An unusual cause of hyperammonemia in a newborn: question

Excerpt

A 28-day-old girl was presented at our hospital because of weakness and poor appetite since shortly after birth, failure to thrive, and a history of urinary infection. The infant was born at full term with a birth weight of 4,035 g. Prenatal, natal, and family history was unremarkable. Both parents were healthy and nonconsanguineous. She had been breast-fed since birth; however, she never fed well and did not regain her birth weight. Because 20–25 leukocytes/high power field was shown in urine microscopic examination and 100,000 colonies/ml of Klebsiella pneumoniae were grown in the urine specimen collected in a perineal bag, she was admitted to another hospital at the 10th day of life and treated with cefotaxime for 7 days. There was no clinical improvement after discharge, and leukocyturia persisted. …