Which of the following conditions is associated with a mutation in DNA gyrase, leading to antibiotic resistance in bacteria?

The correct answer relates to Escherichia coli, which is commonly associated with mutations in DNA gyrase that confer resistance to fluoroquinolone antibiotics. DNA gyrase is an essential enzyme in bacteria that plays a critical role in DNA replication by introducing negative supercoils into DNA. This action is necessary for the proper functioning of replication and transcription processes.

When mutations occur in the genes encoding DNA gyrase, such as the gyrA or gyrB genes, the enzyme's structure can change, leading to a decreased binding affinity for fluoroquinolones. As a result, bacteria like Escherichia coli can survive despite the presence of these antibiotics, thereby displaying antibiotic resistance. This resistance is particularly significant because fluoroquinolones are often used as a first-line treatment for various bacterial infections.

Other bacterial species listed are also known to develop antibiotic resistance mechanisms, but the specific connection to mutations in DNA gyrase is most prominently associated with Escherichia coli. Understanding this relationship highlights the importance of monitoring genetic mutations and their implications in clinical microbiology and antibiotic treatment strategies.