You will be fine!!!! that stuff wouldbe so processed that there would not be listeria in it!
I asked my OB specifically about ricotta as I make apasta with it and I LOVE it and had been missing it SO much. She told me to go for it (she is quite relaxed) as long as the ricotta is from a reputable shop/supermarket etc and not home made on a farm or something.. she said as long as it is pasteurised etc as all Aus cheese would be I shouldnt stress too much as the chances are so so so low...