Phages as delivery vehicles and phage display

Bacteriophages (Phages in short) were introduced as the natural enemy of bacteria that may act as alternatives to antibiotics to overcome the challenge of antibiotic resistance. However, in the recent history of science, phages have been employed in different molecular tools and used in numerous therapeutic and diagnostic approaches. Furthermore, thanks to the phage`s highly specific host range limited to prokaryotes, phage particles can be used as safe delivery vehicles and display systems. In this chapter, different phage display systems are introduced, in addition to various applications of phage display as a molecular and therapeutic tool in developing vaccines, antibacterial, and anti-cancer treatments.

Phages for treatment Pseudomonas aeruginosa infection

Pseudomonas aeruginosa is denoted as one of the highly threatening bacteria to the public health. It has acquired many virulent factors and resistant genes that make it difficult to control with conventional antibiotics. Thus, bacteriophage therapy (phage therapy) is a proposed alternative to antibiotics to fight against multidrug-resistant P. aeruginosa. Many phages have been isolated that exhibit a broad spectrum of activity against P. aeruginosa. In this chapter, the common virulent factors and the prevalence of antibiotic-resistance genes in P. aeruginosa were reported. In addition, recent efforts in the field of phage therapy against P. aeruginosa were highlighted, including wild-type phages, genetically modified phages, phage cocktails, and phage in combination with antibiotics against P. aeruginosa in the planktonic and biofilm forms. Recent regulations on phage therapy were also covered in this chapter.

Pseudomonas Phage ZCPS1 Endolysin as a Potential Therapeutic Agent

The challenge of antibiotic resistance has gained much attention in recent years due to the rapid emergence of resistant bacteria infecting humans and risking industries. Thus, alternatives to antibiotics are being actively searched for. In this regard, bacteriophages and their enzymes, such as endolysins, are a very attractive alternative. Endolysins are the lytic enzymes, which are produced during the late phase of the lytic bacteriophage replication cycle to target the bacterial cell walls for progeny release. Here, we cloned, expressed, and purified LysZC1 endolysin from Pseudomonas phage ZCPS1. The structural alignment, molecular dynamic simulation, and CD studies suggested LysZC1 to be majorly helical, which is highly similar to various phage-encoded lysozymes with glycoside hydrolase activity. Our endpoint turbidity reduction assay displayed the lytic activity against various Gram-positive and Gram-negative pathogens. Although in synergism with EDTA, LysZC1 demonstrated significant activity against Gram-negative pathogens, it demonstrated the highest activity against Bacillus cereus. Moreover, LysZC1 was able to reduce the numbers of logarithmic-phase B. cereus by more than 2 log₁₀ CFU/mL in 1 h and also acted on the stationary-phase culture. Remarkably, LysZC1 presented exceptional thermal stability, pH tolerance, and storage conditions, as it maintained the antibacterial activity against its host after nearly one year of storage at 4 °C and after being heated at temperatures as high as 100 °C for 10 min. Our data suggest that LysZC1 is a potential candidate as a therapeutic agent against bacterial infection and an antibacterial bio-control tool in food preservation technology.

Learning From Mistakes: The Role of Phages in Pandemics

The misuse of antibiotics is leading to the emergence of multidrug-resistant (MDR) bacteria, and in the absence of available treatments, this has become a major global threat. In the middle of the recent severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic, which has challenged the whole world, the emergence of MDR bacteria is increasing due to prophylactic administration of antibiotics to intensive care unit patients to prevent secondary bacterial infections. This is just an example underscoring the need to seek alternative treatments against MDR bacteria. To this end, phage therapy has been proposed as a promising tool. However, further research in the field is mandatory to assure safety protocols and to develop appropriate regulations for its use in clinics. This requires investing more in such non-conventional or alternative therapeutic approaches, to develop new treatment regimens capable of reducing the emergence of MDR and preventing future global public health concerns that could lead to incalculable human and economic losses.

Phage-Encoded Endolysins

Due to the global emergence of antibiotic resistance, there has been an increase in research surrounding endolysins as an alternative therapeutic. Endolysins are phage-encoded enzymes, utilized by mature phage virions to hydrolyze the cell wall from within. There is significant evidence that proves the ability of endolysins to degrade the peptidoglycan externally without the assistance of phage. Thus, their incorporation in therapeutic strategies has opened new options for therapeutic application against bacterial infections in the human and veterinary sectors, as well as within the agricultural and biotechnology sectors. While endolysins show promising results within the laboratory, it is important to document their resistance, safety, and immunogenicity for in-vivo application. This review aims to provide new insights into the synergy between endolysins and antibiotics, as well as the formulation of endolysins. Thus, it provides crucial information for clinical trials involving endolysins.

Value of Sodium-Glucose Co-Transporter 2 Inhibitor Versus Traditional Medication in Microalbuminuric Diabetic Patients

BACKGROUND

Sodium glucose co-transporter 2 inhibitor (SGLT2i) is a new arment in the prevention and treatment of diabetic kidney disease with a potential effect on reducing and preventing Chronic Kidney Disease (CKD) progression.

OBJECTIVE

To evaluate the effect of SGLT2 inhibitor in comparison to traditional medication in diabetic patients with microalbuminuria.

METHODS

A total of 60 diabetic patients with microalbuminuria were divided into group I, where 30 patients were treated by traditional medications (RAAS blockers) and group II where 30 patients were treated by Dapagliflozin added to the traditional medications. All patients were followed up for 6 months and their Urine Albumin/Creatinine Ratio (UACR) and eGFR changes were monitered.

RESULTS

UACR significantly declined after 6 months of treatment in group II with a p-value <0.001. There were no significant eGFR changes between both groups. Systolic blood pressure decreases in both groups, but the decrease was highly significant in group II (pvalue<0.001). Diastolic blood pressure decreases significantly in both groups (p-value<0.001). Also, bodyweight reduced significantly in group II with a p-value<0.001.

CONCLUSION

Dapagliflozin, when added to traditional medications (RAAS Blockers), leads to a significant reduction in microalbuminuria with no significant eGFR changes.

Encapsulation of E. coli phage ZCEC5 in chitosan-alginate beads as a delivery system in phage therapy

Bacteriophages can be used successfully to treat pathogenic bacteria in the food chain including zoonotic pathogens that colonize the intestines of farm animals. However, harsh gastric conditions of low pH and digestive enzyme activities affect phage viability, and accordingly reduce their effectiveness. We report the development of a natural protective barrier suitable for oral administration to farm animals that confers acid stability before functional release of bead-encapsulated phages. Escherichia coli bacteriophage ZSEC5 is rendered inactive at pH 2.0 but encapsulation in chitosan–alginate bead with a honey and gelatin matrix limited titer reductions to 1 log₁₀ PFU mL⁻¹. The encapsulated phage titers were stable upon storage in water but achieved near complete release over 4–5 h in a simulated intestinal solution (0.1% bile salt, 0.4% pancreatin, 50 mM KH₂PO₄ pH 7.5) at 37 °C. Exposure of E. coli O157:H7 to the bead-encapsulated phage preparations produced a delayed response, reaching a maximal reductions of 4.2 to 4.8 log₁₀ CFU mL⁻¹ after 10 h at 37 °C under simulated intestinal conditions compared to a maximal reduction of 5.1 log₁₀ CFU mL⁻¹ at 3 h for free phage applied at MOI = 1. Bead-encapsulation is a promising reliable and cost-effective method for the functional delivery of bacteriophage targeting intestinal bacteria of farm animals.

VALIDATION OF CLIF-C-ACLF SCORE FOR ALCOHOLIC LIVER CIRRHOSIS

The concept of acute-on-chronic liver failure (ACLF) covers acute deterioration of the liver function in patients with alcoholic cirrhosis (ALC) caused by secondary or extra-hepatic provoking factors (PF) leading to dysfunction of target organs. CLIF-C-ACLF score refers to the number of decompensated organs/systems and is recommended for predicting outcome in patients with ALC. Objective - to compare the diagnostic value of the Child-Pugh score and the CLIF-C-ACLF score for predicting short-term mortality in patients with ALC. The clinical data of 150 patients with ALC were retrospectively analyzed. Enrolled patients were divided into 2 groups according to the presence / absence of PF 3 months before the death: I group (n = 83) - without PF (CLF), group II (n= 67) - with PF (ACLF). To assess the severity of ALC we used the Child-Pugh score and the CLIF-C-ACLF score. Infectious complications were considered as PF. The sensitivity of the STMP by Child-Pugh score in group 1 was 100% (95% CI 58.9-100), specificity was 38.9% (95% CI 30.9-47.4). The sensitivity for the CLIF-C-ACLF score was 100% (95% CI 58.9-100), specificity-93.75% (95% CI 88.5-97.1).A. The sensitivity of STMP by Child-Pugh score in group II was 100% (95% CI 54.1-100), specificity was 29.5% (95% CI -42.6 to 18.5). The sensitivity of STMP by CLIF-C-ACLF in score II was 100% (95% CI 58.9-100), specificity was 88.5% (95% CI 77.8-95.2). The CLIF-C-ACLF corresponded to the model of excellent quality in groups I (0.99) and II (0.97) and was higher than the Child-Pugh score in both groups (p = 0.012 and p = 0.015 respectively). The diagnostic value of the CLIF-C-ACLF score for predicting short-term mortality in patients with ALC is higher than Child-Pugh, especially for acute decompensation of ALC caused by precipitating factors.

Stage I seminoma: Treatment outcomes in a low-income country

OBJECTIVE

The aim of this report is to address treatment outcomes of patients with early-stage seminoma in a developing country with special reference to patients with history of surgical violation of the scrotum and the potential predictors of disease relapse.

PATIENTS AND METHODS

Seventy four patients with pure seminoma were treated at King Hussein Cancer Center (Amman, Jordan) between 2003 and 2010. All patients underwent orchiectomy. All but 3 patients received adjuvant radiotherapy. Patients who underwent surgical violation of the scrotum prior to referral were managed by further excision or irradiation of the scrotal scar. The follow-up ranged from 1 to 200 months (mean, 33 months).

RESULTS

At the time of follow-up; all but one patient remain alive. The 3-year relapse-free survival for the entire cohort was 95.9%. Three patients were burdened by relapse, all of whom received adjuvant irradiation following inguinal orchiectomy and initially harbored tumors larger than 4cm upon pathological examination. Median time to relapse was 14 months (range, 8-25 months). None were associated with elevated tumor markers prior to detection of relapse. All but one patient were successfully salvaged by chemotherapy.

CONCLUSIONS

Our results confirm the excellent prognosis for patients with early-stage seminoma treated by orchiectomy and adjuvant radiotherapy in a developing country. Although all patients burdened by relapse demonstrated adverse pathological findings upon initial assessment, no consistent predictor of relapse was found. Scrotal scar re-excision or irradiation in patients with prior history of surgical violation of the scrotum is effective in preventing local failure.

KEYWORDS

Seminoma, stage I, radiotherapy, scrotal violation, developing country, management.

Eight primary malignancies: case report and review of literature

The incidence of multiple primary malignancies has increased over the past years secondary to the long-term survival of cancer patients due to improvements in the early detection and adequate treatment of cancer. We present a patient with eight primary malignant tumors and review the relevant literature. Our patient was a 59-year-old female with Crohn disease with an otherwise non-contributory medical history. Risk factors for multiple primary tumors were not detected in our patient. At a follow-up of 108 months from the time of diagnosis of the first malignancy, our patient was still alive. Similar long-term survival has been reported in the literature. Due to the realistic potential for long-term survival, we recommend aggressive treatment of these patients.

Eight primary malignancies: case report and review of literature

The incidence of multiple primary malignancies has increased over the past years secondary to the long-term survival of cancer patients due to improvements in the early detection and adequate treatment of cancer. We present a patient with eight primary malignant tumors and review the relevant literature. Our patient was a 59-year-old female with Crohn disease with an otherwise non-contributory medical history. Risk factors for multiple primary tumors were not detected in our patient. At a follow-up of 108 months from the time of diagnosis of the first malignancy, our patient was still alive. Similar long-term survival has been reported in the literature. Due to the realistic potential for long-term survival, we recommend aggressive treatment of these patients.