Final answer:
Antibiotics are used to kill or inhibit the growth of bacteria, which are the microorganisms targeted by such treatments. They are not effective against non-bacterial pathogens such as viruses or fungi.
Step-by-step explanation:
Antibiotics are designed to treat infections caused by bacteria. They work by killing the bacteria or inhibiting their growth. When considering microorganisms that would be killed by antibiotic treatment, typically we are referring to bacterial infections. Antibiotics are not effective against viruses, fungi, or other non-bacterial pathogens. For instance, if a patient's cerebrospinal fluid (CSF) is cultured and bacteria are found to grow, these would likely be the target of antibiotic treatment. If a patient is diagnosed with bacterial meningitis, antibiotics are often prescribed to target the bacteria, even if initial tests like a Gram stain do not show bacteria, due to the seriousness of the disease. The correct type of bacteria must be identified to ensure the prescribed antibiotic will be effective, as some are more suited for gram-positive bacteria, while others are more effective against gram-negative bacteria.