The Univeristy of Melbourne The Royal Melbourne Hopspital

A joint venture between The University of Melbourne and The Royal Melbourne Hospital


30 Jan 2019

Melbourne researchers discover highly drug-resistant strain of Shigella

Using cutting-edge genomics, researchers at the Doherty Institute have discovered a highly drug-resistant strain of Shigella in Victoria, persistent in men who have sex with men (MSM) and returned travellers.

Shigellosis is a highly contagious intestinal bacteria that causes dysentery – it’s estimated to cause 190 million cases of diarrhoea globally a year.

In low and middle-income countries, the burden of Shigellosis is concentrated in children, with inadequate sanitation and contaminated food and/or water the most common mode of acquisition.

However, in high-income countries, Shigellosis occurs predominantly in returning travellers, or in MSM, and is often considered a sexually-transmitted infection.

Using whole genome sequencing (WGS), researchers at the University of Melbourne’s Microbiological Diagnostic Unit Public Health Laboratory (MDU PHL) at the Doherty Institute, tested all the Shigella cases in Victoria over a two-year period.

Combining these results with epidemiological data, the team were able to identify a global outbreak of the multi-drug resistant strain of shigella.

MDU PHL Deputy Director Dr Deborah Williamson who led the study, (recently published in journal, Clinical Infectious Diseases), said this study shows Shigella posts an ongoing public health threat in Australia and globally.

“We found very high rates of antimicrobial resistance to common antibiotics used to treat Shigella in Australia, highlighting an urgent need to adopt multidisciplinary public health measures and educational messages to interrupt transmission and prevent infection,” Dr Williamson said.

“Of all the cases we tested, we found that most cases were in either MSM or returning travellers, but that drug-resistance to antibiotics used for treatment was much more common in the cases that could be attributed to MSM.

“With one antibiotic, azithromycin, already ineffective for treatment of shigella in MSM in Victoria, we desperately need improved surveillance in Australia and beyond. Clinicians need to be aware that shigella is often an STI so they can promote safe sexual practices and more awareness around the appropriate use of antibiotics for MSM who present with STI symptoms.”