Does Antibiotic Resistance Evolve in Hospitals?

Abstract

Nosocomial outbreaks of bacteria are well documented. Based on these incidents, and the heavy usage of antibiotics in hospitals, it has been assumed that antibiotic resistance evolves in hospital environments. To test this assumption, we studied resistance phenotypes of bacteria collected from patient isolates at a community hospital over a 2.5-year period. A graphical model analysis shows no association between resistance and patient information other than time of arrival. This allows us to focus on time-course data. We introduce a hospital transmission model, based on negative binomial delay. Our main contribution is a statistical hypothesis test called the Nosocomial Evolution of Resistance Detector (NERD). It calculates the significance of resistance trends occurring in a hospital. It can inform hospital staff about the effects of various practices and interventions, can help detect clonal outbreaks, and is available as an R package. We applied the NERD method to each of the 16 antibiotics in the study via 16 hypothesis tests. For 13 of the antibiotics, we found that the hospital environment had no significant effect on the evolution of resistance; the hospital is merely a piece of the larger picture. The p-values obtained for the other three antibiotics (cefepime, ceftazidime, and gentamicin) indicate that particular care should be taken in hospital practices with these antibiotics. One of the three, ceftazidime, was significant after accounting for multiple hypotheses, indicating a trend of decreased resistance for this drug.

Metapopulation ecology links antibiotic resistance, consumption and patient transfers in a network of hospital wards

“…The low influence of connectivity on the incidence of resistant E. cloacae complex variants can be explained by their local selection. While resistance in E. coli and K. pneumoniae typically requires gene acquisition 34,35 , E. cloacae complex can resist cephalosporins and carbapenems through increased AmpC betalactamase and decreased porin expression [36][37][38] . Such resistance emerges through adaptation and de novo mutations that are rapidly selected from the local reservoir of susceptible progenitors 39,40 .…”

“…The rationale behind hospital-based antibiotic stewardship is based on the assumption that AMR evolves in hospitals. Yet, there is surprisingly limited evidence to support this assumption [36][37][38] . Ecological studies have repeatedly identified associations between the use of antibiotics and AMR prevalence, but such associations do not necessarily reflect AMR selection 19 .…”

Water-Based Scalable Methods for Self-Cleaning Antibacterial ZnO-Nanostructured Surfaces

“…1 Additionally, recent research is pointing out that there is growing antibiotic resistance of pathogens in hospitalized patients. 2 − 4 Methicillin-resistant Staphylococcus aureus is a characteristic example because its treatment is still a significant challenge worldwide. 5 − 8 Using smart antibacterial materials in hospitals could halt the transmission of such pathogens.…”

Growth rate assays reveal fitness consequences of β-lactamases

“…Moreover, many isolates of bacteria are resistant to multiple antibiotics so identifying appropriate treatments remains a challenge [14]. We have previously used these patient isolates to study broad trends in resistance [15]; in this work we study the correlation between isolate growth rates and clinical resistance classifications as well as the presence of known resistance genes.…”