Final answer:
Mycoplasma genitalium should be suspected in cases of NGU where azithromycin is ineffective, with moxifloxacin being the treatment of choice. It's crucial to consider the antibiotics' susceptibility as resistance can play a significant role in treatment failure.
Step-by-step explanation:
Non-Gonococcal Urethritis and Treatment
Non-Gonococcal Urethritis (NGU) should be suspected as a cause of urethritis in young males if azithromycin has not been effective.
Mycoplasma genitalium is often responsible for recurrent or persistent infections of NGU and should be suspected when first-line treatments such as azithromycin are unsuccessful.
Although azithromycin is generally a good initial option, resistance in M. genitalium is concerning.
Consequently, the treatment of choice for M. genitalium, especially in the context of persistent NGU following azithromycin treatment, might be moxifloxacin.
It is important to consider that tetracyclines and doxycycline are not effective against this organism, and while fluoroquinolones like moxifloxacin can be used, increasing resistance is something to be attentive to.
Therefore, species identification and susceptibility testing may be an essential step for choosing the correct antibiotic.
The treatment of NGU may also target other potential pathogens such as Chlamydia trachomatis and Ureaplasma urealyticum; however, the choice of antibiotics can differ significantly based on the identified or suspected pathogen.
It is also critical to treat any sexual partners to prevent reinfection and to control the spread of the infection.