Question

31. An example of vertical gene transfer of antibiotic resistance is the

a. development of vancomycin resistance via the acquisition of an Enterococcus resistance gene

b. uptake of beta-lactamase genes by Streptococcus pneumoniae.

c. development of antibiotic resistance via ribosomal mutation.

d. transduction of an antibiotic resistance cassette from one strain of MRSA to another.

e. transfer of conjugative plasmids carrying resistances genes from one strain to another.

Answer 1

31. C. Development of antibiotic resistance via ribosomal mutation is an example of vertical gene transfer of antibiotic resistance.

Vertical gene transfer is the mechanism by which transfer of genetic material occurs between parents and offspring. Therefore the offspring will acquire the characteristics from the parent. This contributes to antibiotic resistance development in bacteria. When bacteria grow in the presence of an antibiotic, mutations occurring in them may confer to evolution of the strain to survive in the environment by producing proteins that degrade the compound. Ribosomal mutations also contribute to evolution of bacterial strains with antibiotic resistance.

Development of resistance by acquisition of genes from other bacterium or the transfer of conjugative plasmids from one to another is an example of conjugation. Uptake of genes from the environment by competent bacterium is transformation. Note that conjugation, transformation and transduction are all types of horizontal gene transfer mechanisms.