In the context of high levels of antimicrobial resistance, switching from azithromycin to doxycycline for presumptive treatment of M. genitalium, followed by resistance-guided therapy, cured ≥92% of infections, with infrequent selection of macrolide resistance.

Escalating resistance to azithromycin and moxifloxacin is being reported for Mycoplasma genitalium in the Asia-Pacific region. Analyzing 140 infections, we found pretreatment fluoroquinolone-resistance mutations in parC (13.6%) and gyrA (5%). ParC S83 changes were associated with moxifloxacin failure. Combined macrolide/fluoroquinolone-resistance mutations were in 8.6% of specimens, for which recommended therapies would be ineffective.

During 2016–2017, we tested asymptomatic men who have sex with men (MSM) in Melbourne, Australia, for Mycoplasma genitalium and macrolide resistance mutations in urine and anorectal swab specimens by using PCR. We compared M. genitalium detection rates for those asymptomatic men to those for MSM with proctitis and nongonococcal urethritis (NGU) over the same period. Of 1,001 asymptomatic MSM, 95 had M. genitalium; 84.2% were macrolide resistant, and 17% were co-infected with Neisseria gonorrhoeae or Chlamydia trachomatis. Rectal positivity for M. genitalium was 7.0% and urine positivity was 2.7%. M. genitalium was not more commonly detected in the rectums of MSM (n = 355, 5.6%) with symptoms of proctitis over the same period but was more commonly detected in MSM (n = 1,019, 8.1%) with NGU. M. genitalium is common and predominantly macrolide-resistant in asymptomatic MSM. M. genitalium is not associated with proctitis in this population.

The bacterial loads for gonococcal infections of the pharynx and rectum were determined among men with male sexual partners. The median bacterial load for rectal infections (18,960 copies/swab) was significantly higher than the load for pharyngeal infections (2,100 copies/swab; P ‫؍‬ 0.001). Bacterial loads among men with symptomatic proctitis were strikingly high (median, 278,000 copies/swab).Gonorrhea is one of the most common sexually transmitted diseases, and study results suggest that rectal gonorrhea enhances HIV transmission (1-3).There are limited data on the transmissibility of gonorrhea, particularly from the pharynx and rectum. To examine potential transmissibility from these sites, we measured gonococcal bacterial loads and examined associated clinical and laboratory factors.All men who have sex with men (MSM) attending the Melbourne Sexual Health Centre between January 2010 and April 2010 who underwent testing for sexually transmitted infections were included. Pharyngeal and rectal specimens were obtained using cotton-tipped swabs. Rectal specimens were obtained either by blind anal swabbing or, in men with symptomatic proctitis, via anoscopy. Swabs were plated onto modified Thayer-Martin medium, placed into phosphate-buffered saline, and then analyzed using real-time quantitative PCR (qPCR) targeting the opa gene of Neisseria gonorrhoeae (4). Positive PCR tests were confirmed using real-time PCR targeting the gonococcal porA pseudogene (7). Gonococcal loads were quantified by comparing the crossing threshold for each sample to the crossing threshold of a standard curve constructed by amplifying different, known copy numbers of N. gonorrhoeae in an opa assay. To determine the adequacy of sample collection, a qPCR targeting the 260-bp region of ␤-globin was performed.Inoculated culture plates were incubated at 36°C in 5% CO 2 for 48 h. Presumptive N. gonorrhoeae colonies were oxidase tested, and identification of specimens to the species level was confirmed by carbohydrate reaction tests. Specimens that were culture positive and/or PCR positive were regarded as representing true infections. The McNemar test was used to compare detection of gonorrhea by culture versus PCR. The Mann-Whitney test was used to compare bacterial loads. The Human Research Ethics Committee of the Alfred Hospital approved the study.Specimens were obtained from 1,076 MSM. The median age of the subjects was 32 (range, 18 to 69). For testing using both culture and PCR, 1,011 rectal and 1,076 pharyngeal specimens were obtained. There were 43 (3.9%) confirmed PCR-positive pharyngeal specimens, of which 17 were also culture positive (sensitivity, 39%). There were 47 (4.6%) confirmed PCR-positive rectal specimens, of which 25 were also culture positive (sensitivity, 53%).Twelve men had concurrent gonorrheal infections of the pharynx and rectum. A further 10 were concurrently infected at the urethra and rectum, while 2 were concurrently infected at the urethra, pharynx, and rectum. Five men were coinfected with rectal chlamydia and g...

Extended azithromycin 1.5g was no more effective than a single 1g dose at achieving cure of M. genitalium urethritis and importantly did not reduce the selection of macrolide resistance. Nonmacrolide and new approaches for the treatment of M. genitalium urethritis are required.