Azithromycin-resistant Neisseria gonorrhoeae has overtaken carbapenemase-producing Enterobacteriaceae as the most commonly reported organism that cannot be treated by last line antibiotics.
According to the first annual report of the National Alert System for Critical Antimicrobial Resistances (CARAlert), azithromycin-resistant N. gonorrhoeae accounted for more than 62% of all CARs reported in February and March this year.
The report found at least 37% of all critical antimicrobial resistances were from patients in the community.
In the 12 months between March 2016 and March 2017, a total of 1,064 reports of highly resistant bacteria were lodged with the new alert system, managed by the Australian Commission on Safety and Quality in Health Care.
Professor John Turnidge, senior medical advisor for the Commission’s Antimicrobial Use and Resistance in Australia project, said the N. gonorrhoeae finding was unexpected.
“Azithromycin was relatively recently introduced as a back-up to standard treatment so there was a lot of interest in finding so much resistance.”
It was the predominant CAR reported across all age groups from teenagers to 40-49 year olds.
Fortunately the vast major of N. gonorrhoeae infections were still treatable, Professor Turnidge said.
The report found carbapenemase-producing Enterobacteriaceae had been the most commonly reported organisms until the end of 2016.
The majority (68%) was found in people 60 years of age and older – consistent with their need for more frequent medical attention.
IMP-type carbapenemase, mainly IMP-4, was now endemic on the eastern seaboard of Australia in several species of Enterobacteriaceae.
Professor Turnidge said IMP had also been identified in seagull droppings in Port Kembla and in a strain of Salmonella isolated from a sick cat in Sydney.
“This gene complex is now widely distributed in nature although at a very low level.”
Professor Turnidge said while there had been an improvement in antimicrobial stewardship in recent years, there was still room for improvement.
“The most important thing we can do is to modify our behavior and only prescribe antibiotics appropriately,” he said.