Neonatal sepsis can be caused by bacteria such as Escherichia coli (E coli), Listeria, and some strains of streptococcus. Group B streptococcus (GBS) has been a major cause of neonatal sepsis. Newborns with sepsis appear generally ill—they are listless, do not feed well, often have a gray color, and may have a fever or a low body temperature. The diagnosis is based on the symptoms and the presence of bacteria, a virus, or a fungus in the blood, urine, or spinal fluid. Neonates with clinical signs of sepsis should have a complete blood count (CBC), differential with smear, blood culture, urine culture (not necessary for evaluation of early-onset sepsis), and lumbar puncture (LP), if clinically feasible, as soon as possible. Neonates with respiratory symptoms require chest x-ray. Doctors diagnose sepsis based on the newborn's symptoms and the results of tests. Doctors do several tests, including blood tests, to try to determine the specific bacterium, virus, or fungus that is causing the infection. A blood culture, sometimes a urine culture, and a spinal tap (lumbar puncture) are also done. Supportive Care. While antibiotics are the definitive treatment for neonatal sepsis, neonates should receive adequate supportive care, aiming to maintain physiological stability during their antibiotic therapy and recovery, to optimise their outcomes. This may include respiratory, cardiovascular, and feeding support.