Table 1 Major characteristics of phage therapy

Narrow specificity

• Phages target specific bacterial strains rather than broad ranges of species like antibiotics

• Types of phages:

Lytic phages: they kill bacteria by causing cell lysis and are commonly used in therapy

Lysogenic phages: they integrate into bacterial DNA, sometimes spreading resistance genes

• Phage selection: effective treatment requires selecting phages tailored to the bacterial strain

Bacterial resistance

• Mechanisms include surface receptor mutations, CRISPR–Cas, restriction enzymes, and abortive infection

• Phage cocktails are used to prevent resistance and target multiple strains

Immunogenicity

• Phage proteins can trigger immune responses, reducing effectiveness in chronic infections

• Neutralizing antibodies (IgM, IgG) can diminish treatment efficacy

• Phage lysis can result in the release of bacterial toxins, causing inflammation, with adjuvant therapies being explored to reduce these effects

Inflammation caused by phage-induced bacterial lysis

• Phage-induced bacterial lysis can result in the release of bacterial components, causing acute inflammatory response