Mohamed, S. A., T. M. Samir, O. M. N. E. Y. A. M. HELMY, N. M. Elhosseiny, A. A. Ali, A. A. El-Kholy, and A. S. Attia, "A Novel Surface-Exposed Polypeptide Is Successfully Employed as a Target for Developing a Prototype One-Step Immunochromatographic Strip for Specific and Sensitive Direct Detection of Staphylococcus aureus Causing Neonatal Sepsis", Biomolecules, vol. 10, issue 11, pp. 1580, 2020. biomolecules-10-01580.pdf
Elhosseiny, N. M., N. B. Elhezawy, R. M. Sayed, M. S. Khattab, M. Y. El Far, and A. S. Attia, "γ-Glutamyltransferase as a Novel Virulence Factor of Acinetobacter baumannii Inducing Alveolar Wall Destruction and Renal Damage in Systemic Disease.", The Journal of infectious diseases, vol. 222, issue 5, pp. 871-879, 2020. Abstract

A thorough understanding of Acinetobacter baumannii pathogenicity is the key to identifying novel drug targets. In the current study, we characterize the γ-glutamyltransferase enzyme (GGT) as a novel virulence factor. A GGT assay showed that the enzyme is secreted via the type II secretion system and results in higher extracellular activity for the hypervirulent AB5075 than the laboratory-adapted strain American Type Culture Collection 17978. Enzyme-linked immunosorbent assay revealed that the former secretes larger amounts of GGT, and a rifampicin messenger RNA stability study showed that one reason for this could be the longer AB5075 ggt transcript half-life. Infection models confirmed that GGT is required for the virulence of A. baumannii. Finally, we show that clinical isolates with significantly higher extracellular GGT activity resulted in more severe infections, and assay of immune response and tissue damage markers confirm this correlation. The current findings establish for the first time the role of the GGT in the pathogenicity of A. baumannii.

Kamel, A. M., S. F. Farid, A. S. Attia, and M. E. Raziky, "Association of vitamin D binding protein polymorphisms with response to therapy in Egyptian chronic hepatitis C patients.", Journal of infection in developing countries, vol. 11, issue 10, pp. 781-790, 2017. Abstract8830-1-60988-2-10-20171106.pdf

INTRODUCTION: Vitamin D binding protein (VDBP) is a potential modulator of immune response and is associated with clinical progression of many diseases. Our aim was to assess influence of baseline 25-hydroxyvitamin D levels and VDBP single nucleotide polymorphisms (SNPs), rs4588 (C > A) and rs7041 (G > T), on baseline clinical parameters and response to interferon based therapy in chronic hepatitis C patients in Egypt.

METHODOLOGY: Genotyping was performed by RFLP (Restriction Fragment Length Polymorphism) in 112 treatment naïve hepatitis C patients and 50 healthy controls. Vitamin D levels were assessed by ELISA. HCV RNA quantification was performed by PCR to assess therapy outcome.

RESULTS: Patients with VDBP WT+ diplotype (3 or 4 VDBP major alleles) had higher viral response rates at weeks 12, 48, and 72 (p = 0.046, 0.034 and 0.029, respectively) and lower base line viral load (p = 0.016). Multivariate logistic regression identified VDBP WT+ diplotype as an independent predictor of sustained viral response (SVR; p = 0.014, RR = 4.716, 95% CI = 1.371 - 16.609). Interestingly, WT- diplotype (less than 3 VDBP major alleles) was associated with significant liver fibrosis (p = 0.045).

CONCLUSIONS: VDBP WT+ diplotype is associated with lower baseline viral load and better therapy outcome in HCV treatment naïve patients. The rs4588 genotype is associated with SVR in the Egyptian population.

Elhosseiny, N. M., and A. S. Attia, "Acinetobacter: an emerging pathogen with a versatile secretome.", Emerging microbes & infections, vol. 7, issue 1, pp. 33, 2018. Abstractacinetobacter_an_emerging_pathogen_with_a_versatile_secretome..pdf

Acinetobacter baumannii is a notorious pathogen that has emerged as a healthcare nightmare in recent years because it causes serious infections that are associated with high morbidity and mortality rates. Due to its exceptional ability to acquire resistance to almost all available antibiotics, A. baumannii is currently ranked as the first pathogen on the World Health Organization's priority list for the development of new antibiotics. The versatile range of effectors secreted by A. baumannii represents a large proportion of the virulence arsenal identified in this bacterium to date. Thus, these factors, together with the secretory machinery responsible for their extrusion into the extracellular milieu, are key targets for novel therapeutics that are greatly needed to combat this deadly pathogen. In this review, we provide a comprehensive, up-to-date overview of the organization and regulatory aspects of the Acinetobacter secretion systems, with a special emphasis on their versatile substrates that could be targeted to fight the deadly infections caused by this elusive pathogen.

Elhosseiny, N. M., N. B. Elhezawy, and A. S. Attia, "Comparative proteomics analyses of Acinetobacter baumannii strains ATCC 17978 and AB5075 reveal the differential role of type II secretion system secretomes in lung colonization and ciprofloxacin resistance.", Microbial pathogenesis, vol. 128, pp. 20-27, 2019. Abstractcomparative_proteomics_paper_final.pdf

Acinetobacter baumannii is an emerging nosocomial pathogen with alarming antibiotic resistance profiles. A better understanding of the virulence and resistance mechanisms of this pathogen is necessary for identifying new methods to combat its infections in a more efficient way. In this regard, the type II secretion system (T2SS) of A. baumannii is an attractive target majorly secreting lipid-metabolizing enzymes and contributes significantly to its virulence. No attempts have been made to study the differential role, and the nature of T2SS secreted proteins among different strains of A. baumannii. In this study, we compare T2SS substrates and functions between A. baumannii strains ATCC 17978, and the MDR highly virulent strain AB5075. The functional categories of the T2-secreted proteins were analyzed, and the virulence potential of the tested strains was compared in vivo using a murine pneumonia model. Biofilm formation was compared using crystal violet assay in micro-titer plates. The contribution to antibiotic resistance was measured by determining the minimum inhibitory concentration (MIC) of different classes of antibiotic. Results indicate that the T2SS secretome gives a colonization advantage to AB5075 over ATCC 1797 but is more important for biofilm formation by the latter. Transposon insertional inactivation of the general secretory pathway protein D (gspD), which is a key component in the structure of the T2SS, significantly increased the MIC of AB5075 to ciprofloxacin. Our report is the first to describe the strain-dependent evolution of the T2SS secretome in relation to the virulence and antibiotic resistance attributes of Gram-negative species.

Gowayed, M. A., K. Rothe, M. Rossol, A. S. Attia, U. Wagner, C. Baerwald, H. S. El-Abhar, and R. Refaat, "The role of α7nAChR in controlling the anti-inflammatory/anti-arthritic action of galantamine.", Biochemical pharmacology, vol. 170, pp. 113665, 2019. Abstractthe_role_of_a7nachr_in_controlling_the_anti-inflammatory_anti-arthritic_action_of_galantamine.pdf

OBJECTIVE: The evolution of the "cholinergic anti-inflammatory pathway" and the fact that the α 7 subunit of the nicotinic acetylcholine receptor (α7nAChR) is present in the spleen, joint and on the surface of lymphocytes, opened up the prospective in this study of targeting the α7nAChR by the anticholinesterase and cholinergic drug, galantamine, to control inflammation in rheumatoid arthritis (RA).

METHODS: Twelve-adjuvant arthritic rats were exposed to the selective α7nAChR blocker methylcaconitine citrate 15 min before galantamine treatment. As control, six adjuvant arthritic rats were treated with galantamine and six others were untreated. After five days TNF-α levels were assessed in spleen and joints, while reduced glutathione was measured in blood and joint tissue. In the second part, magnetically sorted CD4 + T cells from peripheral blood mononuclear cells of RA patients and healthy donors were used to sort CD4 + CD25 - primary T cells (Tresp) and CD4 + CD25 + CD127low Tregs. The suppressive function of Tregs was investigated after incubation with galantamine using flow cytometry. Cell culture supernatants were analyzed for TNF-α and IL-10 levels after three days incubation period of Tregs with Tresp. The effect of galantamine on Tregs was then blocked by α-Bungarotoxin and the same assay has been repeated.

RESULTS & CONCLUSION: Selective α7nAChR blockade interrupted the anti-inflammatory effect of galantamine in the spleen and joints of arthritic rats. In healthy donors, galantamine could strengthen the suppressive activity of Tregs; while in RA patients it did not modulate the function of Tregs significantly. Further studies are necessary to investigate whether modulation of the cholinergic nervous system, especially α7nAChR, could have impact on the disturbed immune system in RA, which may open up a new treatment option of autoimmune diseases.

Choucry, A. M., M. Y. Al-Shorbagy, A. S. Attia, and H. S. El-Abhar, "Pharmacological Manipulation of Trk, p75NTR, and NGF Balance Restores Memory Deficit in Global Ischemia/Reperfusion Model in Rats.", Journal of molecular neuroscience : MN, vol. 68, issue 1, pp. 78-90, 2019. Abstractchoucry2019_article_pharmacologicalmanipulationoft.pdf

Long-term memory impairment is reported in more than 50% of cardiac arrest survivors. Monosialoganglioside (GM1) provided neuroprotection in experimental models of stroke but failed to replicate its promise clinically for unknown reasons. GM1 stimulates the release of nerve growth factor (NGF), which is synthesized as a precursor protein (pro-NGF) that either mediates apoptosis through the p75 neurotrophin receptor (p75NTR) or is cleaved by the protease furin (FUR) to yield mature NGF, the latter supporting survival through tropomyosin kinase receptor (Trk). The flavanol epicatechin (EPI) inhibits p75NTR-mediated signaling and apoptosis by pro-NGF. The aim of the current work is to test whether these two drugs affect, or communicate with, each other in the setting of CNS injuries. Using the two-vessel occlusion model of global ischemia/reperfusion (I/R), we tested if pharmacological modulation of Trk, p75NTR, and NGF balance with GM1, EPI, and their combination, can correct the memory deficit that follows this insult. Finally, we tested if FUR insufficiency and/or p75NTR-mediated apoptosis negatively affect the neurotherapeutic effect of GM1. Key proteins for Trk and p75NTR, FUR, and both forms of NGF were assessed. All treatment regiments successfully improved spatial memory retention and acquisition. A week after the insult, most Trk and p75NTR proteins were normal, but pro/mature NGF ratio remained sharply elevated and was associated with the poorest memory performance. Pharmacological correction of this balance was achieved by reinforcing Trk and p75NTR signaling. GM1 increased FUR levels, while concomitant administration of EPI weakened GM1 effect on pro-survival Trk and p75NTR mediators. GM1 neuroprotection is therefore not limited by FUR but could be dependent on p75NTR. Graphical Abstract "."

El Far, M. Y., H. A. El-Mahallawy, and A. S. Attia, "Tracing the dissemination of the international clones of multidrug-resistant Acinetobacter baumannii among cancer patients in Egypt using the PCR-based open reading frame typing (POT) method.", Journal of global antimicrobial resistance, vol. 19, pp. 210-215, 2019. Abstractel_far_et_al_2019_-final_version.pdf

OBJECTIVES: The aim of this study was to perform an epidemiological surveillance of multidrug-resistant (MDR) Acinetobacter baumannii genetic lineages among cancer patients in Egypt using the PCR-based open reading frame typing (POT) method.

METHODS: A total of 160 MDR A. baumannii isolates were collected between January 2015 and December 2017 at a tertiary-care centre in Egypt. VITEK®2 system was used for preliminary species identification and antimicrobial susceptibility testing. The POT method was applied for confirmation of species identification and molecular epidemiological typing of the isolates.

RESULTS: MDR A. baumannii isolates were classified into 15 POT types, including POT 122 (n=69), POT 69 (n=22) and other miscellaneous POT types (MPOTs) including POT 0, 8, 10, 12, 14, 40, 44, 52, 56, 93, 104, 106 and 108 (n=69). POT 122 isolates infected or colonised 61% of patients hospitalised in surgical wards and 54% of patients diagnosed with solid tumours and 51% were adults; whereas MPOT isolates infected or colonised 51% of patients hospitalised in paediatric wards and 49% of patients diagnosed with haematological malignancies and 51% were paediatric patients (P=0.007, 0.001 and 0.004, respectively). MPOT isolates were recovered from 46% of the collected blood specimens, whilst POT 122 isolates were recovered from 61% of the collected respiratory specimens (P=0.05).

CONCLUSION: The current study demonstrates that the easy, low-cost POT method is convenient for rapid delineation of A. baumannii clonal diversity in a tertiary-care hospital in Egypt.

Nour El-Din, H. T., N. M. Elhosseiny, M. A. El-Gendy, A. A. Mahmoud, M. M. M. Hussein, and A. S. Attia, "A Rapid Lysostaphin Production Approach and a Convenient Novel Lysostaphin Loaded Nano-emulgel; As a Sustainable Low-Cost Methicillin-Resistant Combating Platform.", Biomolecules, vol. 10, issue 3, 2020. Abstractbiomolecules-10-00435-final_published_form.pdf

is a Gram-positive pathogen that is capable of infecting almost every organ in the human body. Alarmingly, the rapid emergence of methicillin-resistant strains (MRSA) jeopardizes the available treatment options. Herein, we propose sustainable, low-cost production of recombinant lysostaphin (rLST), which is a native bacteriocin destroying the staphylococcal cell wall through its endopeptidase activity. We combined the use of BL21(DE3)/pET15b, factorial design, and simple Ni-NTA affinity chromatography to optimize rLST production. The enzyme yield was up to 50 mg/L culture, surpassing reported systems. Our rLST demonstrated superlative biofilm combating ability by inhibiting staphylococcal biofilms formation and detachment of already formed biofilms, compared to vancomycin and linezolid. Furthermore, we aimed at developing a novel rLST topical formula targeting staphylococcal skin infections. The phase inversion composition (PIC) method fulfilled this aim with its simple preparatory steps and affordable components. LST nano-emulgel (LNEG) was able to extend active LST release up to 8 h and cure skin infections in a murine skin model. We are introducing a rapid, convenient rLST production platform with an outcome of pure, active rLST incorporated into an effective LNEG formula with scaling-up potential to satisfy the needs of both research and therapeutic purposes.

Elfaky, M. A., M. A. M. Yassien, A. S. Attia, M. Salah, and M. S. E. A. Mansy, "Antimicrobial resistance pattern of biofilm forming Pseudomonas aeruginosa isolated from patients with nasogastric and endotracheal tubes", World Journal of Pharmaceutical Sciences, vol. 3, no. 3, pp. 401-406, 2015. Abstract