Authors: Loncaric Igor, Cabal Rosel Adriana, Szostak Michael P, Licka Theresia, Allerberger Franz, Ruppitsch Werner, Spergser Joachim
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Multi-drug Resistant Klebsiella in Austrian Horses — A Zoonotic Concern Between autumn 2012 and October 2019, researchers in Austria identified seven genetically distinct cephalosporin-resistant Klebsiella isolates from diseased horses, with whole-genome sequencing revealing four *K. pneumoniae*, two *K. michiganensis*, and one *K. oxytoca* strain. All isolates demonstrated multi-drug resistance phenotypes; six carried extended-spectrum β-lactamase (ESBL) genes—primarily CTX-M cefotaximases—whilst one additionally expressed AmpC-type resistance through CMY-2 and TEM/SHV β-lactamases. The *K. pneumoniae* population proved particularly concerning, encompassing four different sequence types (ST147, ST307, ST1228, and a novel ST4848), and notably, all but one isolate carried virulence genes including yersiniabactin-producing capacity. For equine practitioners, these findings underscore that resistant Klebsiella infections in horses represent not merely a therapeutic challenge but a genuine zoonotic risk; given the close contact between handlers, veterinarians, and horses, transmission pathways warrant serious consideration in biosecurity protocols and antimicrobial stewardship decisions. Ongoing surveillance of these resistance patterns in equine populations remains essential to track evolution and inform treatment guidelines.
Read the full abstract on PubMed
Practical Takeaways
- •Be aware that antibiotic-resistant Klebsiella infections in horses may not respond to broad-spectrum cephalosporin treatment; culture and sensitivity testing is essential before treatment
- •Implement strict biosecurity and hygiene protocols when handling diseased horses with suspected resistant bacterial infections due to potential zoonotic transmission risk to human handlers and veterinarians
- •Report isolates of multi-drug resistant Klebsiella to appropriate authorities as part of antimicrobial resistance surveillance, particularly when multiple resistance mechanisms are detected
Key Findings
- •Seven cefotaxime-resistant Klebsiella isolates from diseased horses identified between 2012-2019, comprising K. pneumoniae (n=4), K. michiganensis (n=2), and K. oxytoca (n=1)
- •All isolates displayed multi-drug resistant phenotypes with six carrying CTX-M cefotaximases and one carrying CMY-2 cephamycinase plus SHV and TEM β-lactamases
- •Four different sequence types detected among K. pneumoniae isolates including novel ST4848, with virulence genes including yersiniabactin detected across isolates
- •Multi-drug resistant Klebsiella in horses represents a public health concern due to close contact between horses and humans