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2020
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
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.

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.

2019
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.

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 "."

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.

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.

2018
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.

2017
Nagy, Y. I., M. M. M. Hussein, Y. M. Ragab, and A. S. Attia, "Isogenic mutations in the Moraxella catarrhalis CydDC system display pleiotropic phenotypes and reveal the role of a palindrome sequence in its transcriptional regulation.", Microbiological research, vol. 202, pp. 71-79, 2017 Sep. Abstract1-s2.0-s0944501317305050-main.pdf

Moraxella catarrhalis is becoming an important human respiratory tract pathogen affecting significant proportions from the population. However, still little is known about its physiology and molecular regulation. To this end, the CydDC, which is a heterodimeric ATP binding cassette transporter that has been shown to contribute to the maintenance of the redox homeostasis across the periplasm in other Gram-negative bacteria, is studied here. Amino acids multiple sequence alignments indicated that M. catarrhalis CydC is different from the CydC proteins of the bacterial species in which this system has been previously studied. These findings prompted further interest in studying this system in M. catarrhalis. Isogenic mutant in the CydDC system showed suppression in growth rate, hypersensitivity to oxidative and reductive stress and increased accumulation of intracellular cysteine levels. In addition, the growth of cydCmutant exhibited hypersensitivity to exogenous cysteine; however, it did not display a significant difference from its wild-type counterpart in the murine pulmonary clearance model. Moreover, a palindrome was detected 94bp upstream of the cydD ORF suggesting it might act as a potential regulatory element. Real-time reverse transcription-PCR analysis showed that deletion/change in the palindrome resulted into alterations in the transcription levels of cydC. A better understanding of such system and its regulation helps in developing better ways to combat M. catarrhalis infections.

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.

2016
Samir, R., S. H. Hussein, N. M. Elhosseiny, M. S. Khattab, A. E. Shawky, and A. S. Attia, "Adaptation to Potassium-Limitation Is Essential for Acinetobacter baumannii Pneumonia Pathogenesis", The Journal of Infectious Diseases, vol. 214, issue 12: Oxford University Press, pp. 2006 - 2013, 2016. Abstractj_infect_dis.-2016-samir-2006-13.pdf

Background. Acinetobacter baumannii is challenging the healthcare community through wide range of untreatable infections. New targets need to be explored for the development of therapeutics.

Methods. The potassium dependent protein (Kdp) system was investigated via bioinformatics and genetic tools. An isogenic mutant was constructed in the kdpE gene and complemented in trans. Gene expression and the ability to grow under potassium-limitation were investigated. Finally, the role of KdpE in virulence was examined in the murine pneumonia model.

Results. A. baumannii Kdp system has a distinct arrangement and is well conserved among A. baumannii strains. The genes encoding the five members of the system are transcriptionally-linked. The kdpE gene is up-regulated more than 70-folds under potassium-limitation. TheΔkdpE mutant showed a significant growth defect under potassium-limitation and in the colonization of mice lungs. These defects could be restored upon introducing the kdpE gene on a multi-copy plasmid. Proteomic analyses indicated that KdpE could be regulating several proteins with potential involvement in pathogenesis.

Conclusion. For the first time, the A. baumannii KdpE is shown to be crucial for successful pneumonia infection and its targeting can be a viable approach to treat these fatal infections.

Abdelaziz, D. H., N. M. Elhosseiny, S. A. Khaleel, N. A. Sabry, A. S. Attia, and M. H. El‐Sayed, "Association Between Combined Presence of Hepatitis C Virus and Polymorphisms in Different Genes With Toxicities of Methotrexate and 6‐Mercaptopurine in Children With Acute Lymphoblastic Leukemia", Pediatric Blood and Cancer , vol. 63, issue 9, pp. 1539-45, 2016. Abstractabdelaziz_et_al-2016-pediatric_blood__cancer.pdf

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Hennawy, M. G., N. M. Elhosseiny, H. Sultan, W. Abdelfattah, Y. Akl, N. A. Sabry, and A. S. Attia, "The effect of α 1-antitrypsin deficiency combined with increased bacterial loads on chronic obstructive pulmonary disease pharmacotherapy: A prospective, parallel, controlled pilot study", Journal of Advanced Research, vol. 7, issue 6: Elsevier, pp. 1019-1028, 2016. Abstract2016-jar-copd_paper_final_version.pdf

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Yassin, G. M., M. A. Amin, and A. S. Attia, "Immunoinformatics identifies a lactoferrin binding protein A peptide as a promising vaccine with a global protective prospective against Moraxella catarrhalis", The Journal of Infectious Diseases, vol. 213 , issue 12: Oxford University Press, pp. 1938-1945, 2016. Abstractj_infect_dis.-2016-yassin-1938-45.pdf

Background. Moraxella catarrhalis is an established pathogen that is causing substantial infections to both children and adults. However, so far there is no effective vaccine that could halt the spread of these infections.

Methods. Immunoinformatics tools were used to predict M. catarrhalis epitopes that would be capable of offering immunoprotection among major proportions of human populations worldwide. Mice were immunized with the best three peptides then challenged with M. catarrhalis in the pulmonary clearance model. Finally, antibodies against these epitopes were detected in humans.

Results. Immunoinformatics analyses identified 44 epitopes which are predicted to be good MHC-II binders and at the same time show high population coverages worldwide. Upon intraperitoneal mice immunization with the best three peptides, peptide “A” derived from the lactoferrin binding protein A showed superior activity in immunogenicity and in clearing M. catarrhalis from mice lungs. Higher clearance was obtained upon combining intraperitoneal with intranasal immunization. Upon examining the sera from otitis media children infected with M. catarrhalis, antibodies levels against peptide “A” were significantly lower than those detected in non-otitis media ones.

Conclusion. Peptide “A” is the first promising peptide-based vaccine against M. catarrhalis. Immunoinformatics predicts it should have a global protection around the world.

Elhosseiny, N. M., O. M. El-Tayeb, A. S. Yassin, S. Lory, and A. S. Attia, "The secretome of Acinetobacter baumannii ATCC 17978 type II secretion system reveals a novel plasmid encoded phospholipase that could be implicated in lung colonization", International Journal of Medical Microbiology, vol. 306, issue 8: Urban & Fischer, pp. 633-641, 2016. Abstract1-s2.0-s1438422116301199-main.pdf

Acinetobacter baumannii infections are compounded with a striking lack of treatment options. In many Gram-negative bacteria, secreted proteins play an important early role in avoiding host defences. Typically, these proteins are targeted to the external environment or into host cells using dedicated transport systems. Despite the fact that medically relevant species of Acinetobacter possess a type II secretion system (T2SS), only recently, its significance as an important pathway for delivering virulence factors has gained attention.

Using in silico analysis to characterize the genetic determinants of the T2SS, which are found clustered in other organisms, in Acinetobacter species, they appear to have a unique genetic organization and are distributed throughout the genome. When compared to other T2SS orthologs, individual components of the T2SS apparatus showed the highest similarity to those of Pseudomonas aeruginosa. A mutant of Acinetobacter baumannii strain ATCC 17978 lacking the secretin component of the T2SS (ΔgspD), together with a trans-complemented mutant, were tested in a series of in vitro and in vivo assays to determine the role of T2SS in pathogenicity. The ΔgspD mutant displayed decreased lipolytic activity, associated with attenuated colonization ability in a murine pneumonia model. These phenotypes are linked to LipAN, a novel plasmid-encoded phospholipase, identified through mass spectroscopy as a T2SS substrate. Recombinant LipAN showed specific phospholipase activity in vitro. Proteomics on the T2-dependent secretome of ATCC 17978 strain revealed its potential dedication to the secretion of a number of lipolytic enzymes, among others which could contribute to its virulence. This study highlights the role of T2SS as an active contributor to the virulence of A. baumannii potentially through secretion of a newly identified phospholipase.

2015
Abdel-Fattah, A. M., E. L. - S. H. A. Nashy, E. - T. A. Sabiel, M. M. Hussien, and A. S. Attia, Novel Keratinolytic Activity of Cyberlindnera fabianii Nrc3 Aza as A Plant Growth Promoting Agent (PGPA), , vol. 3, issue 4, pp. 609 - 618, 2015. Abstract
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Elhosseiny, N. M., M. A. Amin, A. S. Yassin, and A. S. Attia, "Acinetobacter baumannii universal stress protein A plays a pivotal role in stress response and is essential for pneumonia and sepsis pathogenesis", International Journal of Medical Microbiology, vol. 305, no. 1: Urban & Fischer, pp. 114–123, 2015. AbstractElhosseiny et al 2015-IJMM-305;114-123.pdf

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Ali, M. A., H. S. El-Abhar, M. A. Kamel, and A. S. Attia, "Antidiabetic effect of galantamine: novel effect for a known centrally acting drug", PloS one, vol. 10, no. 8: Public Library of Science, pp. e0134648, 2015. AbstractAli et al 2015-pone.0134648.pdf

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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: Atom and Cell Publishers, pp. 401–406, 2015. AbstractElfeky et al 2015-WJPS-3;401-406.pdf

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Joslin, S. N., C. Pybus, M. Labandeira-Rey, A. S. Evans, A. S. Attia, C. A. Brautigam, and E. J. Hansen, "A Moraxella catarrhalis Two-Component Signal Transduction System Necessary for Growth in Liquid Media Affects Production of Two Lysozyme Inhibitors", Infection and immunity, vol. 83, no. 1: American Society for Microbiology, pp. 146–160, 2015. AbstractJoslin et al 2015-IAI-83;146-160.pdf

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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
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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
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Mahmoud-Awny, M., A. S. Attia, M. F. Abd-Ellah, and H. S. El-Abhar, "Mangiferin Mitigates Gastric Ulcer in Ischemia/Reperfused Rats: Involvement of PPAR-$\gamma$, NF-$ąppa$B and Nrf2/HO-1 Signaling Pathways", PloS one, vol. 10, no. 7: Public Library of Science, pp. e0132497, 2015. Abstract
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, "Novel Keratinase Enzyme from Cyberlindnera Fabianii NRC3 Aza with Promising Keratin-Biodegradation & Hide-Dehairing Activities", JOURNAL OF INDIAN LEATHER TECHNOLOGISTS’ ASSOCIATION (JILTA), vol. 65, no. 08: Indian Leather Technologists’ Association, pp. 17–25, 2015. Abstract
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2014
Elfaky, M. A., M. A. Yassien, A. S. Attia, M. S. Mansy, and M. S. E. Ashour, "Microbiological studies on resistance patterns of antimicrobial agents among Gram negative respiratory tract pathogens", African Journal of Microbiology Research, vol. 8, no. 27: Academic Journals, pp. 2583–2591, 2014. Abstract
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Khalil, M. A. F., H. M. E. Azzazy, A. S. Attia, and A. G. M. Hashem, "A sensitive colorimetric assay for identification of Acinetobacter baumannii using unmodified gold nanoparticles", Journal of applied microbiology, vol. 117, no. 2, pp. 465–471, 2014. Abstract
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2013
Attia, A. S., J. E. Cassat, S. O. Aranmolate, L. J. Zimmerman, K. L. Boyd, and E. P. Skaar, "Analysis of the Staphylococcus aureus abscess proteome identifies antimicrobial host proteins and bacterial stress responses at the host–pathogen interface", Pathogens and disease, vol. 69, no. 1, pp. 36–48, 2013. Abstract
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Fouad, M., A. S. Attia, W. M. Tawakkol, and A. G. M. Hashem, "Emergence of carbapenem-resistant Acinetobacter baumannii harboring the OXA-23 carbapenemase in intensive care units of Egyptian hospitals", International Journal of Infectious Diseases, vol. 17, no. 12: Elsevier, pp. e1252–e1254, 2013. Abstract
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2012
Elghanam, M. S., A. S. Attia, H. A. Shoeb, A. G. M. Hashem, and others, "Expression and purification of hepatitis B surface antigen S from Escherichia coli; a new simple method", BMC research notes, vol. 5, no. 1: BioMed Central Ltd, pp. 125, 2012. Abstract
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Wakeman, C. A., N. D. Hammer, D. L. Stauff, A. S. Attia, L. L. Anzaldi, S. I. Dikalov, W. M. Calcutt, and E. P. Skaar, "Menaquinone biosynthesis potentiates haem toxicity in Staphylococcus aureus", Molecular microbiology, vol. 86, no. 6, pp. 1376–1392, 2012. Abstract
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Attia, A. S., K. A. Schroeder, E. H. Seeley, K. J. Wilson, N. D. Hammer, D. C. Colvin, L. M. Manier, J. J. Nicklay, K. L. Rose, J. C. Gore, et al., "Monitoring the inflammatory response to infection through the integration of MALDI IMS and MRI", Cell host & microbe, vol. 11, no. 6: Cell Press, pp. 664–673, 2012. Abstract
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2010
Torres, V. J., A. S. Attia, W. J. Mason, M. I. Hood, B. D. Corbin, F. C. Beasley, K. L. Anderson, D. L. Stauff, W. H. McDonald, L. J. Zimmerman, et al., "Staphylococcus aureus fur regulates the expression of virulence factors that contribute to the pathogenesis of pneumonia", Infection and immunity, 2010/01/27, vol. 78, no. 4, pp. 1618-28, Apr, 2010. AbstractWebsite

The tremendous success of Staphylococcus aureus as a pathogen is due to the controlled expression of a diverse array of virulence factors. The effects of host environments on the expression of virulence factors and the mechanisms by which S. aureus adapts to colonize distinct host tissues are largely unknown. Vertebrates have evolved to sequester nutrient iron from invading bacteria, and iron availability is a signal that alerts pathogenic microorganisms when they enter the hostile host environment. Consistent with this, we report here that S. aureus senses alterations in the iron status via the ferric uptake regulator (Fur) and alters the abundance of a large number of virulence factors. These Fur-mediated changes protect S. aureus against killing by neutrophils, and Fur is required for full staphylococcal virulence in a murine model of infection. A potential mechanistic explanation for the impact of Fur on virulence is provided by the observation that Fur coordinates the reciprocal expression of cytolysins and a subset of immunomodulatory proteins. More specifically, S. aureus lacking fur exhibits decreased expression of immunomodulatory proteins and increased expression of cytolysins. These findings reveal that Fur is involved in initiating a regulatory program that organizes the expression of virulence factors during the pathogenesis of S. aureus pneumonia.

Attia, A. S., "Archives of Clinical Microbiology: New Vision", Archives of Clinical Microbiology, vol. 1, no. 2: IMedPub, 2010. Abstract
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Attia, A. S., M. A. Benson, D. L. Stauff, V. J. Torres, and E. P. Skaar, "Membrane damage elicits an immunomodulatory program in Staphylococcus aureus", PLoS Pathog, vol. 6, no. 3, pp. e1000802, 2010. Abstract
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Torres, V. J., A. S. Attia, W. J. Mason, I. M. Hood, B. D. Corbin, F. C. Beasley, K. L. Anderson, D. L. Stauff, H. W. McDonald, L. J. Zimmerman, et al., "Staphylococcus aureus fur regulates the expression of virulence factors that contribute to the pathogenesis of pneumonia", Infection and immunity, vol. 78, no. 4: Am Soc Microbiol, pp. 1618–1628, 2010. Abstract
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2009
Attia, A. S., J. L. Sedillo, T. C. Hoopman, W. Liu, L. Liu, C. A. Brautigam, and E. J. Hansen, "Identification of a bacteriocin and its cognate immunity factor expressed by Moraxella catarrhalis", BMC microbiology, vol. 9, no. 1: BioMed Central Ltd, pp. 207, 2009. Abstract
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2008
Brooks, M. J., J. L. Sedillo, N. Wagner, W. Wang, A. S. Attia, H. Wong, C. A. Laurence, E. J. Hansen, and S. D. Gray-Owen, "Moraxella catarrhalis binding to host cellular receptors is mediated by sequence-specific determinants not conserved among all UspA1 protein variants", Infection and immunity, 2008/08/06, vol. 76, no. 11, pp. 5322-9, Nov, 2008. AbstractWebsite

The Moraxella catarrhalis ubiquitous surface proteins (UspAs) are autotransporter molecules reported to interact with a variety of different host proteins and to affect processes ranging from serum resistance to cellular adhesion. The role of UspA1 as an adhesin has been confirmed with a number of different human cell types and is mediated by binding to eukaryotic proteins including carcinoembryonic antigen-related cellular adhesion molecules (CEACAMs), fibronectin, and laminin. A distinct difference in the ability of prototypical M. catarrhalis strains to adhere to CEACAM-expressing cell lines prompted us to perform strain-specific structure-function analyses of UspA1 proteins. In this study, we characterized CEACAM binding by a diverse set of UspA1 proteins and showed that 3 out of 10 UspA1 proteins were incapable of binding CEACAM. This difference resulted from the absence of a distinct CEACAM binding motif in nonadhering strains. Our sequence analysis also revealed a single M. catarrhalis isolate that lacked the fibronectin-binding motif and was defective in adherence to Chang conjunctival epithelial cells. These results clearly demonstrate that UspA1-associated adhesive functions are not universally conserved. Instead, UspA1 proteins must be considered as variants with the potential to confer both different cell tropisms and host cell responses.

Attia, A. S., J. L. Sedillo, W. Wang, W. Liu, C. A. Brautigam, W. Winkler, and E. J. Hansen, "Moraxella catarrhalis expresses an unusual Hfq protein", Infection and immunity, 2008/03/26, vol. 76, no. 6, pp. 2520-30, Jun, 2008. AbstractWebsite

The Hfq protein is recognized as a global regulatory molecule that facilitates certain RNA-RNA interactions in bacteria. BLAST analysis identified a 630-nucleotide open reading frame in the genome of Moraxella catarrhalis ATCC 43617 that was highly conserved among M. catarrhalis strains and which encoded a predicted protein with significant homology to the Hfq protein of Escherichia coli. This protein, containing 210 amino acids, was more than twice as large as the Hfq proteins previously described for other bacteria. The C-terminal half of the M. catarrhalis Hfq protein was very hydrophilic and contained two different types of amino acid repeats. A mutation in the M. catarrhalis hfq gene affected both the growth rate of this organism and its sensitivity to at least two different types of stress in vitro. Provision of the wild-type M. catarrhalis hfq gene in trans eliminated these phenotypic differences in the hfq mutant. This M. catarrhalis hfq mutant exhibited altered expression of some cell envelope proteins relative to the wild-type parent strain and also had a growth advantage in a continuous flow biofilm system. The presence of the wild-type M. catarrhalis hfq gene in trans in an E. coli hfq mutant fully reversed the modest growth deficiency of this E. coli mutant and partially reversed the stress sensitivity of this E. coli mutant to methyl viologen. The use of an electrophoretic mobility shift assay showed that this M. catarrhalis Hfq protein could bind RNA derived from a gene whose expression was altered in the M. catarrhalis hfq mutant.

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