Thanks for the query.
The reports you have given shows that your brother has got enteritis
(Intestinal infection). The organism is isolated too. You would require antibiotics to treat the condition, for around five to seven days.
Today’s research indicates that a move toward individualizing the dosing
of prescription agents is warranted and it can happen only after physical consultation. So please consult your general practitioner for a prescription.
Meanwhile you can give your brother oral rehydration saline, which would be easily available at your nearest pharmacy. He can also have probiotics. They contain large amount of lactobacilli which are normally present in the intestine. It would help the body to counter the infection.
Hope I have answered your query. Let me know if I can assist you further.