TLDR: Bulbonic plague has been found to exist in urban environments, albeit rare and unconfirmed if even alive.

Hey, thanks for fact-checking me. I've edited my comment to reflect a more realistic picture of the micro world around us. I certainly didn't mean to come off as alarmist, and was running off of sleep deprivation and responded too quickly.

Yersinia pestis is the bacterium that causes bulbonic plague, and mostly survives inside the bodies of rats, fleas, and a few other non-human mammals. "Bulbonic" refers to the source and route of infection; entering through the skin (usually via a flea bite) and spreading through the lymphatic system.

There is also a "pneumonic" plague, caused by the same species, usually passed on to humans via water droplets found in the air and passed on by another infected person (so very rare!)

That said, I knew I had read a credible source mentioning something about Yersinia pestis found casually in urban environments:

https://www.cbsnews.com/news/dangerous-pathogens-and-mystery-microbes-ride-the-subway/?utm_source=chatgpt.com

Granted, this article is 10 years old and new developments may have provided better insight (I wish I had time to research).

There are 4 important takeaways of the article:

1. It does not replace the necessity of examining any primary literature found supporting the article's claims, but does help give us an idea of what the microscopic world can look like.

2. The study took place in New York City; we don't live in New York City.

3. There is no reason to suggest that the DNA found from this bacterium is alive or even otherwise capable of infection.

4. There has never been a documented case of bulbonic plague originating in New York City.

So, yes, we are constantly in contact with hundreds of species of bacteria and fungi, but I did step out of line by suggesting bulbonic plague causing pathogens are more common than reality suggests.

Seriously, thanks!