Hospital-acquired infections

Healthcare-Associated Adverse Events in Alternate Level of Care Patients Awaiting Long-Term Care in Hospital

INTRODUCTION

A growing number of Canadian older adults are designated alternate level of care (ALC) and await placement into long-term care (LTC) while admitted to hospital. This creates infrastructural challenges by using resources allocated for acute care during disproportionately long hospital stays. For ALC patients, hospital environments maladapted to their needs impart risk of healthcare-associated adverse events.

METHODS

In this retrospective descriptive study, we examined healthcare-associated adverse events in 156 ALC patients, 65 years old and older, awaiting long-term care while admitted to two hospitals in London, Ontario in 2015-2018. We recorded incidence of infections and antimicrobial days prescribed. We recorded incidence of non-infectious adverse events including delirium, falls, venothrombotic events, and pressure ulcers. We used a restricted cubic spline model to characterize adverse events as a function of length of stay.

RESULTS

Patients waited an average of 56 ALC days (ranging from 6 to 333 days) before LTC placement, with seven deaths occurring prior to placement. We recorded 362 total adverse events accrued over 8668 ALC days: 94 infections and 268 non-infectious adverse events. The most common hospital-acquired infections were urinary-tract infections and respiratory infections. The most common non-infectious adverse events were delirium and falls. A total of 620 antimicrobial days were prescribed for infections.

CONCLUSIONS

ALC patients incur a meaningful and predictable number of adverse events during their stay in acute care. The incidence of these adverse events should be used to educate stakeholders on risks of ALC stay and to advocate for strategies to minimize ALC days.

Phytochemical profiling as a solution to palliate disinfectant limitations

The indiscriminate use of biocides for general disinfection has contributed to the increased incidence of antimicrobial tolerant microorganisms. This study aims to assess the potential of seven phytochemicals (tyrosol, caffeic acid, ferulic acid, cinnamaldehyde, coumaric acid, cinnamic acid and eugenol) in the control of planktonic and sessile cells of Staphylococcus aureus and Escherichia coli. Cinnamaldehyde and eugenol showed antimicrobial properties, minimum inhibitory concentrations of 3-5 and 5-12 mM and minimum bactericidal concentrations of 10-12 and 10-14 mM against S. aureus and E. coli, respectively. Cinnamic acid was able to completely control adhered bacteria with effects comparable to peracetic acid and sodium hypochlorite and it was more effective than hydrogen peroxide (all at 10 mM). This phytochemical caused significant changes in bacterial membrane hydrophilicity. The observed effectiveness of phytochemicals makes them interesting alternatives and/or complementary products to commonly used biocidal products. Cinnamic acid is of particular interest for the control of sessile cells.

Natural extracts stimulate membrane-associated mechanisms of resistance in Gram-negative bacteria

Several mechanisms are involved in the bacterial resistance towards antimicrobial agents. The membrane-associated mechanisms of resistance were studied in Escherichia coli strains after incubation with Thymus maroccanus essential oil, its major components (carvacrol and thymol) or with certain antibiotics. The minimum inhibitory concentration (MIC) and the expression of membrane proteins, porins and efflux pumps were determined in wild type and derivative strains. Derivative strains adapted to different compounds displayed a high level of resistance to all tested antibiotics. The MIC increase is associated with an overexpression of an efflux pump immunorelated to AcrAB-TolC in various variants. Interestingly, the expression of outer membrane proteins slightly decreases in these strains. We demonstrate that the increase in antibiotic resistance correlates with membrane changes observed in the variants. This type of bacterial adaptation to natural compounds can occur in vivo providing the emergence/selection of bacteria less susceptible to clinically used antibiotics.

SIGNIFICANCE AND IMPACT OF THE STUDY

Thymus maroccanus essential oil and some major components are able to select variants that modify the expression of transporters involved in the influx (porins) and in the efflux (AcrAB family) of various drugs. Importantly, these membrane proteins are involved in the transport of natural compounds and several antibiotic families. This special 'membrane adaptation' can explain the persistence of less susceptible/tolerant bacteria in the environment where natural compounds are present and the continuous stimulation of efflux systems in these bacteria.