Where would a 10 day old twin develop Pantoea Agglomerans and her fraternal twin does not after C-section?

Question

Where would a a 10-day twin develop a bacterial blood infection from Pantoea Agglomerans and her fraternal twin does not after a C-section?  My daughter-in-law delivered fraternal twins 16 days ago, both twins over 6 pounds, nursing well.  Shortly after coming home, the girl twin started sleeping more and taking forever to nurse, where as the boy twin was more alert and nursed within 15 to 20 minutes.  About 10 days of life, the girl twin developed a trunkal rash and also aspirated some breastmilk which lead to some difficulty breathing. After a trip to the ER, she was admitted and tests showed signs of bacteria in her urine, but not a true UTI.  Spinal tap, normal, preliminary labs, normal, xray did show reflux.  However at 13 days of life, blood cultures grew Pantoea Agglomeras and was placed on two super power antibiotics and increased to a 21 day admission after now consulting Infectious Disease.  

So my question is where would this little girl pick up this bacteria and not her brother.  She has been either at the hospital or her home. Is this going to affect any of her major organs?  Can you shed some light on this?