title: Synergistic activity of antibiotics combined with ivermectin to kill body lice.
abstract: Ivermectin and doxycycline have been found to be independently effective in killing body lice. In this study, 450 body lice were artificially fed on a Parafilm™ membrane with human blood associated with antibiotics (doxycycline, erythromycin, rifampicin and azithromycin) alone and in combination with ivermectin. Fluorescence in situ hybridisation and spectral deconvolution were performed to evaluate bacterial transcriptional activity following antibiotic intake by the lice. In the first series, a lethal effect of antibiotics on lice was observed compared with the control group at 18 days (log-rank test, P≤10(-3)), with a significant difference between groups in the production of nits (P=0.019, Kruskal-Wallis test). A high lethal effect of ivermectin alone (50ng/mL) was observed compared with the control group (log-rank test, P≤10(-3)). Fluorescence of bacteriocytes in lice treated with 20μg/mL doxycycline was lower than in untreated lice (P<0.0001, Kruskal-Wallis test). In the second series with antibiotic-ivermectin combinations, a synergistic lethal effect on treated lice (log-rank test, P<10(-6)) was observed compared with the control group at 18 days, associated with a significant decrease in the production of nits (P≤0.001, Kruskal-Wallis test). Additionally, survival of lice in the combination treatment groups compared with ivermectin alone was significant (log-rank test, P=0.0008). These data demonstrate that the synergistic effect of combinations of antibiotics and ivermectin could be used to achieve complete eradication of lice and to avoid selection of a resistant louse population.
authors.affiliation: Aix-Marseille Université, IHU Méditerranée Infection, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Faculté de Médecine et de Pharmacie, 27 Bd. Jean Moulin, 13385 Marseille cedex 5, France.
authors.forename: Abdoul Karim
authors.initials: AK
authors.lastname: Sangaré
authors.affiliation: Aix-Marseille Université, IHU Méditerranée Infection, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Faculté de Médecine et de Pharmacie, 27 Bd. Jean Moulin, 13385 Marseille cedex 5, France.
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Rolain
authors.affiliation: Aix-Marseille Université, UMR912 SESSTIM (AMU-Inserm-IRD), Department of Public Health and Medical Information, Centre Hospitalier Universitaire La Timone, 13005 Marseille, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Gaudart
authors.affiliation: Aix-Marseille Université, IHU Méditerranée Infection, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Faculté de Médecine et de Pharmacie, 27 Bd. Jean Moulin, 13385 Marseille cedex 5, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Weber
authors.affiliation: Aix-Marseille Université, IHU Méditerranée Infection, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Faculté de Médecine et de Pharmacie, 27 Bd. Jean Moulin, 13385 Marseille cedex 5, France. Electronic address: didier.raoult@gmail.com.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004318:Doxycycline / Q000627:therapeutic use*; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007306:Insecticides / Q000627:therapeutic use; D007559:Ivermectin / Q000627:therapeutic use*; D010373:Lice Infestations / Q000188:drug therapy*; D010374:Pediculus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D007306:Insecticides; D007559:Ivermectin; D004318:Doxycycline
keywords: Antibiotics; Ivermectin; Pediculus humanus humanus; Synergistic treatment