- FDA granted a breakthrough designation to Australia-based SpeeDx to expedite the path to U.S. clearance for a molecular test that detects both N. gonorrhea and a patient's susceptibility or resistance to the antibiotic ciprofloxacin.
- Results from the ResistancePlus GC test can be used to determine whether patients can be treated with ciprofloxacin rather than ceftriaxone, the current front-line treatment for gonorrhea.
- There have been reports in the United Kingdom and Australia of resistance to ceftriaxone, an antibiotic used to treat many kinds of bacterial infections, including organisms that are resistant to other antibiotics.
Gonorrhea, along with syphilis and chlamydia, is curable with antibiotics, but the prevalence of all three sexually transmitted diseases (STDs) is rising. The Centers for Disease Control and Prevention has expressed concern about a steep rise in gonorrhea diagnoses, which increased 67% to 555,608 cases between 2013 and 2017.
An estimated 78 million people globally are affected by gonorrhea. Neisseria gonorrhoeae has developed resistance to a series of antibiotics used to treat the bacteria over the decades, including sulfonamides, penicillin, tetracycline, spectinomycin, fluoroquinolones, macrolides and cephalosporins.
In 2017, the World Health Organization's Global Gonococcal Antimicrobial Surveillance Programme said the injectable extended-spectrum cephalosporin (ESC) ceftriaxone was the only remaining monotherapy for gonorrhea in most countries. Because gonococcal resistance or treatment failures to the last-line ESC cefixime and to a lesser extent ceftriaxone were verified in many countries, dual antimicrobial therapy with ceftriaxone plus azithromycin was recommended.
The CDC's National Action Plan for Combating Antibiotic-Resistant Bacteria has set a target of maintaining the prevalence of ceftriaxone-resistant N. gonorrhoeae below 2% compared to estimates from 2013. The agency has encouraged the development of diagnostic tests that can determine the antibiotic-resistance profiles of resistant bacterial threats of high importance to public health, including N. gonorrhoeae.
The British Association of Sexual Health and HIV, in its recently updated gonorrhea management guidelines, recommended the use of ciprofloxacin over ceftriaxone if antibiotic susceptibility results are available prior to treatment.
The SpeeDx test has received the CE mark for use in Europe and clearance by the Therapeutic Goods Association in Australia. It detects both N. gonorrhea and sequences in the gyrA gene of the bacteria associated with susceptibility or resistance to ciprofloxacin, which is a previous front-line antibiotic treatment for the infection.
SpeeDx is also conducting clinical trials for a ResistancePlus MG test to detect the sexually transmitted infection Mycoplasma genitalium and genetic markers linked to antibiotic resistance. In recent years, Mgen prevalence has increased globally and developed high rates of resistance to azithromycin, the company said.