Question

please help me (make sure the answers are correct please)

The author of a general biology textbook writes in reference to the development of antibiotic resistance, "The speed at which bacteria reproduce ensures that sooner or later a mutant bacterium will appear that is able to resist the antibiotic." How might this mutant bacterial cell appear? In 1976, an outbreak of pulmonary (lung) infections among participants at an American Legion convention in Philadelphia led to the identification of a new disease: Legionnaires' Disease. The bacterial organism, Legionella pneumophila, responsible for the disease, had never before been known to be pathogenic. From your knowledge of bacterial genetics, explain how it might have acquired the ability to cause disease.

Answer 1

Answer 4. As in bacteria DNA replication and transcription co-occur and uses the same template DNA so when there is an error during the DNA replication due to any reason it results in changes in the cell as the replication rate is higher in bacterial cells. They reproduce quickly and so multiple generations can carry and start expressing the mutated genes in a very short amount of time. Thus any new characteristic can get acquired in a very short amount of time and can lead to the development of a new strain of bacteria.

Answer 5. It is considered that L. pneumophila acquired its pathogenicity outside human i.e. in its protozoan host. It took up some characteristics from its protozoan host and mutated which when replicated gave the bacterium the characteristic to cause infection to humans if it comes in contact with the human alveolar macrophage cells. So, basically it just evolved or mutated its ability of causing inffection to host and applied it to humans.