The Effect of FOXP3+Regulatory T Cells on Infectious and Inflammatory Diseases

CD4+CD25+FOXP3+regulatory T cells (Tregs) contribute to the maintenance of immune homeostasis and tolerance in the body. The expression levels and functional stability of FOXP3 control the function and plasticity of Tregs. Tregs critically impact infectious diseases, especially by regulating the threshold of immune responses to pathogenic microorganisms. The functional regulatory mechanism and cell-specific surface markers of Tregs in different tissues and inflammatory microenvironments have been investigated in depth, which can provide novel ideas and strategies for immunotherapies targeting infectious diseases.Copyright © 2021. All rights reserved.

Listeriosis and the COVID-19 pandemic

Listeriosis is a saprozoonotic infection that occurs when eating foods contaminated with Listeria. Invasive forms of listeriosis can have extremely severe consequences. Respiratory viral diseases predispose to the occurrence of combined viral-bacterial infections. With a mixed infection of listeriosis and COVID-19, a severe course of the disease is observed, which has a serious prognosis. The aim of the study was to analyze the frequency of various variants of invasive listeriosis and their outcomes in the period before the COVID-19 pandemic and against the background of its development, as well as to determine the genetic diversity of L. monocytogenes isolates. Material and methods. We analyzed 55 cases of invasive listeriosis in patients observed in 2018-2021 in various medical organizations in Moscow. The diagnosis was established on the basis of epidemiological, clinical and laboratory data, listeriosis was confirmed by bacteriological and molecular genetic methods, COVID-19 was confirmed by the detection of SARS-CoV-2 RNA in an oropharyngeal swab using real-time RT-PCR, as well as computed tomography of the lungs. Results. During the current COVID-19 pandemic (2020-2021), the incidence of listeriosis in pregnant women and invasive listeriosis occurring in the form of sepsis and/or lesions of the central nervous system did not differ significantly from similar indicators registered in 2018-2019. Listeria sepsis and/or meningitis/meningoencephalitis in association with severe SARS-CoV-2 novel coronavirus infection are at high risk of death. During the years of the COVID-19 pandemic, the diversity and range of L. monocytogenes genotypes in invasive listeriosis changed, new genotypes appeared that were not previously characteristic of the Russian Federation. Conclusion. The likelihood of developing listeriosis sepsis and/or meningitis/meningoencephalitis against the background of a severe course of COVID-19, and a high risk of an adverse outcome, require increased awareness of medical workers in the field of diagnosis and treatment of invasive listeriosis in order to conduct the earliest and most adequate antibiotic therapy.Copyright © 2022 Geotar Media Publishing Group. All Rights Reserved.

HOCl as a Promising Candidate for Effective Containment of Covid 19 From Biological and Non-Biological Surfaces

Covid 19 is a pandemic disease spread almost in the whole world. To date, no medical advancement to curb the virus. Coronavirus is an enveloped virus transmitted from the biological and non-biological surface by direct or indirect contact. Limited literature revealed that the enveloped virus can be killed by disinfectants. There are many biocidal agents used for decontamination of the virus, yet they have many issues like toxicity, killing time, activation requirement, etc. Some are specific to the inanimate surface but not used by a human being. This current situation showed an urgent need for a biocidal agent which can act on biological as well as non-biological surfaces without any potential toxicity. Moreover, it should be easy to handle, inexpensive, and safe for the environment. Hypochlorous acid is a weak acid that acts as a powerful disinfectant and shows biocidal efficacy against a wide range of microorganisms. Hypochlorous acid is simple to use, inexpensive, eco-friendly, non-toxic, and stable. The properties of HOCl can be regulated at the site of preparation and therefore, its compliance is high. Hypochlorous acid seems to be a promising agent in disinfection and sterilization in healthcare facilities. Due to its diverse biocidal actions, it may be used as a potent disinfectant against novel coronavirus.Copyright © 2022 Bentham Science Publishers.

Molecularly imprinted polymer-based nanodiagnostics for clinically pertinent bacteria and virus detection for future pandemics

There seems to be a growing curiosity for utilizing MIPs to recognize molecules that can be applied in numerous fields, such as biomimetic antibodies, detection of viruses and bacteria, the broad range of sensing devices, etc., owing to its scalability and economic viability. MIPs have higher thermal and chemical stability, delivering a promising potential for recognizing bacteria and viruses. The bacteria and virus imprinted polymer exhibit elongated product life-time, reproducible fabrication, robustness, reusability, sensitivity, and high target selectivity. Moreover, the MIPs could give consistent screening along with negligible false positive/negative outcomes, which is vital for the control and prevention of viral and bacterial infections. In the viral and bacterial imprinting process, critical aspects, such as compositional complexity, fragility, solubility, and target size, should be systematically evaluated and analytically considered. Although, the application of MIPs has a number of drawbacks and challenges that require solving to develop sensing platforms with high specificity and sensitivity for clinical application. In the present review, current progress and advancement regarding the reasoning and applications of MIPs as recognition molecules in various biosensors for detecting bacteria and viruses and its existing noteworthy challenges along with future perspectives are also reflected.

Nanotechnology for ultrafast nucleic acid amplification

Nucleic acid detection has been one of the most valued tools in point-of-care diagnostics from life science, agriculture, food safety and environmental surveillance, because of its high sensitivity, great specificity and simple operation. Since polymerase chain reactions (PCR) were discovered, more and more researchers attach importance to exploring ultrafast nucleic acid amplification methods for further expediting the process of detection and curbing infectious diseases' high spread rate, especially after the coronavirus disease 2019 (COVID-19) worldwide pandemic event. Nowadays, nanotechnology as one of the most cut-ting-edge technologies has aroused growing attention. In this review, we describe new advances in na-notechnology research for ultrafast nucleic acid amplification. We have introduced commonly used nanotechnologies, namely nanofluidics, nanoporous materials, nanoparticles and so on. Recent advances in these nanotechnologies for ultrafast sample pretreatments, accelerated enzymatic amplification and rapid heating/cooling processes was summarized. Finally, challenges and perspectives for the future applications of ultrafast nucleic acid amplification are presented.(c) 2022 Elsevier Ltd. All rights reserved.

A concerted mechanism involving ACAT and SREBPs by which oxysterols deplete accessible cholesterol to restrict microbial infection.

Most of the cholesterol in the plasma membranes (PMs) of animal cells is sequestered through interactions with phospholipids and transmembrane domains of proteins. However, as cholesterol concentration rises above the PM's sequestration capacity, a new pool of cholesterol, called accessible cholesterol, emerges. The transport of accessible cholesterol between the PM and the endoplasmic reticulum (ER) is critical to maintain cholesterol homeostasis. This pathway has also been implicated in the suppression of both bacterial and viral pathogens by immunomodulatory oxysterols. Here, we describe a mechanism of depletion of accessible cholesterol from PMs by the oxysterol 25-hydroxycholesterol (25HC). We show that 25HC-mediated activation of acyl coenzyme A: cholesterol acyltransferase (ACAT) in the ER creates an imbalance in the equilibrium distribution of accessible cholesterol between the ER and PM. This imbalance triggers the rapid internalization of accessible cholesterol from the PM, and this depletion is sustained for long periods of time through 25HC-mediated suppression of SREBPs and continued activation of ACAT. In support of a physiological role for this mechanism, 25HC failed to suppress Zika virus and human coronavirus infection in ACAT-deficient cells, and Listeria monocytogenes infection in ACAT-deficient cells and mice. We propose that selective depletion of accessible PM cholesterol triggered by ACAT activation and sustained through SREBP suppression underpins the immunological activities of 25HC and a functionally related class of oxysterols.

Biological Efficacy of Compounds from Stingless Honey and Sting Honey against Two Pathogenic Bacteria: An In Vitro and In Silico Study.

Honey inhibits bacterial growth due to the high sugar concentration, hydrogen peroxide generation, and proteinaceous compounds present in it. In this study, the antibacterial activity of stingless and sting honey against foodborne pathogenic bacteria isolated from spoiled milk samples was examined. The isolated bacterial strains were confirmed as Bacillus cereus and Listeriamonocytogenes through morphological, biochemical, and 16 s RNA analysis. Physiochemical characterizations of the honey samples revealed that both of the honey samples had an acidic pH, low water content, moderate reducing sugar content, and higher proline content. Through the disc diffusion method, the antibacterial activities of the samples were assayed and better results were observed for the 50 mg/disc honey. Both stingless and sting honey showed the most positive efficacy against Bacillus cereus. Therefore, an in silico study was conducted against this bacterium with some common compounds of honey. From several retrieved constituents of stingless and sting honey, 2,4-dihydroxy-2,5-dimethyl 3(2H)-furan-3-one (furan) and 4H-pyran-4-one,2,3-dihydro of both samples and beta.-D-glucopyranose from the stingless revealed high ligand-protein binding efficiencies for the target protein (6d5z, hemolysin II). The root-mean-square deviation, solvent-accessible surface area, the radius of gyration, root-mean-square fluctuations, and hydrogen bonds were used to ensure the binding stability of the docked complexes in the atomistic simulation and confirmed their stability. The combined effort of wet and dry lab-based work support, to some extent, that the antimicrobial properties of honey have great potential for application in medicine as well as in the food industries.

Contamination assessment of Listeria monocytogenes in fresh pork in the post-epidemic era

[Background] The epidemic of novel coronavirus disease 2019 (COVID-19) at the end of 2019 brought challenges to food safety. 【Objective】To evaluate the contamination of Listeria monocytogenes in fresh pork sold in the post-epidemic era. [Methods] During the epidemic period from 2020 to 2021, fresh pork from different locations, different packaging methods and different seasons were selected to analyze the contamination rate and contamination level of Listeria monocytogenes, and the epidemiological characteristics of the isolated strains were analyzed. [Results] The contamination rate of Listeria monocytogenes in fresh pork was 15.28% (77/504), and the contamination rate in pork direct-sale stores and farmers' markets was higher than that in supermarkets. Among different packaging methods, the contamination rates of pre-packaging and simple packaging were higher than those of bulk samples, and there were significant differences in the contamination rates in different quarters, with the highest contamination rate in the third quarter, which was 27.78%. Quantitative results found that 40.26% exceeded 10 MPN/g (MPN: most probable number), and 3 samples had contamination levels over 100 MPN/g. The results of serotype analysis showed that 1/2a-3a (48.05%) and 1/2c-3c (44.16%) were the main serotypes. The results of drug resistance test showed that 19.50% of the isolates were multi-drug resistant, 2 (2.60%) were sensitive to all antibiotics, 68 (88.30%) were resistant to oxacillin, and 46 (59.70%) were resistant to oxacillin. Ampicillin-resistant, 45 strains (58.40%) were resistant to cefotaxime. 【Conclusion】In the post-epidemic era, there are different degrees of Listeria monocytogenes contamination in the marketed fresh pork in different locations, different packaging methods and different seasons. The contamination level of individual products is high, and the serum distribution and drug resistance characteristics are diverse. It is necessary to strengthen food safety supervision to reduce the occurrence of foodborne diseases.

Listeriosis and the COVID-19 pandemic

Listeriosis is a saprozoonotic infection that occurs when eating foods contaminated with Listeria. Invasive forms of listeriosis can have extremely severe consequences. Respiratory viral diseases predispose to the occurrence of combined viral-bacterial infections. With a mixed infection of listeriosis and COVID-19, a severe course of the disease is observed, which has a serious prognosis. The aim of the study was to analyze the frequency of various variants of invasive listeriosis and their outcomes in the period before the COVID-19 pandemic and against the background of its development, as well as to determine the genetic diversity of L. monocytogenes isolates. Material and methods. We analyzed 55 cases of invasive listeriosis in patients observed in 2018-2021 in various medical organizations in Moscow. The diagnosis was established on the basis of epidemiological, clinical and laboratory data, listeriosis was confirmed by bacteriological and molecular genetic methods, COVID-19 was confirmed by the detection of SARS-CoV-2 RNA in an oropharyngeal swab using real-time RT-PCR, as well as computed tomography of the lungs. Results. During the current COVID-19 pandemic (2020-2021), the incidence of listeriosis in pregnant women and invasive listeriosis occurring in the form of sepsis and/or lesions of the central nervous system did not differ significantly from similar indicators registered in 2018-2019. Listeria sepsis and/or meningitis/meningoencephalitis in association with severe SARS-CoV-2 novel coronavirus infection are at high risk of death. During the years of the COVID-19 pandemic, the diversity and range of L. monocytogenes genotypes in invasive listeriosis changed, new genotypes appeared that were not previously characteristic of the Russian Federation. Conclusion. The likelihood of developing listeriosis sepsis and/or meningitis/meningoencephalitis against the background of a severe course of COVID-19, and a high risk of an adverse outcome, require increased awareness of medical workers in the field of diagnosis and treatment of invasive listeriosis in order to conduct the earliest and most adequate antibiotic therapy. © 2022 Geotar Media Publishing Group. All Rights Reserved.

56th Congress of Veterinary Epidemiology

This proceedings contains 10 papers on risk management policy of the ministry of health, labour and welfare for ensuring safe wild game meat, prospective of application of food safety risk assessment for game meat, coronavirus disease (COVID-19) for animal owners, shelter medicine and COVID-19, the characteristics of bats as natural reservoirs of the novel coronavirus, chalkbrood in honey bees and its control measures, the economic impact of classical swine fever in Japan, benzalkonium chloride resistance in Listeria monocytogenes isolated in Japan, COVID-19 outbreak and epidemiological research in Japan and the amendment of the act on domestic animal infectious diseases control.

Phage Display-Derived Monoclonal Antibodies Against Internalins A and B Allow Specific Detection of Listeria monocytogenes.

Listeria monocytogenes is the causative agent of listeriosis, a highly lethal disease initiated after the ingestion of Listeria-contaminated food. This species comprises different serovars, from which 4b, 1/2a, and 1/2b cause most of the infections. Among the different proteins involved in pathogenesis, the internalins A (InlA) and B (InlB) are the best characterized, since they play a major role in the enterocyte entry of Listeria cells during early infection. Due to their covalent attachment to the cell wall and location on the bacterial surface, along with their exclusive presence in the pathogenic L. monocytogenes, these proteins are also used as detection targets for this species. Even though huge advancements were achieved in the enrichment steps for subsequent Listeria detection, few studies have focused on the improvement of the antibodies for immunodetection. In the present study, recombinant InlA and InlB produced in Escherichia coli were used as targets to generate antibodies via phage display using the human naïve antibody libraries HAL9 and HAL10. A set of five recombinant antibodies (four against InlA, and one against InlB) were produced in scFv-Fc format and tested in indirect ELISA against a panel of 19 Listeria strains (17 species; including the three main serovars of L. monocytogenes) and 16 non-Listeria species. All five antibodies were able to recognize L. monocytogenes with 100% sensitivity (CI 29.24-100.0) and specificity (CI 88.78-100.0) in all three analyzed antibody concentrations. These findings show that phage display-derived antibodies can improve the biological tools to develop better immunodiagnostics for L. monocytogenes.

Investigating the Anti-Viral and Anti-Bacterial activities of Jordanian Medicinal plants: A narrative review

The diversity in Jordan’s flora due to its geographical areas make is well noted in the scientific literature. The challenge of disease and death caused by infectious diseases like viruses and bacteria, and as infectious diseases evolve and pathogens develop resistance to existing pharmaceuticals, the search for new novel leads, possibly with different modes of action, against bacterial and viral diseases has intensified in recent years. The intent of this review is to provide prevalent information on the antibacterial and antiviral potential in medicinal plants in Jordan, mode of action, type of viruses and bacteria, and phytochemical contents. It has been demonstrated by several studies presented in this review that medicinal plants in Jordan are rich in phytochemicals and possess antiviral and antibacterial properties.

Biological activities of Egyptian grape and mulberry by-products and their potential use as natural sources of food additives and nutraceuticals foods

Interest in the biological role of bioactive compounds present in plant by-products has increased over the last few years. This study aimed to investigate the nutritive value and biological activities of Egyptian Grape leaves (GL), Grape seeds (GS) and Mulberry leaves (ML), as well as investigate the impact of P-irradiation for improving the utilization of these plant by-products. The dose level 5.0 kGy showed highest the content of crude protein (24.42, 19.41 and 13.50 mg/100 g), as well as crude fiber (34.26 and 21.18 mg/100 g) for ML, GL and GS, respectively. Mulberry leaves has a highest content of protein and fiber at dose 5.0 kGy compared with GL and GS. The highest total phenolic content was found in GS (9.75 mg/g DW), followed by GL (7.32 mg/g DW) and the lowest in ML (5.97 mg/g DW). While ML had a higher total flavonoids content (5.61 mg/g DW) than GS (4.88 mg/g DW) and GL (2.86 mg/g DW). Total phenolic and flavonoid contents were significantly increased at 5.0 kGy. The highest level (83.25% and 80.24%) of scavenging activity (DPPH %) and inhibition activity of HCT 116 cells was recorded at 5.0 kGy by GS. All extracts irradiated at 5.0 kGy exhibited varying degrees of antibacterial activity against (Gram+ve and Gram-ve), the GS followed by GL then ML showed strong antibacterial activity with a diameter of inhibition zone of 26.2, 24.5 and 19.7 mm, against L. monocytoganes, respectively and 24.4, 21.4 and 17.2 against S. typhimurium, respectively. This study suggests that P-irradiation is an effective technique to enhance the recovery of phenolics and flavonoids from GL, GS and ML. Also in current study, antioxidant, antibacterial and anticancer activity has been suggested to appear a clear positive relationship with the total phenolic material. This study has proved that the Egyptian GL, GS and ML are rich sources of valuable phytochemicals and nutrients that can serve as a potential source of nutraceuticals and multifunctional food additives (antimicrobial, antioxidant, and anticancer). Phenolic compounds recovered from GL, GS and ML may have a potential role in fighting the COVID-19.

A Rare Case of Meningitis and Symptomatic Hydrocephalus by Listeria Monocytogenes in Dermatomyositis: A Case Report

Background. Listeria monocytogenes is a gram-positive, facultative anaerobic bacillus common in the intestinal flora of many animals and humans. We describe an unusual case of meningitis by Listeria monocytogenes (LM) complicated by hydrocephalus in a child with dermatomyositis. Methods. A 15-year-old girl presented to an outside hospital (OH) after a threeday history of headache, fever and was hospitalized with a diagnosis of meningitis and lumbar puncture performed. CSF sample could not be evaluated clearly due to its hemorrhagic nature. Her past medical history was significant for dermatomyositis for five years. She had received induction of IVIG five days prior. She was also taking cyclosporin A and hydroxychloroquine. She was empirically treated with intravenous cefotaxime, vancomycin, and acyclovir. She was urgently transferred to the theatre for an external shunt placement in the right lateral ventricle. The interval between the first symptoms and the diagnosis of hydrocephalus was around 4 days. CSF from this catheter showed growth of LM with sensitivity to meropenem and resistance to erythromycin, ampicillin, and sulfamethoxazole-trimethoprim. Gram staining of CSF resulted negative for bacteria. Cefotaxime was switched to intravenous meropenem. Immunological screening of cellular and humoral immunity, complement, and blood iron levels were normal. SARS-Cov2 PCR and HIV tests were negative. Herpes virus, mycobacterium tuberculosis real-time PCR, respiratory viral panel studied in the CSF sample were negative. MRI and Angio of the brain showed no abnormality. She is being followed in the pediatric intensive care unit as intubated. Results. In patients who received immunosuppressive medication, L. monocytogenes should be evaluated in the differential diagnosis of central nervous system infections. Even if effective antibiotic therapy has been initiated, this case highlights the need of recognizing early hydrocephalus as a consequence of Listeria meningitis in children with neurological deterioration a few days after initial presentation. Conclusion. The literature on the management and outcome of Listeria meningitis-related hydrocephalus in children is limited.

Mechanisms of Microbial Disinfectant Resistance

Disinfectants can effectively inhibit or kill microorganisms on the surface of objects and transmission media, which are widely used in food, hygiene, health, pandemic prevention and other fields. During the COVID-19 pandemic, the global use of disinfectants increased sharply, which played an important role in effectively preventing and controlling the spread of the virus and preventing the spread of the pandemic. However, improper use of disinfectants will reduce its effectiveness and even induce microbial resistance, which may increase the risk of infectious disease transmission. The disinfectant resistance gene of microorganism will also aggravate its pollution and transmission risk through vertical reproduction or horizontal transfer between the same or different species, which seriously threatens public health safety. At present, the wide emergence of antibiotic resistance gene (ARG) has attracted global attention to public health, but the understanding of disinfectant resistance is very limited. This paper reviews the research on microbial resistance to disinfectants in recent years, focusing on the mechanism of microbial resistance by forming biofilm, reducing cell membrane permeability, over expressing efflux pump, producing specific enzymes to eliminate or attenuate disinfectants, and changing action targets. The formation of strong biofilm can effectively prevent disinfectants from approaching microorganisms, reduce microbial sensitivity and improve resistance;the reduction of cell membrane permeability depends on the changes of membrane protein, phospholipid and lipopolysaccharide, which can reduce the entry of disinfectants into microbial cells;the overexpression of efflux pump system is conducive to microorganisms to discharge harmful substances in cells;the action of specific enzymes can degrade the effective components of disinfectants or improve microbial immunity;the change of target can reduce the combination of disinfectant and action site, so as to reduce the disinfection effect. In addition, aiming at the acquisition and transmission of microbial disinfectant resistance, the chromosome and plasmid mediated resistance genes as well as the relationship between microbial disinfectant resistance and antibiotic resistance in the environment were discussed. Disinfectant resistance genes can be transferred and transmitted by transformation, transduction or conjugation through mobile genetic elements such as plasmids and phages, which puts forward new requirements for scientific disinfection.

Sanitation and customer service strategies implemented during COVID-19 correlated with lower Listeria monocytogenes prevalence in retail delicatessens

The purpose of this study was to evaluate the prevalence of L. monocytogenes and validate a predictive statistical model for assessing L. monocytogenes contamination risk at retail which coincided with the COVID-19 pandemic. Ten environmental samples per store were collected during daily operations two times over 12 months in 44 retail deli departments across seven states. Each sample was tested for L. monocytogenes and other Listeria spp.;confirmation was conducted via whole genome sequencing and PCR amplification of the sigB gene, respectively. A 117-question survey was developed based on previous work in retail deli departments and distributed to store or deli managers once during sampling. Survey questions were correlated with L. monocytogenes using linear regression and ANOVA statistical models. A Firth's bias-corrected logistic regression model was developed to predict the probability of a deli having high L. monocytogenes prevalence (>10%). L. monocytogenes prevalence decreased from 5.8% prior to March 2020 to 4.3% during the pandemic. Squeegees and standing water had the highest L. monocytogenes prevalence of all sampling sites in the study;L. monocytogenes was not found on scales or trash cans. Cleaning and sanitation protocols most highly correlated with L. monocytogenes prevalence. The logistic regression model accurately predicted high L. monocytogenes prevalence in 10/17 stores with high prevalence (α < 0.0001, β = 0.1186) during the COVID-19 pandemic. The COVID-19 pandemic heightened awareness of disease transmission and the importance of sanitation to prevent spread of SARS-CoV-2. This study indicates that there were additional benefits to enhanced sanitation and changes in service practices (i.e., reduced L. monocytogenes prevalence and therefore reduced risk of transmission to foods) beyond decreasing SARS-CoV-2 transmission. © 2021 Elsevier Ltd

Treatment and prevention of community-acquired bacterial meningitis

Bacterial meningitis is a serious infection that requires immediate treatment. Recommended empiric antimicrobial therapy is based upon the most likely pathogen, according to a patient’s age and immune status. Antimicrobial therapy should be modified after identification of the causative microorganism and results of susceptibility tests. Preventive measures include the use of vaccines that target Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae, as well as the use of chemoprophylaxis in selected situations. Pharmacists are in a key position to recommend appropriate antimicrobial therapy for the treatment and prophylaxis of bacterial meningitis and to ensure that patients are receiving recommended vaccinations.

Hyper-Virulent Listeria monocytogenes Strains Associated With Respiratory Infections in Central Italy.

Listeria monocytogenes (Lm) is a foodborne pathogen causing listeriosis. Invasive forms of the disease mainly manifest as septicaemia, meningitis and maternal-neonatal infections. Lm-associated respiratory infections are very rare and little known. We reported two Lm respiratory infection cases occurred in Central Italy during the summer of 2020, in the midst of the SARS-CoV2 pandemic. In addition to collect the epidemiological and clinical characteristics of the patients, we used Whole Genome Sequencing to study the genomes of the Lm isolates investigating their virulence and antimicrobial profiles and the presence of genetic mobile elements. Both the strains belonged to hypervirulent MLST clonal complexes (CC). In addition to the Listeria Pathogenicity Island 1 (LIPI-1), the CC1 strain also carried LIPI-3 and the CC4 both LIPI-3 and LIPI-4. Genetic determinants for antimicrobial and disinfectants resistance were found. The CC1 genome presented prophage sequences but they did not interrupt the comK gene, involved in the phagosomal escape of Lm. None of the strains carried plasmids. Lm is an important, although rare, opportunistic pathogen for respiratory tract and lung infections. To avoid dangerous diagnostic delays of these severe clinical forms, it is important to sensitize hospital laboratories to this rare manifestation of listeriosis considering Lm in the differential diagnosis of respiratory infections.

Prevalence of Listeria monocytogenes and Salmonella spp. in Different Ready to Eat Foods from Large Retailers and Canteens over a 2-Year Period in Northern Italy.

This study aims to give an overview of the prevalence of Listeria monocytogenes and Salmonella spp. in 9727 samples (2996 for L. monocytogenes and 6731 for Salmonella spp.) from different categories of ready-to-eat (RTE) foods, collected over 2 years from 28 large retailers and 148 canteens in the regions of northern Italy. The RTE samples were classified into two groups according to the preparation methods: (i) multi-ingredient preparations consisting of fully cooked food ready for immediate consumption, or with minimal further handling before consumption (Group A), and (ii) multi-ingredient preparations consisting of cooked and uncooked food, or preparations consisting of only raw ingredients (Group B). L. monocytogenes and Salmonella spp. were investigated in both of these categories. The overall prevalence of L. monocytogenes and Salmonella spp. was 0.13% and 0.07%, respectively. More specifically, L. monocytogenes was found in 0.04% of 2442 analysed RTE food samples belonging to group A and in 0.54% of 554 samples belonging to group B. Furthermore, 0.03% of 5367 RTE food samples from group A and 0.21% of 1364 samples from group B tested positive for Salmonella spp. In conclusion, the results obtained in this study can provide a significant contribution to L. monocytogenes and Salmonella spp. risk analysis in RTE foods.

COVID-19 Impairs Immune Response to Candida albicans.

Infection with SARS-CoV-2 can lead to Coronavirus disease-2019 (COVID-19) and result in severe acute respiratory distress syndrome (ARDS). Recent reports indicate an increased rate of fungal coinfections during COVID-19. With incomplete understanding of the pathogenesis and without any causative therapy available, secondary infections may be detrimental to the prognosis. We monitored 11 COVID-19 patients with ARDS for their immune phenotype, plasma cytokines, and clinical parameters on the day of ICU admission and on day 4 and day 7 of their ICU stay. Whole blood stimulation assays with lipopolysaccharide (LPS), heat-killed Listeria monocytogenes (HKLM), Aspergillus fumigatus, and Candida albicans were used to mimic secondary infections, and changes in immune phenotype and cytokine release were assessed. COVID-19 patients displayed an immune phenotype characterized by increased HLA-DR+CD38+ and PD-1+ CD4+ and CD8+ T cells, and elevated CD8+CD244+ lymphocytes, compared to healthy controls. Monocyte activation markers and cytokines IL-6, IL-8, TNF, IL-10, and sIL2Rα were elevated, corresponding to monocyte activation syndrome, while IL-1ß levels were low. LPS, HKLM and Aspergillus fumigatus antigen stimulation provoked an immune response that did not differ between COVID-19 patients and healthy controls, while COVID-19 patients showed an attenuated monocyte CD80 upregulation and abrogated release of IL-6, TNF, IL-1α, and IL-1ß toward Candida albicans. This study adds further detail to the characterization of the immune response in critically ill COVID-19 patients and hints at an increased susceptibility for Candida albicans infection.