RE: That is why Methocillin, that previously was immune to degradation by penicillinase, now has resistance present in some populations. Through mutation of the penicillinase gene.
Well, we’re back to the original question...you talk about an ability to survive…penicillin, methicillin, and cephalosporins, etc.
But what about the observation that the gene that confers antibiotic resistance typically resides on plasmids, which are free-floating loops of DNA that were manufactured by other bacteria and released?
For instance, Regular old methicillin-resistant Staphylococcus aureus is not normally harmful, but when a single bacterium acquired the methicillin-resistant plasmid from its immediate environment, it and its descendants became more fit to survive in the antibiotic-laden environment of hospitals.
Here unfortunately, I see the typical EQUIVOCATION.
Evolution is described in textbooks as the way that nature manufactures new genetic information from nothing. However, when this bacteria “evolved,” NO NEW INFORMATION was generated.
Rather, old information from an old plasmid was acquired by the bacteria, which used its well-designed DNA acquisition machinery (sorry for the term, I know you don’t like the word design, you can substitute another word for it if you wish, maybe — pre-existing DNA ? ).
So, why is it not euqally reasonable to conclude that this bacteria is built-in (ooops, sorry for that word) to survive well?
So how did bacteria acquire the ability to bind and metabolize (and thus render harmless) Methocillin?
Through mutation of the Penicillinase gene. Obviously.
Why did this mutation persist in the population?
Through natural selection of genetic variation. Obviously.
So why would bacteria HAVE an error prone DNA polymerase and why would it be expressed during times of stress?