Amplifying on my answer in this subthread and I now see mjn's comment, it's complicated. Simple mutations only take you so far, they change something that's necessary for the antibiotic to work. E.g. a surface protein that brings it inside gets trashed, or a enzyme or structure that it works against changes enough to be resistant while still functioning enough for survival.
The nastier stuff, like β-lactamases---enzymes that destroy the β-lactam ring that is the "active ingredent" of so many antibiotics ... and that it's used by so many families that humans can tolerate is telling---are obviously a lot more sophisticated. Bacteria developed them to compete with the molds that produce β-lactam antibiotics, and they spread from one species to another, especially in plasmids as the article notes.
A great deal of this is not new mechanisms of resistance being developed, but long existing ones becoming prevalent. Somewhat like in the good old days when a drug company could make its money back bring an antibiotic to market, and scouring the globe for molds that produced ones, improper use of antibiotics (e.g. not switching to one of different mechanism quickly enough, especially likely in places like India where they're in practice available over the counter) plus widespread global travel is allowing the best mechanisms to survive and sort of thrive.
Not thrive in most environments of course, just in humans who are under the selection pressures of antibiotics.
The nastier stuff, like β-lactamases---enzymes that destroy the β-lactam ring that is the "active ingredent" of so many antibiotics ... and that it's used by so many families that humans can tolerate is telling---are obviously a lot more sophisticated. Bacteria developed them to compete with the molds that produce β-lactam antibiotics, and they spread from one species to another, especially in plasmids as the article notes.
A great deal of this is not new mechanisms of resistance being developed, but long existing ones becoming prevalent. Somewhat like in the good old days when a drug company could make its money back bring an antibiotic to market, and scouring the globe for molds that produced ones, improper use of antibiotics (e.g. not switching to one of different mechanism quickly enough, especially likely in places like India where they're in practice available over the counter) plus widespread global travel is allowing the best mechanisms to survive and sort of thrive.
Not thrive in most environments of course, just in humans who are under the selection pressures of antibiotics.