Fourteen years in resistance

Abstract

Resistance trends have changed greatly over the 14 years (1997-2011) whilst I was Director of the UK Antibiotic Resistance Monitoring and Reference Laboratory (ARMRL). Meticillin-resistant Staphylococcus aureus (MRSA) first rose, then fell with improved infection control, although with the decline of one major clone beginning before these improvements. Resistant pneumococci too have declined following conjugate vaccine deployment. If the situation against Gram-positive pathogens has improved, that against Gram-negatives has worsened, with the spread of (i) quinolone- and cephalosporin-resistant Enterobacteriaceae, (ii) Acinetobacter with OXA carbapenemases, (iii) Enterobacteriaceae with biochemically diverse carbapenemases and (iv) gonococci resistant to fluoroquinolones and, latterly, cefixime. Laboratory, clinical and commercial aspects have also changed. Susceptibility testing is more standardised, with pharmacodynamic breakpoints. Treatments regimens are more driven by guidelines. The industry has fewer big profitable companies and more small companies without sales income. There is good and bad here. The quality of routine susceptibility testing has improved, but its speed has not. Pharmacodynamics adds science, but over-optimism has led to poor dose selection in several trials. Guidelines discourage poor therapy but concentrate selection onto a diminishing range of antibiotics, threatening their utility. Small companies are more nimble, but less resilient. Last, more than anything, the world has changed, with the rise of India and China, which account for 33% of the world's population and increasingly provide sophisticated health care, but also have huge resistance problems. These shifts present huge challenges for the future of chemotherapy and for the edifice of modern medicine that depends upon it.