Identification and disruption of bacteria associated with sheep scab mites - novel means of control?

Psoroptes ovis mites, which cause psoroptic mange (sheep scab), were investigated to identify potential bacterial targets for endosymbiont control of sheep scab. In addition, transmission of bacteria to the sheep skin was investigated through the characterisation of bacteria present in P. ovis faecal trails and on the fleece environment by internal transcribed spacer (ITS) sequencing. A diverse range of bacteria was identified in addition to a potential endosymbiont candidate, Comamonas sp, which was detected in P. ovis by both ITS PCR and endosymbiont-specific PCR. Disruption of these bacteria within P. ovis, through the use of antibiotics, was explored; with significant reduction in mean mite survival when administered antibiotic diets compared with controls (LR4 = 23.12, P < 0.001). The antibiotic treatments also significantly affected the bacterial density (CFU/mite) within P. ovis, indicating that mite survival may be linked to the bacterial communities that they harbour. Although antibiotics are not suitable for practical application, these results suggest disrupting bacteria associated with P. ovis should be further investigated for novel control.