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Abstract Neonatal sepsis is defined as a clinical syndrome of bacteremia with Systemic signs and symptoms of infection in the first 4 weeks of life. Approximately 1 million deaths per year occurring in the neonatal period (0-28 days) are caused by infection, accounting for over 25% of global neonatal deaths. The aim of the present work is to study neonatal sepsis in different hospitals in Alexandria and El Behira, characterize its microbiological and antibiotic susceptibility profile as well as the major mechanisms of antibiotic resistance will be examined using different phenotypic methods detection of in the present study. The study was carried out in the department of Microbiology in the period between February 2017 until February 2018. After the approval of the Ethical Committee of the Medical Research Institute (MRI), one hundred andsixty eight bacterial isolates identified as a causative agent of neonatal sepsis. Blood samples were collected from the neonates with suspected sepsis for blood cultures.Blood was withdrawn using aseptic precautions from a peripheral vein.Blood cultures were processed in BacT/ALERT 3D system.Identification and susceptibility testing of isolates were carried out using VITEK 2 compact System. Mechanisms for antibiotic resistance were determined as follows: Phenotypic detection of ESBL was performed by the chromID ESBL agar and Combined disk test (CDT). Phenotypic detection of carbapenemases was carried out by chromID CARBA agar and MHT. Phenotypic detection of Metallo-β-lactamases (MBL) was performed using Combination disk test using one disk of imipenem alone and one with imipenem/EDTA. Gram negative isolates represented 80.95% of all isolates. K.pneumoniae ssp pneumonia was the most frequent isolate representing (76.47%) of gram negative isolates and (61.9%) of all isolates. Staphylococcus spp represented 15.4% of all isolated. The majority of isolates had late onset sepsis (LOS) 61.3% while early onset sepsis (EOS) constituted 38.7% of all isolates. Klebsiella pneumoniae was the most common isolates in both early and late sepsis. K.pneumoniae isolate were resistant to Beta-lactams, (99%) to cephalosporin and (80.7%) to carbapenems,while 86.6% of isolates were resistant to all aminoglycoside, 65.4% were resistant to Ciprofloxacin. Colistin resistance was demonstrated in 18.27%. All CoNS isolates were sensitive to Vancomycin, Teicoplanin, Linezolid and Clindamycin, while 50 % of isolates were MRCoNS (Methicillin resistant Staphylococci) positive for cefoxitin screening test. None of the isolates showed inducible clindamycin resistant. As regardes E. coli isolates (69.2%) were resistant to all aminoglycosides, 54% were resistant to ciprofloxacin, and 84.6 % were resistant to ceftazidime and cefepime while 46% were resistant to carbapenem. None of isolated showed colistin resistance. All Acinetobacter bumannii complex isolates were resistant to all antibiotics included in GN 222 card except: Gentamycin and Tobramycin where 17% of isolates were sensitive to both aminoglycosides.However all isolates were sensitive to colistin. The four Pseudomonas aeruginosa isolates were sensitive to colistin, whereas three isolates (75%) were sensitive to Carbapenam, Gentamicin and Tobramycin. Phenotypic detection of Methicillin resistance among S.aureus was carriedout using (75%) isolates were positive to chrOMagar™ MRSA test. These results were Commensurate with the results obtained by GP AST carried out by Vitek for cefoxitin screening. ESBL production on chromID®ESBL agar was positive in 76 % of Enterobacteriaceae (64.5% in Klebsiella pneumoniae, 76.9% E.coli and 100% K.pneumoniae spp oxytoca). ESBLdetection among the 121 Enterobacteriaceae isolates using Compound Disk Test (CDT) were (62.8%) of all isolate. All Carbapenem resistant Enterobacteriaceae isolates were positive for chromID CARBA agar. MHT test was positive in 76.9 % of carbapenem resistant in Gram negative bacteria (79.7% in K.pneumoniae , 50 % in E.coli and 83.3 in Acinetobacter bumannii) MHT was negative in K.pneumoniae spp oxytoca.MBL test was positive in 70.3 % of carbapenem resistant isolates. |