In-vitro efficacy of a botanical acaricide and its active ingredients against larvae of susceptible and acaricide-resistant strains of Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae).

Ticks and tick-borne diseases are a major constraint for a sustainable cattle industry in the tropical and subtropical regions of the world. The development of resistance to most of the commonly used acaricides has led to an assessment of herbal products for acaricidal activity as an eco-friendly tick control alternative. A botanical product, Essentria® IC-3 insect concentrate containing rosemary oil (10%), geraniol (5%) and peppermint oil (2%), acts on target pests by blocking octopamine. Essentria® IC-3 and its active components were evaluated for larvicidal activity against several susceptible and acaricide-resistant strains of the cattle fever tick, Rhipicephalus (Boophilus) microplus Canestrini by Larval Packet test using 14-21 d old unfed larvae. The efficacy was assessed by measuring percent larval mortality and estimating lethal concentrations at 50% (LC50) and 95% (LC95) with 95% confidence limits (CL) using probit analysis. The LC50 and LC95 (95% CL) values for Essentria® IC-3 against the susceptible strain were estimated as 0.647% (0.59-0.69) and 1.033% (0.94-1.19), respectively, whereas, LC50 and LC95 values for other strains were variable, ranging from 0.597-1.674% and 0.927-2.236%, respectively. Among the various active ingredients, the larvicidal property of Essentria® IC-3 seem to be attributable mainly to geraniol and the LC50 and LC95 (95% CL) values for geraniol against the susceptible Deutch strain were estimated as 0.656% (0.61-0.69) and 1.114% (1.03-1.25), respectively. The comparison of LC50 and LC95 values of acaricide-resistant strains showed susceptibility comparable to Deutch against geraniol except for the Las Palmas strain. We report a low level of resistance in some of the acaricide-resistant strains against the herbal acaricide in the cattle tick for the first time, possibly due to cross-resistance to chemical acaricides.

Various Tip Applications and Temperature Changes of Er,Cr:YSGG-Laser Irradiated Implants In Vitro.

The impact of the laser tip on implant temperature when irradiating implants with lasers to treat peri-implantitis has received little attention. The present study was designed to assess the influence of two laser tips (sapphire chisel [MC3] and radial firing perio [RFP]) on temperature change of an implant irradiated with an Er,Cr:YSGG laser in vitro under various operational conditions. The results suggest that Er,Cr:YSGG irradiation using either tip with supplemental cooling can be a thermally safe approach to implant decontamination. However, use of the RFP tip consistently resulted in a greater temperature rise. The MC3 tip thus may be preferable to the RFP tip for open-flap implant debridement.

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus.

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricidal activity against Rhipicephalus (Boophilus) microplus. However, there are no studies that show efficacy differences of essential oils between susceptible and organophosphate resistant strains of R. (B.) microplus. The aim of the present study was to compare acaricidal effects of essential oils extracted from two different genotypes of L. gracilis and the main monoterpenes on larvae of both susceptible and organophosphate resistant R. (B.) microplus larvae. The efficacy of the essential oil of two genotypes of L. gracilis (106 and 201) and their monoterpenes carvacrol and thymol was measured using the larval immersion test on coumaphos-resistant and susceptible strains of R. (B.) microplus. Lethal concentrations were calculated using GraphPad Prism 6.0. Chemical analysis was performed by GC-MS and FID. Thymol and carvacrol were observed to be major constituents in 106 and 201L. gracilis genotype essential oils, respectively. Essential oils of both genotypes were more effective against organophosphate-resistant tick strain than susceptible tick strain. Carvacrol was 3.2 times more toxic to organophosphate resistant strain than to susceptible strain. Thymol was equally toxic to resistant and susceptible tick strains. The significantly higher efficacy monoterpene carvacrol against resistant ticks may lead to development of new natural product acaricide formulations for use to control organophosphate resistant R. (B.) microplus populations.

In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits.

The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro application was done in five replicates for each concentration in petri dishes in the laboratory. The treated mites were observed at 1, 12, and 24 h post application (PA) for lemon oil effect. In addition, oxidative stress profile was evaluated for the treated mite. Dependent on in vitro results, 20 % lemon oil was used in vivo trial. Twenty-four naturally infected rabbits were divided into three groups of eight: 20 % lemon oil, deltamethrin, and untreated control. The infected parts of rabbits were treated topically once a week for four successive weeks. In vitro application results showed that lemon oil 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h PA. The oxidative stress profile revealed that mites treated with 20 % lemon oil had significantly (P < 0.05) higher hydrogen peroxide and malondialdehyde when compared with mites treated with deltamethrin or distilled water. In vivo application of 20 % lemon oil on naturally infected rabbits showed complete recovery from clinical signs, absence of mite in microscopic examination from the second week of treatment. In addition, productive performance was significantly better than infected untreated group. Also, the treated tissue showed stoppage of scale formation and hair growth faster than deltamethrin-treated rabbits. Consequently, lemon oil has remarkable miticidal activity in vitro and in vivo applications.

Treatment of the contaminated implant surface using the Er,Cr:YSGG laser.

Treatment of the contaminated implant surface by mechanical and chemotherapeutic means has met with mixed success. Incomplete surface debridement or alteration of the implant surface could compromise attempts at grafting and reintegration of the implant body. Development of a laser system operating at 2780 nm and using an ablative hydrokinetic process offers the possibility for more efficient decontamination and debridement. The Er,Cr: YSGG laser is evaluated and compared with the most commonly used chemotherapeutic modality for treatment of the implant surface. A scanning electron microscope study is presented comparing YSGG ablation to citric acid treatment of the titanium plasma sprayed and HA-coated implant surface. We can conclude that laser ablation using the YSGG laser is highly efficient at removing potential contaminants on the roughened implant surface while demonstrating no effects on the titanium substrate.