Disclaimer: although strictly not spoiler info (they're all details that were mentioned before), reading the answers kind of spoils the excitement and all the built-ups that lead to the grand conclusion. I advise you to just continue reading chapter 151, which would clear your confusion.
The Claymore anime storyline is indeed different from that in the Claymore manga, albeit only substantially different for the ending. As the manga was still ongoing, the anime had to end at the conclusion of the Northern Campaign arc, but they somehow made the ending different.
Before the final chapters in the manga, Priscilla remained undefeated since she slew Teresa. What's more, she never met Clare and her comrades in the Northern Campaign arc, and would not have been defeated by Clare were she to meet her at that time. This was different in the anime, as you said, Priscilla was defeated by Clare, and seemingly more by her desire for revenge than by Teresa's flesh and soul, and therefore talent and power, that resided within Clare.
Teresa was killed for sure, in both the anime and the manga, but she still lived within Clare because Clare took up her flesh and blood (from her severed head) to become an unusual Claymore who is 1/4 yoma and 3/4 human. The Teresa that appears in chapter 150 is Clare's awakened form.