Final answer:
In microbial antagonism, the presence of some microorganisms prevents others from growing. An example of microbial antagonism is Lactobacillus producing lactic acid to inhibit pathogen growth, but producing vitamin K which supports microbial growth does not represent antagonism. This has implications for preventing and managing infections. The answer is option B.
Step-by-step explanation:
The concept we are discussing here is microbial antagonism, where the presence of one microorganism inhibits the growth of another, potentially pathogenic, microorganism. Microbial antagonism often involves mechanisms such as the production of acids or bacteriocins which can target and kill other potential pathogens. However, the scenario where bacteria produce vitamin K, which allows fungi and other bacteria to grow, is likely not an example of microbial antagonism. This is because vitamin K production would support the growth of other microorganisms rather than inhibiting it.
Several examples exist to illustrate microbial antagonism: On the skin, the Staphylococcus epidermidis and Propionibacterium acnes produce bacteriocins that can kill other bacteria. In the gastrointestinal tract, beneficial bacteria like Lactobacillus spp. produce lactic acid, lowering the pH and inhibiting the growth of pathogens such as yeasts. On the other hand, antibiotic usage can disturb the balance of these beneficial microbes, leading to overgrowth of pathogenic species.
Ultimately, the presence of beneficial microbes helps prevent infections by occupying niches and producing substances that hinder pathogenic microbial colonization. When this balance is disrupted, it can lead to increased susceptibility to infections. Hence, understanding microbial interactions within the host is critical for managing and preventing diseases.