The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England.

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

Surveillance of Antibacterial Usage during the COVID-19 Pandemic in England, 2020.

Changes in antibacterial prescribing during the COVID-19 pandemic were anticipated given that the clinical features of severe respiratory infection syndrome caused by SARS-CoV-2 mirror bacterial respiratory tract infections. Antibacterial consumption was measured in items/1000 population for primary care and in Defined Daily Doses (DDDs)/1000 admissions for secondary care in England from 2015 to October 2020. Interrupted time-series analyses were conducted to evaluate the effects of the pandemic on antibacterial consumption. In the community, the rate of antibacterial items prescribed decreased further in 2020 (by an extra 1.4% per month, 95% CI: -2.3 to -0.5) compared to before COVID-19. In hospitals, the volume of antibacterial use decreased during COVID-19 overall (-12.1% compared to pre-COVID, 95% CI: -19.1 to -4.4), although the rate of usage in hospitals increased steeply in April 2020. Use of antibacterials prescribed for respiratory infections and broad-spectrum antibacterials (predominately 'Watch' antibacterials in hospitals) increased in both settings. Overall volumes of antibacterial use at the beginning of the COVID-19 pandemic decreased in both primary and secondary settings, although there were increases in the rate of usage in hospitals in April 2020 and in specific antibacterials. This highlights the importance of antimicrobial stewardship during pandemics to ensure appropriate prescribing and avoid negative consequences on patient outcomes and antimicrobial resistance.

Antimicrobial stewardship: an evaluation of structure and process and their association with antimicrobial prescribing in NHS hospitals in England.

BACKGROUND: Rigorous antimicrobial stewardship programmes (ASPs) are an essential strategy against antimicrobial resistance. OBJECTIVES: To evaluate and score ASPs in acute English NHS hospitals and determine association of ASP scores with antimicrobial prescribing. METHODS: ASP structure and process were evaluated through an online survey in 148/152 acute hospitals in 2017. Scores were assigned to quality indicators based on resource- and labour-intensiveness, and their association with total and modified WHO-categorized 'Access', 'Watch' and 'Reserve' (AwaRe) prescribing was analysed. RESULTS: The survey response rate was 97% with 78% of trusts submitting antimicrobial prescribing data. Over 80% of ASPs contained stewardship teams, policies and access to outpatient parenteral antimicrobial therapy, whilst less than 50% scored well for leadership or funding. High process performance was observed for antimicrobial pre-authorization, prescribing review and feedback, restricted susceptibility reporting, antimicrobial consumption monitoring, adherence to guidelines and junior doctor training. Low process attainment included education of senior prescribers and lack of resistance surveillance data distribution. Between 2016 and 2017, there was no difference in total trust prescribing (P = 0.117) although carbapenem prescribing fell (incidence rate ratio = 0.93, 95% CI 0.88-0.98) in non-teaching hospitals; 'Watch' prescribing also increased for specialist hospitals (OR = 1.10, 95% CI 1.01-1.20), as did 'Reserve' category prescribing in teaching (OR = 1.58, 95% CI 1.23-3.02) and specialist hospitals (OR = 3.09, 95% CI 2.02-4.74). A high process score was associated with lower 'Reserve' prescribing (OR = 0.82, 95% CI 0.67-1.01). CONCLUSIONS: All responding trusts had established ASPs. The association of a scoring system with total and 'AWaRe' prescribing to assess effectiveness of ASPs merits further study.

A process evaluation of the UK-wide Antibiotic Guardian campaign: developing engagement on antimicrobial resistance.

Background: Public Health England developed and led a new UK-wide pledge campaign aiming to improve behaviours around the prudent use and prescription of antibiotics. This paper presents a process evaluation for the first season of the campaign to determine the impact of the campaign and inform future campaigns. Methods: Data were collected from AntibioticGuardian.com and Google analytics between August 2014 and January 2015. The primary outcome was the decision to pledge and was assessed according to target audience, location, source and route of referral to the website. Results: There were 47 158 unique visits to the website and 12 509 visitors made a pledge (26.5%) to become Antibiotic Guardians (AGs); 69% were healthcare professionals. Social media directed the most traffic to the website (24% of the public that signed up cited social media as how they discovered the campaign), other acquisition routes such as self-directed, email or website referral, were more effective at encouraging visitors to pledge. Conclusions: The campaign completed its goal of 10 000 AGs in the first year. Further work is required to improve engagement with target audiences and determine whether this campaign has an impact on antibiotic consumption and prescribing behaviour among the public and healthcare professionals.

Large mobile genetic elements carrying resistance genes that do not confer a fitness burden in healthcare-associated meticillin-resistant Staphylococcus aureus.

Healthcare-associated (HA) meticillin-resistant Staphylococcus aureus (MRSA) clone CC22 SCCmecIV (EMRSA-15) has recently overtaken CC30/ST36 SCCmecII (EMRSA-16) as the dominant clone in UK hospitals. CC22 SCCmecIV shows greater fitness than CC30 SCCmecII, although both are successful global pathogens. The aim of this study was to test whether mobile genetic elements (MGEs), specifically SCCmec and large plasmids encoding resistance genes, are a burden and contribute to this fitness difference. Thirty-nine clinical isolates of MRSA and meticillin-sensitive S. aureus from lineages CC30 and CC22 with a variety of antibiotic resistance genes were grown in the absence of antibiotics. A range of relative fitness measures were used to compare clinical isolates with and without SCCmecII and SCCmecIV. The same fitness measures were used to compare eight isolates with and without naturally occurring large antibiotic resistance plasmids carrying gentamicin resistance (determined by microarray) and an isolate with an introduced plasmid. Growth rate, competitive ability during co-culture and survival after desiccation were then compared. Carriage of SCCmecII contributed to the reduced fitness of CC30 MRSA. However, we found no evidence of a fitness cost due to carriage of SCCmecIV in CC22, or large antibiotic resistance plasmids in CC30 or multiple resistances in both lineages. In conclusion, many large MGEs are not a fitness burden. Surprisingly, lineage background was the most important determinant of fitness. Our results suggest CC22 SCCmecIV will remain a successful healthcare-associated clone, and resistance to meticillin and gentamicin is likely to be maintained even in the absence of antibiotic pressure.

Shift in dominant hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) clones over time.

OBJECTIVES: The majority of HA-MRSA infections are caused by endogenous infection and by only a small number of clones. The reasons for the success of some clones over others are unknown. METHODS: We investigated the evolution of an MRSA population from a large, acute-care teaching hospital in London, UK over a 10 year period. MRSA incidence and antibiotic prescribing were correlated with changes in resistance genes and prevalence of clonal groups. RESULTS: Three clones caused the majority of infections, CC30 SCCmecII (EMRSA-16), CC22 SCCmecIV (EMRSA-15) and ST239 SCCmecIII. Clones that were multidrug resistant were selected for, and CC22 became dominant once it acquired a wide range of extra resistance genes. CC22 MRSA was also the fittest clone in an independent growth assay and a competition assay, and had a greater ability to survive desiccation. No individual isolate was fully drug resistant, and there was evidence of substantial horizontal gene transfer (HGT) as well as resistance gene loss within the clonal groups. The exception was fluoroquinolone resistance, which was rarely lost by any of the dominant hospital clones, suggesting that this resistance contributes to selection and survival of HA-MRSA. In support of this, a decrease in hospital-wide ciprofloxacin (a fluoroquinolone) prescribing was strongly associated with an overall decrease in MRSA infection. CONCLUSION: Our data suggest successful HA-MRSA clones such as CC22 SCCmecIV are resistant to fluoroquinolones as well as fitter and able to acquire, but not necessarily accumulate, resistance to a wide range of additional antibiotics.

Shuffling of mobile genetic elements (MGEs) in successful healthcare-associated MRSA (HA-MRSA).

Methicillin-resistant Staphylococcus aureus (MRSA) CC22 SCCmecIV is a successful hospital-associated (HA-) MRSA, widespread throughout the world, and now the dominant clone in UK hospitals. We have recently shown that MRSA CC22 is a particularly fit clone, and it rose to dominance in a UK hospital at the same time as it began acquiring an increased range of antibiotic resistances. These resistances were not accumulated by individual CC22 isolates, but appear to shuffle frequently between isolates of the MRSA CC22 population. Resistances are often encoded on mobile genetic elements (MGEs) that include plasmids, transposons, bacteriophage and S. aureus pathogenicity islands (SaPIs). Using multi-strain whole genome microarrays, we show that there is enormous diversity of MGE carried within a MRSA CC22 SCCmecIV population, even among isolates from the same hospital and time period. MGE profiles were so variable that they could be used to track the spread of variant isolates within the hospital. We exploited this to show that the majority of patients colonised with MRSA at hospital admission that subsequently became infected were infected with their own colonising isolate. Our studies reveal MGE spread, stability, selection and clonal adaptation to the healthcare setting may be key to the success of HA-MRSA clones, presumably by allowing rapid adaptation to antibiotic exposure and new hosts.