Browsing by Author "Khalaf N.G."

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Molecular characterization of carbapenem-insensitive Acinetobacter baumannii in Egypt
(Elsevier B.V., 2014) Al-Agamy M.H.; Khalaf N.G.; Tawfick M.M.; Shibl A.M.; El Kholy A.A.; Pharmaceutics and Microbiology Department; College of Pharmacy; King Saud University; PO Box 2457; Riyadh 11451; Saudi Arabia; Microbiology and Immunology Department; Faculty of Pharmacy; Al-Azhar University; Cairo; Egypt; Microbiology and Immunology Department; Faculty of Pharmacy; Modern Arts and Science University; Sixth of October City; Egypt; Clinical Pathology Department; Faculty of Medicine; Cairo University; Cairo; Egypt
Objectives: This study investigated the prevalence of diverse Ambler class ?-lactamase-encoding genes in 40 carbapenem-insensitive Acinetobacter baumannii isolates collected from two hospitals in Egypt during the period January-March 2012. Methods: The resistance levels to different groups of antimicrobial agents were determined. PCR was used to detect the different Ambler class ?-lactamases encoding the following genes: blaTEM, blaSHV, blaCTX-M, blaVEB, blaPER, blaGES, blaVIM, blaIMP, blaSIM, blaSPM, blaGIM, blaNDM, blaADC, blaOXA-23, blaOXA-24, blaOXA-51, and blaOXA-58. ISAba1 and int1 were detected by PCR. Results: The isolates were 100% resistant to amoxicillin-clavulanate, aztreonam, cefepime, cefotaxime, and ceftazidime. Of the isolates, 5% were resistant to colistin, 45% to amikacin, 70% to imipenem, and 85% to ciprofloxacin. The blaADC- and blaOXA-51-like genes were detected in the entire collection. The prevalences of blaOXA-23, blaOXA-24, and blaOXA-58 were 50%, 7.5%, and 5%, respectively. However, the prevalences of blaTEM-, blaPER-, and blaGES-like genes were 87.5%, 55%, and 27.5%, respectively. SHV, CTX-M, VEB, KPC, and MBL encoding genes were not detected. The ISAba1 was found upstream to blaOXA-51, blaOXA-23, and blaADC in 85%, 80%, and 50%, respectively. Of note, 45% (18/40) of the isolates co-produced extended-spectrum ?-lactamases (PER and GES) and carbapenemases (OXA-23 and OXA-58). Conclusions: The blaADC-, blaTEM-, blaPER-, blaOXA-23-, and blaGES-like genes were found to be the most prevalent types of ?-lactamase-encoding gene in A. baumannii collected from Egypt. A high level of carbapenem resistance is mediated by blaOXA-23, blaOXA-24, and blaOXA-58 (minimum inhibitory concentration (MIC) 32 to >256?g/ml), and a low level of carbapenem resistance is mediated by blaGES (MIC 4-16?g/ml) and by up-regulation of ISAba1-OXA-51 (MIC 1-4?g/ml). Class B MBL was not identified to play a role in carbapenem resistance in A. baumannii isolates from Egypt. � 2014 The Authors.
An outbreak of methicillin resistant staphylococcus epidermidis among neonates in a hospital in Saudi Arabia
(2011) El Hafez M.A.; Khalaf N.G.; El Ahmady M.; El Aziz A.A.; El Gawad Hashim A.; Department of Microbiology and Immunology; Faculty of Pharmacy; Helwan University; Cairo; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Modern Arts and Science University; Cairo; Egypt; Department of Microbiology and Immunology; Faculty of Medicine; Zagazig University; ElSharkiya; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Tanta University; Tanta; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Cairo University; Cairo; Egypt
Introduction: Staphylococcus epidermidis is a pathogen associated with nosocomial infection in neonatal intensive care units (NICU). This study investigates an outbreak of methicillin resistant S. epidermidis in an NICU in a hospital in Saudi Arabia. Methodology: A total of 41 isolates identified as Gram-positive cocci were obtained from blood culture, umbilical wound swabs and endotracheal aspirate specimens of neonates, of which 29 were identified as S. epidermidis. Bacterial identification at the species level and determination of antibiotic resistance were performed by MicroScan (Dade Behring, USA). Genotyping was completed using randomly amplified polymorphic DNA (RAPD) and the mecA gene was detected by PCR. Results: All 29 S. epidermidis isolates were found to be resistant to oxacillin and were positive for the mecA gene. The isolates showed several multidrug-resistance patterns; the resistance rates to gentamicin, erythromycin, clindamycin, and trimethoprim/sulfamethoxazole were 89.7%, 86.2%, 75.9% and 72.4%, respectively. All isolates were susceptible to vancomycin, teicoplanin, rifampin, synercid, and ciprofloxacin. Several genotypic and phenotypic patterns were detected among the S. epidermidis isolates: antibiogram typing showed seven different patterns, one of which was shared by 65% of the isolates, whereas the most prevalent RAPD genotype was shared by only five S. epidermidis isolates, and did not correlate with antibiotic resistance phenotype. Conclusion: The diverse clonal origin of tested isolates indicates the presence of multiple S. epidermidis strains among neonates in the NICU setting. 2011 El Hafez et al.
The scope of bacterial resistance to antibiotics in some countries in the middle East and North Africa
(2012) Khalaf N.G.; Hanson N.D.; Department of Microbiology and Immunology; Faculty of Pharmacy; Modern Science and Art University; Cario; Egypt; Creighton University School of Medicine; Center for Research in Anti-Infectives and Biotechnology; Department of Medical Microbiology and Immunology; 2500 California Plaza; Omaha; NE 68178; United States
Data available on bacterial resistance to antibiotics in the Middle East and some African countries mainly comprised sporadic nosocomial outbreaks. However, some surveillance studies, such as the PEARLS and ARMed have examined resistance determinants and patterns of common nosocomial pathogens in some Middle Eastern and North African countries. But no national surveillance figures have been published in any of these individual countries. In this chapter we will present reported rates of bacterial resistance to antibiotics in clinically important pathogens such as MRSA, Escherichia coli and other selected Enterobacteriaceae in this geographical region. In addition, we will discuss studies on nosocomial pathogens notorious for multidrug resistance such as Acinetobacter baumannii, Pseudomonas aeruginosa, as well as ESBL producers of the Enterobacteriaceae that are prevalent in some Middle Eastern and African countries. These clinically important pathogens were reported to possess various ESBL genes of the TEM-, SHV-, CTX-M-families; as well as the carbapenem hydrolyzing metallo-and OXA-type ?-lactamases. Other resistance determinants were also reported and include the integron associated qnr gene, and the aac (6')-Ib-cr gene which codes for aminoglycoside resistance and reduced susceptibility to ciprofloxacin. In addition, community acquired infections caused by MRSA and ESBL producers of the Enterobacteriaceae that have been reported in this geographical region will be covered. Because of the disturbing high rates of bacterial resistance to antibiotics in this geographical region, some countries found it compelling to initiate Infection Control programs to hamper the spread of resistant pathogens. � 2012 Bentham Science Publishers. All rights reserved.