Outcome and feasibility of radiotherapy bridging in large B-cell lymphoma patients receiving CD19 CAR T in the UK

Radiotherapy (RT) has potential synergistic effects with chimeric antigen receptor (CAR) T but is not widely used as bridging therapy due to logistical challenges and lack of standardised protocols. We analysed RT bridging in a multicentre national cohort of large B-cell lymphoma patients approved for 3L axicabtagene ciloleucel or tisagenlecleucel across 12 UK centres. Of 763 approved patients, 722 were leukapheresed, 717 had data available on bridging therapy. 169/717 (24%) received RT bridging, 129 as single modality and 40 as combined modality treatment (CMT). Of 169 patients, 65.7% had advanced stage, 36.9% bulky disease, 86.5% elevated LDH, 41.7% international prognostic index (IPI) ≥3 and 15.2% double/triple hit at the time of approval. Use of RT bridging varied from 11% to 32% between centres and increased over time. Vein-to-vein time and infusion rate did not differ between bridging modalities. RT-bridged patients had favourable outcomes with 1-year progression-free survival (PFS) of 56% for single modality and 47% for CMT (1-year PFS 43% for systemic bridging). This is the largest cohort of LBCL patients receiving RT bridging prior to CAR T reported to date. Our results show that RT bridging can be safely and effectively used even in advanced stage and high-risk disease, with low dropout rates and excellent outcomes.

Parents' priorities and preferences for treatment of children with ADHD: Qualitative inquiry in the MADDY study

BACKGROUND

Parents' lived experiences of having a child with ADHD may shape their decision making regarding ADHD treatment options for their child. The aim of this study was to explore parents' experiences of living with a child with ADHD in the family and how their experiences influence their perspectives on treatment preferences and priorities.

METHODS

A phenomenological qualitative design was used. Semistructured interviews were conducted with parents of children with ADHD who were enrolled in a multisite randomized controlled trial. Interviews were transcribed verbatim, and transcripts at each site were double coded. Initial codes were derived directly from the text. Qualitative data were analysed with an inductive approach.

RESULTS

Twenty-three parents were interviewed: eight from Alberta, Canada; eight from Portland, Oregon, USA; and seven from Columbus, Ohio, USA. Among the parents, 69% were married, 86% completed college education and 52% reported household income over $80,000. Among the children, the mean age was 9.6 years (SD = 1.8 years), 78% were boys and 48% were never medicated for their ADHD. Two major themes emerged from the analysis. Theme 1 was 'impact of ADHD on families within and outside the home' with the following subthemes: 'reconfiguring the home life', 'trial-and-error of accommodations at school' and 'responding to social pressures to fit in'. Theme 2 was 'enabling appropriate and accessible treatments for families' with the following subthemes: 'finding the "right fit" with professionals and treatments' and 'factors influencing inequitable access to treatments'.

CONCLUSIONS

Parents described shared experiences and identified similar barriers, preferences and priorities for ADHD treatments regardless of demographic differences by site. Families desired access to family-centred, multimodal approaches to ADHD treatment. Further research is needed to identify the specific structural changes to healthcare, services and policies that will better support this approach.

OP0038 VITAMIN D AND MARINE n-3 FATTY ACID SUPPLEMENTATION FOR PREVENTION OF AUTOIMMUNE DISEASE IN THE VITAL RANDOMIZED CONTROLLED TRIAL: OUTCOMES OVER 7 YEARS

Background

Strong biologic rationale supports both vitamin D and marine omega-3 (n-3) fatty acids for prevention of autoimmune disease (AD). Within the randomized, double-blind, placebo-controlled VITamin D and OmegA-3 TriaL (VITAL), we tested the effects of these supplements on AD incidence. We previously reported results after 5.3 years of randomized follow-up showing overall protective effects for vitamin D on AD incidence (HR 0.78, 95% CI 0.61-0.99) and suggestive results for n-3 fatty acids (HR 0.85, 95%CI 0.67-1.08)1.

Objectives

We aimed to test effects of these supplements with two more years of post-intervention follow-up in VITAL.

Methods

VITAL enrolled and randomized men and women (age ≥50 and ≥55 years, respectively) in a 2-by-2 factorial design to vitamin D3 (2000 IU/d) and/or n-3 fatty acids (1000 mg/d) or placebo and followed for median 5.3 years. Here, we followed participants for another 2 years of observation to assess for sustained effects. Incident AD diagnoses were reported by participants annually and confirmed by medical record review by expert physicians using existing classification criteria. The primary endpoint was total incident AD, including rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), autoimmune thyroid disease (AITD), psoriasis, and all others. Pre-specified secondary endpoints included individual common AD; and probable AD. Cox models calcuated hazard ratios (HR) for incident ADs.

Results

Of 25,871 participants randomized, 71% self-reported non-Hispanic Whites, 20% Black, 9% other racial/ethnic groups, 51% women, mean age was 67.1 years. During 7.5 years median follow-up, confirmed AD was diagnosed in 156 participants in vitamin D arm vs 198 in vitamin D placebo arm, HR 0.79 (0.64-0.97). Incident AD was confirmed in 167 participants in n-3 fatty acid arm and 187 in n-3 fatty acid placebo arm, HR 0.89 (0.72-1.10). For vitamin D, HRs trended toward reduction for RA 0.67 (0.37- 1.21), PMR 0.69 (0.46-1.03) and psoriasis 0.57 (0.33-0.99). For n-3 fatty acids, HRs trended toward reduction for RA 0.55 (0.30-1.10) and AITD 0.61 (0.33-1.12). Vitamin D’s effect on AD incidence was stronger in those with body mass index (BMI) < 25 (HR 0.65, 0.44-0.96) than ≥ 25 kg/m2 (p interaction 0.01).

Conclusion

Supplementation for 5.3 years with 2000 IU/day vitamin D (compared to placebo), followed by 2 years of observational follow-up, significantly reduced overall incident AD by 21% in older adults. HRs for RA, PMR and psoriasis trended toward reduction with vitamin D, with stronger effect in those with normal BMI. Supplementation with 1000 mg/day n-3 fatty acids did not significantly reduce total AD.

References

[1]Hahn J et al, BMJ, 2022 Jan 26;376: e066452.

Table 1.

Hazard Ratios for Primary and Secondary Endpoints, by Randomized Assignment to Vitamin D/Placebo (Left), N-3 Fatty Acids/Placebo (Right)a

EndpointVitamin D3(N=12,927)Placebo (N=12,944)Hazard Ratio (95% CI)pN-3 Fatty Acids (N=12,933)Placebo (N=12,938)Hazard Ratio (95% CI)pPrimary: Confirmed AD1561980.79 (0.64-0.97)0.031671870.89 (0.72-1.10)0.27Secondary:Confirmed + probable AD2653210.83 (0.70-0.97)0.022713150.86 (0.73-1.01)0.06Excluding subjects with any pre-randomization AD Confirmed AD1271620. 79 (0.62-0.99)0.041411480.95 (0.75-1.20)0.66 Confirmed + probable AD2112700. 78 (0.65-0.94)0.0072322490.93 (0.78-1.11)0.41Excluding first 2 years follow-up Confirmed AD861300.66 (0.50-0.87)0.0031041120.92 (0.71-1.21)0.56 Confirmed + probable AD1472050.72 (0.58-0.89)0.0021721800.95 (0.77-1.17)0.63Individual ADb RA18270.67 (0.37-1.21)0.1816290.55 (0.30-1.01)0.06 PMR39570.69 (0.46-1.03)0.0746500.92 (0.61-1.37)0.67 AITD27181.50 (0.82-2.71)0.1917280.61 (0.33-1.12)0.11 Psoriasis20350.57 (0.33-0.99)0.0534211.62 (0.94-2.79)0.08

aAnalyses from Cox regression models controlled for age, sex, race, and other (n-3 fatty acid or vitamin D) randomization group bConfirmed AD.

Figure 1.

Disclosure of Interests

Karen Costenbader Consultant of: Astra Zeneca, Glaxo Smith Kline, Neutrolis, Grant/research support from: Merck, Exagen, Gilead, Nancy Cook: None declared, I-min Lee: None declared, Jill Hahn: None declared, Joseph Walter: None declared, Vadim Bubes: None declared, Gregory Kotler: None declared, Nicole Yang: None declared, Sonia Friedman: None declared, Erik Alexander: None declared, JoAnn Manson: None declared.

Ileal pouch-anal anastomosis in ulcerative colitis: outcomes, functional results, and quality of life in patients with more than 10-year follow-up

PURPOSE

Ileal pouch-anal anastomosis (IPAA) has become the surgical procedure of choice for patients with ulcerative colitis (UC). IPAA was incorporated into our institution in 1984, and thereafter, more than 200 procedures have been performed. The functional results and morbidity of this surgery have been reported previously. However, long-term functional outcomes and quality of life have not been evaluated.

METHODS

As a cohort study, we identified all consecutive patients who underwent IPAA for UC between 1984 and 2017 and selected those with more than 10-year follow-up. Demographic data, morbidity, and pouch survival information were obtained. Long-term functional results and quality of life were evaluated through an e-mail survey using the Öresland score and the Cleveland Global Quality of Life scales, respectively.

RESULTS

Of 201 patients, 116 met the inclusion criteria. Median follow-up was 20 (10-34) years. Early post-operative complications (30 days) were observed in 19 (16.4%) patients and 66 (56.9%) presented adverse events. The IPAA preservation rate at 10 and 20 years was 96.5% and 93.1%, respectively. Long-term functional scores presented a median of 6 (1-15) points. IPAA function was satisfactory in 11 (20.0%) patients, acceptable in 18 (32.7%), and deficient in 26 (47.3%). The median score for global quality of life was 0.8 (0.23-1.0) points.

CONCLUSION

IPAA as treatment for UC meets the expectations of cure of the disease, maintaining adequate long-term intestinal functionality associated with a good quality of life in most patients.

Influence of subsidies and promotional strategies on outcomes in a beneficiary-based commercial weight-loss programme

To determine whether initial engagement, continued participation, and weight loss vary by subsidy and promotional strategies in a beneficiary-based, commercial weight-loss programme. We conducted a retrospective analysis of data from 2013 to 2016. Our dependent variables included initial engagement (≥1 calls; ≥2 weights), coach calls and weight change. Our independent variables were subsidy strategy (total subsidy (n = 9) vs cost sharing (n = 3)) and combination of promotional-subsidy strategies (mixed campaign + total subsidy (n = 6) vs mass media + total subsidy (n = 3)). We used logistic and linear regression analyses adjusted for beneficiary factors and clustering by organization. From 12 participating organizations, 26 068 beneficiaries registered of which 6215 initially engaged. Cost sharing was associated with significantly greater initial engagement as compared to total subsidy (OR 3.73, P < 0.001); however, no significant between-group differences existed in calls or weight change. Mass media + total subsidy group had significantly greater calls and weight loss at 12 months compared to mixed campaign + total subsidy (-2.6% vs -1.8%, P = 0.04). Cost sharing may promote greater initial engagement, although does not contribute to better participation or weight loss relative to total subsidy. If organizations elect total subsidy, then pairing this strategy with a mass media campaign may promote greater participation and weight loss among beneficiaries.

Effects of a behavioural weight loss intervention in people with serious mental illness: Subgroup analyses from the ACHIEVE trial

BACKGROUND

Persons with serious mental illnesses (SMI) such as schizophrenia and bipolar disorder have an increased risk of obesity and related chronic diseases and die 10-20years earlier than the overall population, primarily due to cardiovascular disease. In the ACHIEVE trial, a behavioural weight loss intervention led to clinically significant weight loss in persons with SMI. As the field turns its attention to intervention scale-up, it is important to understand whether the effectiveness of behavioural weight loss interventions for people with SMI, like ACHIEVE, differ for specific subgroups.

METHODS

This study examined whether the effectiveness of the ACHIEVE intervention differed by participant characteristics (e.g. age, sex, race, psychiatric diagnosis, body mass index) and/or their weight-related attitudes and behaviours (e.g. eating, food preparation, and shopping habits). We used likelihood-based mixed effects models to examine whether the baseline to 18 month effects of the ACHIEVE intervention differed across subgroups.

RESULTS

No statistically significant differences were found in the effectiveness of the ACHIEVE intervention across any of the subgroups examined.

CONCLUSIONS

These findings suggest that the ACHIEVE behavioural weight loss intervention is broadly applicable to the diverse population of individuals with SMI.

Long-term retention in an employer-based, commercial weight-loss programme

The aim of this study is to examine factors associated with long-term retention in a commercial weight-loss programme. We conducted a retrospective analysis of an employer-based, commercial programme from 2013 to 2016. Our dependent variable was 'long-term retention', defined as continuously enrolled participants who actively engaged through coach calls at 6 and 12 months. Independent variables included baseline demographics, programme engagement and weight change. We conducted multivariate logistic regression analyses assessing for differences in long-term retention by several factors, adjusted for employer clustering. Overall, 68.3% were retained at 6% and 45.9% at 12 months. Greater number of coach calls and website logins during the first 3 months significantly increased the odds of long-term retention, while having chronic conditions significantly decreased the odds. Weight-loss success (≥5% loss at 6 months) was significantly associated with increased odds of retention (12-month: odds ratio [OR] 2.80, P < 0.001), while early weight-loss failure (≥0% weight change at 1 month) significantly decreased odds of retention (12-month: OR 0.66, P = 0.008). In an employer-based, commercial weight loss programme, greater early programme engagement was associated with long-term retention. Given these programmes' popularity and potential reach, our results could be used to develop and test strategies designed to improve retention in commercial weight-loss programmes.

Factors associated with early dropout in an employer-based commercial weight-loss program

OBJECTIVE

Minimizing program dropout is essential for weight-loss success, but factors that influence dropout among commercial programs are unclear. This study's objective was to determine factors associated with early dropout in a commercial weight-loss program.

METHODS

A retrospective analysis of a remotely delivered, employer-based commercial program from 2013 to 2016 was conducted. The dependent variable was 'early dropout', defined as enrollees who disengaged from telephone coaching by month 2's end. Independent variables included demographics, program website engagement and early weight change. Multivariate logistic regression analyses were used to assess for differences in early dropout by several factors, adjusted for employer clustering.

RESULTS

Of the 5,274 participants, 26.8% dropped out early. Having ≥1 chronic condition (odds ratio [OR] 1.41, p < 0.001) and 'weight-loss failure' defined as ≥0% weight change at month 1's end (OR 1.86, p < 0.001) had significantly increased odds of early dropout. Increasing age by 10-year intervals (OR 0.90, p = 0.002) and 'meeting the website login goal' defined as ≥90 logins in 3 months (OR 0.13, p < 0.001) significantly decreased the odds of early dropout.

CONCLUSIONS

Presence of comorbidities, less online engagement and weight-loss failure were associated with early dropout in a commercial program. Strategies to prevent dropout among high-risk participants, such as increased support or program tailoring, should be developed and tested.

Mycobacterium chimaera infection following cardiac surgery in the United Kingdom: clinical features and outcome of the first 30 cases

OBJECTIVES

Mycobacterium chimaera infection following cardiac surgery, due to contaminated cardiopulmonary bypass heater-cooler units, has been reported worldwide. However, the spectrum of clinical disease remains poorly understood. To address this, we report the clinical and laboratory features, treatment and outcome of the first 30 UK cases.

METHODS

Case note review was performed for cases identified retrospectively through outbreak investigations and prospectively through ongoing surveillance. Case definition was Mycobacterium chimaera detected in any clinical specimen, history of cardiothoracic surgery with cardiopulmonary bypass, and compatible clinical presentation.

RESULTS

Thirty patients were identified (28 with prosthetic material) exhibiting a spectrum of disease including prosthetic valve endocarditis (14/30), sternal wound infection (2/30), aortic graft infection (4/30) and disseminated (non-cardiac) disease (10/30). Patients presented a median of 14 months post surgery (maximum 5 years) most commonly complaining of fever and weight loss. Investigations frequently revealed lymphopenia, thrombocytopenia, liver cholestasis and non-necrotizing granulomatous inflammation. Diagnostic sensitivity for a single mycobacterial blood culture was 68% but increased if multiple samples were sent. In all, 27 patients started macrolide-based combination treatment and 14 had further surgery. To date, 18 patients have died (60%) a median of 30 months (interquartile range 20-39 months) after initial surgery. Survival analysis identified younger age, mitral valve surgery, mechanical valve replacement, higher serum sodium concentration and lower C-reactive protein as factors associated with better survival.

CONCLUSIONS

Mycobacterium chimaera infection following cardiac surgery is associated with a wide spectrum of disease. The diagnosis should be considered in all patients who develop an unexplained illness following cardiac surgery.

Role of Food Handlers in Norovirus Outbreaks in London and South East England, 2013 to 2015

Outbreaks caused by norovirus infection are common and occur throughout the year. Outbreaks can be related to food outlets either through a contaminated food source or an infected food handler. Both asymptomatic and symptomatic food handlers are potentially implicated in outbreaks, but evidence of transmission is limited. To understand potential food handler transmission in outbreak scenarios, epidemiological and microbiological data on possible and confirmed norovirus outbreaks reported in London and South East England in a 2-year period were reviewed. One hundred eighty-six outbreaks were associated with a food outlet or registered caterer in this period. These occurred throughout the year with peaks in quarter 1 of study years. A case series of 17 outbreaks investigated by the local field epidemiological service were evaluated further, representing more than 606 cases. In five outbreaks, symptomatic food handlers were tested and found positive for norovirus. In four outbreaks, symptomatic food handlers were not tested. Asymptomatic food handlers were tested in three outbreaks but positive for norovirus in one only. Environmental sampling did not identify the causative agent conclusively in any of the outbreaks included in this analysis. Food sampling identified norovirus in one outbreak. Recommendations from this study include for outbreak investigations to encourage testing of symptomatic food handlers and for food and environmental samples to be taken as soon as possible. In addition, sampling of asymptomatic food handlers should be considered when possible. However, in light of the complexity in conclusively identifying a source of infection, general measures to improve hand hygiene are recommended, with specific education among food handlers about the potential for foodborne pathogen transmission during asymptomatic infection, as well as reinforcing the importance of self-exclusion from food handling activities when symptomatic.

Innovative business approaches for incenting health promotion in sub-Saharan Africa: progress and persisting challenges

Non-communicable chronic diseases related to behaviors such as tobacco use, overeating, excess alcohol intake and physical inactivity account for increasing morbidity and mortality in South Africa. Over the last 15 years, Discovery Health, the largest private health plan in South Africa, has developed a voluntary health promotion program called Vitality with over 1.5 million members. Vitality was designed with many applications drawn from the growing field of behavioral economics, including the use of incentives and rewards. Incentives offered on the program are aimed at lowering the financial barriers to activities such as visiting the gym, buying healthy food or receiving preventive screening. Members accrue points for engagement which translate into discounts on a range of goods and services. Although the full impact of the program cannot yet be quantified, engagement with the program is continually increasing and there is compelling evidence that this translates into better health and cost outcomes.

Development and implementation of Baltimore Healthy Eating Zones: a youth-targeted intervention to improve the urban food environment

Poor accessibility to affordable healthy foods is associated with higher rates of obesity and diet-related chronic diseases. We present our process evaluation of a youth-targeted environmental intervention (Baltimore Healthy Eating Zones) that aimed to increase the availability of healthy foods and promote these foods through signage, taste tests and other interactive activities in low-income Baltimore City. Trained peer educators reinforced program messages. Dose, fidelity and reach-as measured by food stocking, posting of print materials, distribution of giveaways and number of interactions with community members-were collected in six recreation centers and 21 nearby corner stores and carryouts. Participating stores stocked promoted foods and promotional print materials with moderate fidelity. Interactive sessions were implemented with high reach and dose among both adults and youth aged 10-14 years, with more than 4000 interactions. Recreation centers appear to be a promising location to interact with low-income youth and reinforce exposure to messages.

SU-E-T-255: A Novel Rectal Obturator for Prostate Radiotherapy Improves the Spatial Distribution of Dose and Reduces the Predicted Risk for Rectal Bleeding and Subjective Sphincter Control

PURPOSE

To investigate the effects of an endorectal device during prostate radiotherapy on the spatial distribution of dose to the ano-rectal region and quantify implications for normal-tissue-complication probabilities.

METHODS

Twenty-three patients with localised prostate cancer, referred for external beam radiotherapy had 2 CT scans acquired, without and with the rectal obturator (ProSpare) in-situ. For each patient two dose distributions were generated, based on both CT scans. Dose-surface maps for the rectal surface and the anal surface were generated and mean dose as well as a spatial measure (circumference of the dose distribution) were determined for all patients, with and without ProSpare. Using previously published NTCP models, the effect of ProSpare on NTCP was investigated for rectal bleeding and subjective sphincter control.

RESULTS

In a previous study subjective sphincter control correlated strongest with mean dose and lateral extent at 53 Gy. The use of ProSpare resulted in a highly significant reduction of the lateral extent at 53 Gy (p=0.006), mean dose (p=0.0009) and NTCP according to the LKB model (p=0.002 for grade 2 and p=0.001 for grade >=1). In a previous study we reported that rectal bleeding correlated most strongly with the lateral extent at 55 Gy and presented the constraint that it should not exceed 42% of the circumference. Using ProSpare resulted in a significant reduction of the lateral extent at 55 Gy (p=0.001) and significantly more patients met that proposed constraint (p=0.047). ProSpare resulted in a significant reduction of NTCP for grade-2 rectal bleeding (p=0.007) and a reduction for rectal bleeding grade >=1 (p=0.053).

CONCLUSIONS

ProSpare resulted in a significant reduction of mean dose to the anal sphincter and a significant reduction of the lateral extent at 55 Gy. This corresponded to a significant reduction in the predicted risk of reporting subjective sphincter control and grade-2 rectal bleeding.

Major multinational food and beverage companies and informal sector contributions to global food consumption: implications for nutrition policy

BACKGROUND

In recent years, 10 major multinational food and beverage companies have worked together within the International Food and Beverage Alliance (IFBA) to increase their commitments to public health. Current IFBA commitments include initiatives to improve the nutrition quality of products and how these products are advertised to children. The impact and magnitude of IFBA member contributions to the total market share of packaged foods and beverages consumed remain incompletely understood, however.

METHODS

In order to evaluate this impact, we examined packaged food and soft drink company shares provided by Euromonitor, an international independent market analysis company. Packaged foods include baby food, bakery, canned/preserved food, chilled/processed food, confectionery, dairy, dried processed food, frozen processed food, ice cream, meal replacement, noodles, oils and fats, pasta, ready meals, sauces, dressings and condiments, snack bars, soup, spreads, and sweet and savoury snacks. Soft drinks include carbonates, packaged fruit/vegetable juice, bottled water, functional drinks, concentrates, ready-to-drink tea, ready-to-drink coffee and Asian specialty drinks. We calculated the market shares for IFBA companies, globally and within nine countries--the US, China, India, Egypt, South Africa, Brazil, Mexico, Turkey and the UK.

RESULTS

Worldwide, the top ten packaged food companies account for 15.2% of sales, with each individual company contributing less than 3.3%. The top ten soft drink companies account for 52.3% of sales worldwide; Coca-Cola and PepsiCo lead with 25.9% and 11.5% of sales, respectively.

CONCLUSIONS

Although the top ten soft drink companies account for half of global sales, the top ten packaged food companies account for only a small proportion of market share with most individual companies contributing less than 3.3% each. Major multinational companies need to be joined by the myriad of small- and medium-sized enterprises in developing and implementing programs to improve the health of the public, globally. Without full participation of these companies, the impact of commitments made by IFBA members and other major multinational food and beverage companies will remain limited.

Differential regulation of the proapoptotic multidomain protein Bak by p53 and p73 at the promoter level

During apoptosis Bcl-2 proteins control permeabilization of the mitochondrial outer membrane leading to the release of cytochrome c. Essential gatekeepers for cytochrome c release are the proapoptotic multidomain proteins, Bax, and Bak. The expression of Bax is upregulated upon cellular stress by the tumor suppressor p53. Despite the high functional homology of Bax and Bak, little is known about how the bak gene is regulated. To investigate its transcriptional regulation in further detail, we have analyzed a region spanning 8200 bp upstream of the bak start codon (within exon 2) for transcription factor-binding sites, and identified three p53 consensus sites (BS1-3). Reporter gene assays in combination with site-directed mutagenesis revealed that only one putative p53-binding site (BS3) is necessary and sufficient for induction of reporter gene expression by p53. Consistently, p53 induces expression of endogenous Bak. At the mRNA level, induction of Bak expression is weaker than induction of Puma and p21. Interestingly, Bak expression can also be induced by p73 that binds however to each of the three p53-binding sites within the bak promoter region. Our data suggest that expression of Bak can be induced by both, p53 and p73 utilizing different binding sites within the bak promoter.

Effects of organic matter on acidic electrolysed water for reduction of foodborne pathogens on lettuce and spinach

AIMS

To evaluate the efficacy of acidic electrolysed water (EW) in the presence of organic matter (bovine serum) on the inoculated surfaces of lettuce and spinach.

MATERIALS AND RESULTS

Lettuce and spinach leaves were inoculated with a cocktail of three strains each of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes and treated with deionized water, acidic EW and acidic EW containing bovine serum (5, 10, 15 and 20 ml l(-1)) for 15 s, 30 s, 1 min, 3 min and 5 min at room temperature (22 +/- 2 degrees C). In the absence of bovine serum, acidic EW treatment reduced levels of cells below the detection limit (0.7 log) in 5 min. In the presence of bovine serum, bactericidal activity of acidic EW decreased with increasing serum concentration.

CONCLUSIONS

Organic matter reduces the effectiveness of acidic EW for reducing pathogens on the surfaces of lettuce and spinach.

SIGNIFICANCE AND IMPACT OF THE STUDY

From a practical standpoint, organic matter reduces the efficacy of acidic EW. This study was conducted to confirm the effect of organic matter on the properties of acidic EW in the inactivation of foodborne pathogens on the surface of vegetables.

Effect of electrolyzed water for reduction of foodborne pathogens on lettuce and spinach

The ability of electrolyzed water (EW) to inactivate foodborne pathogens on the surfaces of lettuce and spinach was investigated. Lettuce and spinach leaves were inoculated with a cocktail of 3 strains each of Escherichia col O157:H7, Salmnonella Typhimurium, and Listeria monocytogenes and treated with acidic electrolyzed water (AC-EW), alkaline electrolyzed water (AK-EW), alkaline electrolyzed water followed by acidic electrolyzed water (sequential treatment, AK-EW + AC-EW), deionized water followed by acidic electrolyzed water (sequential treatment, DW + AC-EW), and deionized water (control, DW) for 15, 30 s, and 1, 3, and 5 min at room temperature (22 +/- 2 degrees C). For all 3 pathogens, the same pattern of microbial reduction on lettuce and spinach were apparent. The relative efficacy of reduction was AC-EW > DW + AC-EW approximately = AK-EW + AC-EW > AK-EW > control. After a 3-min treatment of AC-EW, the 3 tested pathogens were reduced below the detection limit (0.7 log). DW + AC-EW and AK-EW + AC-EW produced the same levels of reduction after 5 min when compared to the control. AK-EW did not reduce levels of pathogens even after a 5-min treatment on lettuce and spinach. Results suggest that AC-EW treatment was able to significantly reduce populations of the 3 tested pathogens from the surfaces of lettuce and spinach with increasing time of exposure.

Fate of foodborne pathogens on green onions and tomatoes by electrolysed water

AIMS

To investigate the efficacy of electrolysed water (EW) in killing Escherichia coli O157:H7, Salmonella typhimurium and Listeria monocytogenes on the surfaces of spot-inoculated green onions and tomatoes.

METHODS AND RESULTS

Green onions and tomatoes were inoculated with a cocktail of three strains each of E. coli O157:H7, Salm. typhimurium and L. monocytogenes and treated with acidic electrolysed water (AC-EW), alkaline electrolysed water (AK-EW), alkaline electrolysed water followed by acidic electrolysed water (AK-EW + AC-EW), deionized water followed by acidic electrolysed water (DW + AC-EW) and deionized water (control, DW) for 15 s, 30 s, 1 min, 3 min and 5 min at room temperature (22 +/- 2 degrees C). The relative efficacy of reduction was AC-EW > DW + AC-EW approximately AK-EW + AC-EW > AK-EW > DW.

CONCLUSIONS

Acidic EW treatment was able to significantly reduce populations of the three tested pathogens from the surfaces of green onions and tomatoes with increasing exposure time.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rinsing in acidic EW reveals an effective method to control the presence of E. coli O157:H7, Salm. typhimurium and L. monocytogenes on the surfaces of fresh green onions and tomatoes, without affecting their organoleptic characteristics. This indicates its potential application for the decontamination of fresh produce surfaces.