Listeriosis associated with pre-prepared sandwich consumption in hospital in England, 2017.

A case of listeriosis occurred in a hospitalised patient in England in July 2017. Analysis by whole genome sequencing of the Listeria monocytogenes from the patient's blood culture was identified as clonal complex (CC) 121. This culture was indistinguishable to isolates from sandwiches, salads and the maufacturing environment of Company X which supplied these products widely to the National Health Service. Whilst an inpatient, the case was served sandwiches produced by this company on 12 occasions. No other cases infected by this type were detected in the UK between 2016 and 2020. Between 2016 and 2020, more than 3000 samples of food, food ingredients and environmental swabs from this company were tested. Listeria monocytogenes contamination rates declined after July 2017 from 31% to 0.3% for salads and 3% to 0% for sandwiches. A monophyletic group of 127 L. monocytogenes CC121 isolates was recovered during 2016-2019 and was used to estimate the time of the most recent common ancestor as 2014 (95% CI of between 2012 and 2016). These results represent persistent contamination of equipment, food contact surfaces and foods at a food manufacturer by a single L. monocytogenes strain. Colonisation and persistent contamination of food and production environments are risks for public health.

Breathprints of childhood obesity: changes in volatile organic compounds in obese children compared with lean controls.

OBJECTIVE: The objective of this study was to investigate changes in volatile organic compounds (VOCs) in exhaled breath in overweight/obese children compared with their lean counterparts. STUDY DESIGN: Single exhaled breath was collected and analyzed per protocol using selective ion flow tube mass spectrometry (SIFT-MS). RESULTS: Sixty overweight/obese children and 55 lean controls were included. Compared with the lean group, the obese group was significantly older (14.1 ± 2.8 vs. 12.1 ± 3.0 years), taller (164.8 ± 10.9 vs. 153.3 ± 17.1 cm) and more likely to be Caucasian (60% vs. 35.2%); P < 0.05 for all. A comparison of the SIFT-MS results of the obese group with the lean group revealed differences in concentration of more than 50 compounds. A panel of four VOCs can identify the presence of overweight/obesity with excellent accuracy. Further analysis revealed that breath isoprene, 1-decene, 1-octene, ammonia and hydrogen sulfide were significantly higher in the obese group compared with the lean group (P value < 0.01 for all). CONCLUSION: Obese children have a unique pattern of exhaled VOCs. Changes in VOCs observed in this study may help to gain insight into pathophysiological processes and pathways leading to the development of childhood obesity.

Fluidised bed pyrolysis and catalytic pyrolysis of scrap tyres.

Pyrolysis of scrap tyres was undertaken in a semi-continuous fluidised bed reactor in relation to the temperature of the fluidised bed. Subsequently, a fixed bed of Zeolite catalyst was placed in the freeboard of the reactor. The catalyst temperature was held constant at 500 degrees C and the influence of the temperature of the fluidised bed over the same temperature range as the uncatalysed pyrolysis examined. Two Zeolite catalysts were examined, a Y-type Zeolite catalyst and Zeolite ZSM-5 catalyst of differing pore size and surface activity. The main aim of the work was to examine the production of certain single ring aromatic compounds in the derived pyrolysis oil which are known to be of commercial value. The oils were therefore analysed in detail to determine the concentration of benzene, toluene, xylenes and limonene. In addition, detailed analyses of the derived gases under pyrolysis and catalytic pyrolysis conditions were determined. The influence of the temperature of pyrolysis was to increase the yield of benzene, toluene and xylenes but decrease the yield of limonene. In the presence of the catalyst, the yield of oil was reduced with a consequent increase in the gas yield. Benzene, toluene and xylenes present in the oils showed a significant increase in the presence of both of the catalysts. The two catalysts used, although of differing surface acidities and selective pore sizes, produced similar concentrations of benzene, toluene, xylene and limonene.