Surface sterilization methods impact measures of internal microbial diversity in ticks

Binetruy Florian, Dupraz Marlène, Buysse Marie, Duron Olivier. 2019. Surface sterilization methods impact measures of internal microbial diversity in ticks. Parasites and Vectors, 12:268, 10 p.

https://doi.org/10.1186/s13071-019-3517-5

Article de revue ; Article de recherche ; Article de revue à facteur d'impact Revue en libre accès total

Prévisualisation

Version publiée - Anglais
Sous licence

.
Binetruy et al. - 2019 - Surface sterilization methods impact measures of i.pdf
Télécharger (1MB) | Prévisualisation

Quartile : Q1, Sujet : TROPICAL MEDICINE / Quartile : Q1, Sujet : PARASITOLOGY

Résumé : Background: Ticks are obligate blood feeders transmitting major pathogens worldwide. Over the past few years, considerable research efforts have focused on the diversity, distribution and impact of gut and intracellular bacterial symbionts on tick development and tick-borne pathogen transmission. The study of this internal microbiome requires the use of a sterilization method to remove external (i.e. cuticular) microbes present on the tick's surface and to avoid any further contamination. Several sterilization methods exist, including ethanol- or bleach-based treatments that are both effective in killing microbes but with different potential effects on DNA denaturation. Methods: We examined how these different sterilization methods impact the measure of internal microbial diversity hosted by the Cayenne tick Amblyomma cajennense (sensu stricto). Bacterial barcoding investigations based on 16S rRNA gene sequences were conducted on two batches of 50 individuals each: Ticks of the first batch were sterilized with bleach diluted at 1% and the second batch with 70% ethanol. Tick external microbiome was also determined from cuticle smearing and water samples used for tick washing. Results: Bacterial barcoding investigations showed major differences between ethanol- and bleach-treated specimens. Both methods led to the detection of major intracellular bacteria associated with A. cajennense (s.s.) but ethanol-treated ticks always harbored a higher bacterial diversity than bleach-treated ticks. Further examinations of tick gut and tick external microbiome revealed that ethanol-based surface sterilization method is inefficient to eliminate the DNA of external bacteria. Conclusions: We herein provide evidence that studies investigating the internal microbiome of ticks should consider bleach as the gold standard to efficiently remove cuticular bacterial DNA. Indeed, this method does not impact the internal bacterial diversity hosted by ticks and is thus a better method than the ethanol-based one for studying the internal microbiome.

Mots-clés Agrovoc : stérilisation, Amblyomma cajennense, éthanol, agent pathogène, vecteur de maladie, évaluation de l'impact, maladie transmissible par tiques, microbiome

Mots-clés complémentaires : barcoding moléculaire, eau de javel

Mots-clés libres : 16S rRNA, Bacterial communities, Tick microbiome, Metabarcoding, Amblyomma

Classification Agris : L72 - Organismes nuisibles des animaux

Champ stratégique Cirad : CTS 4 (2019-) - Santé des plantes, des animaux et des écosystèmes

Auteurs et affiliations