Bacterial infections have become much more of a threat to human health due to which of the following? A. an increase in acquired antibiotic resistance by innocuous strains
B. horizontal transfer of pathogenicity
C. an increased use of antibiotics, horizontal transfer of pathogenicity, and an increase in acquired antibiotic resistance by innocuous strains the increased use of antibiotics
D. an increased use of antibiotics coupled with an increase in acquired antibiotic resistance by innocuous strains

C

Explanation:

Infections caused by bacteria have become much more of a threat to human health due to increased use of antibiotics, horizontal transfer of pathogenicity, and an increase in acquired antibiotic resistance by innocuous strains due to the increased use of antibiotics.

Increased and unregulated use of antibiotics has led to the development of antibiotic resistance by different bacterial strains as a result of evolution by natural selection. The unregulated use of antibiotic act as a selection pressure on the bacterial population. Those that are naturally able to withstand the presence of antibiotics are selected for and the weak individuals gradually fade off from the population, leaving the strong, antibiotic-resistant ones behind.

The potential of bacterial strains to also transfer transposable genetic elements horizontally from one individual to another could make bacteria that are non-virulent before to become virulent.

Correct option: C.