[SgtHooper]

That which is outside (can’t believe it to be true) could easily be brought inside.

[pfflier]

Once on a surface it could be spread by multiple means.The analysis seems to indicate it was commonly know bacteria on earth.

With all the traffic of people and supplies I guess the contamination came with some of that traffic.

If it originated from the outside it would be a much more significant find implying that bacterial could survive and be transported in a deep space vacuum.