The Chromosomal Toxin Gene yafQ Is a Determinant of Multidrug Tolerance for Escherichia coli Growing in a Biofilm▿

Escherichia coli is refractory to elevated doses of antibiotics when it is growing in a biofilm, and this is potentially due to high numbers of multidrug-tolerant persister cells in the surface-adherent population. Previously, the chromosomal toxin-antitoxin loci hipBA and relBE have been linked to the frequency at which persister cells occur in E. coli populations. In the present study, we focused on the dinJ-yafQ-encoded toxin-antitoxin system and hypothesized that deletion of the toxin gene yafQ might influence cell survival in antibiotic-exposed biofilms. By using confocal laser scanning microscopy and viable cell counting, it was determined that a ΔyafQ mutant produced biofilms with a structure and a cell density equivalent to those of the parental strain. In-depth susceptibility testing identified that relative to wild-type E. coli, the ΔyafQ strain had up to a ∼2,400-fold decrease in cell survival after the biofilms were exposed to bactericidal concentrations of cefazolin or tobramycin. Corresponding to these data, controlled overexpression of yafQ from a high-copy-number plasmid resulted in up to a ∼10,000-fold increase in the number of biofilm cells surviving exposure to these bactericidal drugs. In contrast, neither the inactivation nor the overexpression of yafQ affected the tolerance of biofilms to doxycycline or rifampin (rifampicin). Furthermore, deletion of yafQ did not affect the tolerance of stationary-phase planktonic cells to any of the antibacterials tested. These results suggest that yafQ mediates the tolerance of E. coli biofilms to multiple but specific antibiotics; moreover, our data imply that this cellular pathway for persistence is likely different from that of multidrug-tolerant cells in stationary-phase planktonic cell cultures

Facilitators and barriers to implementation of Alberta family integrated care (FICare) in level II neonatal intensive care units: a qualitative process evaluation substudy of a multicentre cluster-randomised controlled trial using the consolidated framework for implementation research

ObjectiveTo evaluate the barriers and facilitators to implementing Alberta Family Integrated Care (AB-FICare [2019 Benzies]), a model of care for integrating parents into level II neonatal intensive care units (NICUs) care teams, from the perspective of healthcare providers (HCP) and hospital administrators.DesignQualitative process evaluation substudy.SettingTen level II NICUs in six cities across Alberta, Canada.ParticipantsHCP and hospital administrators (n=32) who were involved in the cluster-randomised controlled trial of AB-FICare in level II NICUs.MethodsPost-implementation semi-structured interviews were conducted via phone or in-person. The Consolidated Framework for Implementation Research was used to develop interview guides, code transcripts and analyse data.ResultsKey facilitators to implementation of AB-FICare included (1) a receptive implementation climate, (2) compatibility of the intervention with individual and organisational practices, (3) available resources and access to knowledge and information for HCP and hospital administrators, (4) engagement of key stakeholders across the organisation, (5) engagement of and outcomes for intervention participants, and (6) reflecting and evaluating on implementation progress and patient and family outcomes. Barriers were (1) design quality and packaging of the intervention, (2) relative priority of AB-FICare in relation to other initiatives, and (3) learning climate within the organisation. Mixed influences on implementation depending on contextual factors were coded to eight constructs: intervention source, cost, peer pressure, external policy and incentives, staff needs and resources, structural characteristics, organisational incentives and rewards, and knowledge, beliefs and attitudes.ConclusionsThe characteristics of an organisation and the implementation process had largely positive influences, which can be leveraged for implementation of AB-FICare in the NICU. We recommend site-specific consultations to mitigate barriers and assess how swing factors might impact implementation given the local context, with the goal that strategies can be put in place to manage their influence on implementation.Trial registration numberNCT02879799