Autochthonous transmission of extensively drug-resistant Neisseria gonorrhoeae in Germany, 2025

A teenage boy in Germany, with no travel history and no obvious risk factor by conventional reckoning, is diagnosed with a gonorrhea infection that no standard antibiotic can reliably treat. That single case, one of four reported by Regina Selb, Hana Tlapák, and colleagues in 2025, is the kind of clinical moment that public health researchers have been dreading for years. Gonorrhea has always been treatable. That was nearly the point — a common infection, easily cleared, allowing individuals to move on. But Neisseria gonorrhoeae, the bacterium responsible for gonorrhea, is a resistance-acquiring machine. It has defeated penicillin, then tetracyclines, and then fluoroquinolones. The current last line of defense is ceftriaxone, an injectable cephalosporin antibiotic. When that fails, there is no standard backup. Extensively drug-resistant, or XDR, means resistance to ceftriaxone, resistance to cefixime, an older oral cephalosporin, high-level resistance to azithromycin, and resistance to at least two other agents. That's not a theoretical category. Two of the four German isolates in this report met that definition. Here's what actually happened. Four men in the German state of North Rhine-Westphalia developed gonorrhea infections in early 2025. All were heterosexual, and their ages ranged from the late teens to the mid-sixties. None had traveled abroad recently. That word, autochthonous, meaning locally acquired, does significant work in this paper. It indicates these were not imported cases arriving from a high-resistance region overseas. The bacteria were already circulating. The men presented with symptomatic urethritis, the textbook urethral infection, and their isolates were sent to the Robert Koch Institute, Germany's national public health agency, for confirmation. Central lab testing showed azithromycin minimum inhibitory concentrations, the amount of drug needed to stop bacterial growth, greater than two hundred fifty-six milligrams per liter in all three viable isolates. That is an astronomically high number. Cefixime minimum inhibitory concentrations were one milligram per liter, interpreted as resistant. For two of the isolates, ceftriaxone minimum inhibitory concentrations came in at zero point one-nine milligrams per liter, which is resistant under current European guidelines. The third viable isolate had a ceftriaxone reading of zero point one twenty-five milligrams per liter, just at the susceptible threshold. All isolates were also resistant to ciprofloxacin and tetracycline. Treatment was complicated but not hopeless. Case one, the teenage patient, received a single two-gram intravenous dose of ceftriaxone plus one point five grams of azithromycin orally. The test of cure at four weeks was successful. Case two, a man in his mid-forties, received two grams of ceftriaxone intravenously daily for three days and was also cured at four weeks. A third patient in his mid-sixties received ceftriaxone plus azithromycin intramuscularly, was declared symptom-free, but declined the follow-up test of cure. The fourth patient, another teenager, had his isolate initially reported as ceftriaxone-resistant, but the Robert Koch Institute retesting found a susceptible reading. He left before receiving intravenous treatment and did not return. His outcome is unknown. The treatment successes are real but fragile. Selb and colleagues note that the relatively low ceftriaxone minimum inhibitory concentrations, resistant by current thresholds but not exceedingly high, likely explain why higher doses still worked in these cases. The margin is shrinking, but it is not gone. Now here is where the molecular biology becomes genuinely revelatory. Whole-genome sequencing, essentially reading the complete DNA of each bacterial isolate, allowed the research team to build a high-resolution fingerprint. Three of the four isolates shared the same multilocus sequence type, MLST ST18091. They also carried the same two resistance mutations. The first is the mosaic penA-60.001 allele: a scrambled version of the gene encoding the protein that cephalosporin antibiotics are supposed to bind to. When it's mosaic, meaning it is a patchwork of different gene segments, the drug cannot grip the target properly. The second mutation is A2045G in the twenty-three S ribosomal RNA gene, present in all four copies of that gene in each isolate. That mutation blocks azithromycin from binding to the ribosome, the cell's protein-making machinery. Together, these two changes explain the resistance profile precisely. The phylogenetic analysis, the genomic family tree, then made the geographic picture clear. Isolates G25-563 and G25-K71 differed by just one single nucleotide polymorphism, one letter change in the genome. G25-1113 differed from those two by two or three such changes. On the tree, these three German isolates clustered together with a previously reported extensively drug-resistant strain from the United Kingdom, H24-496, detected in 2024 and linked to travel to Cambodia. The German and UK isolates form their own clade, a distinct branch separate from other European extensively drug-resistant strains. This is not a coincidence of geography; it is cross-border spread. A lineage that first appeared in Southeast Asia, was detected in the United Kingdom in 2024, and is now transmitting locally in Germany in 2025. So what does this mean if you are a sexually active person who takes your health seriously? Start here: this cluster is occurring in heterosexual men. Prior extensively drug-resistant gonorrhea cases globally have mostly appeared in men who have sex with men and in travelers. These four cases are different. They suggest the resistant strain is moving into broader sexual networks. The transmission context, Selb and colleagues note, likely involved sex workers and their clients, but the age range, from teenagers to people in their sixties, underscores that there is no demographic profile that makes someone immune. The practical implications are specific. If you are getting tested for gonorrhea, culture-based testing matters more than ever. A standard PCR test tells you whether the bacterium is present but does not indicate whether that bacterium responds to treatment. Culture, which involves growing the bacteria in a lab, is what allows antibiotic susceptibility testing. Without culture, resistance is invisible. In Germany, cases with reduced susceptibility to azithromycin, cefixime, or ceftriaxone are now notifiable under the Infection Protection Act, and Go-Surv-AMR, the national Gonococci Resistance Surveillance program, is the system that flagged these cases and connected the dots genomically. Selb and colleagues are explicit: without culture-based surveillance, additional transmission events may have gone unnoticed. The paper also raises a harder point. Asymptomatic infections, more common in women and at extragenital sites like the throat and rectum, can drive transmission without anyone knowing. If you have no symptoms, you may not seek testing. If you are tested only by PCR, resistance will not be detected. If partners are not notified, the chain continues. This is not a problem unique to any one community; it is a structural gap in how sexually transmitted infection care currently works. The research team calls for accessible sexually transmitted infection services, including testing, susceptibility testing, test of cure, and expert consultation, targeted at sex workers and their clients, men who have sex with men, and young people. They describe existing infrastructure in North Rhine-Westphalia: free, anonymous sexually transmitted infection testing and treatment for sex workers, supported by the Robert Koch Institute reference laboratory. That kind of service is what allowed these cases to be caught; expanding it is what prevents the next cluster from going undetected. Germany went from one extensively drug-resistant gonorrhea case in 2023 to one in 2024, to four in 2025 — all locally acquired, all in the same state, and all genetically related. That is not a plateau. Go-Surv-AMR, embedded in an integrated genomic surveillance framework, is what made that trajectory visible. The system worked. The question the paper raises is whether it can keep working at the scale the problem demands. For sex-positive individuals, the honest takeaway is this: gonorrhea remains treatable in most cases, but the window is narrowing. Get cultured, not just swabbed. Get tested regularly. Make sure your partners know. And if a treatment does not work or a clinician mentions resistance, push for susceptibility testing and a test of cure. This is a warning that the surveillance system caught. The tools to act on it exist. Use them. This lecture was created by ennepō. Go to https://ennepo.ai to Discover, Create and Follow the latest research in your field. Read when you can. Listen when you want to.