A 2-day old premature baby boy born to a 22-year-old woman developed pneumonia. The mother showed the symptoms of urinary tract infection after the delivery. A blood specimen was taken from the baby, beta-hemolytic colonies were observed in the culture plate after 24 hours. 
Which of the following could be the possible pathogen that can be easily spread from the mother to the baby and cause pneumonia?

A 4-year-old boy developed an erythematous rash around his face and on arms with skin color turning red, during the physical examination swollen lymph nodes around the infection was reported but no other symptoms were seen. The specimen was collected from the infected area, the pathogen isolated was found to be gram-positive cocci.
What could be the possible diagnosis?