Potential sources of contamination on textiles and hard surfaces identified as high-touch sites near the patient environment.

The hospital environment represents an important mediator for the transmission of healthcare-associated infections through direct and indirect hand contact with hard surfaces and textiles. In this study, bacteria on high-touch sites, including textiles and hard surfaces in two care wards in Sweden, were identified using microbiological culture methods and 16S rDNA sequencing. During a cross-sectional study, 176 high-touch hard surfaces and textiles were identified and further analysed using microbiological culture for quantification of total aerobic bacteria, Staphylococcus aureus, Clostridium difficile and Enterobacteriacae. The bacterial population structures were further analysed in 26 samples using 16S rDNA sequencing. The study showed a higher frequency of unique direct hand-textile contacts (36 per hour), compared to hard surfaces (2.2 per hour). Hard surfaces met the recommended standard of ≤ 5 CFU/cm2 for aerobic bacteria and ≤ 1 CFU/cm2 for S. aureus (53% and 35%, respectively) to a higher extent compared to textiles (19% and 30%, respectively) (P = 0.0488). The number of bacterial genera was higher on textiles than on the hard surfaces. Staphylococcus (30.4%) and Corynebacterium (10.9%) were the most representative genera for textiles and Streptococcus (13.3%) for hard surfaces. The fact that a big percentage of the textiles did not fulfil the criteria for cleanliness, combined with the higher bacterial diversity, compared to hard surfaces, are indicators that textiles were bacterial reservoirs and potential risk vectors for bacterial transmission. However, since most of the bacteria found in the study belonged to the normal flora, it was not possible to draw conclusions of textiles and hard surfaces as sources of healthcare associated infections.

The origin of off-odours in packaged rucola (Eruca sativa).

Rucola (Eruca sativa) was decontaminated and then reinoculated with selected microorganisms. The produce was then stored in three different atmospheres and at two temperatures. The accumulation of off-odours in the packaging headspace was analysed. A dozen compounds were detected by olfactometry but only dimethyl sulphide and dimethyl disulphide were considered to have a strong or moderate intensity. Thus, they were identified as the substances causing an unpleasant smell inside the bags. Inoculation with microorganisms resulted in higher production of off-odours. Samples inoculated with Pseudomonadaceae&Xanthamonadaceae were particularly potent in producing the two sulphides. The off-odour problem was much more prominent in samples that were kept in a packaging material that did not allow gas exchange resulting in oxygen levels below 1%. Higher levels of sulphides were detected at 8°C than at 4°C.