptidase enzyme (whose function in the bacterial life cycle is to synthesize the bacterial wall).Resistance to methicillin in strains of S. aureus is a growing problem worldwide, and staphylococcus gold is an agent that spreads easily and the behavior of the process is aggressive, with which this agent not only carries resistance to methicillin , but rather all ß-lactam antibiotics, including cephalosporins and carbapenem.