A patient with a history of a haematological malignancy, chronic myeloid leukaemia (CML), was admitted with neutropaenic sepsis having had a low white blood cell count for months. The patient was profoundly short of breath with a PaO2 of 6kPa on 15L of oxygen. The chest X-ray showed extensive shadowing in both lungs, and the blood results show that the patient had a degree of renal impairment (their serum creatinine was raised). The Microbiology Registrar was called overnight for antibiotic advice as the patient was being wheeled from the Emergency Department to the Critical Care Unit where the intention was to provide respiratory support. What would you advise?
 
The possible cause of the patient’s pneumonia is very broad including all of the normal causes of community acquired pneumonia. However, the immunosuppression also introduces the potential of opportunistic microorganisms as well. Opportunistic infections are those caused by microorganisms which exploit the fact that the patient’s immune system doesn’t work properly but which don’t cause infection in normal patients. It is tempting to throw every treatment you can think of at this kind of patient “cos crikey they are sick”.

My last blog was about the impending doom of the post-antibiotic era and one of the points raised by readers was “what about phages”? Well it’s such a good question that this is going to be the topic of this week’s blog!
 
Bacteriophages, or “phages” as they are commonly known, are viruses that infect bacterial cells. They attach to the outside of bacterial cells and inject genes into the bacterium which causes lysis and destroys the infecting bacteria. To me they look a bit like the lunar module that NASA launched into space back in the 1960s.