Nitrofurantoin resistance as an indicator for multidrug resistance: an assessment of <i>Escherichia coli</i> urinary tract specimens in England, 2015–19
Rebecca Guy, Jamie Rudman, Hannah Higgins, Emma Carter, Katherine L. Henderson, Alicia Demirjian, Sarah Gerver
Abstract
Abstract Objectives To determine whether MDR occurs more frequently in nitrofurantoin-resistant Escherichia coli urinary isolates in England, compared with nitrofurantoin-susceptible isolates. Methods Using routine E. coli urine isolate antibiotic susceptibility laboratory surveillance data for England, 2015–19 inclusive, the percentage of MDR or XDR phenotype was estimated for nitrofurantoin-susceptible and nitrofurantoin-resistant laboratory-reported urinary tract samples by region, patient sex and age group. Results Resistance to nitrofurantoin among E. coli urinary samples decreased slightly year on year from 2.9% in 2015 to 2.3% in 2019. Among E. coli UTIs tested for nitrofurantoin susceptibility and ≥3 additional antibiotics, the percentage that were MDR was consistently 15%–20% percentage points higher for nitrofurantoin-resistant isolates compared with nitrofurantoin-susceptible isolates. Similarly, the percentage of isolates with an XDR phenotype was higher among nitrofurantoin-resistant versus -susceptible isolates (8.7% versus 1.4%, respectively, in 2019); this disparity was greater in male patients, although variation was seen by age group in both sexes. Regional variation was also noted, with the highest MDR percentage amongst nitrofurantoin-resistant E. coli urinary samples in the London region (36.7% in 2019); the lowest was in the North East (2019: 16.9%). Conclusions MDR and XDR phenotypes occur more frequently in nitrofurantoin-resistant E. coli urinary isolates in England, compared with nitrofurantoin-susceptible isolates. However, nitrofurantoin resistance is low (&lt;3%) overall. This latest study provides important insights into trends in nitrofurantoin resistance and MDR, which is of particular concern for patients ≥75 years old and those who are male. It also emphasises geographical heterogeneities within England in nitrofurantoin resistance and MDR.