How can eubacteria be harmful to humans?

Eubacteria can be harmful to humans by causing a variety of infections and diseases. Pathogenic strains, such as Escherichia coli and Streptococcus pneumoniae, can lead to conditions like food poisoning, respiratory infections, and urinary tract infections. These bacteria can produce toxins that damage tissues or disrupt normal bodily functions. Additionally, antibiotic resistance in some eubacteria poses a significant public health challenge, making infections harder to treat.