چکیده (انگلیسی):

Objective: To examine adding polymyxin B (PMB) if is effective and appropriate to bull
extender, and decrease bacteria damage.
Methods: PMB were added to extender (Andromed®) in different values (0, 50, 100,
500, 1000 mg/mL). The prepared samples were cryopreserved, thawed and analyzed for
viability (by eosin–nigrosin staining) and plasma membrane function (by hypo osmotic
solution test) in 3 different times (immediately, 1 h & 2 h later).
Results: The result showed that both parameters significantly increased in 50 and
100 mg/mL treatments. Moreover, by passing time, plasma membrane function significantly
increased. But, in high dosage (1000 mg/mL), the toxicity effect of PMB was seen,
and in both parameters the differences were significantly lower than the control treatment
(0 mg/mL).
Conclusion: Our study indicates that adding PMB to bull extender is efficient and
appropriate, but, it must be mentioned that addictive amount will be due to extender
composition, existence of other antibiotics and, importantly, the load of bacterial
contamination in the semen.