Penicillin and resistance, etc.

Factual Questions
1

First, although this is about a specific medical issue that I am facing, I am not looking for medical advice, just scientific information. The personal details are for clarification; not because I am looking for medical advice. I am looking to better understand antibiotic resistance.

I’ve had tooth problems lately. The last 2 times (about 1 and 2 years ago) I believe that I was prescribed Amoxicillin (?sp?). I took them for a few days before getting the tooth pulled, and then for a few days afterward.

Recently I’ve had the same problem. I moved to a new town and immediately got a new dentist. I got a cleaning and x-rays on Friday, and we scheduled the extraction for Monday. She prescribed me Penicillin, and I believe that this was because I am currently poor and it is free at Meijer’s. I got the prescription filled that day and started taking it as prescribed. On Monday I had the tooth pulled. On Wednesday I’m still feeling pain and swelling, expecially after attempting to eat a hamburger and fries (It hit like a sonofabitch when I thought, 2 days later, that I was OK to eat solid foods carefully.)

I might have a problem with another tooth, but I think that the x-rays would have picked that up.

One of my current hypotheses is that I am immune/resistant to regular old penicillin. I am thinking of Penicillin as 1st generation penicillin; and that maybe I need 3rd or 4th generation penicillin, because of built up resistances.

My father has worked in the medical field most of his life and (despite being a creationist) believes in microevolution and understands not overusing antibiotics. So it’s not as though my parents fed me antibiotics every time I got the sniffles. On the other hand, I am pushing 40, this is my 6rd or so tooth issue (each involving antibiotics for a few days, followed by either a root canal or extraction) in the last 20 years or so. I don’t recall what antibiotics were prescribed years ago, but I believe that it was Amoxicillin the last 2 times (1 and 2 years ago), and Penicillin this time.
1.) Is it possible or likely that immunity/resistance is an issue here?

2.) Is the immunity/resistance based on ME, or the INFECTION? IOW, if immunity/resistance is a factor, is it because of what antibiotics I have taken in my lifetime? Or is it based on what antibiotics that this particular infection has faced and/or become immune to? This leads to question 3:

3.) Does my infection come from inside me? Or does it come from something externally? (IE. In a typical situation where someone has an infected tooth, does the infection come from inside the patient? Or does it come from something that the patient ate that travelled through a cavity in the tooth to the jaw to infect the typical patient?)
Obviously, all responses will be generalizations and not based on my particular situation. You are not my doctor and I am not your patient.

I apologize if things are unclear. I am currently using liquid pain killers.

2

Do you have any evidence that the pain and swelling are due to infection, rather than the natural result of the trauma of the operation?

3

To answer the general questions (not in order).

You have a wide selection of bacteria in mouth all the time. Some cause problems like decay. Some can get into those decayed areas and cause an abscess.

The resistance pattern of those bugs is a reflection of both what the generational ancestors of those bugs have been exposed to and survived long before you were ever colonized by them, and what the generations within you have experienced. You can have a resistant bug without ever having been on an antibiotic yourself.

Other reasons for resistance include the antibiotic not being good for the sort of bug that is causing an infection in any cases, or the infection being at a location here the medicine does not get to (such as inside a persistent abscess).

I hope that helps.

4

It’s not that you might be immune or resistant to penicillin; it’s that the bacteria might be.

5

No, other than my non-recollation of not having these problems after my prior 2 extractions. I seem to recall that the pain essentially ended after the procedure (root canal or extraction) was over by a day or 2. I recall the only complications from extraction being that I had to be very careful to not get “dry socket” for the first few days despite (carefully) smoking. I could certainly be misremembering, due to my use of liquid painkillers (Busch Light, typically).

However, to keep this in GQ and not violate the rules, I’d like to focus on the issues of antibiotic resistance and not my current situation.

6

Does this mean (or imply) that regular-ol’ penicillin is essentially useless here* and now?

  • in the US, or even in the industrualized world.
7

No. I believe he’s noting that (to the best of my recollection) no antibiotic is 100% effective against all types of bacteria. You may simply have been infected by a species of bacteria that is not affected by penicillin.

8

For the usual bacteria found in the mouth that cause dental infections, there really is no difference in their susceptibility to all the many types of penicillin antibiotics (penicillin, amoxicillin, ampicillin, . . .); they should all be effective (or ineffective). Phrased differently, the mouth bacteria that cause dental infections are almost all sensitive to penicillins. And, even with repeated exposure to penicillins, they usually retain their susceptibility to that class of antibiotic.

OTOH, penicillin antibiotics aren’t particularly good at getting into bone. So, if it seems as if the infection has gone deep, into the bone around the tooth (the socket), it may be more effective to use a different class of antibiotics (such as clindamycin). But again, that’s not because the bacteria are resistant to penicillin, it’s just that penicillin can’t get to the site of the infection.

9

Close, but more resistance than you may think.

Indeed plain Penicillin is often not used because of it may not get to effective concentrations where it needs to be in dental infections; amoxicillin and amox/clav have better penetration to the sites. (Not giving specific medical advice.)

10

In more score years than I care to consider (or divulge), I’ve never encountered a single instance of Prevotella (bacteroides) infection that didn’t respond to a penicillin. So, I am suspicious of that 34% resistance claim and wonder if that’s representative of North American cultures. OTOH, subdiaphragmatic bacteroides species are often resistant to penicillin so it’s clear that the genus is not uniformly sensitive. Maybe I shouldn’t be surprised, then, at increasing resistance.