Contamination of fresh produce could represent a public health concern because no terminal kill step is applied during harvest or at the processing facility to kill pathogens. In addition, once ...contaminated, pathogens may internalize into produce and be protected from disinfectants during the postharvest processing step. The objective of the current study was to determine the potential internalization of Escherichia coli O157:H7 into spinach roots and subsequent transfer to the edible parts. Because curli are involved in biofilm formation, we investigated whether their presence influence the internalization of E. coli O157:H7 into spinach. Further, the effect of the spinach cultivar on E. coli O157:H7 internalization was evaluated. Spinach plants were grown in contaminated soil as well as hydroponically to prevent mechanical wounding of the roots and inadvertent transfer of pathogens from the contamination source to the non-exposed plant surfaces. Results showed that E. coli O157:H7 could internalize into hydroponically grown intact spinach plants through the root system and move to the stem and leaf level. The incidence of internalization was significantly higher in hydroponically grown plants when roots were exposed to 7log CFU/mL compared to those exposed to 5log CFU/mL. The effect of cultivar on E. coli O157:H7 internalization was not significant (P>0.05) for the analyzed spinach varieties, internalization incidences showing almost equal distribution between Space and Waitiki, 49.06% and 50.94% respectively. Wounding of the root system in hydroponically grown spinach increased the incidence of E. coli O157:H7 internalization and translocation to the edible portions of the plant. Experimental contamination of the plants grown in soil resulted in a greater number of internalization events then in those grown hydroponically, suggesting that E. coli O157:H7 internalization is dependent on root damage, which is more likely to occur when plants are grown in soil. Curli expression by E. coli O157:H7 had no significant effect on its root uptake by spinach plants.
•E. coli O157:H7 may internalize into hydroponically grown spinach plants via roots.•E. coli O157:H7 internalization is dependent on root damage.•The spinach cultivar does not affect E. coli O157:H7 internalization.•Curli expression by E. coli O157:H7 doesn't affect its root uptake by spinach plant.
Chemical signaling between a mammalian host and intestinal microbes is health and maintenance of 'healthy' intestinal microbiota. Escherichia coli O157:H7 can hijack host- and microbiota-produced ...chemical signals for survival in a harsh and nutritionally competitive gastrointestinal environment and for intestinal colonization. Norepinephrine (NE) produced by sympathetic neurons of the enteric nervous system has been shown in vitro to induce expression of genes controlling E. coli O157:H7 swimming motility, acid resistance, and adherence to epithelial cells. A previous study used a microarray approach to identify differentially expressed genes in E. coli O157:H7 strain EDL933 in response to NE. To elucidate a comprehensive transcriptional response to NE, we performed RNA-Seq on rRNA-depleted RNA of E. coli O157:H7 strain NADC 6564, an isolate of a foodborne E. coli O157:H7 strain 86-24. The reads generated by RNA-Seq were mapped to NADC 6564 genome using HiSat2. The mapped reads were quantified by htseq-count against the genome of strain NADC 6564. The differentially expressed genes were identified by analyzing quantified reads by DESeq2.
Of the 585 differentially expressed genes (≥ 2.0-fold; p < 0.05), many encoded pathways promoting ability of E. coli O157:H7 strain NADC 6564 to colonize intestines of carrier animals and to produce disease in an incidental human host through increased adherence to epithelial cells and production of Shiga toxins. In addition, NE exposure also induced the expression of genes encoding pathways conferring prolonged survival at extreme acidity, controlling influx/efflux of specific nutrients/metabolites, and modulating tolerance to various stressors. A correlation was also observed between the EvgS/EvgA signal transduction system and the ability of bacterial cells to survive exposure to high acidity for several hours. Many genes involved in nitrogen, sulfur, and amino acid uptake were upregulated while genes linked to iron (Fe
) acquisition and transport were downregulated.
The availability of physiological levels of NE in gastrointestinal tract could serve as an important cue for E. coli O157:H7 to engineer its virulence, stress, and metabolic pathways for colonization in reservoir animals, such as cattle, causing illness in humans, and surviving outside of a host.
Importance
Coronavirus disease (COVID‐19) causes an immunosuppressed state and increases risk of secondary infections like mucormycosis. We evaluated clinical features, predisposing factors, ...diagnosis and outcomes for mucormycosis among patients with COVID‐19 infection.
Methods
This prospective, observational, multi‐centre study included 47 consecutive patients with mucormycosis, diagnosed during their course of COVID‐19 illness, between January 3 and March 27, 2021. Data regarding demography, underlying medical conditions, COVID‐19 illness and treatment were collected. Clinical presentations of mucormycosis, imaging and biochemical characteristics and outcome were recorded.
Results
Of the 2567 COVID‐19 patients admitted to 3 tertiary centres, 47 (1.8%) were diagnosed with mucormycosis. Mean age was 55 ± 12.8years, and majority suffered from diabetes mellitus (n = 36, 76.6%). Most were not COVID‐19 vaccinated (n = 31, 66.0%) and majority (n = 43, 91.5%) had developed moderate‐to‐severe pneumonia, while 20 (42.6%) required invasive ventilation. All patients had received corticosteroids and broad‐spectrum antibiotics while most (n = 37, 78.7%) received at least one anti‐viral medication. Mean time elapsed from COVID‐19 diagnosis to mucormycosis was 12.1 ± 4.6days. Eleven (23.4%) subjects succumbed to their disease, mostly (n = 8, 72.7%) within 7 days of diagnosis. Among the patients who died, 10 (90.9%) had pre‐existing diabetes mellitus, only 2 (18.2%) had received just one vaccine dose and all developed moderate‐to‐severe pneumonia, requiring oxygen supplementation and mechanical ventilation.
Conclusions
Mucormycosis can occur among COVID‐19 patients, especially with poor glycaemic control, widespread and injudicious use of corticosteroids and broad‐spectrum antibiotics, and invasive ventilation. Owing to the high mortality, high index of suspicion is required to ensure timely diagnosis and appropriate treatment in high‐risk populations.
Coronavirus disease 2019 (COVID-19) is an emerging infectious disease of pandemic proportions. Healthcare workers in Singapore working in high-risk areas were mandated to wear personal protective ...equipment (PPE) such as N95 face mask and protective eyewear while attending to patients.
We sought to determine the risk factors associated with the development of de novo PPE-associated headaches as well as the perceived impact of these headaches on their personal health and work performance. The impact of COVID-19 on pre-existing headache disorders was also investigated.
This is a cross-sectional study among healthcare workers at our tertiary institution who were working in high-risk hospital areas during COVID-19. All respondents completed a self-administered questionnaire.
A total of 158 healthcare workers participated in the study. Majority 126/158 (77.8%) were aged 21-35 years. Participants included nurses 102/158 (64.6%), doctors 51/158 (32.3%), and paramedical staff 5/158 (3.2%). Pre-existing primary headache diagnosis was present in about a third 46/158 (29.1%) of respondents. Those based at the emergency department had higher average daily duration of combined PPE exposure compared to those working in isolation wards 7.0 (SD 2.2) vs 5.2 (SD 2.4) hours, P < .0001 or medical ICU 7.0 (SD 2.2) vs 2.2 (SD 0.41) hours, P < .0001. Out of 158 respondents, 128 (81.0%) respondents developed de novo PPE-associated headaches. A pre-existing primary headache diagnosis (OR = 4.20, 95% CI 1.48-15.40; P = .030) and combined PPE usage for >4 hours per day (OR 3.91, 95% CI 1.35-11.31; P = .012) were independently associated with de novo PPE-associated headaches. Since COVID-19 outbreak, 42/46 (91.3%) of respondents with pre-existing headache diagnosis either "agreed" or "strongly agreed" that the increased PPE usage had affected the control of their background headaches, which affected their level of work performance.
Most healthcare workers develop de novo PPE-associated headaches or exacerbation of their pre-existing headache disorders.
Hybrid materials possessing piezo‐ and ferroelectric properties emerge as excellent alternatives to conventional piezoceramics due to their merits of facile synthesis, lightweight nature, ease of ...fabrication and mechanical flexibility. Inspired by the structural stability of aminophosphonium compounds, here we report the first A3BX6 type cyanometallate Ph2(iPrNH)2P3Fe(CN)6 (1), which shows a ferroelectric saturation polarization (Ps) of 3.71 μC cm−2. Compound 1 exhibits a high electrostrictive coefficient (Q33) of 0.73 m4 C−2, far exceeding those of piezoceramics (0.034–0.096 m4 C−2). Piezoresponse force microscopy (PFM) analysis demonstrates the polarization switching and domain structure of 1 further confirming its ferroelectric nature. Furthermore, thermoplastic polyurethane (TPU) polymer composite films of 1 were prepared and employed as piezoelectric nanogenerators. Notably, the 15 wt % 1‐TPU device gave a maximum output voltage of 13.57 V and a power density of 6.03 μW cm−2.
A ferroelectric Iron (III) cyanometallate complex stabilized by organo‐aminophosphonium cations was synthesized and utilized for efficient piezoelectric energy harvesting and storage applications.
•‘The Mask’ is the current byword and a precious possession.•For healthcare workers, wearing mask is a necessity for personal protection.•For general public, the mask is perhaps the most-powerful ...psychological symbol.•The mask undermines all other recommended practices of infection control measures.•We present evolution, types, filtration efficiency and recommended uses of mask.
‘The Mask’ has become a byword and a precious possession universally. Except for its use by the medical fraternity, answers to the common questions-whether it provides enough protection, which type is optimal for the general public and who really needs to don it, remain poorly understood. For a frontline healthcare worker, wearing mask is a necessity as an important person protection equipment, it is perhaps the most-powerful psychological symbol for the general public. Surprisingly, it even undermines all other recommended practices of infection control and breaking the transmission chain of Covid-19, like hand washing, personal hygiene and social distancing. ‘The mask’ has evolved with time and yet there is a need to further improve the design for safety, tolerability and comfort. In this review we present the journey of face mask, originating from the first masks aimed at stopping the bad smell to its industrial use to its all-important place in the medical field. Various types of face masks, their filtration efficiency, reusability and current recommendations for their use are presented.
We tested the hypothesis that single-cell RNA-sequencing (scRNA-seq) analysis of human kidney allograft biopsies will reveal distinct cell types and states and yield insights to decipher the complex ...heterogeneity of alloimmune injury. We selected 3 biopsies of kidney cortex from 3 individuals for scRNA-seq and processed them fresh using an identical protocol on the 10x Chromium platform; (i) HK: native kidney biopsy from a living donor, (ii) AK1: allograft kidney with transplant glomerulopathy, tubulointerstitial fibrosis, and worsening graft function, and (iii) AK2: allograft kidney after successful treatment of active antibody-mediated rejection. We did not study T-cell-mediated rejections. We generated 7217 high-quality single cell transcriptomes. Taking advantage of the recipient-donor sex mismatches revealed by X and Y chromosome autosomal gene expression, we determined that in AK1 with fibrosis, 42 months after transplantation, more than half of the kidney allograft fibroblasts were recipient-derived and therefore likely migratory and graft infiltrative, whereas in AK2 without fibrosis, 84 months after transplantation, most fibroblasts were donor-organ-derived. Furthermore, AK1 was enriched for tubular progenitor cells overexpressing profibrotic extracellular matrix genes. AK2, eight months after successful treatment of rejection, contained plasmablast cells with high expression of immunoglobulins, endothelial cell elaboration of T cell chemoattractant cytokines, and persistent presence of cytotoxic T cells. In addition to these key findings, our analysis revealed unique cell types and states in the kidney. Altogether, single-cell transcriptomics yielded novel mechanistic insights, which could pave the way for individualizing the care of transplant recipients.
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