Abcess = pus / nanah (in Malay). with 'es' mean more than one abcess or pus collections. It's pus in medical term.
RIP for your agouti. It's wet tail disease. It's too late as it will died within 24 hours if not treatment. Clean your cage and all the accessories and disinfect with diluted delto and wash it several times with water. Change all the bedding, food and water for your the other hamster. Observe your hamster from now to the next few days, if any of the signs of wet tail, please bring it to the vet ASAP, or else it will end up with the same ending. Wet tail is very contagious and deadly to hamsters. One of my hamster died of wet tail too.

Yes, Kiko is ours. She still as tame as before with 'can do whatever you like on me' attitude.       
Observe your gold and if it is not eating for the next few hours, bring to the vet as wet tail is very contagious and infected hamster usually can't last for 2 days or even less than 24 hours.