Browsing by Author "Ashour H.M."

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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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    Molecular typing and virulence analysis of multidrug resistant Klebsiella pneumoniae clinical isolates recovered from Egyptian hospitals
    (Nature Publishing Group, 2016) Wasfi R.; Elkhatib W.F.; Ashour H.M.; Department of Microbiology and Immunology; Faculty of Pharmacy; October University for Modern Sciences and Arts; Giza; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Ain Shams University; Cairo; Egypt; Department of Pharmacy Practice; School of Pharmacy; Chapman University; Orange; CA; United States; Department of Biological Sciences; College of Arts and Sciences; University of South Florida St. Petersburg; St. Petersburg; FL; United States; Department of Microbiology and Immunology; Faculty of Pharmacy; Cairo University; Cairo; Egypt
    Klebsiella pneumonia infection rates have increased dramatically. Molecular typing and virulence analysis are powerful tools that can shed light on Klebsiella pneumonia infections. Whereas 77.7% (28/36) of clinical isolates indicated multidrug resistant (MDR) patterns, 50% (18/36) indicated carpabenem resistance. Gene prevalence for the AcrAB efflux pump (82.14%) was more than that of the mdtK efflux pump (32.14%) in the MDR isolates. FimH-1 and mrkD genes were prevalent in wound and blood isolates. FimH-1 gene was prevalent in sputum while mrkD gene was prevalent in urine. Serum resistance associated with outer membrane protein coding gene (traT) was found in all blood isolates. IucC, entB, and Irp-1 were detected in 32.14%, 78.5% and 10.7% of MDR isolates, respectively. We used two Polymerase Chain Reaction (PCR) analyses: Enterobacterial Repetitive Intergenic Consensus (ERIC) and Random Amplified Polymorphic DNA (RAPD). ERIC-PCR revealed 21 and RAPD-PCR revealed 18 distinct patterns of isolates with similarity ?80%. ERIC genotyping significantly correlated with resistance patterns and virulence determinants. RAPD genotyping significantly correlated with resistance patterns but not with virulence determinants. Both RAPD and ERIC genotyping methods had no correlation with the capsule types. These findings can help up better predict MDR Klebsiella pneumoniae outbreaks associated with specific genotyping patterns. � The Author(s) 2016.
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    Probiotic Lactobacillus sp. inhibit growth, biofilm formation and gene expression of caries-inducing Streptococcus mutans
    (Blackwell Publishing Inc., 2018) Wasfi R.; Abd El-Rahman O.A.; Zafer M.M.; Ashour H.M.; 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; Al-Azhar University (Girls); Cairo; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Ahram Canadian University (ACU); Giza; Egypt; Department of Biological Sciences; College of Arts and Sciences; University of South Florida St. Petersburg; St. Petersburg; FL; United States; Department of Microbiology and Immunology; Faculty of Pharmacy; Cairo University; Cairo; Egypt
    Streptococcus mutans contributes significantly to dental caries, which arises from homoeostasic imbalance between host and microbiota. We hypothesized that Lactobacillus sp. inhibits growth, biofilm formation and gene expression of Streptococcus mutans. Antibacterial (agar diffusion method) and antibiofilm (crystal violet assay) characteristics of probiotic Lactobacillus sp. against Streptococcus mutans (ATCC 25175) were evaluated. We investigated whether Lactobacillus casei (ATCC 393), Lactobacillus reuteri (ATCC 23272), Lactobacillus plantarum (ATCC 14917) or Lactobacillus salivarius (ATCC 11741) inhibit expression of Streptococcus mutans genes involved in biofilm formation, quorum sensing or stress survival using quantitative real-time polymerase chain reaction (qPCR). Growth changes (OD600) in the presence of pH-neutralized, catalase-treated or trypsin-treated Lactobacillus sp. supernatants were assessed to identify roles of organic acids, peroxides and bacteriocin. Susceptibility testing indicated antibacterial (pH-dependent) and antibiofilm activities of Lactobacillus sp. against Streptococcus mutans. Scanning electron microscopy revealed reduction in microcolony formation and exopolysaccharide structural changes. Of the oral normal flora, L.salivarius exhibited the highest antibiofilm and peroxide-dependent antimicrobial activities. All biofilm-forming cells treated with Lactobacillus sp. supernatants showed reduced expression of genes involved in exopolysaccharide production, acid tolerance and quorum sensing. Thus, Lactobacillus sp. can inhibit tooth decay by limiting growth and virulence properties of Streptococcus mutans. � 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.