The invention provides methods for treating or preventing microbial (eg, bacterial) infections and means for performing these methods. In particular, treatment of infections requiring rapid and durable therapy is made possible, such as for treating acute conditions such as septicemia, sepsis, SIRS or septic shock. The invention is particularly useful, for example, for treatment of microbes such as for environmental, food and beverage use. The invention relates inter alia to methods of controlling microbiologically influenced corrosion (MIC) or biofouling of a substrate or fluid in an industrial or domestic system. The invention also useful for the treatment of pathogenic bacterial infections in subjects receiving a treatment for a disease or condition, such as a transplant or a treatment for cancer, a viral infection or an autoimmune disease.