Changes in the Blood Viscosity in Patients With SARS-CoV-2 Infection

Coronavirus disease 2019 (COVID-19) is caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2-induced hyperinflammation together with alteration of plasma proteins, erythrocyte deformability, and platelet activation, may affect blood viscosity. Thus, this review aimed to study the link between SARS-CoV-2 infection and alteration of blood viscosity in COVID-19 patients. In order to review findings related to hyperviscosity in COVID-19, we suggested a protocol for narrative review of related published COVID-19 articles. Hyperviscosity syndrome is developed in different hematological disorders including multiple myeloma, sickle cell anemia, Waldenstorm macroglobulinemia, polycythemia, and leukemia. In COVID-19, SARS-CoV-2 may affect erythrocyte morphology via binding of membrane cluster of differentiation 147 (CD147) receptors, and B and 3 proteins on the erythrocyte membrane. Variations in erythrocyte fragility and deformability with endothelial dysfunction and oxidative stress in SARS-CoV-2 infection may cause hyperviscosity syndrome in COVID-19. Of interest, hyperviscosity syndrome in COVID-19 may cause poor tissue perfusion, peripheral vascular resistance, and thrombosis. Most of the COVID-19 patients with a blood viscosity more than 3.5 cp may develop coagulation disorders. Of interest, hyperviscosity syndrome is more commonly developed in vaccine recipients who had formerly received the COVID-19 vaccine due to higher underlying immunoglobulin concentrations, and only infrequently in those who have not received the COVID-19 vaccine. Taken together, these observations are untimely too early to give a final connotation between COVID-19 vaccination and the risk for development of hyperviscosity syndrome, consequently prospective and retrospective studies are necessary in this regard.

Hyperviscosity syndrome in COVID-19 and related vaccines: exploring of uncertainties

Hyperviscosity syndrome (HVS) recently emerged as a complication of coronavirus disease 2019 (COVID-19) and COVID-19 vaccines. Therefore, the objectives of this critical review are to establish the association between COVID-19 and COVID-19 vaccines with the development of HVS. HVS may develop in various viral infections due to impairment of humoral and cellular immunity with elevation of immunoglobulins. COVID-19 can increase blood viscosity (BV) through modulation of fibrinogen, albumin, lipoproteins, and red blood cell (RBC) indices. HVS can cause cardiovascular and neurological complications in COVID-19 like myocardial infarction (MI) and stroke. HVS with or without abnormal RBCs function in COVID-19 participates in the reduction of tissue oxygenation with the development of cardio-metabolic complications and long COVID-19. Besides, HVS may develop in vaccine recipients with previous COVID-19 due to higher underlying Ig concentrations and rarely without previous COVID-19. Similarly, patients with metabolic syndrome are at the highest risk for propagation of HVS after COVID-19 vaccination. In conclusion, COVID-19 and related vaccines are linked with the development of HVS, mainly in patients with previous COVID-19 and underlying metabolic derangements. The possible mechanism of HVS in COVID-19 and related vaccines is increasing levels of fibrinogen and immunoglobulins. However, dehydration, oxidative stress, and inflammatory reactions are regarded as additional contributing factors in the pathogenesis of HVS in COVID-19. However, this critical review cannot determine the final causal relationship between COVID-19 and related vaccines and the development of HVS. Prospective and retrospective studies are warranted in this field.

Exploring the Therapeutic Potentials of Exopolysaccharides Derived From Lactic Acid Bacteria and Bifidobacteria: Antioxidant, Antitumor, and Periodontal Regeneration

The metabolites of lactic acid bacteria (LAB) and bifidobacteria (Bb) have recently received a lot of attention due to their ability to protect interactions in blood and tissues, as well as their biodegradability and biocompatibility in human tissue. Exopolysaccharides (EPS) derived from bacteria have a long history of use in therapeutic and other industrial applications with no adverse effects. In this regard, EPSs were isolated and characterized from LAB and Bb culture supernatants to determine their antioxidant, antitumor, and periodontal regeneration properties. The antioxidant capacity of the EPSs varied with concentration (0.625-20 mg/ml). The highest antioxidant activity was found in LAB: Streptococcus thermophiles DSM 24731-EPS1, Lactobacillus delbrueckii ssp. bulgaricus DSM 20081T-EPS5, Limosilactobacillus fermentum DSM 20049-EPS6, and Bb; Bifidobacterium longum ssp. longum DSM 200707-EPS10. Human breast cancer cells (MCF7), human colon cancer cells (CaCo2), human liver cancer cells (HepG2), and human embryonic kidney 293 (HEK 293) cells were used as controls to assess the antitumor properties of the selected EPSs. According to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay, EPS5 had the highest cytotoxicity against MCF7, CaCo2, and HepG2, with IC50 values of 7.91, 10.69, and 9.12 mg/ml, respectively. Lactate dehydrogenase (LDH) activity was significantly higher in cell lines treated with EPS5-IC50 values compared to other EPSs-IC50 values (p < 0.05). Real time (RT)-PCR results showed that EPS5 treatment increased Bax, Caspase 8, Caspase 3, and p53 gene expression. The expression of the BCL2, MCL1, and Vimentin genes, on the other hand, was reduced. The MTT test was used to examine the effect of EPS5 on the viability of human periodontal ligament fibroblast cells (hPDLFCs), and it was discovered that EPS5 increased hPDLFC viability. According to high-performance liquid chromatography (HPLC) analysis, galactose made up 12.5% of EPS5. The findings of this study pave the way for the use of EPS, which hold great promise for a variety of therapeutic purposes such as antioxidant, antitumor, and periodontal regeneration.

Enhanced Efficacy of Some Antibiotics in Presence of Silver Nanoparticles Against Multidrug Resistant Pseudomonas aeruginosa Recovered From Burn Wound Infections

Burn wound infections with multidrug-resistant (MDR) bacteria are shown in many countries as severe widespread health threats. Consequently, attention has been devoted to new nanoparticle-based materials in the field of antimicrobial chemotherapy for burn wound infections. This study aimed to evaluate both in vitro and in vivo efficacies of nanoparticle–antibiotic combinations as new classes of materials subjected against MDR Pseudomonas aeruginosa. Out of 40 Gram-negative isolates, 23 P. aeruginosa were recovered from patients with burn wound infections attending different hospitals in Tanta, Egypt. The susceptibility test revealed that 95.7% of P. aeruginosa isolates were MDR with a high incidence of resistance against carbenicillin. Antibacterial activities of silver nanoparticles (Ag-NPs) against the isolates examined showed various inhibition zone diameters ranging from 11 to 17 mm. Strong synergistic efficacy of neomycin was reported in combination with Ag-NPs against MDR P. aeruginosa P₈ and P₁₄ isolates. The in vivo effectiveness of various pharmaceutical formulations prepared from a combination of neomycin antibiotic with Ag-NPs in the treatment of induced bacterially infected mice burns showed that maximum healing activity along with faster wound contraction reported with the combination of neomycin-Ag-NPs in the spray formulation. Generally, data indicated that incorporating Ag-NPs in combination with certain antibiotics may be a new, promising application for wound treatments, especially burns infected with MDR P. aeruginosa.

Evaluation of the impact of adaptation of Klebsiella pneumoniae clinical isolates to benzalkonium chloride on biofilm formation

Background

The percentage of the multidrug resistant Klebsiella pneumoniae clinical isolates is increasing worldwide. The excessive exposure of K. pneumoniae isolates to sublethal concentrations of biocides like benzalkonium chloride (BAC) in health care settings and communities could be one of the causes contributing in the global spread of antibiotic resistance.

Results

We collected 50 K. pneumoniae isolates and these isolates were daily exposed to gradually increasing sublethal concentrations of BAC. The consequence of adaptation to BAC on the cell surface hydrophobicity (CSH) and biofilm formation of K. pneumoniae isolates was explored. Remarkably, 16% of the tested isolates showed an increase in the cell surface hydrophobicity and 26% displayed an enhanced biofilm formation. To evaluate whether the influence of BAC adaptation on the biofilm formation was demonstrated at the transcriptional level, the RT-PCR was employed. Noteworthy, we found that 60% of the tested isolates exhibited an overexpression of the biofilm gene (bssS). After sequencing of this gene in K. pneumoniae isolates before and after BAC adaptation and performing pairwise alignment, 100% identity was detected; a finding that means the absence of mutation after adaptation to BAC.

Conclusion

This study suggests that the widespread and increased use of biocides like BAC at sublethal concentrations has led to an increase biofilm formation by K. pneumoniae isolates. Enhanced biofilm formation could result in treatment failure of the infections generated by this pathogen.

Antimicrobial activity of bacteriocins produced by Enterococcus isolates recovered from Egyptian homemade dairy products against some foodborne pathogens

The increasing mandate for fresh-like food products and the possible hazards of chemically preserved foods necessitate the search for alternatives. Bacteriocins represent a promising food biopreservative. In the present study, one hundred enterococci isolates recovered from Egyptian raw cow milk and homemade dairy products were screened for bacteriocin production. The overall detection rate was 10%. Three isolates, namely, Enterococcus faecalis (OE-7 and OE-12) and Enterococcus hirae (OE-9), showed the highest antibacterial activity with narrow spectrum against multidrug-resistant (MDR) Gram-positive foodborne bacteria: Enterococcus faecalis and Staphylococcus aureus. The antimicrobial activity was completely abolished by trypsin and proteinase K but not affected by lipase and/or amylase indicating the protein nature of the antimicrobial activity. Optimum conditions for bacteriocin production were cultivation in MRS broth at 37 °C, pH 6-6.5 for 16-24 h. The tested bacteriocins exhibited bactericidal activity on S. aureus subsp. aureus ATCC 25923; such activity was further investigated by transmission electron microscopy that revealed leakage and lysis of treated cells. Characterization of tested bacteriocins revealed high activity in a wide range of pH and temperature, storage stability, and heat resistance. PCR analysis revealed that the tested isolates produced multiple enterocins showing homology with the enterocins L50A, AS-48, and 31. Finally, this study reported potent antibacterial activity of bacteriocins derived from dairy products Enterococci against MDR foodborne and spoilage pathogens. The potency, specificity, and stability of these bacteriocins presented promising perspectives for application as biopreservatives in the food industry. The biopreservation of foods by bacteriocins produced by lactic acid bacteria recovered directly from foods remains an innovative approach.

Molecular characterization of virulence and drug resistance genes-producing Escherichia coli isolated from chicken meat: Metal oxide nanoparticles as novel antibacterial agents

Escherichia coli is a major global foodborne pathogen, infecting a wide range of animals and contaminating their meat products. E. coli, can lead to high morbidity and mortality with a huge economic loss especially if foodborne diseases are associated with multidrug resistant (MDR)- and multivirulent-producing pathogens. Due to the increased resistance to common antimicrobials used to treat livestock animals and human infections, the discovery of new and innovative nanomaterials are in high demand. Recently, metal oxides can be considered as effective inorganic agents with antimicrobial features. Hence, this study might be the first to evaluate the efficiency of metal oxide nanoparticles (MO-NPs) as novel antibacterial agents against MDR/multivirulent E. coli pathogens isolated from chicken meat. The occurrence of pathogenic E. coli was determined in fresh warm chicken meat parts (breast, thigh, liver and gizzard). Ninety-one of 132 (69%) chicken meat parts were Escherichia -positive with E. coli as the only species isolated. Out of identified 240 E. coli strains, 72.5% (174/240) were classified as MDR E. coli strains. Fifty-five profile patterns were obtained. From each pattern, one strain was randomly selected for further analysis of virulence and resistance genes. Extracted DNA was assessed for the presence of antibiotic resistance genes (bla_IMP-7, bla_IMP-25, bla_TEM, bla_SHV, bla_OXA-2, tetA, aadA, and aac(3)-IV) and virulence genes (stx1, stx2, hlyA, eaeA, aggR, eltB, estIb, papA, afa and hlyD). Clustering analyses revealed that 10 E. coli harboring the highest number of virulence and resistance genes were shifted together into one cluster designated as cluster X. The average activities of zinc peroxide nanoparticles (ZnO₂-NPs) were higher than that of zinc oxide nanoparticles (ZnO-NPs) and titanium dioxide nanoparticles (TiO₂-NPs) by 20% and 29%, respectively. The anti-inflammatory activity of ZnO₂-NPs in comparison with aspirin was assessed using membrane stabilization, albumin denaturation, and proteinase inhibition methods. Significant anti-inflammatory activity of ZnO₂-NPs was achieved at concentration levels of 500-1000 μg/ml. It seems that MO-NPs are effective alternative agents, since they exhibited a competitive antibacterial capability against MDR/multivirulent-producing E. coli pathogens isolated from chicken meat. Hence, ZnO₂-NPs are a promising nanoparticles-based material for controlling foodborne pathogens, thereby valued for food safety applications.

Impact of triclosan adaptation on membrane properties, efflux and antimicrobial resistance of Escherichia coli clinical isolates

AIM

Analysing the effect of step-wise exposure of Escherichia coli isolates to sublethal concentrations of triclosan (TCS) that is widely used as an antiseptic, preservative and disinfectant.

METHODS AND RESULTS

Changes in the tolerance to the biocide itself and the cross-resistance to clinically important antibiotics were analysed. The involvement of efflux mechanism was studied as well as the possible implication of modifications in cytoplasmic membrane properties including integrity, permeability, potential and depolarization in the resistance mechanisms. Most of E. coli isolates that were adapted to TCS showed increased antimicrobial resistance, lower outer and inner membrane permeability, higher membrane depolarization, more negative membrane potential and enhanced efflux activity using qRT-PCR. Nonsignificant change in membrane integrity was found in the adapted cells.

CONCLUSION

This study suggests that the extensive use of TCS at sublethal concentrations contributed to the emergence of antibiotic resistance in E. coli clinical isolates, by inducing changes in bacterial membrane properties and enhancing the efflux system.

SIGNIFICANCE AND IMPACT OF THE STUDY

The extensive usage of TCS has a deleterious effect on the spread of antibiotic resistance, and more studies are needed to investigate the molecular mechanisms underlying the effects of TCS.