الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The aim of this study was to spot light the different aerobic bacterial species isolated from sepsis, identify CoNS to the species level and evaluate the phenotypic and genotypic properties of CoNS isolates. The study was conducted on 150 cases admitted to Mansoura children University Hospital and Aga central Hospital, 50 cases were control (wihout CVP), 100 cases were septicemic (with CVP). Blood sampels were taken at the time of admission and after three days. They were examined for bacterial growth automatically using BACT/ALERT. Identification of the isolates was done by the conventional microbiological standard tests for gram positive cocci such as colony morphology, gram staining, catalase and coagulase tests. Positive culture for CoNS, further identification of different spp. of Coagulase–negative staphylococci was done using BD phoenix system. CoNS isolates were submitted to a disk diffusion susceptibility test with cefoxitin (FOX) 30 μg to confirm MRSA. Finally Detection of mecA gene expression by PCR (agar gel electrophoresis). There was statistically significant difference between control and septicemic cases regarding the clinical and laboratory data (P value <0.0001). Isolated organisms were 62 % gram negative (the most isolated organisms were K pneumonie 23%, E. coli 11%), 38 % gram positive (the most isolated organisms were staph aureus 42%, CoNS 20%). The most frequently isolated species of CoNS was Staph. epidermidis (30%) followed by Staph. Hemolyticus (20%) and Staph. Hominis, (20%). All studied CONS species were methicillin resistant by MIC and Disc diffusion methods with complete agreement between manual and automated method. All CONS species were penicillins resistant and cephalosporins resistant (except staph. capitis). Among the 19 cases of CoNS, Mec A gene expression was positive in 9 cases (47.4%). Positive mec A gene was significantly associated with higher incidence of LOS (60%).