The aetiology of human cytomegalovirus (CMV) in tumorigenesis is still a matter of debate. Mounting evidence suggests that the pathogen may offer a degree of protection against various malig- nancies. The association between CMV and brain/ central nervous system (CNS) tumours has yet to be fully elucidated, and studies inquiring into this issue from a global standpoint are lacking. We have investigated the relationship between CMV and CNS tumours the world-over and reviewed relevant litera- ture published so far. Works inquiring into the inter- play between CMV and CNS neoplasia published by November 2022 were reviewed through the PubMed® database. We also analysed the correlation between available country-specific CMV seroprevalence and the age-standardized CNS tumour incidence rates for the year 2020 for 73 countries using the data pro- vided by the International Agency for Research on Cancer (IARC) of the World Health Organization. Statistical assessment was done using Spearman’s correlation. The survey of literature yielded con- flicting opinions on the aetiology of CMV in CNS malignancies. Oncomodulation as a mechanism of pathogenesis would seem to prevail over frank on- cogenesis. On the contrary, analysis of global data revealed a significant negative correlation (p=0.001, Spearman’s ρ=-0.541) between CMV seroprevalence and the age-standardized incidence of brain tumours. Interestingly, the inverse association holds for inci- dence rates of all cancers combined as well (p=0.001, Spearman’s ρ=-0.732). A number of studies speak in favour of an immune-mediated anti-oncogenic effect against brain tumours in CMV-infected individuals. This is supported by recent success of CMV-derived therapies against gliomas. Our study offers novel data hinting at an oncoprotective capacity of CMV the world-over, which corroborates experimental re- search done so far. Extensive exploration of the mo- lecular arsenal of CMV, host-pathogen interactions and CMV seroepidemiology are warranted in order to fully clarify this pathogen’s role in CNS tumour dynamics.

Beneficial Pseudomonas spp. and Bacillus spp. are ubiquitous in soils and colonize the plant microbiome, including the rhizosphere, phyllo- sphere, and endosphere. Their beneficial effects on host plants are due to a wide range of secondary metabolites that act through several mechanisms, including direct antibiosis (antifungal, antibacteri- al, antiviral, and antinematicidal), competition for nutrients, promotion of plant growth and the in- duction of systemic resistance (ISR) in host plants. The genus Pseudomonas includes a variety of species with beneficial effects on plant health that play an important role in sustainable agriculture. The ma- jor secondary metabolites involved in biocontrol are phenazine-1-carboxylic acid, phenazine-1-carbox- amide, pyrrolnitrin, pyoluteorin, 2,4-diacetylphloro- glucinol, nunamycin, nunapeptin, brasmycin, bras- peptin, sessilins, orfamides, HCN and various vola- tile organic compounds. Competition for nutrients, such as iron uptake, is based on siderophores such as pyoverdine and pyochelin. Plant-growth promotion is mediated by 1-aminocyclopropane-1-carboxylate deaminase, indoleacetic acid, abscisic acid, gibberel- lic acid, and cytokinins, as well as vitamins niacin, pantothenic acid, thiamine, riboflavin, and biotin. Endospore-forming Bacillus species also inhibit phytopathogens, including all of the above mecha- nisms underlined by a wide range of structurally di- verse compounds. Direct inhibition of vast variety of phytopathogens is achieved by compounds such as volatiles, bacteriocins, and lipopeptides, i.e., iturins, surfactins, fengycins, and kurstakins. Indirect effects are performed by phytostimulating compounds such as auxins, gibberellins, cytokinins and abscisic acid, which positively influence plant growth and devel- opment. They also induce systemic resistance in the host plant through the production of volatiles. Ex- pression of defense-related proteins is induced in plants by lipopeptides, polyketides, and volatiles that activate the jasmonic acid, salicylic acid, or ethylene signaling pathways. They also have the ability to in- hibit quorum sensing of various phytopathogens. As a result, higher biomass and nutritional quality, im- proved nutrient mobilization and uptake, enhanced tolerance to biotic and abiotic stresses, and shaping of the microbiota are all positive effects that healthy plants acquire from Pseudomonas and Bacillus bene- ficial strains. This review aims to highlight the most important aspects of Pseudomonas spp. and Bacillus spp. secondary metabolites in the control of phyto- pathogens and their beneficial properties for the host plant. Bioformulations based on their metabolites could replace synthetic pesticides and enable sustain- able agricultural practices.

Since it was identified in Wuhan, China, in December 2019, the novel coronavirus has caused devastating severe respiratory infections in the human population worldwide. A new coronavirus named SARS-CoV-2 was isolated from a cluster of pneumonia patients and spread rapidly throughout the planet, establishing the global epidemic COVID-19, making it one of the most serious health disasters in modern public health history. Despite the slow evolutionary rate, SARS-CoV-2 increased transmissibility, virulence and/or immune evasion. Its long-persisting among humans has enabled it to acquire significant genetic diversity. For little, over three years, COVID-19 has driven through five global waves caused by several SARS-CoV-2 variants of concern (VOC). From 2020 until now, we identified Alpha, Beta, Gamma, Delta and the last-fifth SARS- CoV-2 VOC, Omicron. Several reasons make the last VOC so concerning: many mutations, especially in the viral spike protein, and accumulating evidence for increased transmission efficiency and escape from neutralising antibodies. Omicron has outcompeted the previously dominating Delta VOC in an unbelievably short time. It is highly transmissible but seems less pathogenic than pre-existing SARS-CoV-2 variants of concern. Increasing population immunity (whether through vaccination and/or previous infections) raises hopes that severe COVID-19 will become rare and present in risk groups of patients, such as older adults with comorbidities. Hopefully, SARS-CoV-2 will become endemic, similar to seasonal coronaviruses. Because Omicron probably isn’t the last SARS-CoV-2, we should learn to live with this coronavirus in the present and future.