CRISPR-Cas System: An Approach With Potentials for COVID-19 Diagnosis and Therapeutics

Time to re-set our thinking about airways disease: lessons from history, the resurgence of chronic bronchitis / PBB and modern concepts in microbiology

In contrast to significant declines in deaths due to lung cancer and cardiac disease in Westernised countries, the mortality due to 'chronic obstructive pulmonary disease' (COPD) has minimally changed in recent decades while 'the incidence of bronchiectasis' is on the rise. The current focus on producing guidelines for these two airway 'diseases' has hindered progress in both treatment and prevention. The elephant in the room is that neither COPD nor bronchiectasis is a disease but rather a consequence of progressive untreated airway inflammation. To make this case, it is important to review the evolution of our understanding of airway disease and how a pathological appearance (bronchiectasis) and an arbitrary physiological marker of impaired airways (COPD) came to be labelled as 'diseases'. Valuable insights into the natural history of airway disease can be obtained from the pre-antibiotic era. The dramatic impacts of antibiotics on the prevalence of significant airway disease, especially in childhood and early adult life, have largely been forgotten and will be revisited as will the misinterpretation of trials undertaken in those with chronic (bacterial) bronchitis. In the past decades, paediatricians have observed a progressive increase in what is termed 'persistent bacterial bronchitis' (PBB). This condition shares all the same characteristics as 'chronic bronchitis', which is prevalent in young children during the pre-antibiotic era. Additionally, the radiological appearance of bronchiectasis is once again becoming more common in children and, more recently, in adults. Adult physicians remain sceptical about the existence of PBB; however, in one study aimed at assessing the efficacy of antibiotics in adults with persistent symptoms, researchers discovered that the majority of patients exhibiting symptoms of PBB were already on long-term macrolides. In recent decades, there has been a growing recognition of the importance of the respiratory microbiome and an understanding of the ability of bacteria to persist in potentially hostile environments through strategies such as biofilms, intracellular communities, and persister bacteria. This is a challenging field that will likely require new approaches to diagnosis and treatment; however, it needs to be embraced if real progress is to be made.

PANoptosis: a potential new target for programmed cell death in breast cancer treatment and prognosis

Breast cancer is a prevalent and severe form of cancer that affects women all over the world. The incidence and mortality of breast cancer continue to rise due to factors such as population growth and the aging of the population. There is a growing area of research focused on a cell death mechanism known as PANoptosis. This mechanism is primarily regulated by the PANoptosome complex and displays important characteristics of cell death, including pyroptosis, apoptosis, and/or necroptosis, without being strictly defined by the cell death pathway. PANoptosis acts as a defensive response to external stimuli and pathogens, contributing to the maintenance of cellular homeostasis and overall stability. Increasing evidence suggests that programmed cell death (PCD) plays an important role in the development of breast cancer, and PANoptosis, as a novel form of PCD, may be a crucial factor in the development of breast cancer, potentially leading to the identification of new therapeutic strategies. Therefore, the concept of PANoptosis not only deepens our understanding of PCD, but also opens up new avenues for treating malignant diseases, including breast cancer. This review aims to provide an overview of the definition of PANoptosis, systematically explore the interplay between PANoptosis and various forms of PCD, and discuss its implications for breast cancer. Additionally, it delves into the current progress and future directions of PANoptosis research in the context of breast cancer, establishing a theoretical foundation for the development of molecular targets within critical signaling pathways related to PANoptosis, as well as multi-target combination therapy approaches, with the goal of inducing PANoptosis as part of breast cancer treatment.

Antifungal Susceptibility and Biological Characteristics of Fonsecaea monophora Causing Cerebral Phaeohyphomycosis in Jinhua, China

Background

The management of cerebral abscesses caused by dark-pigmented Fonsecaea monophora in healthy individuals continues to be challenging due to no consensus on the therapeutic regimen. Due to the absence of an accurate identification method, Fonsecaea species are often misidentified due to indistinct morphology features.

Materials and Methods

An F. monophora strain from an immunocompetent host with cerebral abscess was collected and identified by ITS rDNA molecular sequencing. The ITS sequences of the isolate were compared with that of the other ten Chinese F. monophora isolates obtained from GenBank for difference comparison and phylogenetic analysis. Fluorescence, Gram stains, and medan lactate were used to observe the colonial morphology. Antifungal susceptibility testing was implemented to demonstrate the antibiotic susceptibility profile. Galleria mellonella larvae were used as a model to study virulence of F. monophora. Medical records and clinical data of the patient were collected and analyzed.

Results

Antifungal susceptibility testing indicated that triazole antifungal drugs possess remarkable antifungal effect against F. monophora, and satisfactory antifungal effect of itraconazole was corresponding to the drug susceptibility results. Compared with the GM test, the serum G test was found to be more sensitive. The virulence and melanization in G. mellonella models for F. monophora were observed, and the death rates of infected larvae were positively related to injected concentrations of fungus. The phylogenetic tree was constructed from the ITS sequences of the clinical isolate along with ten Chinese F. monophora isolates, revealing that there is high relatedness in F. monophora strains collected from China.

Conclusion

F. monophora is an important neurotropic dematiaceous fungus and increasingly causing disease in immunocompetent individuals by means of noninvasive ways. Fungal culture, stainings, and molecular methods could be utilized to identify the etiologic agent. Triazole antifungal drugs can be applied as empiric therapeutic agents for phaeohyphomycosis.

Association of underlying comorbidities and progression of COVID-19 infection amongst 2586 patients hospitalised in the National Capital Region of India: a retrospective cohort study

This study is conducted to observe the association of diabetes (DM), hypertension (HTN) and chronic kidney disease (CKD) on the prognosis and mortality of COVID-19 infection in hospital admitted patients with above mentioned comorbidities. This is a single centre, observational, retrospective study carried out at Sir Ganga Ram Hospital, Delhi, India. The burden of comorbidities on the prognosis and clinical outcome of COVID-19 patients admitted patients from April 8, 2020, to October 4, 2020. Chi-square and relative risk test were used to observe the association of comorbidities and disease prognosis. A total of 2586 patients were included in the study consisting of 69.6% of male patients. All the comorbidities were significantly associated with ICU admission and mortality. The relative risk showed that CKD is most prone to severity as well as mortality of the COVID-19 infection followed by HTN and DM. Further with the increase in number of underlying comorbidities, the risk of ICU admission and mortality also increases. Relative risk of the severity of COVID-19 infection in younger patients with underlying comorbidities are relatively at higher risk of severity of disease as well as to mortality compared to the elderly patients with similar underlying condition. Similarly, it is found that females are relatively at higher risk of mortality as compared to the males having same comorbid conditions except for the hypertensive patients. Diabetes, hypertension and CKD, all are associated with progression of COVID-19 disease to severity and higher mortality risk. The number of underlying comorbid condition is directly proportional to the progression of disease severity and mortality.

DISSEMINATED PURULENT PERITONITIS OUTCOME AFFECTS NKT CELL PHENOTYPE

The aim of our study was to investigate the main characteristics of peripheral blood NKT cell phenotype in patients with disseminated purulent peritonitis (DPP) in dynamics of postoperative period, depending on the disease outcome. Fifty-two patients with acute surgical diseases and injuries of the abdominal organs complicated by DPP, and 68 healthy individuals in control group, were examined. Blood sampling was performed before surgery (preoperative period), as well as on the day 7, 14 and 21 of postoperative period. All patients with DPP were divided into two groups depending on disease outcome in postoperative period: patients with favorable disease outcome (n = 34); and patients with unfavorable outcome (n = 18). Study of the phenotype of blood NKT lymphocytes was performed by flow cytometry using direct immunofluorescence of whole peripheral blood samples with monoclonal antibodies. The low relative and absolute level of NKT cells was observed in DPP patients regardless of outcome disease in preoperative period. At the same time, the absolute level of NKT cells returned to normal only in patients with favorable DPP outcome and only by day 21 after surgery. Patients with favorable DPP outcome by the end of examination period had normalized quantity of mature NKT-lymphocytes and significantly decreased level of cytotoxic cells which was apparently associated with migration of such cell subsets to site of inflammation. A reduced level of non-classical (expressing CD8 marker) mature and cytokine-producing NKT cells was detected only in patients with favorable DPP outcome in preoperative period which returned to normal by the end of postoperative period. At the same time, patients with unfavorable disease outcome had reduced quantity of NKT cells of these subsets by day 21 of postoperative treatment. Patients with favorable outcome had high level of mature and cytotoxic CD11b+ NKT cells already in the preoperative period, while patients with unfavorable DPP outcome had increased level of cytotoxic CD11b+ NKT cells only by day 21 after surgery. The proportion of NKT cells expressing activation markers (CD28 and CD57) was reduced in patients in preoperative period that returned to normal immediately after surgery with favorable outcome, while it recovered with unfavorable outcome closer to the end of postoperative examination. The defined features of NKT cell phenotype in patients with unfavorable DPP outcome characterize disturbances in subset ratio and mechanisms of functioning of this cell fraction. This determines a need to develop immunotherapeutic methods aimed at stimulating immunoregulatory activity of NKT cells.

Mechanism of Multi-Organ Injury in Experimental COVID-19 and Its Inhibition by a Small Molecule Peptide

Severe disease from SARS-CoV-2 infection often progresses to multi-organ failure and results in an increased mortality rate amongst these patients. However, underlying mechanisms of SARS- CoV-2-induced multi-organ failure and subsequent death are still largely unknown. Cytokine storm, increased levels of inflammatory mediators, endothelial dysfunction, coagulation abnormalities, and infiltration of inflammatory cells into the organs contribute to the pathogenesis of COVID-19. One potential consequence of immune/inflammatory events is the acute progression of generalized edema, which may lead to death. We, therefore, examined the involvement of water channels in the development of edema in multiple organs and their contribution to organ dysfunction in a Murine Hepatitis Virus-1 (MHV-1) mouse model of COVID-19. Using this model, we recently reported multi-organ pathological abnormalities and animal death similar to that reported in humans with SARS-CoV-2 infection. We now identified an alteration in protein levels of AQPs 1, 4, 5, and 8 and associated oxidative stress, along with various degrees of tissue edema in multiple organs, which correlate well with animal survival post-MHV-1 infection. Furthermore, our newly created drug (a 15 amino acid synthetic peptide, known as SPIKENET) that was designed to prevent the binding of spike glycoproteins with their receptor(s), angiotensin- converting enzyme 2 (ACE2), and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) (SARS-CoV-2 and MHV-1, respectively), ameliorated animal death and reversed altered levels of AQPs and oxidative stress post-MHV-1 infection. Collectively, our findings suggest the possible involvement of altered aquaporins and the subsequent edema, likely mediated by the virus-induced inflammatory and oxidative stress response, in the pathogenesis of COVID- 19 and the potential of SPIKENET as a therapeutic option.

Role of biomaterials in the diagnosis, prevention, treatment, and study of corona virus disease 2019 (COVID-19)

Recently emerged novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resulting corona virus disease 2019 (COVID-19) led to urgent search for methods to prevent and treat COVID-19. Among important disciplines that were mobilized is the biomaterials science and engineering. Biomaterials offer a range of possibilities to develop disease models, protective, diagnostic, therapeutic, monitoring measures, and vaccines. Among the most important contributions made so far from this field are tissue engineering, organoids, and organ-on-a-chip systems, which have been the important frontiers in developing tissue models for viral infection studies. Also, due to low bioavailability and limited circulation time of conventional antiviral drugs, controlled and targeted drug delivery could be applied alternatively. Fortunately, at the time of writing this paper, we have two successful vaccines and new at-home detection platforms. In this paper, we aim to review recent advances of biomaterial-based platforms for protection, diagnosis, vaccination, therapeutics, and monitoring of SARS-CoV-2 and discuss challenges and possible future research directions in this field.

Tularemia: a re-emerging tick-borne infectious disease

Tularemia is a bacterial disease of humans, wild, and domestic animals. Francisella tularensis, which is a Gram-negative coccobacillus-shaped bacterium, is the causative agent of tularemia. Recently, an increase in the number of human tularemia cases has been noticed in several countries around the world. It has been reported mostly from North America, several Scandinavian countries, and certain Asian countries. The disease spreads through vectors such as mosquitoes, horseflies, deer flies, and ticks. Humans can acquire the disease through direct contact of sick animals, consumption of infected animals, drinking or direct contact of contaminated water, and inhalation of bacteria-loaded aerosols. Low infectious dose, aerosol route of infection, and its ability to induce fatal disease make it a potential agent of biological warfare. Tularemia leads to several clinical forms, such as glandular, ulceroglandular, oculoglandular, oropharyngeal, respiratory, and typhoidal forms. The disease is diagnosed through the use of culture, serology, or molecular methods. Quinolones, tetracyclines, or aminoglycosides are frequently used in the treatment of tularemia. No licensed vaccine is available in the prophylaxis of tularemia and this is need of the time and high-priority research area. This review mostly focuses on general features, importance, current status, and preventive measures of this disease.

A complete categorization of multiscale models of infectious disease systems

Modelling of infectious disease systems has entered a new era in which disease modellers are increasingly turning to multiscale modelling to extend traditional modelling frameworks into new application areas and to achieve higher levels of detail and accuracy in characterizing infectious disease systems. In this paper we present a categorization framework for categorizing multiscale models of infectious disease systems. The categorization framework consists of five integration frameworks and five criteria. We use the categorization framework to give a complete categorization of host-level immuno-epidemiological models (HL-IEMs). This categorization framework is also shown to be applicable in categorizing other types of multiscale models of infectious diseases beyond HL-IEMs through modifying the initial categorization framework presented in this study. Categorization of multiscale models of infectious disease systems in this way is useful in bringing some order to the discussion on the structure of these multiscale models.

Persistent and Recurrent Bacterial Bronchitis-A Paradigm Shift in Our Understanding of Chronic Respiratory Disease

The recent recognition that the conducting airways are not "sterile" and that they have their own dynamic microbiome, together with the rapid advances in our understanding of microbial biofilms and their roles in the causation of respiratory diseases (such as chronic bronchitis, sinusitis, and chronic otitis media), permit us to update the "vicious circle" hypothesis of the causation of bronchiectasis. This proposes that chronic inflammation driven by persistent bacterial bronchitis (PBB) causes damage to both the epithelium, resulting in impaired mucociliary clearance, and to the airway wall, which eventually manifests as bronchiectasis. The link between a "chronic bronchitis" and a persistence of bacterial pathogens, such as non-typable Haemophilus influenzae, was first made more than 100 years ago, and its probable role in the causation of bronchiectasis was proposed soon afterward. The recognition that the "usual suspects" are adept at forming biofilms and hence are able to persist and dominate the normal dynamically changing "healthy microbiome" of the conducting airways provides an explanation for the chronic colonization of the bronchi and for the associated chronic neutrophil-dominated inflammation characteristic of a PBB. Understanding the complex interaction between the host and the microbial communities of the conducting airways in health and disease will be a key component in optimizing pulmonary health in the future.

Malaria Parasites: The Great Escape

Parasites of the genus Plasmodium have a complex life cycle. They alternate between their final mosquito host and their intermediate hosts. The parasite can be either extra- or intracellular, depending on the stage of development. By modifying their shape, motility, and metabolic requirements, the parasite adapts to the different environments in their different hosts. The parasite has evolved to escape the multiple immune mechanisms in the host that try to block parasite development at the different stages of their development. In this article, we describe the mechanisms reported thus far that allow the Plasmodium parasite to evade innate and adaptive immune responses.

Minimal Peptidoglycan (PG) Turnover in Wild-Type and PG Hydrolase and Cell Division Mutants of Streptococcus pneumoniae D39 Growing Planktonically and in Host-Relevant Biofilms

We determined whether there is turnover of the peptidoglycan (PG) cell wall of the ovococcus bacterial pathogen Streptococcus pneumoniae (pneumococcus). Pulse-chase experiments on serotype 2 strain D39 radiolabeled with N-acetylglucosamine revealed little turnover and release of PG breakdown products during growth compared to published reports of PG turnover in Bacillus subtilis. PG dynamics were visualized directly by long-pulse-chase-new-labeling experiments using two colors of fluorescent d-amino acid (FDAA) probes to microscopically detect regions of new PG synthesis. Consistent with minimal PG turnover, hemispherical regions of stable "old" PG persisted in D39 and TIGR4 (serotype 4) cells grown in rich brain heart infusion broth, in D39 cells grown in chemically defined medium containing glucose or galactose as the carbon source, and in D39 cells grown as biofilms on a layer of fixed human epithelial cells. In contrast, B. subtilis exhibited rapid sidewall PG turnover in similar FDAA-labeling experiments. High-performance liquid chromatography (HPLC) analysis of biochemically released peptides from S. pneumoniae PG validated that FDAAs incorporated at low levels into pentamer PG peptides and did not change the overall composition of PG peptides. PG dynamics were also visualized in mutants lacking PG hydrolases that mediate PG remodeling, cell separation, or autolysis and in cells lacking the MapZ and DivIVA division regulators. In all cases, hemispheres of stable old PG were maintained. In PG hydrolase mutants exhibiting aberrant division plane placement, FDAA labeling revealed patches of inert PG at turns and bulge points. We conclude that growing S. pneumoniae cells exhibit minimal PG turnover compared to the PG turnover in rod-shaped cells.

IMPORTANCE

PG cell walls are unique to eubacteria, and many bacterial species turn over and recycle their PG during growth, stress, colonization, and virulence. Consequently, PG breakdown products serve as signals for bacteria to induce antibiotic resistance and as activators of innate immune responses. S. pneumoniae is a commensal bacterium that colonizes the human nasopharynx and opportunistically causes serious respiratory and invasive diseases. The results presented here demonstrate a distinct demarcation between regions of old PG and regions of new PG synthesis and minimal turnover of PG in S. pneumoniae cells growing in culture or in host-relevant biofilms. These findings suggest that S. pneumoniae minimizes the release of PG breakdown products by turnover, which may contribute to evasion of the innate immune system.