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MCR-1 gene found in the US
Petri dish culture plates growing bacteria in the presence of discs containing various antibiotics
This 2014 image shows a CDC microbiologist holding up two petri dish culture plates growing bacteria in the presence of discs containing various antibiotics.

Discovery prompts fear of pan-resistant bacteria

Bacteria carrying the MCR-1 gene, which makes bacteria resistant to the last-resort antibiotic colistin, has been found in a US patient for the first time. The discovery has fuelled fears that a pan-resistant bacteria could develop.

The 49-year-old woman from Pennsylvania had no recent history of travel. She presented at a health clinic in April with symptoms of a urinary tract infection, according to a report in the journal Antimicrobial Agents and Chemotherapy.  
 
E. coli bacteria carrying the MCR-1 gene was found in a urine sample. Researchers wrote: 'To the best of our knowledge, this is the first report of MCR-1 in the USA'.

Colistin is one of the last defence antibiotics used to treat patients with multi-drug-resistant infections. The MCR-1 gene was first detected in China last year and has since been found in the EU.

Health officials are now working together to trace the patient's contacts and determine whether they are at risk.

While the bacteria identified was not pan-resistant, the presence of the gene is concerning as it raises the risk that pan-resistant bacteria could develop. The MCR-1 gene exists on a plasmid, or a small piece of DNA, that can move from one bacterium to another, spreading antibiotic resistance between bacterial species.

Moving forward, the researchers say further testing is critical to determine the gene's true prevalence in the US.

The Centers for Disease Control and Prevention (CDC) is part of a public health response to the discovery of MCR-1.

From autumn this year, its Antibiotic Resistance Lab Network will provide for seven to eight regional labs, as well as labs in all states and seven major cities and territories. These will detect and respond to resistant organisms found in human samples.

State labs will also detect new forms of resistance, including mutations allowing bacteria to survive last resort drugs.

Image © James Gathany/CDC

 

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Equine Disease Surveillance report released for Q4 2025

News Story 1
 The latest Equine Disease Surveillance report has been released, with details on equine disease from Q4 of 2025.

The report, produced by Equine Infectious Disease Surveillance, includes advice on rule changes for equine influenza vaccination.

Statistics and maps detail recent outbreaks of equine herpes virus, equine influenza, equine strangles and equine grass sickness. A series of laboratory reports provides data on virology, bacteriology, parasitology and toxicosis.

This issue also features a case study of orthoflavivus-associated neurological disease in a horse in the UK. 

Click here for more...
News Shorts
NSA webinar explores sheep tailing and castration

The National Sheep Association (NSA) is to host a free webinar on the castration and tail docking of lambs.

The webinar, 'Understanding the tailing and castration consultation: A guide for sheep farmers', will be hosted online on Monday, 2 March 2026 at 7.30pm.

It comes during a government consultation into the methods used for these procedures. Farmers are encouraged to engage before the consultation period closes on Monday, 9 March 2026.

The webinar offers clear and actionable guidance to support farmers to contribute meaningfully to the consultation and prepare for potential changes.

On the panel will be former SVS president Kate Hovers, farmer and vet Ann Van Eetvelt and SRUC professor in Animal Health and Veterinary Sciences Cathy Dwyer. Each panel member will utilise their own specialism and expertise to evaluate risks and outcomes to sheep farming.

Find out more about the webinar on the NSA website.