The emergence of carbapenem resistance in Enterobacteriaceae in South Africa

Abstract

The high levels of extended-spectrum ß-lactamase (ESBL) production recorded among invasive Enterobacteriaceae in South Africa, especially documented for Klebsiella pneumoniae, in both the public sector (55-74%), as reported by Bamford et al in this edition of the SAJEI, and in the private sector (55-60%) shown previously, is disconcerting.^1,2 Carbapenems are the cornerstone of therapy for patients with serious infections caused by ESBL-producing organisms. The high ESBL prevalence amongst bacteraemic pathogens places a tremendous strain on the use of these agents as directed therapy, and empirically as well. In the private sector, the use of imipenem, meropenem and ertapenem, more than doubled in terms of monthly units sold, between January 2009 and June 2011. Not only is this consumption, through selective pressure, creating the ideal environment for the development of carbapenem resistance among the enterobactericeae, but at the same time, carbapenem use has been shown to be a risk factor for subsequent infections with ESBL-producing organisms.³ Excessive use, including inappropriate duration of therapy, is therefore selecting for the very resistance that the class is being used for. A vicious cycle is established in the process. Therefore, the emergence of carbapenem resistance among Enterobacteriaceae in South Africa is inevitable, and as documented for the public sector in this edition of the SAJEI, of major concern.