Lowbury Lecture 2021: tales of the unexpected in antibiotic resistance

Since the 1990s few new antibiotics have become available; during the same period the appearance and spread of bacteria no longer susceptible to first- and second-line antibiotics has accelerated; indeed some bacterial infections have become untreatable with existing antibiotics. Control of antibiotic resistance is multifactorial, and includes restrictive antibiotic use and good infection control. This lecture addresses three aspects of antibiotic resistance, with reference to the Netherlands, that illustrate the complexity of antibiotic resistance epidemiology. Initially selective decontamination of the digestive tract (SDD) was not adopted in the Netherlands because of concern about antibiotic resistance. However, three trials showed that SDD regimens, including four days of systemic cephalosporins, gave better clinical outcomes with no effect on antibiotic-resistant bacteria. Many predictions have been made about the impact of infections with antibiotic-resistant bacteria on human health. However, the situation is complex, because the risk factors for infection with multidrug-resistant bacteria are also risk factors for poor clinical outcome. A study in eight Dutch hospitals estimated the mortality attributable to antibiotic resistance as close to zero. Concern about the emergence of resistance in Staphylococcus aureus has limited the universal use of mupirocin to prevent surgical site infections. However, the risk may have been overstated, and universal decolonization with mupirocin and chlorhexidine has now become standard of care in patients undergoing cardiothoracic or orthopaedic surgery in many Dutch hospitals. Prophylactic antibiotics can improve patient outcomes with acceptable risks of promoting resistance.