Alterations in CD39/CD73 axis of T cells associated with COVID-19 severity.

Purinergic signaling modulates immune function and is involved in the immunopathogenesis of several viral infections. This study aimed to investigate alterations in purinergic pathways in coronavirus disease 2019 (COVID-19) patients. Mild and severe COVID-19 patients had lower extracellular adenosine triphosphate and adenosine levels, and higher cytokines than healthy controls. Mild COVID-19 patients presented lower frequencies of CD4+ CD25+ CD39+ (activated/memory regulatory T cell [mTreg]) and increased frequencies of high-differentiated (CD27- CD28- ) CD8+ T cells compared with healthy controls. Severe COVID-19 patients also showed higher frequencies of CD4+ CD39+ , CD4+ CD25- CD39+ (memory T effector cell), and high-differentiated CD8+ T cells (CD27- CD28- ), and diminished frequencies of CD4+ CD73+ , CD4+ CD25+ CD39+ mTreg cell, CD8+ CD73+ , and low-differentiated CD8+ T cells (CD27+ CD28+ ) in the blood in relation to mild COVID-19 patients and controls. Moreover, severe COVID-19 patients presented higher expression of PD-1 on low-differentiated CD8+ T cells. Both severe and mild COVID-19 patients presented higher frequencies of CD4+ Annexin-V+ and CD8+ Annexin-V+ T cells, indicating increased T-cell apoptosis. Plasma samples collected from severe COVID-19 patients were able to decrease the expression of CD73 on CD4+ and CD8+ T cells of a healthy donor. Interestingly, the in vitro incubation of peripheral blood mononuclear cell from severe COVID-19 patients with adenosine reduced the nuclear factor-κB activation in T cells and monocytes. Together, these data add new knowledge to the COVID-19 immunopathology through purinergic regulation.

Systemic redox imbalance in severe COVID-19 patients.

The aim of this study was to evaluate the systemic redox state and inflammatory markers in intensive care unit (ICU) or non-ICU severe COVID-19 patients during the hospitalization period. Blood samples were collected at hospital admission (T1) (Controls and COVID-19 patients), 5-7 days after admission (T2: 5-7 days after hospital admission), and at the discharge time from the hospital (T3: 0-72 h before leaving hospital or death) to analyze systemic oxidative stress markers and inflammatory variables. The reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) were analyzed in peripheral granulocytes and monocytes. THP-1 human monocytic cell line was incubated with plasma from non-ICU and ICU COVID-19 patients and cell viability and apoptosis rate were analyzed. Higher total antioxidant capacity, protein oxidation, lipid peroxidation, and IL-6 at hospital admission were identified in both non-ICU and ICU COVID-19 patients. ICU COVID-19 patients presented increased C-reactive protein, ROS levels, and protein oxidation over hospitalization period compared to non-ICU patients, despite increased antioxidant status. Granulocytes and monocytes of non-ICU and ICU COVID-19 patients presented lower MMP and higher ROS production compared to the healthy controls, with the highest values found in ICU COVID-19 group. Finally, the incubation of THP-1 cells with plasma acquired from ICU COVID-19 patients at T3 hospitalization period decreased cell viability and apoptosis rate. In conclusion, disturbance in redox state is a hallmark of severe COVID-19 and is associated with cell damage and death.

Body image disorders associated with lifestyle and body composition of female adolescents.

OBJECTIVE: To investigate the association between body image disorders and the lifestyle and body composition of female adolescents. DESIGN: Cross-sectional study. SETTING: The Body Shape Questionnaire (BSQ) and Silhouette Scale and Sociocultural Attitudes Towards Appearance Questionnaire-3 were used to evaluate the participants' body image. Body composition was evaluated by a Dual-Energy X-ray Absorptiometry equipment, and lifestyles were identified by latent class analysis (LCA) using the poLCA package for R. PARTICIPANTS: Female adolescents aged 14-19 years old, in the city of Viçosa-MG, Brazil. RESULTS: In total, 405 girls participated in the study. Almost half of the participants were dissatisfied with their current physical appearance (51·4 %), presented body perception distortions (52·9 %). 47·3 % of the adolescents were dissatisfied with their body according to the BSQ, and another 8 % severely so. Subjects with an 'Inactive and Sedentary' latent lifestyle were 1·71 times as likely to feel dissatisfied as those with active and sedentary or inactive and non-sedentary lifestyles (95 % CI 1·08, 2·90, P = 0·047). Body image disorders showed an association with decreased amounts of moderate and vigorous physical activity, high screen time, increased alcohol consumption and excess body fat. CONCLUSIONS: Particular patterns of lifestyle and body composition seem to be associated in female adolescents with dissatisfaction with, distortion of and excessive concern about appearance. Specifically, physical inactivity, sedentary behaviour, alcohol consumption and high body fat percentage may be strongly linked to body image disorders.

An Examination of the Relationships between Eating-Disorder Symptoms, Difficulties with Emotion Regulation, and Mental Health in People with Binge Eating Disorder.

Eating disorders, such as binge eating disorder, are commonly associated with difficulties with emotion regulation and mental-health complications. However, the relationship between eating-disorder symptoms, difficulties with emotion regulation, and mental health in people with binge eating disorder is unclear. Thus, we investigated associations between eating-disorder symptoms, difficulties with emotion regulation, and mental health in 119 adults with binge eating disorder. Participants were assessed with the Eating Disorder Examination Questionnaire, Loss of Control over Eating Scale, Difficulties in Emotion Regulation Scale, Depression Anxiety and Stress Scale, and the 12-Item Short Form Survey at the pre-treatment phase of a randomized controlled trial. Structural-equation-modelling path analysis was used to investigate relationships between variables. We found that (1) eating-disorder behaviors had a direct association with depression, anxiety, and stress; (2) depression, psychological stress, difficulties with emotion regulation, and eating-disorder psychopathology had a direct association with mental-health-related quality of life; and (3) eating-disorder psychopathology/behaviors and stress had a direct association with difficulties with emotion regulation. Our findings show that depression, stress, difficulties with emotion regulation, and eating-disorder psychopathology were related in important ways to mental-health complications in people with binge eating disorder.

Endotoxin tolerance and low activation of TLR-4/NF-κB axis in monocytes of COVID-19 patients.

Higher endotoxin in the circulation may indicate a compromised state of host immune response against coinfections in severe COVID-19 patients. We evaluated the inflammatory response of monocytes from COVID-19 patients after lipopolysaccharide (LPS) challenge. Whole blood samples of healthy controls, patients with mild COVID-19, and patients with severe COVID-19 were incubated with LPS for 2 h. Severe COVID-19 patients presented higher LPS and sCD14 levels in the plasma than healthy controls and mild COVID-19 patients. In non-stimulated in vitro condition, severe COVID-19 patients presented higher inflammatory cytokines and PGE-2 levels and CD14 + HLA-DRlow monocytes frequency than controls. Moreover, severe COVID-19 patients presented higher NF-κB p65 phosphorylation in CD14 + HLA-DRlow, as well as higher expression of TLR-4 and NF-κB p65 phosphorylation in CD14 + HLA-DRhigh compared to controls. The stimulation of LPS in whole blood of severe COVID-19 patients leads to lower cytokine production but higher PGE-2 levels compared to controls. Endotoxin challenge with both concentrations reduced the frequency of CD14 + HLA-DRlow in severe COVID-19 patients, but the increases in TLR-4 expression and NF-κB p65 phosphorylation were more pronounced in both CD14 + monocytes of healthy controls and mild COVID-19 patients compared to severe COVID-19 group. We conclude that acute SARS-CoV-2 infection is associated with diminished endotoxin response in monocytes. KEY MESSAGES: Severe COVID-19 patients had higher levels of LPS and systemic IL-6 and TNF-α. Severe COVID-19 patients presented higher CD14+HLA-DRlow monocytes. Increased TLR-4/NF-κB axis was identified in monocytes of severe COVID-19. Blunted production of cytokines after whole blood LPS stimulation in severe COVID-19. Lower TLR-4/NF-κB activation in monocytes after LPS stimulation in severe COVID-19.

Viral load is associated with mitochondrial dysfunction and altered monocyte phenotype in acute severe SARS-CoV-2 infection.

Monocytes play a major role in the initial innate immune response to SARS-CoV-2. Although viral load may correlate with several clinical outcomes in COVID-19, much less is known regarding their impact on innate immune phenotype. We evaluated the monocyte phenotype and mitochondrial function in severe COVID-19 patients (n = 22) with different viral burden (determined by the median of viral load of the patients) at hospital admission. Severe COVID-19 patients presented lower frequency of CD14 + CD16- classical monocytes and CD39 expression on CD14 + monocytes, and higher frequency of CD14 + CD16 + intermediate and CD14-CD16 + nonclassical monocytes as compared to healthy controls independently of viral load. COVID-19 patients with high viral load exhibited increased GM-CSF, PGE-2 and lower IFN-α as compared to severe COVID-19 patients with low viral load (p < 0.05). CD14 + monocytes of COVID-19 patients with high viral load presented higher expression of PD-1 but lower HLA-DR on the cell surface than severe COVID-19 patients with low viral load. All COVID-19 patients presented decreased monocyte mitochondria membrane polarization, but high SARS-CoV-2 viral load was associated with increased mitochondrial reactive oxygen species. In this sense, higher viral load induces mitochondrial reactive oxygen species generation associated with exhaustion profile in CD14 + monocytes of severe COVID-19 patients. Altogether, these data shed light on new pathological mechanisms involving SARS-CoV-2 viral load on monocyte activation and mitochondrial function, which were associated with COVID-19 severity.

Increased LPS levels coexist with systemic inflammation and result in monocyte activation in severe COVID-19 patients.

Mucosal barrier alterations may play a role in the pathogenesis of several diseases, including COVID-19. In this study we evaluate the association between bacterial translocation markers and systemic inflammation at the earliest time-point after hospitalization and at the last 72 h of hospitalization in survivors and non-survivors COVID-19 patients. Sixty-six SARS-CoV-2 RT-PCR positive patients and nine non-COVID-19 pneumonia controls were admitted in this study. Blood samples were collected at hospital admission (T1) (Controls and COVID-19 patients) and 0-72 h before hospital discharge (T2, alive or dead) to analyze systemic cytokines and chemokines, lipopolysaccharide (LPS) concentrations and soluble CD14 (sCD14) levels. THP-1 human monocytic cell line was incubated with plasma from survivors and non-survivors COVID-19 patients and their phenotype, activation status, TLR4, and chemokine receptors were analyzed by flow cytometry. COVID-19 patients presented higher IL-6, IFN-γ, TNF-α, TGF-ß1, CCL2/MCP-1, CCL4/MIP-1ß, and CCL5/RANTES levels than controls. Moreover, LPS and sCD14 were higher at hospital admission in SARS-CoV-2-infected patients. Non-survivors COVID-19 patients had increased LPS levels concomitant with higher IL-6, TNF-α, CCL2/MCP-1, and CCL5/RANTES levels at T2. Increased expression of CD16 and CCR5 were identified in THP-1 cells incubated with the plasma of survivor patients obtained at T2. The incubation of THP-1 with T2 plasma of non-survivors COVID-19 leads to higher TLR4, CCR2, CCR5, CCR7, and CD69 expression. In conclusion, the coexistence of increased microbial translocation and hyperinflammation in patients with severe COVID-19 may lead to higher monocyte activation, which may be associated with worsening outcomes, such as death.

Influence of oregano essential oil on the inhibition of selected pathogens in "Alheira" during storage.

BACKGROUND: Plant-derived essential oils (EOs) have shown remarkable antimicrobial potential against spoil- age and pathogenic microorganisms in meat and meat products. The aim of this study was to investigate the influence of oregano EO on the inhibition of Salmonella Enteritidis, Listeria monocytogenes and Staphylo- coccus aureus in an internal mixture of “Alheira” during storage. METHODS: Different concentrations of oregano EO (4%, 1.5%, 0.5%, 0.195% and 0.0975%) were evaluated against the selected pathogens during 21 days of storage at 4°C. The pH and water activity values and lactic acid bacteria (LAB) counts were also evaluated. Finally, sensory assessment was performed. RESULTS: The antibacterial effect varied according to the oregano EO concentration used, and target pathogen. Oregano EO at 4% demonstrated the highest antimicrobial activity against all the pathogens tested. The low- est concentrations used (0.195% and 0.0975%) resulted in ~2–3 log reduction, but only for L. monocytogenes after 21 days of storage. Counts of LAB were ~109 CFU/ml for all samples and no differences in the pH and aw values were detected between samples. However, at a concentration of 0.195%, Oregano EO had a negative impact on consumer acceptance of “Alheira”. CONCLUSIONS: These results could be interesting for the meat industry, as a starting point for other studies that have now to concentrate on strategies to “mask” unpleasant sensorial alterations caused by EOs in “Alheira” and helping the industry to ensure the microbiological safety of its products.

Growth control of Listeria innocua 2030c on vacuum-packaged cold-smoked salmon by lactic acid bacteria.

Five bacteriocin-producing lactic acid bacteria (LAB): Enterococcus faecium ET05, Lactobacillus curvatus ET06, L. curvatus ET30, L. deldrueckii ET32 and Pediococcus acidilactici ET34, selected by their capacity for growth and producing inhibition in vitro at high salt-on-water content, low temperature and anaerobic atmosphere, conditions simulating cold-smoked fish, were inoculated onto salmon fillets, in co-culture with Listeria innocua 2030c, and cold-smoked processed (dry salted for 6 h; drying for 6 h; smoke for 2 h). The finished product was then packed under vacuum and stored at 5 degrees C. Enumeration of LAB and L. innocua was performed during storage. Results showed that strain E. faecium ET05 was the best biopreservative candidate for controlling L. innocua growth in vacuum-packaged cold-smoked salmon (CSS) processed under the salting/drying/smoking parameters referred above. L. curvatus ET30 and L. delbrueckii ET32 also showed a good biopreservation potential for CSS although they were less effective than the former. L. curvatus ET06 and P. acidilactici ET34 showed a bacteriostatic mode of action against the target bacteria in vitro as well as when inoculated into the salmon fillets. This study describes a potential application of five different LAB in the biopreservation of Listeria in CSS.

Antimicrobial effects of a microemulsion and a nanoemulsion on enteric and other pathogens and biofilms.

Some microemulsions and nanoemulsions may have antimicrobial properties and be effective anti-biofilm agents. We examined the abilities of two fine emulsions, designated BCTP and TEOP, to inactivate suspensions of vegetative cells of Salmonella spp. Escherichia coli 0157:H7 (VT-), Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. BCTP is an O/W nanoemulsion of soybean oil and tri-n-butyl phosphate emulsified with Triton X-100, while TEOP is an O/W microemulsion of ethyl oleate with Tween 80 as emulsifier and n-pentanol as a co-emulsifier. BCTP was effective in reducing the cell numbers of L. monocytogenes, while TEOP was effective against all five organisms investigated. The abilities of these emulsions to reduce preformed biofilms of the five bacteria were also investigated. With the exception of the biofilm formed by L. monocytogenes, which surprisingly was not significantly affected by BCTP, all biofilms were inhibited by both BCTP and TEOP.

Could modifications of processing parameters enhance the growth and selection of lactic acid bacteria in cold-smoked salmon to improve preservation by natural means?

Several smoking conditions were examined with the objective of enhancing the numbers of lactic acid bacteria (LAB) by natural means in vacuum-packaged cold-smoked salmon during 21 days of storage at 5 degrees C. Three combinations of salting, drying, and smoking were used: (i) dry salting x time of salting (2 or 6 h); (ii) wet salting (6 h) x dry salting (6 h) x with or without sugar; and (iii) wet salting (6 h) x dry salting (6 h) x different times of smoking (2 or 6 h of drying and 2 or 6 h of smoking). Two batches were processed for each set of conditions. Determinations of pH and salt content in the water phase were carried out for products in each treatment. Microbiological analyses (total viable count, total LAB, Lactobacillus spp., and Enterobacteriaceae) also were conducted at the beginning of storage (t0) and after 21 days of refrigerated storage (tl). There were differential increases in total LAB and lactobacilli during the storage period according to the treatment performed. The most effective treatment to enhance LAB growth was 6 h of dry salting with sugar, 6 h of drying, and 2 h of smoking. These salting-drying-smoking conditions also selected the LAB as the dominant flora at the end of the storage period. The LAB promoted by these processing parameters seem to be potentially useful protective cultures because of their anti-Listeria activity. From the results of this research, we conclude that it is possible to enhance the growth of LAB in general and that of inhibitory strains in particular by suitable choices of processing parameters.

Listeriosis in Portugal: an existing but under reported infection.

BACKGROUND: Listeriosis is a rare disease caused by the bacterium Listeria monocytogenes, the normal vehicle of which is food. The disease, which is largely confined to its risk groups of pregnant women, the elderly and immunocompromised individuals, has increased in incidence in recent years. In Portugal, listeriosis is not a notifiable infection and available data are scarce. The objective of this work was to collate the available information concerning listeriosis in Portugal by compiling a retrospective study of cases recorded over a decade. METHODS: Requests for case data on clinically confirmed listeriosis, recorded over the previous decade, were replied to by 23 hospitals and a National Institute of Health delegation. RESULTS: 35 cases of listeriosis were identified for the period between 1994 and 2003 inclusive, the mortality rate being greater than 17%. According to the data collected in this study for the year 2003, the incidence of this disease in Portugal was at least 1.4 cases per million inhabitants in that year. CONCLUSION: The study demonstrates, for the first time in the widely available literature, that despite their being no cases of listeriosis in Portugal recorded in official reports, the threat of L. monocytogenes to public health is of a similar dimension to that in other countries.

Survival and biofilm formation of Listeria monocytogenes in simulated vaginal fluid: influence of pH and strain origin.

Listeria monocytogenes, the agent responsible for listeriosis, can be transmitted from mother to fetus/neonates by vertical transmission, transplacentally or during passage through the birth canal. The purpose of this study was to investigate the survival and biofilm formation of L. monocytogenes (isolated from clinical cases or from food) in simulated vaginal fluid at different pH values (4.2, 5.5 and 6.5). The results demonstrated that this pathogen is inhibited by the normal vaginal pH, but may proliferate when it increases. Clinical strains were significantly more resistant to pH 4.2 than food isolates. Listeria monocytogenes survived and even grew at the higher pHs investigated, suggesting that fetus/neonates from women having increased vaginal pH values during pregnancy may be at a higher risk of listeriosis. All isolates tested were producers of biofilm at different pH values; however, L. monocytogenes produced higher quantities of biofilm in a nutrient-rich medium. No significant differences in biofilm production were detected between food and clinical isolates. As L. monocytogenes are biofilm producers, this increases the probability of occurrence of neonatal infection.

Application of an Impedimetric Technique for the Detection of Lytic Infection of Salmonella spp. by Specific Phages.

This study was performed to evaluate the adaption of the impedimetric method to detect the lytic infection by Salmonella-specific bacteriophages and to provide a higher selectivity to this rapid method in detecting Salmonella spp. by using specific agents. Three bacteriophages and twelve strains of Salmonella spp. were tested. Each of the twelve strains was used separately to inoculate TSB together with each one of the phages. The inoculum concentration was between 10(6) and 10(7) cfu/mL, at a cell: phage ratio of 1 : 100. From the sample analysis, based on conductance (G) measurements (37 degrees C), the infection could be detected, by observation of both detection-time delay and distinct curve trends. The main conclusions were that kinetic detection by impedance microbiology with phage typing constitutes a method of determining whether a test microorganism is sensitive to the bacteriophage and a method to evaluate whether a lytic bacteriophage is present in a sample, by affecting bacterial growth rate/metabolic change.