Question regarding Antibiotic Resistance?

[69 coupe]

Always wanted to know the answer to this hypothetical Question...

Taking antibiotics when not needed or overused causes resistance, my Question is if you've taken lets say 'Erythromycin' for many months and is not working because your immune system is/are becoming/became resistant. Your Doc's sees this and puts you on another type/strain and you pull through. Hurrah!

My real question is if you fall ill many years later and will be needing antibiotics would the original Antibiotic 'Erythromycin' work again or are you always now resistant to Erythromycin because your immune system knows how to defeat it.

[Flibble]

You don't become resistant to antibiotics, the bacteria do. Your immune system pretty much does nothing to antibiotics. Resistance happens because if you expose bacteria to antibiotics a lot (via overuse) then it will kill off all the bacteria that are not resistant to that antibiotic, leaving only those few hardy specimens that are resistant. These then multiply and before you know it you have a strain that is entirely resistant (e.g. MRSA).

[69 coupe]

Thanks for your explanation, so in my example with Erythromycin does that mean they will be of no use any more to that patient i.e. no point re-prescribing them 3 years down the line when the patient gets another infection; be better giving them Amoxicillin instead for example.

[Flibble]

Erythromycin may still work, it would depend on the bacteria. 3 years down the line it'll be a different strain of bacteria so they may be sensitive to Erythromycin. It's not really anything to do with the patients history what works and what doesn't, it just depends on what bacteria they are infected with.