Flies are common to everyday life across the globe. Wherever there are humans, these pesky insects are always close by: in our homes, landing on our food and waste, buzzing around our hospitals.
Some insects like mosquitos, are known to be vectors. This means they can carry and spread diseases, for example malaria or dengue fever. House flies are not thought to be vectors , but recent evidence suggests they can carry and spread antibiotic resistance genes to humans.
Antibiotic resistance is a growing threat to human health, killing 1.27 million people worldwide in 2019, a number expected to grow to 10 million per year by 2050.
So, do flies contribute to the burden of antibiotic resistance for humans? That’s what IOI researchers including PhD student Shonnette Premchand-Braker want to find out.
The IOI study Arthropods as Vectors of Infection and Antimicrobial Resistance (AVIAR) is investigating the role of flies in spreading antibiotic resistance in hospitals, where the use of antibiotics is high, as is the number of diagnosed multidrug-resistant infections in patients.
The role of flies in the transmission of antibiotic resistance is poorly understood. We don’t really know what to expect with this study, and the data so far has been surprising with the high number of antimicrobial resistance genes isolated from the flies.
Shonnette is a microbiologist by training and has worked in hospitals to diagnose and identify pathogenic bacteria causing patient infections. These skills allow Shonnette to analyse fly samples which will be collected from up to 80 countries across the globe.
The flies are sent to my lab in Oxford after they have been collected and labelled in hospitals. They arrive whole, so our first step is to homogenise them, which basically means we make fly juice. The next step is to prepare bacterial cultures, and then extract and sequence their DNA. We’re looking for antimicrobial resistance genes that we know are related to multidrug-resistant infections.
Alongside flies, Shonnette is also collecting key climate data, including the temperature and humidity of the hospital wards. This is to better understand the impact of geography and climate change on the carriage and spread of antibiotic resistance genes by flies.
The AVIAR study will be one of the first of its kind to build a global profile of what flies can carry.
If the study produced evidence that flies contribute to multidrug-resistant infections, the interventions are relatively simple, like hanging up fly nets, but could make a huge difference in reducing drug-resistant infections in hospitals.
Find out more about the AVIAR study here.