What is a characteristic of narrow-spectrum antibiotics?

Narrow-spectrum antibiotics are defined by their ability to target specific types of bacteria. This selectivity means that they are effective primarily against a limited range of bacteria, often either Gram-positive or Gram-negative organisms, rather than affecting a broad array of bacterial species. This characteristic makes narrow-spectrum antibiotics particularly useful for treating infections caused by known pathogens, allowing for targeted treatment while minimizing damage to beneficial flora and reducing the risk of antibiotic resistance.

In contrast, the other options describe different aspects of antibiotic action or categorize them inaccurately. For instance, the notion that narrow-spectrum antibiotics are effective against a wide range of bacteria is actually a defining feature of broad-spectrum antibiotics. Fungi are not effectively treated with antibiotics, which specifically work against bacteria. Lastly, while antibiotics generally do not target human cells, this property does not specifically define narrow-spectrum antibiotics, as it is a characteristic common to all antibiotics, regardless of their spectrum of activity.