My story started about 8 months ago. I had unprotected oral sex with a new partner. I gave him fellatio, but his erection was poor, and he didn't finish. In 5 days, I felt a sore throat. I visited Urgent Care and was tested with an oral NAAT swab for gonorrhea/chlamydia and strep test. All results were negative, but my sore throat was getting worse. I texted that guy but didn't get any response. A week later, I returned to the UC and asked to retest for GC/CT as I wasn't sure about the accuracy of the previous test (I drank water just before swabbing). The test came back negative again, but I was prescribed doxycycline for 5 days. I felt better after taking doxycycline, but not completely. I still had a sore throat and a yellow discharge coming through the back of my throat. For the last few months, I've visited my PCP and ENT doctors, but with no success. I was tested for syphilis and HIV 3,5 months after exposure, and it also was negative. About 4 months ago, I started feeling pain and morning stiffness in my finger's joint. Also, I got a stye that I'd never had in my life before. At the same time, I began to notice a foul odor and pus taste in my mouth every day. I asked my physician about different types of testing for GC/CT, such as culture tests, but it turns out they don't do culture tests.

1. Where can I be tested with a culture test for CG/CT? (I can't find it anywhere; it's only NAAT. I live in North Carolina)

2. I've read that NAAT might be false-negative due to mutations in DNA sequences. Your thoughts?

3. In several sources I found information that it's more challenging to diagnose, as well as treat, oral gonorrhea. Is it true?

4. What kind of infection could last for such a long time without any improvements (especially if it started after unprotected sex with an unknown partner's status)?

I would not be worried in the least about oral gonorrhea in you at this time.  I have listed the reasons below:

1.  Most people do not have gonorrhea. Thus it is unlikely that your partner 8 months ago had infection.

2.  Even if he did, gonorrhea is rarely transmitted following a single episode of fellatio.  Only a small proportion of single exposures to infected partners result in transmission of infection.

3.  When oral gonorrhea occurs, it typically resolves if untreated over a period of a few weeks

4.  You have been tested with the right test to evaluate for oral gonorrhea.  At the throat NAATs test are about twice as sensitive as culture. Your negative test proves that you did not have oral gonorrhea

This, in answer to your specific questions:

I am confident that you do not have oral gonorrhea.  I suspect that your chronic problems are in no way related to performance of fellatio 8 months ago.  if the problem is bothering you, your next step should be to ask an ENT specials for an evaluation

I hope that this information is helpful. EWH