Using Clustered Regularly Interspaced Short Palindromic Repeats for Recombinant Biosynthesis of Antimicrobial Peptides as Anti-COVID-19 Agents

The SARS-CoV-2 pandemic has caused the death of 5.5 million people and the infection of more than 323 million people as of January 2022. The remarkable increase in pathogenicity and virulence might have occurred as a result of viral RNA mutations. To date, few antiviral drugs have been authorized for emergency use, but not yet approved, to treat mild to moderate COVID-19, with serious drawbacks and side effects. Antimicrobial peptides (AMPs) play an important role in the host’s innate and adaptive immune system against a wide range of microbial infections. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is thought to be used to increase the recombinant biosynthesis of AMPs. There have been studies that reported the production of AMPs using CRISPR. Therefore, CRISPR is expected to play an important role in the production of AMPs as next-generation, safe, affordable, and efficient antiviral drugs in general and for the treatment of COVID-19 in particular, in addition to AMPs being efficient immunomodulators.

Cyclic Dipeptides: The Biological and Structural Landscape with Special Focus on the Anti-Cancer Proline-Based Scaffold

Cyclic dipeptides, also know as diketopiperazines (DKP), the simplest cyclic forms of peptides widespread in nature, are unsurpassed in their structural and bio-functional diversity. DKPs, especially those containing proline, due to their unique features such as, inter alia, extra-rigid conformation, high resistance to enzyme degradation, increased cell permeability, and expandable ability to bind a diverse of targets with better affinity, have emerged in the last years as biologically pre-validated platforms for the drug discovery. Recent advances have revealed their enormous potential in the development of next-generation theranostics, smart delivery systems, and biomaterials. Here, we present an updated review on the biological and structural profile of these appealing biomolecules, with a particular emphasis on those with anticancer properties, since cancers are the main cause of death all over the world. Additionally, we provide a consideration on supramolecular structuring and synthons, based on the proline-based DKP privileged scaffold, for inspiration in the design of compound libraries in search of ideal ligands, innovative self-assembled nanomaterials, and bio-functional architectures.

A Global Review on Short Peptides: Frontiers and Perspectives

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide "drugs" initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.

The Potential of Antimicrobial Peptides as an Antiviral Therapy against COVID-19

COVID-19 is currently considered as a life-threatening pandemic viral infection. Finding an antiviral drug or a vaccine is the only route for humans' survival against it. To date, no specific antiviral treatment has been confirmed. Antimicrobial peptides (AMPs) have been widely regarded as a promising solution to combat harmful microorganisms. They are biologically active molecules produced by different organisms as an essential component of their innate immune response against invading pathogens. Lactoferrin (LF), one of the AMPs, is an iron-binding glycoprotein that is present in several mucosal secretions. The antiviral activity of LF exists against a wide range of human and animal viruses (DNA and RNA). LF was proven to increase the host immunity against viral infection. Since LF is one of the constituents of breast milk and significantly located at the mucosal layers of the human body, it is considered the first line of defense against microbial infection. LF was reported to have antiviral activity against SARS-CoV infection. The significant antiviral activity of LF makes it a potential option as an immunity enhancer, a drug or a drug conjugate with conventional antivirals. The affordability, environmental safety, and efficiency of LFs will make them superior to all other control strategies.

Could photodynamic therapy be utilized as a treatment modality for oral lichen planus?

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory disease. There is no standard treatment modality for OLP. Recently, photodynamic therapy (PDT) has been advocated as a new treatment modality for OLP.

AIM

The aim of the present study is to compare the effect of PDT using methylene blue (MB) as a photosensitizer to the effect of topical corticosteroids in the treatment of erosive OLP lesions.

MATERIALS AND METHODS

Our study included 20 patients with erosive OLP. Patients were divided into two groups. The study group included 10 patents which received MB-PDT. Patients were instructed to use MB as mouth path for 5 min. After 10 min, we applied focal red light on OLP lesions (wavelength 660 nm, Intensity 100-130 m W/cm2) for 2 min. The PDT was applied twice a week for four weeks. In the control group, 10 patients were instructed to apply topical betamethasone valerate ointment 100 mg on OLP lesion three times per day for four weeks. Subjective, objective scores and lesion size were recorded at time zero, after 2 weeks and after 4 weeks from the start of treatments.

RESULTS

Both groups showed statistically significant differences between time zero and the 4^th week of treatment in subjective, objective scores and the area of the lesions. MB-PDT showed a higher degree of improvement than topical corticosteroids between time zero and the 4^th week of treatment.

CONCLUSION

Photodynamic therapy can be used as a treatment for erosive OLP. PDT offers improvement of OLP subjective and objective scores without major side effects.

Virulent Escherichia coli strains among Egyptian patients with acute diarrhoea versus urinary tract infection, and their antibiotic susceptibility

BACKGROUND AND STUDY AIMS

Diarrhoea and urinary tract infection (UTI) are common clinical problems. Meanwhile, Escherichia coli (E. coli), is the commonest bacterial pathogen reported in both of them. This study aimed to evaluate the pathogenic E. coli (PEC) in stool of acute diarrhoea and urine of UTI regarding their virulence genes and their influence on the susceptibility to routinely prescribed antibiotics.

PATIENTS AND METHODS

Twenty two stool and another 22 urine samples of patients with acute diarrhoea and UTI respectively were collected from patients admitted at Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University, Egypt. E. coli isolation, identification of their phyla; chuA, yjaA, and TspE4.C2, and further identification of 10 virulent genes; fimH, papC, papG//, papG///, papEF, afa, sfa, CNF1, iroN & hlyA was performed. Antibiotic susceptibility was studied against quinolones, gentamicin (GM), and trimethoprim-sulphamethoxazole (TMP-SMX).

RESULTS

The studied virulence genes were comparably detected in both pathogenic samples. In diarrheogenic E. coli (DEC); phylum A was significantly related to both ciprofloxacin (CIP) and TMP-SMX resistance, and both of the virulence genes fimH and iroN were significantly related to all the studied antibiotics resistance, while afa was significantly related to nalidixic acid (NA) resistance. In uropathogenic E. coli (UEC); phylum D was significantly related to CIP and levofloxacin resistance, and both of the virulence genes fimH and iroN were significantly related to most of the studied antibiotics resistance.

CONCLUSION

The isolated PEC was evidently and broadly resistant to the studied antibiotics, with limited influence of their phyla and virulence genes (fimH and iroN).

The Japanese ladybirds, Coccinula crotchi and Coccinula sinensis, are infected with very closely related strains of male-killing Flavobacterium

Male-killing is 1 of 4 known strategies that inherited parasitic endosymbionts have evolved to manipulate their host's reproduction. In early male-killing, infected male offspring are killed early in embryogenesis. Within the Insecta, male-killing bacteria have been found in a wide range of hosts. The Coccinellidae families of beetles, better known as ladybirds, are particularly prone to male-killer invasion. In samples of the coccinellid, Coccinula crotchi, from Japan, a new male-killing bacterium was revealed by phenotypic assay. Molecular genetic analysis revealed the identity to be a tetracycline-sensitive Flavobacterium that causes female-biased offspring sex ratio. Furthermore, that Flavobacterium strain was found to be closely related to the Flavobacterium causing male-killing in the congeneric Japanese coccinellid, Coccinula sinensis, which was collected from the same region. However, we found slightly different Flavobacterium strains infecting C. sinensis from regions with different environmental conditions. This may be an indication of horizontal transmission of male-killing Flavobacterium between these 2 ladybird spices. Finally, environmental conditions may affect the spread of male-killing bacteria among their hosts.

The direct effects of male killer infection on fitness of ladybird hosts (Coleoptera: Coccinellidae)

Male killing bacteria are common in insects and are thought to persist in host populations primarily by indirect fitness benefits to infected females, whereas direct fitness effects are generally assumed to be neutral or deleterious. Here, we estimated the effect of male killer infection on direct fitness (number of eggs laid, as a measure of fecundity, together with survival) and other life-history traits (development time and body size) in seven ladybird host/male killer combinations. Effects of male killers on fecundity ranged, as expected, from costly to neutral; however, we found evidence of reduced development time and increased survival and body size in infected strains. Greater body size in Spiroplasma-infected Harmonia axyridis corresponded to greater ovariole number and therefore higher potential fecundity. To our knowledge, this is the first report of direct benefits of male killer infection after explicitly controlling for indirect fitness effects. Neutral or deleterious fitness effects of male killer infection should not therefore be automatically assumed.

Two strains of male-killing Wolbachia in a ladybird, Coccinella undecimpunctata, from a hot climate

Ladybirds are a hot-spot for the invasion of male-killing bacteria. These maternally inherited endosymbionts cause the death of male host embryos, to the benefit of female sibling hosts and the bacteria that they contain. Previous studies have shown that high temperatures can eradicate male-killers from ladybirds, leaving the host free from infection. Here we report the discovery of two maternally inherited sex ratio distorters in populations of a coccinellid, Coccinella undecimpunctata, from a hot lowland region of the Middle East. DNA sequence analysis indicates that the male killing is the result of infection by Wolbachia, that the trait is tetracycline sensitive, and that two distinct strains of Wolbachia co-occur within one beetle population. We discuss the implications of these findings for theories of male-killing and suggest avenues for future field-work on this system.

The value of an egg: resource reallocation in ladybirds (Coleoptera: Coccinellidae) infected with male-killing bacteria

Male-killing bacteria are thought to persist in host populations by vertical transmission and conferring direct and/or indirect fitness benefits to their hosts. Here, we test the role of indirect fitness benefits accrued from resource reallocation in species that engage in sibling egg cannibalism. We found that a single-egg meal significantly increased larval survival in 12 ladybird species, but the value of an egg (to survival) differed substantially between species. Next, we tested the impact of three male-killing bacteria on larval survival in one ladybird species, Adalia bipunctata. Spiroplasma reduced larval survival, whereas Wolbachia and Rickettsia had no effect. However, Spiroplasma-infected larvae showed the greatest response to a single-egg meal. The indirect fitness benefit obtained from a single egg is thus so large that even male-killing bacteria with direct fitness costs can persist in host populations. This study supports the hypothesis that fitness compensation via resource reallocation can explain male-killing bacteria persistence.