Final answer:
Antibiotics are designed to kill bacteria, affecting both gram-positive and gram-negative types, but they are not effective against viruses, fungi, or other non-bacterial pathogens.
Step-by-step explanation:
The types of microorganisms that would be killed by antibiotic treatment are primarily bacteria. This is because antibiotics are designed to target bacterial cells, hindering their ability to multiply, damaging their cell walls, or interfering with their metabolic processes. Depending on the antibiotic's mechanism of action, it can be effective against gram-positive and gram-negative bacteria.
It's essential to note that antibiotics are not effective against viral infections, as the structure and life cycle of viruses are significantly different from those of bacteria. Moreover, antibiotics also do not affect fungi or other non-bacterial pathogens unless the antibiotic has specific anti-fungal properties.
In Cora's case, even though the Gram stain did not show any bacteria, her doctor prescribed antibiotics as a precautionary measure to eliminate any potential bacterial infection that might not have been detected by the Gram stain but could still be present at low levels or in a form that is not easily visible under the microscope.