I am not a pathologist, nor a specialist in really anything anymore, but when an bacteria is removed from a human body, especially one known to have traveled to a foreign country containing different bacteria from the local inhabitants, aren't there legal guidelines, and ethical ones, in the form of laboratory procedures meant to be followed for identifying the strain of bacteria to prevent possible spread should it be a bacteria not local but easily treated, or in the case of a new strain new treatments found to prevent a pandemic?

There is short term reporting requirement for isolation of some microbes - such as biological warfare agents - and there are disease reporting requirements  https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6253a1.htm.    Think the presumption that clinical labs are competent and would promptly engage state health dpts labs and CDC addresses broader issues you mention.   I'd not get too concerned re. "pandemic" - the term has been been overused  https://www.who.int/bulletin/volumes/89/7/11-088815/en/ and become hollywood melodrama ala "Hot Zone."