Introduction: Neonatal sepsis is defined as a clinical syndrome in an infant 28 days of life or younger, manifested by systemic signs of infection and isolation of a bacterial pathogen from the bloodstream[EmanShehab El-Din et al, 2015]. Positive blood culture and sensitivity of the isolate is the best guide to antimicrobial therapy and once started should be modified according to the culture sensitivity reports[Aggarwalet al, 2001].
Aim of the work: To determine clinical and microbiological pattern of neonatal sepsis in Sohag university hospital with special focus on causative pathogens and their response to used antimicrobials.
Patient and methods: Our study conducted over a period of 18 months between October 2015 and April 2017 at Sohag university  hospital and included 75 neonates with suspected sepsis and positive blood culture using Egyptian neonatal network (EGNN) guidelines, subjected to full clinical examination, septic screen(CBC, ESR and CRP) and blood culture and sensitivity tests.
Results: All studied neonates presented with late onset sepsis with higher incidence in infants born via CS especially with low and very low birth weight.The incidence of neonatal sepsis was predominantly due gram negative bacteria mainly Klepseillapneumonae followed by staphylococcus haemolyticusandstaphylococcus epidermidis. Klebseilla isolates showed high sensitivity for aminoglycosides and quinolones antibiotics with resistance to penicillin's group, Staphylococcus isolates showed resistance to penicillin's and aminoglycosides while sensitive to quinolones and nitrofurantions. E.coli and Pseudomonas species showed moderate sensitivity to 3^rd generation cephalosporins, aminoglycosides, quinolones and nitrofurantoins with resistance to classic penicillin's.
Conclusion: In our study gram negative bacteria mainly Klepseillapneumonae was the most causative agent of neonatal sepsis. Most isolated organisms showed resistance to classic penicillins.Klepseillapneumonaeshowed high sensitivity for aminoglycosides and quinolones, Staphylococcus isolates showed high sensitivity to quinolones and nitrofurantions while E.coli and Pseudomonas species showed moderate sensitivity to 3^rd generation cephalosporins, aminoglycosides, quinolones and nitrofurantoins.