REPRODUCTION
Amikacin/Penicillin Semen Extender
Saw Enhanced Antimicrobial Activity in
By Marie Rosenthal, MS The addition of amikacin and penicillin
dent in the Department of Large Animal Clinical Services at the College of Veterinary Medicine. A variety of commercially available semen extenders and several antibiotics are used for this purpose, but Dr. Hernández-Avilés and his group wanted to know whether 2 more narrow-spectrum antibiotics—amikacin and penicillin—would be as effective as other antibiotic types, such as synthetic β-lactams. A 2018 study from his group found that amikacin and penicillin had better antimicrobial activity than new generation antibiotics—synthetic β-lactams or carbapenems—when added to a milkbased semen extender. In that study, they found that both commensal bacteria and certain levels of po-
Source: Dr. Hernández-Aviles
to a commercial semen extender enhanced antimicrobial activity against commensal bacteria without affecting the sperm quality or fertility, according to several studies performed by Camilo HernándezAvilés, DVM, of Texas A&M University. It is normal for the skin of the penis of breeding stallions to harbor nonpathogenic bacteria, and most ejaculates contain some commensal bacteria. However, sometimes ejaculates are contaminated with potentially pathogenic bacteria, usually Klebsiella pneumoniae or Pseudomonas aeruginosa. So, antibiotics are frequently added to inhibit bacterial growth, explained Dr. Hernández-Avilés, a PhD stu-
Collecting a sample. This stallion's semen was contaminated with both commensal and pathogenic bacteria, before and after dilution with INRA-96 extended with added amikacin and penicillin.
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Issue 10/2020 | ModernEquineVet.com
