SPaCE Swab: Point-of-Care Sensor for Simple and Rapid Detection of Acute Wound Infection.

Wound infection is commonly observed after surgery and trauma but is difficult to diagnose and poorly defined in terms of objective clinical parameters. The assumption that bacteria in a wound correlate with infection is false; all wounds contain microorganisms, but not all wounds are clinically infected. This makes it difficult for clinicians to determine true wound infection, especially in wounds with pathogenic biofilms. If an infection is not properly treated, pathogenic virulence factors, such as rhamnolipids from Pseudomonas aeruginosa, can modulate the host immune response and cause tissue breakdown. Life-threatening sepsis can result if the organisms penetrate deep into host tissue. This communication describes the sensor development for five important clinical microbial pathogens commonly found in wounds: Staphylococcus aureus, P. aeruginosa, Candida albicans/auris, and Enterococcus faecalis (the SPaCE pathogens). The sensor contains liposomes encapsulating a self-quenched fluorescent dye. Toxins, expressed by SPaCE infecting pathogens in early-stage infected wounds, break down the liposomes, triggering dye release, thus changing the sensor color from yellow to green, an indication of infection. Five clinical species of bacteria and fungi, up to 20 strains each (totaling 83), were grown as early-stage biofilms in ex vivo porcine burn wounds. The biofilms were then swabbed, and the swab placed in the liposome suspension. The population density of selected pathogens in a porcine wound biofilm was quantified and correlated with colorimetric response. Over 88% of swabs switched the sensor on (107-108 CFU/swab). A pilot clinical study demonstrated a good correlation between sensor switch-on and early-stage wound infection.

Risk taking in general practice: GP out-of-hours referrals to hospital.

BACKGROUND: Emergency admissions to hospital at night and weekends are distressing for patients and disruptive for hospitals. Many of these admissions result from referrals from GP out-of-hours (OOH) providers. AIM: To compare rates of referral to hospital for doctors working OOH before and after the new general medical services contract was introduced in Bristol in 2005; to explore the attitudes of GPs to referral to hospital OOH; and to develop an understanding of the factors that influence GPs when they refer patients to hospital. DESIGN OF STUDY: Cross-sectional comparison of admission rates; postal survey. SETTING: Three OOH providers in south-west England. METHOD: Referral rates were compared for 234 GPs working OOH, and questionnaires explored their attitudes to risk. RESULTS: There was no change in referral rates after the change in contract or in the greater than fourfold variation between those with the lowest and highest referral rates found previously. Female GPs made fewer home visits and had a higher referral rate for patients seen at home. One-hundred and fifty GPs responded to the survey. Logistic regression of three combined survey risk items, sex, and place of visit showed that GPs with low 'tolerance of risk' scores were more likely to be high referrers to hospital (P<0.001). CONCLUSION: GPs' threshold of risk is important for explaining variations in referral to hospital.