Mohamed Abbas Shemis

Background: The increasing incidence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) poses a significant global health concern, particularly with the emergence of difficult-to-treat resistance (DTR), which seriously restricts therapeutic options. Therefore, we aimed to characterize DTR-PA isolates among the studied CRPA; regarding their resistance mechanisms to carbapenems and their antimicrobial susceptibility profiles. Methods: Fifty-two non-duplicate CRPA isolates were collected from clinical specimens. Antimicrobial susceptibility testing was performed using disc diffusion and VITEK2 compact system. Isolates were classified as multidrug-resistant P. aeruginosa (MDR-PA), extensively drug-resistant P. aeruginosa (XDR-PA), and DTR-PA. Conventional PCR was used to detect carbapenemase genes ( bla _NDM , bla _VIM , bla _IMP , bla _KPC , and bla _OXA-48 ). Quantitative real-time PCR (qRT-PCR) identified the over expression of efflux pump genes ( mexB , mexY ) and the down regulation of outer membrane porin ( oprD ) gene. Results: Fifty-two (52) CRPA isolates were categorized according to resistance phenotype into three main groups where 46% were identified as DTR-PA, 38% as XDR-PA, 8% as MDR-PA and 8% remained uncategorized. In DTR-PA, carbapenemase genes were detected in 92% of isolates with bla _NDM being the most prevalent (75%), followed by bla _VIM (54%) and bla _OXA-48 (38%). Co-existence of multiple carbapenemase genes was common. Efflux pump mechanism was the most common mechanism of resistance as overexpression of MexB and MexY was observed in 98% and 71% of isolates, respectively, whereas downregulation of oprD was detected in 92%. The DTR-PA phenotype demonstrated the least sensitive profiles and most of the isolates (92%) were positive to all the studied resistant mechanisms (carbapenemase production, overexpression of efflux pump, and porin loss) with a statistically significant association ( P = 0.001). Conclusions: Difficult to treat Pseudomonas aeruginosa is highly prevalent among CRPA isolates in our setting and is caused by multiple resistance mechanisms, particularly bla _NDM carriage, efflux pump overexpression, and oprD downregulation. These findings underscore the urgent need for enhanced molecular surveillance and antimicrobial stewardship to limit further dissemination of highly resistant Pseudomonas aeruginosa ( P. aeruginosa) iaolates. Future studies utilizing the DTR-PA definition are needed, as this category highlights the most resistant CRPA isolates with maximum resistance profiles that most likely to pose clinical challenges.

Introduction: Seasonal variation of physicochemical parameters and metal concentrations in water sources can affect the type and density of microorganisms. These microorganisms might include pathogenic bacteria, parasites, and viruses. This study aims to investigate contamination of Nile River water at Greater Cairo sites by examining the type of microbiome, physicochemical characteristics, and heavy metal concentrations. Methods: Nile water samples were seasonally collected and centrifuged, and their total DNA was extracted and amplified by polymerase chain reaction (PCR) for qualitative detection of eubacteria, eukaryotes, and adenoviruses. Heavy metals were analyzed in water samples using an atomic absorption spectrometer. Results: No adenoviruses were detected; 97.92% of the samples were positive for eukaryotes, 93.75% for Gram-positive bacteria, and 6.25% for Gram-negative bacteria. Although iron, cadmium, calcium, and copper concentrations were within permissible limits, lead and zinc exceeded the limits at certain sites, with maxima of 93.4 µg/L and 100 mg/L, respectively. Principal component analysis indicated that eukaryotes and Gram-positive bacteria showed positive correlations with temperature and pH, and negative correlations with Zn, Cd, Ca, and Fe. On the other hand, Gram-negative bacteria were positively correlated with dissolved oxygen, and negatively correlated with temperature, pH, total dissolved solids, and Pb. Conclusion: Nile River water in Greater Cairo may be contaminated with pathogenic bacteria, parasites, and fungi. In addition, the physicochemical characteristics and metal pollution of Nile River water correlated with the microbiome type and density in the investigated sites.

The complete eradication of hepatitis C virus (HCV) from both hepatic and extrahepatic compartments following successful direct-acting antiviral (DAA) therapy remains an area of ongoing investigation. This study aimed to detect HCV RNA signals in serum and tissue samples from 40 patients who had achieved a sustained virologic response (SVR). Paired serum samples (pre-treatment and post-SVR) were analyzed concurrently with liver, gallbladder, bile, pancreatic, and splenic tissues. These tissue samples were obtained during clinically indicated surgical procedures performed 4–12 weeks after SVR. HCV RNA was quantified using a real-time PCR assay, adapted exploratorily for tissue matrices. Statistical analysis encompassed paired comparisons for serum samples and descriptive analysis for tissue findings. All patients exhibited complete clearance of serum HCV RNA post-treatment (p < 0.001). Nevertheless, HCV RNA signals were detected in 11 of 40 liver tissue samples (27.5%) and in 6 of 40 gallbladder and bile samples (15%). Furthermore, detection was observed in the sole pancreatic sample (1/1) and in two of three splenic samples (2/3). Due to the constrained sample sizes, the extrahepatic findings are presented descriptively. Viral load measurements varied across tissues and are reported as median values with interquartile ranges. In conclusion, HCV RNA signals were detected in hepatic and selected extrahepatic tissues despite undetectable serum PCR following DAA therapy. It is crucial to note that these findings represent molecular detection exclusively and do not confirm active viral replication or persistence. These results should be considered exploratory and necessitate validation through strand-specific assays and larger patient cohorts.

Egypt has witnessed the emergence of multidrug-resistant (MDR) Klebsiella pneumoniae, which has posed a serious healthcare challenge. The proper treatment choice for MDR-KP infections is not well determined which renders the problem more complicated, thus making the control of such infections a serious challenge for healthcare professionals. This study aims to encapsulate the cationic antimicrobial peptide; Cecropin-B (Cec-B), to increase its lifetime, drug targeting, and efficacy and study the antimicrobial effect of free and encapsulated recombinant rCec-B peptide on multidrug-resistant K. pneumoniae (MDR-KP) isolates. Fifty isolates were collected from different clinical departments at Theodore Bilharz Research Institute. Minimal inhibitory concentrations (MICs) of rCec-B against MDR-KP isolates were determined by the broth microdilution test. In addition, encapsulation of rCec-B peptide into chitosan nanoparticles and studying its bactericidal effect against MDR-KP isolates were also performed. The relative expression of efflux pump and porin coding genes (ArcrB, TolC, mtdK, and Ompk35) was detected by quantitative PCR in treated MDR-KP bacterial isolates compared to untreated isolates. Out of 60 clinical MDR isolates, 50 were MDR-KP. 60% of the isolates were XDR while 40% were MDR. rCec-B were bactericidal on 21 isolates, then these isolates were subjected to treatment using free nanocapsule in addition to the encapsulated peptide. Free capsules showed a mild cytotoxic effect on MDR-KP at the highest concentration. MIC of encapsulated rCec-B was higher than the free peptide. The expression level of genes encoding efflux and porin (ArcrB, TolC, mtdK, and Ompk35) was downregulated after treatment with encapsulated rCec-B. These findings indicate that encapsulated rCec-B is a promising candidate with potent antibacterial activities against drug-resistant K. pneumoniae.

Background: Free doxorubicin (Dox) is used as a chemotherapeutic agent against hepatocellular carcinoma (HCC), but it results in cardiotoxicty as a major side effect. Hence, a controlled Dox drug delivery system is extremely demanded. Methods: Dox was loaded into the non-toxic biodegradable polycaprolactone (PCL) nanocapsules using the double emulsion method. Characterization of Dox-PCL nanocapsules was done using transmission electron microscopy and dynamic light scattering. Encapsulation efficiency and drug loading capacity were quantified using UV–visible spectrophotometry. Drug release was investigated in vitro at both normal (7.4) and cancer (4.8) pHs. Cytotoxicity of Dox-PCL nanocapsules against free Dox was evaluated using the MTT test on normal (Vero) and hepatic cancer (HepG2) cell lines. Results: Spherical nanocapsules (212 ± 2 nm) were succeffully prepared with a zeta potential of (-22.3 ± 2 mv) and a polydisperse index of (0.019 ± 0.01) with a narrow size distribution pattern. The encapsulation efficiency was (73.15 ± 4%) with a drug loading capacity of (16.88 ± 2%). Importantlly, Dox-release from nanocapsules was faster at cancer pH (98%) than at physiological pH (26%). Moreover, although Dox-PCL nanocapsules were less toxic on the normal cell line (GI 50 = 17.99 ± 8.62 µg/ml) than free Dox (GI 50 = 16.53 ± 1.06 µg/ml), the encapsulated Dox showed higher toxic effect on cancer HepG2 cells compared to that caused by the free drug (GI 50 = 2.46 ± 0.49 and 4.22 ± 0.04 µg/ml, respectively). Conclusion: The constructed Dox-PCL nanocapsules constitute a potentially controlled anti-HCC therapy with minimal systemic exposure. Graphical

The interactions between pharmaceuticals and nanomaterials and its potentially resulting toxicological effects in living systems are only insufficiently investigated. In this study, two model compounds, acetaminophen, a pharmaceutical, and cerium dioxide, a manufactured nanomaterial, were investigated in combination and individually. Upon inhalation, cerium dioxide nanomaterials were shown to systemically translocate into other organs, such as the liver. Therefore we picked the human liver cell line HuH-7 cells as an in vitro system to investigate liver toxicity. Possible synergistic or antagonistic metabolic changes after co-exposure scenarios were investigated. Toxicological data of the water soluble tetrazolium (WST-1) assay for cell proliferation and genotoxicity assessment using the Comet assay were combined with an untargeted as well as a targeted lipidomics approach. We found an attenuated cytotoxicity and an altered metabolic profile in co-exposure experiments with cerium dioxide, indicating an interaction of both compounds at these endpoints. Single exposure against cerium dioxide showed a genotoxic effect in the Comet assay. Conversely, acetaminophen exhibited no genotoxic effect. Comet assay data do not indicate an enhancement of genotoxicity after co-exposure. The results obtained in this study highlight the advantage of investigating co-exposure scenarios, especially for bioactive substances.

Context: Linum usitatissimum (Linn); known as Flaxseed, is one of the most important medicinal plants traditionally used for health benefits and also as nutritional purposes. Objective: Estimation of total phenolic and flavonoid contents, and evaluation of the antioxidant, antiinflammatory and anticancer activities have been performed on hexane, ethyl acetate, n-butanol, and methanol extracts and also on fractions of methanol extract (hexane, ethyl acetate, and n-butanol). Materials and Methods: Phenolic and flavonoid contents were detected using spectrophotometric and colorimetric assays. Antioxidant and anti-inflammatory activities were estimated in-vitro. Anticancer activity of extracts was tested on Hepatocellular carcinoma cell line (HepG2) and breast cancer cell line (MCF7). Results: The methanolic extract and its ethyl acetate fraction showed higher contents of total phenols and flavonoids. Also, the methanolic extract showed a higher antioxidant activity. The butanolic and ethyl acetate fractions at concentration 500μg/ml yielded a higher percent of inhibition of protein denaturation; 87.9% and 90%, respectively. The ethyl acetate fraction and the methanolic extract showed an obvious anticancer activity against HepG2 and MCF7 (IC50=60±0.24 and 29.4±0.12μg. ml-1) and (IC50=94.7±0.21 and 227±0.48μg. ml-1), respectively. The GC-MS analysis showed that the methanolic extract had 32 compounds whereas the ethyl acetate and butanol fractions contained 40 and 36 compounds, respectively. Conclusion: Flaxseed contains different biologically active compounds that have been found to possess various activities, which can protect the human body against several diseases.

Antibiotic resistance is increasing at such an alarming rate that it is now one of the greatest global health challenges. Undesirable toxic side-effects of the drugs lead to high rates of non-completion of treatment regimens which in turn leads to the development of drug resistance. We report on the development of delivery systems that enable antibiotics to be toxic against bacterial cells while sparing human cells. The broad-spectrum fluoroquinolone antibiotic moxifloxacin (Mox) was successfully conjugated to poly(ethylene glycol) (PEG) which was further encapsulated into the hydrophobic poly(ε-caprolactone) (PCL) nanoparticles (NPs) with high efficiency, average particle size of 241.8 ± 4 nm and negative zeta potential. Toxicity against erythrocytes and MDBK cell lines and drug release in human plasma were evaluated. Hemocompatibility and reduced cytotoxicity of the PEG–Mox and PCL(PEG–Mox) NPs were demonstrated in comparison to free Mox. Antimicrobial activity was assessed against drug sensitive and resistant: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The antibacterial activity of Mox was largely maintained after conjugation. Our data shows that the toxicity of Mox can be effectively attenuated while, in the case of PEG–Mox, retaining significant antibacterial activity. At the conditions employed in this study for antimicrobial activity the encapsulated conjugate (PCL(PEG–Mox) NPs) did not demonstrate, conclusively, significant antibacterial activity. These systems do, however, hold promise if further developed for improved treatment of bacterial infections.

Background: Podocytes associated proteins are essential in the maintenance of a healthy glomerular filtration barrier, a spectrum of different glomerular diseases occurs due to podocyte abnormalities. Urinary podocytes mRNAs are a more accurate tool for monitoring the progression of different glomerular diseases than proteinuria.Methods: Quantification of podocyte mRNAs in urinary sediment by real time polymerase chain reaction (PCR) of idiopathic nephrotic syndrome, lupus nephritis patients (LN) and the healthy controls, each group contains 15 individuals to be correlated with proteinuria level and eGFR (by MDRD equation).Results: the urinary podocyte mRNAs in both idiopathic nephrotic syndrome and LN groups differed significantly in comparison to that of controls, there was a significant correlation when comparing renal function tests and estimated glomerular filtration rate (by MDRD equation) between nephrotic, LN groups and control group, the value of podocin showed significant correlation in active LN subgroup with its corresponding value in the non-active LN subgroup.Conclusions: This study has revealed that urine pellet podocyte mRNAs can be used as a tool for monitoring the progression of idiopathic nephrotic syndrome and lupus nephritis patients and that urinary podocin can be used as a marker for lupus nephritis activity.