Browsing by Author "Abdulall A.K."

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    Carbapenem-resistant Gram-negative bacteria associated with catheter-related bloodstream infections in three intensive care units in Egypt
    (IEEE Computer Society, 2018) Abdulall A.K.; Tawfick M.M.; El Manakhly A.R.; El Kholy A.; Microbiology and Immunology Department; Faculty of Pharmacy (Girls); Al-Azhar University; Cairo; Egypt; Microbiology and Immunology Department; Faculty of Pharmacy (Boys); Al-Azhar University; Cairo; Egypt; Microbiology and Immunology Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; Giza; Egypt; Infection Control Department; Dar Al Fouad Hospital; 6th October City; Giza; Egypt; Clinical Pathology Department; Faculty of Medicine; Cairo University; Cairo; Egypt
    We aimed to identify the carbapenem-resistant Gram-negative bacteria (GNB) causing catheter-related bloodstream infections (CRBSI) in intensive care units (ICU) in a tertiary care Egyptian hospital, to study their resistance mechanisms by phenotypic and genetic tests, and to use ERIC-PCR for assessing their relatedness. The study was conducted over 2�years in three ICUs in a tertiary care hospital in Egypt during 2015�2016. We identified 194 bloodstream infections (BSIs); 130 (67.01%) were caused by GNB, of which 57 were isolated from CRBSI patients (73.84%). Identification of isolates was performed using conventional methods and MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was done by disc diffusion following CLSI guidelines. Phenotypic detection of carbapenemases enzymes activity was by modified Hodge test and the Carba-NP method. Isolates were investigated for the most common carbapenemases encoding genes bla KPC , bla NDM , and bla OXA-48 using multiplex PCR. Molecular typing of carbapenem-resistant isolates was done by ERIC-PCR followed by sequencing of common resistance genes. The overall rate of CRBSI in our study was 3.6 per 1000 central venous catheter (CVC) days. Among 57 Gram-negative CRBSI isolates, Klebsiella pneumoniae (K. pneumoniae) was the most frequently isolated (27/57; 47.4%), of which more than 70% were resistant to Meropenem. Phenotypic tests for carbapenemases showed that 37.9% of isolates were positive by modified Hodge test and 63.8% by Carba-NP detection. Multiplex PCR assay detected the bla NDM in 28.6% of the isolates and bla KPC in 26.8%, bla NDM and bla KPC were detected together in the same isolate in 5.6%, while bla OXA-48 -like were not detected. ERIC-PCR detected limited genetic relatedness between K. pneumoniae isolates. Elevated resistance rates were observed to all antibiotics including carbapenems among K. pneumoniae isolates causing CRBSI. ERIC-PCR showed that the resistant isolates were mainly polyclonal. Our results call for reinforcement of antimicrobial stewardship and measures to prevent CRBSI. � 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
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    Evaluation of the immunogenicity of each of L-amino oxidase- and L-ascorbic acid-inactivated hepatitis a virus in mice as potential vaccine candidates
    (Slovak University of Agriculture, 2016) Abdullatif A.O.; Tawfick M.M.; Abdulall A.K.; Mohamed A.F.; Microbiology and Immunology Department; Faculty of Pharmacy (Girls); Al-Azhar University; Nasr City; Cairo; Egypt; Microbiology and Immunology Department; Faculty of Pharmacy (Men); Al-Azhar University; Nasr City; Cairo; Egypt; Microbiology and Immunology Department; Faculty of Pharmacy; October University for Modern Sciences and Arts; 6th October City; Giza; Egypt; The Holding Company for Biological Products; Vaccines and Drugs (VACSERA); Dokky; Giza; Egypt
    Hepatitis A virus (HAV) is one of the most common causes of acute viral hepatitis worldwide. Formaldehyde is the currently used inactivating agent in HAV vaccine processing despite of its adverse effects. The current study aimed to evaluate both L-amino acid oxidase (LAO) and L-ascorbic acid (LAA) as alternative inactivants for HAV and the immunogenicity of inactivated HAV in mice. Vero cell line was used for cultivation of HAV. The cytotoxicity of LAO and LAA on Vero cells was evaluated using 3-(4,5-dimethylthiazol-2-yl) 2,5 diphenyl tetrazolium bromide (MTT) assay. The immunogenicity of each LAO- and LAA-inactivated HAV was examined in parallel with reference HAV vaccine in mice. Humoral (total IgG) and cellular immune responses (IFN-? and IL-5) were evaluated in mice sera using ELISA. Both LAO and LAA could efficiently inactivate HAV within 30 and 36 hrs post treatment, respectively, at concentrations of 0.4 ?gm/ml of LAO and 1.5 mg/ml of LAA. Inactivated vaccines were immunogenic to mice on both the humoral and cellular levels. LAO prepared vaccines showed a more promising immune reactivity than LAA prepared ones and alum-adsorbed vaccines were more immunogenic than non-adjuvanted ones. In conclusion, data recorded suggest that both LAO and LAA can be used as inactivating agents for HAV grown in cell culture. LAA- and LAO-inactivated HAV can be potential vaccines as they provide effective humoral and cellular immune responses comparable to that of the reference vaccine. The stability of test vaccines is recommended to be traced at different thermal conditions, in addition to different stabilizers and different pharmaceutical formulations must be tested trying to produce a lyophilized formula for long-term stability. � Faculty of Boitechnology and Food Sciences.