Cytochrome P-450 Monooxygenase Gene Expression Supports a Multifactorial Origin for Acaricide Resistance in Ripicephalus microplus

摘要

This study was done with the objective of establishing a relationship between cytochrome P-450 gene expression and acaricide resistance levels in Mexican isolates of R. microplus , for that purpose the cytochrome P-450 expression levels were measured by real time PCR quantification on acaricide sensitive and resistant strains of ticks, as well as on acaricide resistant an sensitive ticks isolated from cattle at the southeastern Mexican state of Chiapas and the northern Mexican State of Tamaulipas. Acaricide susceptible ticks were used as comparison standard P-450 expression level and adjusted as a baseline of 1 Relative Expression Units (REU). A statistically significant (p<0.0001 unpaired t-test) 3.47±0.302 REU overall increase on the P-450 gene expression level was detected on pyrethroid resistant ticks, we also found a statistically significant (p<0.0001 unpaired t-test) P-450 expression decrement of 0.335±0.054 REU in multiple acaricide resistant ticks, no significant difference on cytochrome P-450 expression level was detected on the organophosphate acaricide resistant strain. Our results suggest that cytochrome P-450 monooxygenases play a role on at least some types of acaricide resistance phenomenon and the assessment of the data reveals a multifactorial causative for organophosphate and pyrethroid resistant R. microplus .