Browsing by Author "Khairalla A.S."

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    Carriage frequency, phenotypic, and genotypic characteristics of methicillin-resistant Staphylococcus aureus isolated from dental health-care personnel, patients, and environment
    (Life Science Journal, 2017) Khairalla A.S.; Wasfi R.; Ashour H.M.; Department of Microbiology and Immunology; Faculty of Pharmacy; Beni-Suef University Egypt; Beni-Suef; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); Giza; Egypt; Department of Biological Sciences; College of Arts and Sciences; University of South Florida St.Petersburg; St.Petersburg; United States; Department of Microbiology and Immunology; Faculty of Pharmacy; Cairo University Egypt; Cairo; Egypt
    There is limited data on methicillin-resistant Staphylococcus aureus (MRSA) carriage in dental clinics.1300 specimens from patients, health personnel, and environmental surfaces of a dental clinic in Egypt were tested for MRSA.Antibiotic susceptibility, biofilm formation, Staphylococcal protein A (spa) typing, SCCmec typing, and PCR-based assays were used to detect mecA, mecC, vanA, Panton-Valentine Leukocidin toxin (PVL), and toxic shock syndrome toxin-1 (tst) genes.Among 34 mecA-positive MRSA isolates, five (14.7%) were PVL-positive, seventeen (50%) were tst-positive, ten (29.4%) were vanA-positive, while none harboured mecC.MRSA hand carriage rates in patients, nurses, and dentists were 9.8%, 6.6%, and 5%.The respective nasal colonization rates were 11.1%, 6.7%, and 9.7%.1.3% of the environmental isolates were MRSA-positive.Strong and moderate biofilm-forming isolates represented 23.5% and 29.4% of MRSA isolates.24 MRSA isolates (70.6%) were multi-resistant and 18 (52.9%) harboured SCCmec IV.Among eight spa types, t223 (26.5%), t267 (23.5%), and t14339 (23.5%) were predominant.We noted an alarming genetic relatedness between 7 (20.6%) MRSA isolates and the epidemic EMRSA-15 clone, as well as a combined occurrence of tst and PVL in 3 (8.8%) isolates.Results suggest high MRSA pathogenicity in dental wards highlighting the need for more efficient surveillance/infection control strategies. � 2017 The Author(s).
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    Effects of selected egyptian honeys on the cellular ultrastructure and the gene expression profile of Escherichia coli
    (Public Library of Science, 2016) Wasfi R.; Elkhatib W.F.; Khairalla A.S.; Department of Microbiology and Immunology; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); Giza; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Ain Shams University; Cairo; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Beni-Suef University; Beni-Suef; Egypt
    The purpose of this study was to: (i) evaluate the antibacterial activities of three Egyptian honeys collected from different floral sources (namely, citrus, clover, and marjoram) against Escherichia coli; (ii) investigate the effects of these honeys on bacterial ultrastructure; and (iii) assess the anti-virulence potential of these honeys, by examining their impacts on the expression of eight selected genes (involved in biofilm formation, quorum sensing, and stress survival) in the test organism. The minimum inhibitory concentration (MIC) of the honey samples against E. coli ATCC 8739 were assessed by the broth microdilution assay in the presence and absence of catalase enzyme. Impacts of the honeys on the cellular ultrastructure and the expression profiles of the selected genes of E. coli were examined using transmission electron microscopy (TEM) and quantitative real-time polymerase chain reaction (qPCR) analysis, respectively. The susceptibility tests showed promising antibacterial activities of all the tested honeys against E. coli. This was supported by the TEM observations, which revealed "ghost" cells lacking DNA, in addition to cells with increased vacuoles, and/or with irregular shrunken cytoplasm. Among the tested honeys, marjoram exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. The qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Our results indicate that some varieties of the Egyptian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets. � 2016 Wasfi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.